[core] Implement data-driven styling for {text,icon}-{color,opacity,halo-color,halo-blur,halo-width} (#7939)

* Add symbol dds attributes and adapt style code generation

* Update to mapbox-gl-js/master

* Refactor SymbolFeature as a subclass of GeometryTileFeature

Prepares for enabling DDS on symbol paint properties by allowing the
SymbolFeatures, which we keep around after constructing SymbolLayout,
to be used in evaluating data-driven paint properties later in the
layout process.

* Draft approach for splitting icon/text paint properties

The `Program` types are set up to bind GL attributes to each of the
data-driven paint properties specified in the `PaintProperties` type
provided.  Since `SymbolPaintProperties` specifies both `Text*` and
`Icon*` properties, the symbolIcon, symbolIconSDF, and symbolGlyph
programs each attempt to bind roughly double the number of attributes
that they actually need.

This change addresses this by:
- Adding the more specific `IconPaintProperties` and `TextPaintProperties` types, which are subsets of the full `SymbolPaintProperties`.
- The symbol layer continues to use its `SymbolPaintProperties paint` member to track layer property state, but it provides helpers that construct objects of each the specific `{Icon,Text}PaintProperties::Evaluated` type, for use by the painter.
- The three symbol programs instantiate `Program<>` using the appropriate `{Icon,Text}PaintProperties` type.

* check in generated style code

* Populate paint buffers for symbol DDS properties

* Address first round of review comments

* Refactor VectorTile{Layer,Feature} to explicitly share data

* Update submodule

include/mbgl/style/layers/symbol_layer.hpp

@@ -169,29 +169,29 @@ public:
 
     // Paint properties
 
-    static PropertyValue<float> getDefaultIconOpacity();
-    PropertyValue<float> getIconOpacity(const optional<std::string>& klass = {}) const;
-    void setIconOpacity(PropertyValue<float>, const optional<std::string>& klass = {});
+    static DataDrivenPropertyValue<float> getDefaultIconOpacity();
+    DataDrivenPropertyValue<float> getIconOpacity(const optional<std::string>& klass = {}) const;
+    void setIconOpacity(DataDrivenPropertyValue<float>, const optional<std::string>& klass = {});
     void setIconOpacityTransition(const TransitionOptions&, const optional<std::string>& klass = {});
 
-    static PropertyValue<Color> getDefaultIconColor();
-    PropertyValue<Color> getIconColor(const optional<std::string>& klass = {}) const;
-    void setIconColor(PropertyValue<Color>, const optional<std::string>& klass = {});
+    static DataDrivenPropertyValue<Color> getDefaultIconColor();
+    DataDrivenPropertyValue<Color> getIconColor(const optional<std::string>& klass = {}) const;
+    void setIconColor(DataDrivenPropertyValue<Color>, const optional<std::string>& klass = {});
     void setIconColorTransition(const TransitionOptions&, const optional<std::string>& klass = {});
 
-    static PropertyValue<Color> getDefaultIconHaloColor();
-    PropertyValue<Color> getIconHaloColor(const optional<std::string>& klass = {}) const;
-    void setIconHaloColor(PropertyValue<Color>, const optional<std::string>& klass = {});
+    static DataDrivenPropertyValue<Color> getDefaultIconHaloColor();
+    DataDrivenPropertyValue<Color> getIconHaloColor(const optional<std::string>& klass = {}) const;
+    void setIconHaloColor(DataDrivenPropertyValue<Color>, const optional<std::string>& klass = {});
     void setIconHaloColorTransition(const TransitionOptions&, const optional<std::string>& klass = {});
 
-    static PropertyValue<float> getDefaultIconHaloWidth();
-    PropertyValue<float> getIconHaloWidth(const optional<std::string>& klass = {}) const;
-    void setIconHaloWidth(PropertyValue<float>, const optional<std::string>& klass = {});
+    static DataDrivenPropertyValue<float> getDefaultIconHaloWidth();
+    DataDrivenPropertyValue<float> getIconHaloWidth(const optional<std::string>& klass = {}) const;
+    void setIconHaloWidth(DataDrivenPropertyValue<float>, const optional<std::string>& klass = {});
     void setIconHaloWidthTransition(const TransitionOptions&, const optional<std::string>& klass = {});
 
-    static PropertyValue<float> getDefaultIconHaloBlur();
-    PropertyValue<float> getIconHaloBlur(const optional<std::string>& klass = {}) const;
-    void setIconHaloBlur(PropertyValue<float>, const optional<std::string>& klass = {});
+    static DataDrivenPropertyValue<float> getDefaultIconHaloBlur();
+    DataDrivenPropertyValue<float> getIconHaloBlur(const optional<std::string>& klass = {}) const;
+    void setIconHaloBlur(DataDrivenPropertyValue<float>, const optional<std::string>& klass = {});
     void setIconHaloBlurTransition(const TransitionOptions&, const optional<std::string>& klass = {});
 
     static PropertyValue<std::array<float, 2>> getDefaultIconTranslate();
@@ -204,29 +204,29 @@ public:
     void setIconTranslateAnchor(PropertyValue<TranslateAnchorType>, const optional<std::string>& klass = {});
     void setIconTranslateAnchorTransition(const TransitionOptions&, const optional<std::string>& klass = {});
 
-    static PropertyValue<float> getDefaultTextOpacity();
-    PropertyValue<float> getTextOpacity(const optional<std::string>& klass = {}) const;
-    void setTextOpacity(PropertyValue<float>, const optional<std::string>& klass = {});
+    static DataDrivenPropertyValue<float> getDefaultTextOpacity();
+    DataDrivenPropertyValue<float> getTextOpacity(const optional<std::string>& klass = {}) const;
+    void setTextOpacity(DataDrivenPropertyValue<float>, const optional<std::string>& klass = {});
     void setTextOpacityTransition(const TransitionOptions&, const optional<std::string>& klass = {});
 
-    static PropertyValue<Color> getDefaultTextColor();
-    PropertyValue<Color> getTextColor(const optional<std::string>& klass = {}) const;
-    void setTextColor(PropertyValue<Color>, const optional<std::string>& klass = {});
+    static DataDrivenPropertyValue<Color> getDefaultTextColor();
+    DataDrivenPropertyValue<Color> getTextColor(const optional<std::string>& klass = {}) const;
+    void setTextColor(DataDrivenPropertyValue<Color>, const optional<std::string>& klass = {});
     void setTextColorTransition(const TransitionOptions&, const optional<std::string>& klass = {});
 
-    static PropertyValue<Color> getDefaultTextHaloColor();
-    PropertyValue<Color> getTextHaloColor(const optional<std::string>& klass = {}) const;
-    void setTextHaloColor(PropertyValue<Color>, const optional<std::string>& klass = {});
+    static DataDrivenPropertyValue<Color> getDefaultTextHaloColor();
+    DataDrivenPropertyValue<Color> getTextHaloColor(const optional<std::string>& klass = {}) const;
+    void setTextHaloColor(DataDrivenPropertyValue<Color>, const optional<std::string>& klass = {});
     void setTextHaloColorTransition(const TransitionOptions&, const optional<std::string>& klass = {});
 
-    static PropertyValue<float> getDefaultTextHaloWidth();
-    PropertyValue<float> getTextHaloWidth(const optional<std::string>& klass = {}) const;
-    void setTextHaloWidth(PropertyValue<float>, const optional<std::string>& klass = {});
+    static DataDrivenPropertyValue<float> getDefaultTextHaloWidth();
+    DataDrivenPropertyValue<float> getTextHaloWidth(const optional<std::string>& klass = {}) const;
+    void setTextHaloWidth(DataDrivenPropertyValue<float>, const optional<std::string>& klass = {});
     void setTextHaloWidthTransition(const TransitionOptions&, const optional<std::string>& klass = {});
 
-    static PropertyValue<float> getDefaultTextHaloBlur();
-    PropertyValue<float> getTextHaloBlur(const optional<std::string>& klass = {}) const;
-    void setTextHaloBlur(PropertyValue<float>, const optional<std::string>& klass = {});
+    static DataDrivenPropertyValue<float> getDefaultTextHaloBlur();
+    DataDrivenPropertyValue<float> getTextHaloBlur(const optional<std::string>& klass = {}) const;
+    void setTextHaloBlur(DataDrivenPropertyValue<float>, const optional<std::string>& klass = {});
     void setTextHaloBlurTransition(const TransitionOptions&, const optional<std::string>& klass = {});
 
     static PropertyValue<std::array<float, 2>> getDefaultTextTranslate();

platform/android/MapboxGLAndroidSDK/src/main/java/com/mapbox/mapboxsdk/style/layers/PropertyFactory.java

@@ -454,11 +454,11 @@ public class PropertyFactory {
   /**
    * The opacity at which the icon will be drawn.
    *
-   * @param <Z> the zoom parameter type
-   * @param function a wrapper {@link CameraFunction} for Float
+   * @param <T> the function input type
+   * @param function a wrapper function for Float
    * @return property wrapper around a Float function
    */
-  public static <Z extends Number> PropertyValue<CameraFunction<Z, Float>> iconOpacity(CameraFunction<Z, Float> function) {
+  public static <T> PropertyValue<Function<T, Float>> iconOpacity(Function<T, Float> function) {
     return new PaintPropertyValue<>("icon-opacity", function);
   }
 
@@ -486,11 +486,11 @@ public class PropertyFactory {
   /**
    * The color of the icon. This can only be used with sdf icons.
    *
-   * @param <Z> the zoom parameter type
-   * @param function a wrapper {@link CameraFunction} for String
+   * @param <T> the function input type
+   * @param function a wrapper function for String
    * @return property wrapper around a String function
    */
-  public static <Z extends Number> PropertyValue<CameraFunction<Z, String>> iconColor(CameraFunction<Z, String> function) {
+  public static <T> PropertyValue<Function<T, String>> iconColor(Function<T, String> function) {
     return new PaintPropertyValue<>("icon-color", function);
   }
 
@@ -518,11 +518,11 @@ public class PropertyFactory {
   /**
    * The color of the icon's halo. Icon halos can only be used with SDF icons.
    *
-   * @param <Z> the zoom parameter type
-   * @param function a wrapper {@link CameraFunction} for String
+   * @param <T> the function input type
+   * @param function a wrapper function for String
    * @return property wrapper around a String function
    */
-  public static <Z extends Number> PropertyValue<CameraFunction<Z, String>> iconHaloColor(CameraFunction<Z, String> function) {
+  public static <T> PropertyValue<Function<T, String>> iconHaloColor(Function<T, String> function) {
     return new PaintPropertyValue<>("icon-halo-color", function);
   }
 
@@ -540,11 +540,11 @@ public class PropertyFactory {
   /**
    * Distance of halo to the icon outline.
    *
-   * @param <Z> the zoom parameter type
-   * @param function a wrapper {@link CameraFunction} for Float
+   * @param <T> the function input type
+   * @param function a wrapper function for Float
    * @return property wrapper around a Float function
    */
-  public static <Z extends Number> PropertyValue<CameraFunction<Z, Float>> iconHaloWidth(CameraFunction<Z, Float> function) {
+  public static <T> PropertyValue<Function<T, Float>> iconHaloWidth(Function<T, Float> function) {
     return new PaintPropertyValue<>("icon-halo-width", function);
   }
 
@@ -562,11 +562,11 @@ public class PropertyFactory {
   /**
    * Fade out the halo towards the outside.
    *
-   * @param <Z> the zoom parameter type
-   * @param function a wrapper {@link CameraFunction} for Float
+   * @param <T> the function input type
+   * @param function a wrapper function for Float
    * @return property wrapper around a Float function
    */
-  public static <Z extends Number> PropertyValue<CameraFunction<Z, Float>> iconHaloBlur(CameraFunction<Z, Float> function) {
+  public static <T> PropertyValue<Function<T, Float>> iconHaloBlur(Function<T, Float> function) {
     return new PaintPropertyValue<>("icon-halo-blur", function);
   }
 
@@ -628,11 +628,11 @@ public class PropertyFactory {
   /**
    * The opacity at which the text will be drawn.
    *
-   * @param <Z> the zoom parameter type
-   * @param function a wrapper {@link CameraFunction} for Float
+   * @param <T> the function input type
+   * @param function a wrapper function for Float
    * @return property wrapper around a Float function
    */
-  public static <Z extends Number> PropertyValue<CameraFunction<Z, Float>> textOpacity(CameraFunction<Z, Float> function) {
+  public static <T> PropertyValue<Function<T, Float>> textOpacity(Function<T, Float> function) {
     return new PaintPropertyValue<>("text-opacity", function);
   }
 
@@ -660,11 +660,11 @@ public class PropertyFactory {
   /**
    * The color with which the text will be drawn.
    *
-   * @param <Z> the zoom parameter type
-   * @param function a wrapper {@link CameraFunction} for String
+   * @param <T> the function input type
+   * @param function a wrapper function for String
    * @return property wrapper around a String function
    */
-  public static <Z extends Number> PropertyValue<CameraFunction<Z, String>> textColor(CameraFunction<Z, String> function) {
+  public static <T> PropertyValue<Function<T, String>> textColor(Function<T, String> function) {
     return new PaintPropertyValue<>("text-color", function);
   }
 
@@ -692,11 +692,11 @@ public class PropertyFactory {
   /**
    * The color of the text's halo, which helps it stand out from backgrounds.
    *
-   * @param <Z> the zoom parameter type
-   * @param function a wrapper {@link CameraFunction} for String
+   * @param <T> the function input type
+   * @param function a wrapper function for String
    * @return property wrapper around a String function
    */
-  public static <Z extends Number> PropertyValue<CameraFunction<Z, String>> textHaloColor(CameraFunction<Z, String> function) {
+  public static <T> PropertyValue<Function<T, String>> textHaloColor(Function<T, String> function) {
     return new PaintPropertyValue<>("text-halo-color", function);
   }
 
@@ -714,11 +714,11 @@ public class PropertyFactory {
   /**
    * Distance of halo to the font outline. Max text halo width is 1/4 of the font-size.
    *
-   * @param <Z> the zoom parameter type
-   * @param function a wrapper {@link CameraFunction} for Float
+   * @param <T> the function input type
+   * @param function a wrapper function for Float
    * @return property wrapper around a Float function
    */
-  public static <Z extends Number> PropertyValue<CameraFunction<Z, Float>> textHaloWidth(CameraFunction<Z, Float> function) {
+  public static <T> PropertyValue<Function<T, Float>> textHaloWidth(Function<T, Float> function) {
     return new PaintPropertyValue<>("text-halo-width", function);
   }
 
@@ -736,11 +736,11 @@ public class PropertyFactory {
   /**
    * The halo's fadeout distance towards the outside.
    *
-   * @param <Z> the zoom parameter type
-   * @param function a wrapper {@link CameraFunction} for Float
+   * @param <T> the function input type
+   * @param function a wrapper function for Float
    * @return property wrapper around a Float function
    */
-  public static <Z extends Number> PropertyValue<CameraFunction<Z, Float>> textHaloBlur(CameraFunction<Z, Float> function) {
+  public static <T> PropertyValue<Function<T, Float>> textHaloBlur(Function<T, Float> function) {
     return new PaintPropertyValue<>("text-halo-blur", function);
   }
 
@@ -1742,7 +1742,7 @@ public class PropertyFactory {
   }
 
   /**
-   * Value to use for a text label. Feature properties are specified using tokens like {field_name}.  (Token replacement is only supported for literal `textField` values--not for property functions.)
+   * Value to use for a text label. Feature properties are specified using tokens like {field_name}.  (Token replacement is only supported for literal {@link PropertyFactory#textField} values--not for property functions.)
    *
    * @param value a String value
    * @return property wrapper around String
@@ -1754,7 +1754,7 @@ public class PropertyFactory {
 
 
   /**
-   * Value to use for a text label. Feature properties are specified using tokens like {field_name}.  (Token replacement is only supported for literal `textField` values--not for property functions.)
+   * Value to use for a text label. Feature properties are specified using tokens like {field_name}.  (Token replacement is only supported for literal {@link PropertyFactory#textField} values--not for property functions.)
    *
    * @param <T> the function input type
    * @param function a wrapper function for String

platform/android/MapboxGLAndroidSDKTestApp/src/androidTest/java/com/mapbox/mapboxsdk/testapp/style/SymbolLayerTest.java

@@ -1597,6 +1597,112 @@ public class SymbolLayerTest extends BaseStyleTest {
     assertEquals(1, ((ExponentialStops) layer.getIconOpacity().getFunction().getStops()).size());
   }
 
+  @Test
+  public void testIconOpacityAsIdentitySourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-opacity");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconOpacity(property("FeaturePropertyA", Stops.<Float>identity()))
+    );
+
+    // Verify
+    assertNotNull(layer.getIconOpacity());
+    assertNotNull(layer.getIconOpacity().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconOpacity().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconOpacity().getFunction()).getProperty());
+    assertEquals(IdentityStops.class, layer.getIconOpacity().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testIconOpacityAsExponentialSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-opacity");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconOpacity(
+        property(
+          "FeaturePropertyA",
+          exponential(
+            stop(0.3f, iconOpacity(0.3f))
+          ).withBase(0.5f)
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getIconOpacity());
+    assertNotNull(layer.getIconOpacity().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconOpacity().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconOpacity().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getIconOpacity().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testIconOpacityAsCategoricalSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-opacity");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconOpacity(
+        property(
+          "FeaturePropertyA",
+          categorical(
+            stop(1.0f, iconOpacity(0.3f))
+          )
+        ).withDefaultValue(0.3f)
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getIconOpacity());
+    assertNotNull(layer.getIconOpacity().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconOpacity().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconOpacity().getFunction()).getProperty());
+    assertEquals(CategoricalStops.class, layer.getIconOpacity().getFunction().getStops().getClass());
+    assertEquals(0.3f, ((SourceFunction) layer.getIconOpacity().getFunction()).getDefaultValue());
+  }
+
+  @Test
+  public void testIconOpacityAsCompositeFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-opacity");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconOpacity(
+        composite(
+          "FeaturePropertyA",
+          exponential(
+            stop(0, 0.3f, iconOpacity(0.9f))
+          ).withBase(0.5f)
+        ).withDefaultValue(0.3f)
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getIconOpacity());
+    assertNotNull(layer.getIconOpacity().getFunction());
+    assertEquals(CompositeFunction.class, layer.getIconOpacity().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((CompositeFunction) layer.getIconOpacity().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getIconOpacity().getFunction().getStops().getClass());
+    assertEquals(1, ((ExponentialStops) layer.getIconOpacity().getFunction().getStops()).size());
+
+    ExponentialStops<Stop.CompositeValue<Float, Float>, Float> stops =
+      (ExponentialStops<Stop.CompositeValue<Float, Float>, Float>) layer.getIconOpacity().getFunction().getStops();
+    Stop<Stop.CompositeValue<Float, Float>, Float> stop = stops.iterator().next();
+    assertEquals(0f, stop.in.zoom, 0.001);
+    assertEquals(0.3f, stop.in.value, 0.001f);
+    assertEquals(0.9f, stop.out, 0.001f);
+  }
+
   @Test
   public void testIconColorAsConstant() {
     checkViewIsDisplayed(R.id.mapView);
@@ -1634,6 +1740,77 @@ public class SymbolLayerTest extends BaseStyleTest {
     assertEquals(1, ((ExponentialStops) layer.getIconColor().getFunction().getStops()).size());
   }
 
+  @Test
+  public void testIconColorAsIdentitySourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-color");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconColor(property("FeaturePropertyA", Stops.<String>identity()))
+    );
+
+    // Verify
+    assertNotNull(layer.getIconColor());
+    assertNotNull(layer.getIconColor().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconColor().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconColor().getFunction()).getProperty());
+    assertEquals(IdentityStops.class, layer.getIconColor().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testIconColorAsExponentialSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-color");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconColor(
+        property(
+          "FeaturePropertyA",
+          exponential(
+            stop(Color.RED, iconColor(Color.RED))
+          ).withBase(0.5f)
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getIconColor());
+    assertNotNull(layer.getIconColor().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconColor().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconColor().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getIconColor().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testIconColorAsCategoricalSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-color");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconColor(
+        property(
+          "FeaturePropertyA",
+          categorical(
+            stop("valueA", iconColor(Color.RED))
+          )
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getIconColor());
+    assertNotNull(layer.getIconColor().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconColor().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconColor().getFunction()).getProperty());
+    assertEquals(CategoricalStops.class, layer.getIconColor().getFunction().getStops().getClass());
+  }
+
   @Test
   public void testIconColorAsIntConstant() {
     checkViewIsDisplayed(R.id.mapView);
@@ -1682,6 +1859,77 @@ public class SymbolLayerTest extends BaseStyleTest {
     assertEquals(1, ((ExponentialStops) layer.getIconHaloColor().getFunction().getStops()).size());
   }
 
+  @Test
+  public void testIconHaloColorAsIdentitySourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-halo-color");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconHaloColor(property("FeaturePropertyA", Stops.<String>identity()))
+    );
+
+    // Verify
+    assertNotNull(layer.getIconHaloColor());
+    assertNotNull(layer.getIconHaloColor().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconHaloColor().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconHaloColor().getFunction()).getProperty());
+    assertEquals(IdentityStops.class, layer.getIconHaloColor().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testIconHaloColorAsExponentialSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-halo-color");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconHaloColor(
+        property(
+          "FeaturePropertyA",
+          exponential(
+            stop(Color.RED, iconHaloColor(Color.RED))
+          ).withBase(0.5f)
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getIconHaloColor());
+    assertNotNull(layer.getIconHaloColor().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconHaloColor().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconHaloColor().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getIconHaloColor().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testIconHaloColorAsCategoricalSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-halo-color");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconHaloColor(
+        property(
+          "FeaturePropertyA",
+          categorical(
+            stop("valueA", iconHaloColor(Color.RED))
+          )
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getIconHaloColor());
+    assertNotNull(layer.getIconHaloColor().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconHaloColor().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconHaloColor().getFunction()).getProperty());
+    assertEquals(CategoricalStops.class, layer.getIconHaloColor().getFunction().getStops().getClass());
+  }
+
   @Test
   public void testIconHaloColorAsIntConstant() {
     checkViewIsDisplayed(R.id.mapView);
@@ -1730,6 +1978,112 @@ public class SymbolLayerTest extends BaseStyleTest {
     assertEquals(1, ((ExponentialStops) layer.getIconHaloWidth().getFunction().getStops()).size());
   }
 
+  @Test
+  public void testIconHaloWidthAsIdentitySourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-halo-width");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconHaloWidth(property("FeaturePropertyA", Stops.<Float>identity()))
+    );
+
+    // Verify
+    assertNotNull(layer.getIconHaloWidth());
+    assertNotNull(layer.getIconHaloWidth().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconHaloWidth().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconHaloWidth().getFunction()).getProperty());
+    assertEquals(IdentityStops.class, layer.getIconHaloWidth().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testIconHaloWidthAsExponentialSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-halo-width");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconHaloWidth(
+        property(
+          "FeaturePropertyA",
+          exponential(
+            stop(0.3f, iconHaloWidth(0.3f))
+          ).withBase(0.5f)
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getIconHaloWidth());
+    assertNotNull(layer.getIconHaloWidth().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconHaloWidth().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconHaloWidth().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getIconHaloWidth().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testIconHaloWidthAsCategoricalSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-halo-width");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconHaloWidth(
+        property(
+          "FeaturePropertyA",
+          categorical(
+            stop(1.0f, iconHaloWidth(0.3f))
+          )
+        ).withDefaultValue(0.3f)
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getIconHaloWidth());
+    assertNotNull(layer.getIconHaloWidth().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconHaloWidth().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconHaloWidth().getFunction()).getProperty());
+    assertEquals(CategoricalStops.class, layer.getIconHaloWidth().getFunction().getStops().getClass());
+    assertEquals(0.3f, ((SourceFunction) layer.getIconHaloWidth().getFunction()).getDefaultValue());
+  }
+
+  @Test
+  public void testIconHaloWidthAsCompositeFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-halo-width");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconHaloWidth(
+        composite(
+          "FeaturePropertyA",
+          exponential(
+            stop(0, 0.3f, iconHaloWidth(0.9f))
+          ).withBase(0.5f)
+        ).withDefaultValue(0.3f)
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getIconHaloWidth());
+    assertNotNull(layer.getIconHaloWidth().getFunction());
+    assertEquals(CompositeFunction.class, layer.getIconHaloWidth().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((CompositeFunction) layer.getIconHaloWidth().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getIconHaloWidth().getFunction().getStops().getClass());
+    assertEquals(1, ((ExponentialStops) layer.getIconHaloWidth().getFunction().getStops()).size());
+
+    ExponentialStops<Stop.CompositeValue<Float, Float>, Float> stops =
+      (ExponentialStops<Stop.CompositeValue<Float, Float>, Float>) layer.getIconHaloWidth().getFunction().getStops();
+    Stop<Stop.CompositeValue<Float, Float>, Float> stop = stops.iterator().next();
+    assertEquals(0f, stop.in.zoom, 0.001);
+    assertEquals(0.3f, stop.in.value, 0.001f);
+    assertEquals(0.9f, stop.out, 0.001f);
+  }
+
   @Test
   public void testIconHaloBlurAsConstant() {
     checkViewIsDisplayed(R.id.mapView);
@@ -1767,6 +2121,112 @@ public class SymbolLayerTest extends BaseStyleTest {
     assertEquals(1, ((ExponentialStops) layer.getIconHaloBlur().getFunction().getStops()).size());
   }
 
+  @Test
+  public void testIconHaloBlurAsIdentitySourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-halo-blur");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconHaloBlur(property("FeaturePropertyA", Stops.<Float>identity()))
+    );
+
+    // Verify
+    assertNotNull(layer.getIconHaloBlur());
+    assertNotNull(layer.getIconHaloBlur().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconHaloBlur().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconHaloBlur().getFunction()).getProperty());
+    assertEquals(IdentityStops.class, layer.getIconHaloBlur().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testIconHaloBlurAsExponentialSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-halo-blur");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconHaloBlur(
+        property(
+          "FeaturePropertyA",
+          exponential(
+            stop(0.3f, iconHaloBlur(0.3f))
+          ).withBase(0.5f)
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getIconHaloBlur());
+    assertNotNull(layer.getIconHaloBlur().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconHaloBlur().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconHaloBlur().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getIconHaloBlur().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testIconHaloBlurAsCategoricalSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-halo-blur");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconHaloBlur(
+        property(
+          "FeaturePropertyA",
+          categorical(
+            stop(1.0f, iconHaloBlur(0.3f))
+          )
+        ).withDefaultValue(0.3f)
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getIconHaloBlur());
+    assertNotNull(layer.getIconHaloBlur().getFunction());
+    assertEquals(SourceFunction.class, layer.getIconHaloBlur().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getIconHaloBlur().getFunction()).getProperty());
+    assertEquals(CategoricalStops.class, layer.getIconHaloBlur().getFunction().getStops().getClass());
+    assertEquals(0.3f, ((SourceFunction) layer.getIconHaloBlur().getFunction()).getDefaultValue());
+  }
+
+  @Test
+  public void testIconHaloBlurAsCompositeFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("icon-halo-blur");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      iconHaloBlur(
+        composite(
+          "FeaturePropertyA",
+          exponential(
+            stop(0, 0.3f, iconHaloBlur(0.9f))
+          ).withBase(0.5f)
+        ).withDefaultValue(0.3f)
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getIconHaloBlur());
+    assertNotNull(layer.getIconHaloBlur().getFunction());
+    assertEquals(CompositeFunction.class, layer.getIconHaloBlur().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((CompositeFunction) layer.getIconHaloBlur().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getIconHaloBlur().getFunction().getStops().getClass());
+    assertEquals(1, ((ExponentialStops) layer.getIconHaloBlur().getFunction().getStops()).size());
+
+    ExponentialStops<Stop.CompositeValue<Float, Float>, Float> stops =
+      (ExponentialStops<Stop.CompositeValue<Float, Float>, Float>) layer.getIconHaloBlur().getFunction().getStops();
+    Stop<Stop.CompositeValue<Float, Float>, Float> stop = stops.iterator().next();
+    assertEquals(0f, stop.in.zoom, 0.001);
+    assertEquals(0.3f, stop.in.value, 0.001f);
+    assertEquals(0.9f, stop.out, 0.001f);
+  }
+
   @Test
   public void testIconTranslateAsConstant() {
     checkViewIsDisplayed(R.id.mapView);
@@ -1877,6 +2337,112 @@ public class SymbolLayerTest extends BaseStyleTest {
     assertEquals(1, ((ExponentialStops) layer.getTextOpacity().getFunction().getStops()).size());
   }
 
+  @Test
+  public void testTextOpacityAsIdentitySourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-opacity");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textOpacity(property("FeaturePropertyA", Stops.<Float>identity()))
+    );
+
+    // Verify
+    assertNotNull(layer.getTextOpacity());
+    assertNotNull(layer.getTextOpacity().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextOpacity().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextOpacity().getFunction()).getProperty());
+    assertEquals(IdentityStops.class, layer.getTextOpacity().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testTextOpacityAsExponentialSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-opacity");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textOpacity(
+        property(
+          "FeaturePropertyA",
+          exponential(
+            stop(0.3f, textOpacity(0.3f))
+          ).withBase(0.5f)
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getTextOpacity());
+    assertNotNull(layer.getTextOpacity().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextOpacity().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextOpacity().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getTextOpacity().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testTextOpacityAsCategoricalSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-opacity");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textOpacity(
+        property(
+          "FeaturePropertyA",
+          categorical(
+            stop(1.0f, textOpacity(0.3f))
+          )
+        ).withDefaultValue(0.3f)
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getTextOpacity());
+    assertNotNull(layer.getTextOpacity().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextOpacity().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextOpacity().getFunction()).getProperty());
+    assertEquals(CategoricalStops.class, layer.getTextOpacity().getFunction().getStops().getClass());
+    assertEquals(0.3f, ((SourceFunction) layer.getTextOpacity().getFunction()).getDefaultValue());
+  }
+
+  @Test
+  public void testTextOpacityAsCompositeFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-opacity");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textOpacity(
+        composite(
+          "FeaturePropertyA",
+          exponential(
+            stop(0, 0.3f, textOpacity(0.9f))
+          ).withBase(0.5f)
+        ).withDefaultValue(0.3f)
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getTextOpacity());
+    assertNotNull(layer.getTextOpacity().getFunction());
+    assertEquals(CompositeFunction.class, layer.getTextOpacity().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((CompositeFunction) layer.getTextOpacity().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getTextOpacity().getFunction().getStops().getClass());
+    assertEquals(1, ((ExponentialStops) layer.getTextOpacity().getFunction().getStops()).size());
+
+    ExponentialStops<Stop.CompositeValue<Float, Float>, Float> stops =
+      (ExponentialStops<Stop.CompositeValue<Float, Float>, Float>) layer.getTextOpacity().getFunction().getStops();
+    Stop<Stop.CompositeValue<Float, Float>, Float> stop = stops.iterator().next();
+    assertEquals(0f, stop.in.zoom, 0.001);
+    assertEquals(0.3f, stop.in.value, 0.001f);
+    assertEquals(0.9f, stop.out, 0.001f);
+  }
+
   @Test
   public void testTextColorAsConstant() {
     checkViewIsDisplayed(R.id.mapView);
@@ -1914,6 +2480,77 @@ public class SymbolLayerTest extends BaseStyleTest {
     assertEquals(1, ((ExponentialStops) layer.getTextColor().getFunction().getStops()).size());
   }
 
+  @Test
+  public void testTextColorAsIdentitySourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-color");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textColor(property("FeaturePropertyA", Stops.<String>identity()))
+    );
+
+    // Verify
+    assertNotNull(layer.getTextColor());
+    assertNotNull(layer.getTextColor().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextColor().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextColor().getFunction()).getProperty());
+    assertEquals(IdentityStops.class, layer.getTextColor().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testTextColorAsExponentialSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-color");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textColor(
+        property(
+          "FeaturePropertyA",
+          exponential(
+            stop(Color.RED, textColor(Color.RED))
+          ).withBase(0.5f)
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getTextColor());
+    assertNotNull(layer.getTextColor().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextColor().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextColor().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getTextColor().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testTextColorAsCategoricalSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-color");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textColor(
+        property(
+          "FeaturePropertyA",
+          categorical(
+            stop("valueA", textColor(Color.RED))
+          )
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getTextColor());
+    assertNotNull(layer.getTextColor().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextColor().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextColor().getFunction()).getProperty());
+    assertEquals(CategoricalStops.class, layer.getTextColor().getFunction().getStops().getClass());
+  }
+
   @Test
   public void testTextColorAsIntConstant() {
     checkViewIsDisplayed(R.id.mapView);
@@ -1962,6 +2599,77 @@ public class SymbolLayerTest extends BaseStyleTest {
     assertEquals(1, ((ExponentialStops) layer.getTextHaloColor().getFunction().getStops()).size());
   }
 
+  @Test
+  public void testTextHaloColorAsIdentitySourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-halo-color");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textHaloColor(property("FeaturePropertyA", Stops.<String>identity()))
+    );
+
+    // Verify
+    assertNotNull(layer.getTextHaloColor());
+    assertNotNull(layer.getTextHaloColor().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextHaloColor().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextHaloColor().getFunction()).getProperty());
+    assertEquals(IdentityStops.class, layer.getTextHaloColor().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testTextHaloColorAsExponentialSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-halo-color");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textHaloColor(
+        property(
+          "FeaturePropertyA",
+          exponential(
+            stop(Color.RED, textHaloColor(Color.RED))
+          ).withBase(0.5f)
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getTextHaloColor());
+    assertNotNull(layer.getTextHaloColor().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextHaloColor().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextHaloColor().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getTextHaloColor().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testTextHaloColorAsCategoricalSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-halo-color");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textHaloColor(
+        property(
+          "FeaturePropertyA",
+          categorical(
+            stop("valueA", textHaloColor(Color.RED))
+          )
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getTextHaloColor());
+    assertNotNull(layer.getTextHaloColor().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextHaloColor().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextHaloColor().getFunction()).getProperty());
+    assertEquals(CategoricalStops.class, layer.getTextHaloColor().getFunction().getStops().getClass());
+  }
+
   @Test
   public void testTextHaloColorAsIntConstant() {
     checkViewIsDisplayed(R.id.mapView);
@@ -2010,6 +2718,112 @@ public class SymbolLayerTest extends BaseStyleTest {
     assertEquals(1, ((ExponentialStops) layer.getTextHaloWidth().getFunction().getStops()).size());
   }
 
+  @Test
+  public void testTextHaloWidthAsIdentitySourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-halo-width");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textHaloWidth(property("FeaturePropertyA", Stops.<Float>identity()))
+    );
+
+    // Verify
+    assertNotNull(layer.getTextHaloWidth());
+    assertNotNull(layer.getTextHaloWidth().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextHaloWidth().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextHaloWidth().getFunction()).getProperty());
+    assertEquals(IdentityStops.class, layer.getTextHaloWidth().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testTextHaloWidthAsExponentialSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-halo-width");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textHaloWidth(
+        property(
+          "FeaturePropertyA",
+          exponential(
+            stop(0.3f, textHaloWidth(0.3f))
+          ).withBase(0.5f)
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getTextHaloWidth());
+    assertNotNull(layer.getTextHaloWidth().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextHaloWidth().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextHaloWidth().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getTextHaloWidth().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testTextHaloWidthAsCategoricalSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-halo-width");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textHaloWidth(
+        property(
+          "FeaturePropertyA",
+          categorical(
+            stop(1.0f, textHaloWidth(0.3f))
+          )
+        ).withDefaultValue(0.3f)
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getTextHaloWidth());
+    assertNotNull(layer.getTextHaloWidth().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextHaloWidth().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextHaloWidth().getFunction()).getProperty());
+    assertEquals(CategoricalStops.class, layer.getTextHaloWidth().getFunction().getStops().getClass());
+    assertEquals(0.3f, ((SourceFunction) layer.getTextHaloWidth().getFunction()).getDefaultValue());
+  }
+
+  @Test
+  public void testTextHaloWidthAsCompositeFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-halo-width");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textHaloWidth(
+        composite(
+          "FeaturePropertyA",
+          exponential(
+            stop(0, 0.3f, textHaloWidth(0.9f))
+          ).withBase(0.5f)
+        ).withDefaultValue(0.3f)
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getTextHaloWidth());
+    assertNotNull(layer.getTextHaloWidth().getFunction());
+    assertEquals(CompositeFunction.class, layer.getTextHaloWidth().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((CompositeFunction) layer.getTextHaloWidth().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getTextHaloWidth().getFunction().getStops().getClass());
+    assertEquals(1, ((ExponentialStops) layer.getTextHaloWidth().getFunction().getStops()).size());
+
+    ExponentialStops<Stop.CompositeValue<Float, Float>, Float> stops =
+      (ExponentialStops<Stop.CompositeValue<Float, Float>, Float>) layer.getTextHaloWidth().getFunction().getStops();
+    Stop<Stop.CompositeValue<Float, Float>, Float> stop = stops.iterator().next();
+    assertEquals(0f, stop.in.zoom, 0.001);
+    assertEquals(0.3f, stop.in.value, 0.001f);
+    assertEquals(0.9f, stop.out, 0.001f);
+  }
+
   @Test
   public void testTextHaloBlurAsConstant() {
     checkViewIsDisplayed(R.id.mapView);
@@ -2047,6 +2861,112 @@ public class SymbolLayerTest extends BaseStyleTest {
     assertEquals(1, ((ExponentialStops) layer.getTextHaloBlur().getFunction().getStops()).size());
   }
 
+  @Test
+  public void testTextHaloBlurAsIdentitySourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-halo-blur");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textHaloBlur(property("FeaturePropertyA", Stops.<Float>identity()))
+    );
+
+    // Verify
+    assertNotNull(layer.getTextHaloBlur());
+    assertNotNull(layer.getTextHaloBlur().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextHaloBlur().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextHaloBlur().getFunction()).getProperty());
+    assertEquals(IdentityStops.class, layer.getTextHaloBlur().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testTextHaloBlurAsExponentialSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-halo-blur");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textHaloBlur(
+        property(
+          "FeaturePropertyA",
+          exponential(
+            stop(0.3f, textHaloBlur(0.3f))
+          ).withBase(0.5f)
+        )
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getTextHaloBlur());
+    assertNotNull(layer.getTextHaloBlur().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextHaloBlur().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextHaloBlur().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getTextHaloBlur().getFunction().getStops().getClass());
+  }
+
+  @Test
+  public void testTextHaloBlurAsCategoricalSourceFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-halo-blur");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textHaloBlur(
+        property(
+          "FeaturePropertyA",
+          categorical(
+            stop(1.0f, textHaloBlur(0.3f))
+          )
+        ).withDefaultValue(0.3f)
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getTextHaloBlur());
+    assertNotNull(layer.getTextHaloBlur().getFunction());
+    assertEquals(SourceFunction.class, layer.getTextHaloBlur().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((SourceFunction) layer.getTextHaloBlur().getFunction()).getProperty());
+    assertEquals(CategoricalStops.class, layer.getTextHaloBlur().getFunction().getStops().getClass());
+    assertEquals(0.3f, ((SourceFunction) layer.getTextHaloBlur().getFunction()).getDefaultValue());
+  }
+
+  @Test
+  public void testTextHaloBlurAsCompositeFunction() {
+    checkViewIsDisplayed(R.id.mapView);
+    Timber.i("text-halo-blur");
+    assertNotNull(layer);
+
+    // Set
+    layer.setProperties(
+      textHaloBlur(
+        composite(
+          "FeaturePropertyA",
+          exponential(
+            stop(0, 0.3f, textHaloBlur(0.9f))
+          ).withBase(0.5f)
+        ).withDefaultValue(0.3f)
+      )
+    );
+
+    // Verify
+    assertNotNull(layer.getTextHaloBlur());
+    assertNotNull(layer.getTextHaloBlur().getFunction());
+    assertEquals(CompositeFunction.class, layer.getTextHaloBlur().getFunction().getClass());
+    assertEquals("FeaturePropertyA", ((CompositeFunction) layer.getTextHaloBlur().getFunction()).getProperty());
+    assertEquals(ExponentialStops.class, layer.getTextHaloBlur().getFunction().getStops().getClass());
+    assertEquals(1, ((ExponentialStops) layer.getTextHaloBlur().getFunction().getStops()).size());
+
+    ExponentialStops<Stop.CompositeValue<Float, Float>, Float> stops =
+      (ExponentialStops<Stop.CompositeValue<Float, Float>, Float>) layer.getTextHaloBlur().getFunction().getStops();
+    Stop<Stop.CompositeValue<Float, Float>, Float> stop = stops.iterator().next();
+    assertEquals(0f, stop.in.zoom, 0.001);
+    assertEquals(0.3f, stop.in.value, 0.001f);
+    assertEquals(0.9f, stop.out, 0.001f);
+  }
+
   @Test
   public void testTextTranslateAsConstant() {
     checkViewIsDisplayed(R.id.mapView);

platform/darwin/src/MGLSymbolStyleLayer.h

@@ -1204,6 +1204,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<UIColor *> *iconColor;
 #else
@@ -1224,6 +1233,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<NSColor *> *iconColor;
 #endif
@@ -1246,6 +1264,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<NSNumber *> *iconHaloBlur;
 
@@ -1267,6 +1294,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<UIColor *> *iconHaloColor;
 #else
@@ -1287,6 +1323,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<NSColor *> *iconHaloColor;
 #endif
@@ -1309,6 +1354,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<NSNumber *> *iconHaloWidth;
 
@@ -1328,6 +1382,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<NSNumber *> *iconOpacity;
 
@@ -1426,6 +1489,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<UIColor *> *textColor;
 #else
@@ -1445,6 +1517,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<NSColor *> *textColor;
 #endif
@@ -1467,6 +1548,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<NSNumber *> *textHaloBlur;
 
@@ -1487,6 +1577,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<UIColor *> *textHaloColor;
 #else
@@ -1506,6 +1605,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<NSColor *> *textHaloColor;
 #endif
@@ -1529,6 +1637,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<NSNumber *> *textHaloWidth;
 
@@ -1548,6 +1665,15 @@ MGL_EXPORT
  * `MGLCameraStyleFunction` with an interpolation mode of:
    * `MGLInterpolationModeExponential`
    * `MGLInterpolationModeInterval`
+ * `MGLSourceStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
+   * `MGLInterpolationModeIdentity`
+ * `MGLCompositeStyleFunction` with an interpolation mode of:
+   * `MGLInterpolationModeExponential`
+   * `MGLInterpolationModeInterval`
+   * `MGLInterpolationModeCategorical`
  */
 @property (nonatomic, null_resettable) MGLStyleValue<NSNumber *> *textOpacity;
 

platform/darwin/src/MGLSymbolStyleLayer.mm

@@ -890,7 +890,7 @@ namespace mbgl {
 - (void)setIconColor:(MGLStyleValue<MGLColor *> *)iconColor {
     MGLAssertStyleLayerIsValid();
 
-    auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toInterpolatablePropertyValue(iconColor);
+    auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toDataDrivenPropertyValue(iconColor);
     self.rawLayer->setIconColor(mbglValue);
 }
 
@@ -899,15 +899,15 @@ namespace mbgl {
 
     auto propertyValue = self.rawLayer->getIconColor();
     if (propertyValue.isUndefined()) {
-        return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(self.rawLayer->getDefaultIconColor());
+        return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toDataDrivenStyleValue(self.rawLayer->getDefaultIconColor());
     }
-    return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(propertyValue);
+    return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toDataDrivenStyleValue(propertyValue);
 }
 
 - (void)setIconHaloBlur:(MGLStyleValue<NSNumber *> *)iconHaloBlur {
     MGLAssertStyleLayerIsValid();
 
-    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toInterpolatablePropertyValue(iconHaloBlur);
+    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenPropertyValue(iconHaloBlur);
     self.rawLayer->setIconHaloBlur(mbglValue);
 }
 
@@ -916,15 +916,15 @@ namespace mbgl {
 
     auto propertyValue = self.rawLayer->getIconHaloBlur();
     if (propertyValue.isUndefined()) {
-        return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(self.rawLayer->getDefaultIconHaloBlur());
+        return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(self.rawLayer->getDefaultIconHaloBlur());
     }
-    return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
+    return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(propertyValue);
 }
 
 - (void)setIconHaloColor:(MGLStyleValue<MGLColor *> *)iconHaloColor {
     MGLAssertStyleLayerIsValid();
 
-    auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toInterpolatablePropertyValue(iconHaloColor);
+    auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toDataDrivenPropertyValue(iconHaloColor);
     self.rawLayer->setIconHaloColor(mbglValue);
 }
 
@@ -933,15 +933,15 @@ namespace mbgl {
 
     auto propertyValue = self.rawLayer->getIconHaloColor();
     if (propertyValue.isUndefined()) {
-        return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(self.rawLayer->getDefaultIconHaloColor());
+        return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toDataDrivenStyleValue(self.rawLayer->getDefaultIconHaloColor());
     }
-    return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(propertyValue);
+    return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toDataDrivenStyleValue(propertyValue);
 }
 
 - (void)setIconHaloWidth:(MGLStyleValue<NSNumber *> *)iconHaloWidth {
     MGLAssertStyleLayerIsValid();
 
-    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toInterpolatablePropertyValue(iconHaloWidth);
+    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenPropertyValue(iconHaloWidth);
     self.rawLayer->setIconHaloWidth(mbglValue);
 }
 
@@ -950,15 +950,15 @@ namespace mbgl {
 
     auto propertyValue = self.rawLayer->getIconHaloWidth();
     if (propertyValue.isUndefined()) {
-        return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(self.rawLayer->getDefaultIconHaloWidth());
+        return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(self.rawLayer->getDefaultIconHaloWidth());
     }
-    return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
+    return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(propertyValue);
 }
 
 - (void)setIconOpacity:(MGLStyleValue<NSNumber *> *)iconOpacity {
     MGLAssertStyleLayerIsValid();
 
-    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toInterpolatablePropertyValue(iconOpacity);
+    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenPropertyValue(iconOpacity);
     self.rawLayer->setIconOpacity(mbglValue);
 }
 
@@ -967,9 +967,9 @@ namespace mbgl {
 
     auto propertyValue = self.rawLayer->getIconOpacity();
     if (propertyValue.isUndefined()) {
-        return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(self.rawLayer->getDefaultIconOpacity());
+        return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(self.rawLayer->getDefaultIconOpacity());
     }
-    return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
+    return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(propertyValue);
 }
 
 - (void)setIconTranslation:(MGLStyleValue<NSValue *> *)iconTranslation {
@@ -1023,7 +1023,7 @@ namespace mbgl {
 - (void)setTextColor:(MGLStyleValue<MGLColor *> *)textColor {
     MGLAssertStyleLayerIsValid();
 
-    auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toInterpolatablePropertyValue(textColor);
+    auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toDataDrivenPropertyValue(textColor);
     self.rawLayer->setTextColor(mbglValue);
 }
 
@@ -1032,15 +1032,15 @@ namespace mbgl {
 
     auto propertyValue = self.rawLayer->getTextColor();
     if (propertyValue.isUndefined()) {
-        return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(self.rawLayer->getDefaultTextColor());
+        return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toDataDrivenStyleValue(self.rawLayer->getDefaultTextColor());
     }
-    return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(propertyValue);
+    return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toDataDrivenStyleValue(propertyValue);
 }
 
 - (void)setTextHaloBlur:(MGLStyleValue<NSNumber *> *)textHaloBlur {
     MGLAssertStyleLayerIsValid();
 
-    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toInterpolatablePropertyValue(textHaloBlur);
+    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenPropertyValue(textHaloBlur);
     self.rawLayer->setTextHaloBlur(mbglValue);
 }
 
@@ -1049,15 +1049,15 @@ namespace mbgl {
 
     auto propertyValue = self.rawLayer->getTextHaloBlur();
     if (propertyValue.isUndefined()) {
-        return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(self.rawLayer->getDefaultTextHaloBlur());
+        return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(self.rawLayer->getDefaultTextHaloBlur());
     }
-    return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
+    return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(propertyValue);
 }
 
 - (void)setTextHaloColor:(MGLStyleValue<MGLColor *> *)textHaloColor {
     MGLAssertStyleLayerIsValid();
 
-    auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toInterpolatablePropertyValue(textHaloColor);
+    auto mbglValue = MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toDataDrivenPropertyValue(textHaloColor);
     self.rawLayer->setTextHaloColor(mbglValue);
 }
 
@@ -1066,15 +1066,15 @@ namespace mbgl {
 
     auto propertyValue = self.rawLayer->getTextHaloColor();
     if (propertyValue.isUndefined()) {
-        return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(self.rawLayer->getDefaultTextHaloColor());
+        return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toDataDrivenStyleValue(self.rawLayer->getDefaultTextHaloColor());
     }
-    return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toStyleValue(propertyValue);
+    return MGLStyleValueTransformer<mbgl::Color, MGLColor *>().toDataDrivenStyleValue(propertyValue);
 }
 
 - (void)setTextHaloWidth:(MGLStyleValue<NSNumber *> *)textHaloWidth {
     MGLAssertStyleLayerIsValid();
 
-    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toInterpolatablePropertyValue(textHaloWidth);
+    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenPropertyValue(textHaloWidth);
     self.rawLayer->setTextHaloWidth(mbglValue);
 }
 
@@ -1083,15 +1083,15 @@ namespace mbgl {
 
     auto propertyValue = self.rawLayer->getTextHaloWidth();
     if (propertyValue.isUndefined()) {
-        return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(self.rawLayer->getDefaultTextHaloWidth());
+        return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(self.rawLayer->getDefaultTextHaloWidth());
     }
-    return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
+    return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(propertyValue);
 }
 
 - (void)setTextOpacity:(MGLStyleValue<NSNumber *> *)textOpacity {
     MGLAssertStyleLayerIsValid();
 
-    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toInterpolatablePropertyValue(textOpacity);
+    auto mbglValue = MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenPropertyValue(textOpacity);
     self.rawLayer->setTextOpacity(mbglValue);
 }
 
@@ -1100,9 +1100,9 @@ namespace mbgl {
 
     auto propertyValue = self.rawLayer->getTextOpacity();
     if (propertyValue.isUndefined()) {
-        return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(self.rawLayer->getDefaultTextOpacity());
+        return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(self.rawLayer->getDefaultTextOpacity());
     }
-    return MGLStyleValueTransformer<float, NSNumber *>().toStyleValue(propertyValue);
+    return MGLStyleValueTransformer<float, NSNumber *>().toDataDrivenStyleValue(propertyValue);
 }
 
 - (void)setTextTranslation:(MGLStyleValue<NSValue *> *)textTranslation {

platform/darwin/test/MGLSymbolStyleLayerTests.mm

@@ -1421,7 +1421,7 @@
 
         MGLStyleValue<MGLColor *> *constantStyleValue = [MGLStyleValue<MGLColor *> valueWithRawValue:[MGLColor redColor]];
         layer.iconColor = constantStyleValue;
-        mbgl::style::PropertyValue<mbgl::Color> propertyValue = { { 1, 0, 0, 1 } };
+        mbgl::style::DataDrivenPropertyValue<mbgl::Color> propertyValue = { { 1, 0, 0, 1 } };
         XCTAssertEqual(rawLayer->getIconColor(), propertyValue,
                        @"Setting iconColor to a constant value should update icon-color.");
         XCTAssertEqualObjects(layer.iconColor, constantStyleValue,
@@ -1438,6 +1438,29 @@
         XCTAssertEqualObjects(layer.iconColor, functionStyleValue,
                               @"iconColor should round-trip camera functions.");
 
+        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeExponential sourceStops:@{@18: constantStyleValue} attributeName:@"keyName" options:nil];
+        layer.iconColor = functionStyleValue;
+
+        mbgl::style::ExponentialStops<mbgl::Color> exponentialStops = { {{18, { 1, 0, 0, 1 }}}, 1.0 };
+        propertyValue = mbgl::style::SourceFunction<mbgl::Color> { "keyName", exponentialStops };
+
+        XCTAssertEqual(rawLayer->getIconColor(), propertyValue,
+                       @"Setting iconColor to a source function should update icon-color.");
+        XCTAssertEqualObjects(layer.iconColor, functionStyleValue,
+                              @"iconColor should round-trip source functions.");
+
+        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeExponential compositeStops:@{@10: @{@18: constantStyleValue}} attributeName:@"keyName" options:nil];
+        layer.iconColor = functionStyleValue;
+
+        std::map<float, mbgl::Color> innerStops { {18, { 1, 0, 0, 1 }} };
+        mbgl::style::CompositeExponentialStops<mbgl::Color> compositeStops { { {10.0, innerStops} }, 1.0 };
+
+        propertyValue = mbgl::style::CompositeFunction<mbgl::Color> { "keyName", compositeStops };
+
+        XCTAssertEqual(rawLayer->getIconColor(), propertyValue,
+                       @"Setting iconColor to a composite function should update icon-color.");
+        XCTAssertEqualObjects(layer.iconColor, functionStyleValue,
+                              @"iconColor should round-trip composite functions.");                                                                                                          
                               
 
         layer.iconColor = nil;
@@ -1445,11 +1468,6 @@
                       @"Unsetting iconColor should return icon-color to the default value.");
         XCTAssertEqualObjects(layer.iconColor, defaultStyleValue,
                               @"iconColor should return the default value after being unset.");
-
-        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeIdentity sourceStops:nil attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.iconColor = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
-        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeInterval compositeStops:@{@18: constantStyleValue} attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.iconColor = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
     }
 
     // icon-halo-blur
@@ -1460,7 +1478,7 @@
 
         MGLStyleValue<NSNumber *> *constantStyleValue = [MGLStyleValue<NSNumber *> valueWithRawValue:@0xff];
         layer.iconHaloBlur = constantStyleValue;
-        mbgl::style::PropertyValue<float> propertyValue = { 0xff };
+        mbgl::style::DataDrivenPropertyValue<float> propertyValue = { 0xff };
         XCTAssertEqual(rawLayer->getIconHaloBlur(), propertyValue,
                        @"Setting iconHaloBlur to a constant value should update icon-halo-blur.");
         XCTAssertEqualObjects(layer.iconHaloBlur, constantStyleValue,
@@ -1477,6 +1495,29 @@
         XCTAssertEqualObjects(layer.iconHaloBlur, functionStyleValue,
                               @"iconHaloBlur should round-trip camera functions.");
 
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential sourceStops:@{@18: constantStyleValue} attributeName:@"keyName" options:nil];
+        layer.iconHaloBlur = functionStyleValue;
+
+        mbgl::style::ExponentialStops<float> exponentialStops = { {{18, 0xff}}, 1.0 };
+        propertyValue = mbgl::style::SourceFunction<float> { "keyName", exponentialStops };
+
+        XCTAssertEqual(rawLayer->getIconHaloBlur(), propertyValue,
+                       @"Setting iconHaloBlur to a source function should update icon-halo-blur.");
+        XCTAssertEqualObjects(layer.iconHaloBlur, functionStyleValue,
+                              @"iconHaloBlur should round-trip source functions.");
+
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential compositeStops:@{@10: @{@18: constantStyleValue}} attributeName:@"keyName" options:nil];
+        layer.iconHaloBlur = functionStyleValue;
+
+        std::map<float, float> innerStops { {18, 0xff} };
+        mbgl::style::CompositeExponentialStops<float> compositeStops { { {10.0, innerStops} }, 1.0 };
+
+        propertyValue = mbgl::style::CompositeFunction<float> { "keyName", compositeStops };
+
+        XCTAssertEqual(rawLayer->getIconHaloBlur(), propertyValue,
+                       @"Setting iconHaloBlur to a composite function should update icon-halo-blur.");
+        XCTAssertEqualObjects(layer.iconHaloBlur, functionStyleValue,
+                              @"iconHaloBlur should round-trip composite functions.");                                                                                                          
                               
 
         layer.iconHaloBlur = nil;
@@ -1484,11 +1525,6 @@
                       @"Unsetting iconHaloBlur should return icon-halo-blur to the default value.");
         XCTAssertEqualObjects(layer.iconHaloBlur, defaultStyleValue,
                               @"iconHaloBlur should return the default value after being unset.");
-
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeIdentity sourceStops:nil attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.iconHaloBlur = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeInterval compositeStops:@{@18: constantStyleValue} attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.iconHaloBlur = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
     }
 
     // icon-halo-color
@@ -1499,7 +1535,7 @@
 
         MGLStyleValue<MGLColor *> *constantStyleValue = [MGLStyleValue<MGLColor *> valueWithRawValue:[MGLColor redColor]];
         layer.iconHaloColor = constantStyleValue;
-        mbgl::style::PropertyValue<mbgl::Color> propertyValue = { { 1, 0, 0, 1 } };
+        mbgl::style::DataDrivenPropertyValue<mbgl::Color> propertyValue = { { 1, 0, 0, 1 } };
         XCTAssertEqual(rawLayer->getIconHaloColor(), propertyValue,
                        @"Setting iconHaloColor to a constant value should update icon-halo-color.");
         XCTAssertEqualObjects(layer.iconHaloColor, constantStyleValue,
@@ -1516,6 +1552,29 @@
         XCTAssertEqualObjects(layer.iconHaloColor, functionStyleValue,
                               @"iconHaloColor should round-trip camera functions.");
 
+        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeExponential sourceStops:@{@18: constantStyleValue} attributeName:@"keyName" options:nil];
+        layer.iconHaloColor = functionStyleValue;
+
+        mbgl::style::ExponentialStops<mbgl::Color> exponentialStops = { {{18, { 1, 0, 0, 1 }}}, 1.0 };
+        propertyValue = mbgl::style::SourceFunction<mbgl::Color> { "keyName", exponentialStops };
+
+        XCTAssertEqual(rawLayer->getIconHaloColor(), propertyValue,
+                       @"Setting iconHaloColor to a source function should update icon-halo-color.");
+        XCTAssertEqualObjects(layer.iconHaloColor, functionStyleValue,
+                              @"iconHaloColor should round-trip source functions.");
+
+        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeExponential compositeStops:@{@10: @{@18: constantStyleValue}} attributeName:@"keyName" options:nil];
+        layer.iconHaloColor = functionStyleValue;
+
+        std::map<float, mbgl::Color> innerStops { {18, { 1, 0, 0, 1 }} };
+        mbgl::style::CompositeExponentialStops<mbgl::Color> compositeStops { { {10.0, innerStops} }, 1.0 };
+
+        propertyValue = mbgl::style::CompositeFunction<mbgl::Color> { "keyName", compositeStops };
+
+        XCTAssertEqual(rawLayer->getIconHaloColor(), propertyValue,
+                       @"Setting iconHaloColor to a composite function should update icon-halo-color.");
+        XCTAssertEqualObjects(layer.iconHaloColor, functionStyleValue,
+                              @"iconHaloColor should round-trip composite functions.");                                                                                                          
                               
 
         layer.iconHaloColor = nil;
@@ -1523,11 +1582,6 @@
                       @"Unsetting iconHaloColor should return icon-halo-color to the default value.");
         XCTAssertEqualObjects(layer.iconHaloColor, defaultStyleValue,
                               @"iconHaloColor should return the default value after being unset.");
-
-        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeIdentity sourceStops:nil attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.iconHaloColor = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
-        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeInterval compositeStops:@{@18: constantStyleValue} attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.iconHaloColor = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
     }
 
     // icon-halo-width
@@ -1538,7 +1592,7 @@
 
         MGLStyleValue<NSNumber *> *constantStyleValue = [MGLStyleValue<NSNumber *> valueWithRawValue:@0xff];
         layer.iconHaloWidth = constantStyleValue;
-        mbgl::style::PropertyValue<float> propertyValue = { 0xff };
+        mbgl::style::DataDrivenPropertyValue<float> propertyValue = { 0xff };
         XCTAssertEqual(rawLayer->getIconHaloWidth(), propertyValue,
                        @"Setting iconHaloWidth to a constant value should update icon-halo-width.");
         XCTAssertEqualObjects(layer.iconHaloWidth, constantStyleValue,
@@ -1555,6 +1609,29 @@
         XCTAssertEqualObjects(layer.iconHaloWidth, functionStyleValue,
                               @"iconHaloWidth should round-trip camera functions.");
 
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential sourceStops:@{@18: constantStyleValue} attributeName:@"keyName" options:nil];
+        layer.iconHaloWidth = functionStyleValue;
+
+        mbgl::style::ExponentialStops<float> exponentialStops = { {{18, 0xff}}, 1.0 };
+        propertyValue = mbgl::style::SourceFunction<float> { "keyName", exponentialStops };
+
+        XCTAssertEqual(rawLayer->getIconHaloWidth(), propertyValue,
+                       @"Setting iconHaloWidth to a source function should update icon-halo-width.");
+        XCTAssertEqualObjects(layer.iconHaloWidth, functionStyleValue,
+                              @"iconHaloWidth should round-trip source functions.");
+
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential compositeStops:@{@10: @{@18: constantStyleValue}} attributeName:@"keyName" options:nil];
+        layer.iconHaloWidth = functionStyleValue;
+
+        std::map<float, float> innerStops { {18, 0xff} };
+        mbgl::style::CompositeExponentialStops<float> compositeStops { { {10.0, innerStops} }, 1.0 };
+
+        propertyValue = mbgl::style::CompositeFunction<float> { "keyName", compositeStops };
+
+        XCTAssertEqual(rawLayer->getIconHaloWidth(), propertyValue,
+                       @"Setting iconHaloWidth to a composite function should update icon-halo-width.");
+        XCTAssertEqualObjects(layer.iconHaloWidth, functionStyleValue,
+                              @"iconHaloWidth should round-trip composite functions.");                                                                                                          
                               
 
         layer.iconHaloWidth = nil;
@@ -1562,11 +1639,6 @@
                       @"Unsetting iconHaloWidth should return icon-halo-width to the default value.");
         XCTAssertEqualObjects(layer.iconHaloWidth, defaultStyleValue,
                               @"iconHaloWidth should return the default value after being unset.");
-
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeIdentity sourceStops:nil attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.iconHaloWidth = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeInterval compositeStops:@{@18: constantStyleValue} attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.iconHaloWidth = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
     }
 
     // icon-opacity
@@ -1577,7 +1649,7 @@
 
         MGLStyleValue<NSNumber *> *constantStyleValue = [MGLStyleValue<NSNumber *> valueWithRawValue:@0xff];
         layer.iconOpacity = constantStyleValue;
-        mbgl::style::PropertyValue<float> propertyValue = { 0xff };
+        mbgl::style::DataDrivenPropertyValue<float> propertyValue = { 0xff };
         XCTAssertEqual(rawLayer->getIconOpacity(), propertyValue,
                        @"Setting iconOpacity to a constant value should update icon-opacity.");
         XCTAssertEqualObjects(layer.iconOpacity, constantStyleValue,
@@ -1594,6 +1666,29 @@
         XCTAssertEqualObjects(layer.iconOpacity, functionStyleValue,
                               @"iconOpacity should round-trip camera functions.");
 
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential sourceStops:@{@18: constantStyleValue} attributeName:@"keyName" options:nil];
+        layer.iconOpacity = functionStyleValue;
+
+        mbgl::style::ExponentialStops<float> exponentialStops = { {{18, 0xff}}, 1.0 };
+        propertyValue = mbgl::style::SourceFunction<float> { "keyName", exponentialStops };
+
+        XCTAssertEqual(rawLayer->getIconOpacity(), propertyValue,
+                       @"Setting iconOpacity to a source function should update icon-opacity.");
+        XCTAssertEqualObjects(layer.iconOpacity, functionStyleValue,
+                              @"iconOpacity should round-trip source functions.");
+
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential compositeStops:@{@10: @{@18: constantStyleValue}} attributeName:@"keyName" options:nil];
+        layer.iconOpacity = functionStyleValue;
+
+        std::map<float, float> innerStops { {18, 0xff} };
+        mbgl::style::CompositeExponentialStops<float> compositeStops { { {10.0, innerStops} }, 1.0 };
+
+        propertyValue = mbgl::style::CompositeFunction<float> { "keyName", compositeStops };
+
+        XCTAssertEqual(rawLayer->getIconOpacity(), propertyValue,
+                       @"Setting iconOpacity to a composite function should update icon-opacity.");
+        XCTAssertEqualObjects(layer.iconOpacity, functionStyleValue,
+                              @"iconOpacity should round-trip composite functions.");                                                                                                          
                               
 
         layer.iconOpacity = nil;
@@ -1601,11 +1696,6 @@
                       @"Unsetting iconOpacity should return icon-opacity to the default value.");
         XCTAssertEqualObjects(layer.iconOpacity, defaultStyleValue,
                               @"iconOpacity should return the default value after being unset.");
-
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeIdentity sourceStops:nil attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.iconOpacity = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeInterval compositeStops:@{@18: constantStyleValue} attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.iconOpacity = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
     }
 
     // icon-translate
@@ -1700,7 +1790,7 @@
 
         MGLStyleValue<MGLColor *> *constantStyleValue = [MGLStyleValue<MGLColor *> valueWithRawValue:[MGLColor redColor]];
         layer.textColor = constantStyleValue;
-        mbgl::style::PropertyValue<mbgl::Color> propertyValue = { { 1, 0, 0, 1 } };
+        mbgl::style::DataDrivenPropertyValue<mbgl::Color> propertyValue = { { 1, 0, 0, 1 } };
         XCTAssertEqual(rawLayer->getTextColor(), propertyValue,
                        @"Setting textColor to a constant value should update text-color.");
         XCTAssertEqualObjects(layer.textColor, constantStyleValue,
@@ -1717,6 +1807,29 @@
         XCTAssertEqualObjects(layer.textColor, functionStyleValue,
                               @"textColor should round-trip camera functions.");
 
+        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeExponential sourceStops:@{@18: constantStyleValue} attributeName:@"keyName" options:nil];
+        layer.textColor = functionStyleValue;
+
+        mbgl::style::ExponentialStops<mbgl::Color> exponentialStops = { {{18, { 1, 0, 0, 1 }}}, 1.0 };
+        propertyValue = mbgl::style::SourceFunction<mbgl::Color> { "keyName", exponentialStops };
+
+        XCTAssertEqual(rawLayer->getTextColor(), propertyValue,
+                       @"Setting textColor to a source function should update text-color.");
+        XCTAssertEqualObjects(layer.textColor, functionStyleValue,
+                              @"textColor should round-trip source functions.");
+
+        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeExponential compositeStops:@{@10: @{@18: constantStyleValue}} attributeName:@"keyName" options:nil];
+        layer.textColor = functionStyleValue;
+
+        std::map<float, mbgl::Color> innerStops { {18, { 1, 0, 0, 1 }} };
+        mbgl::style::CompositeExponentialStops<mbgl::Color> compositeStops { { {10.0, innerStops} }, 1.0 };
+
+        propertyValue = mbgl::style::CompositeFunction<mbgl::Color> { "keyName", compositeStops };
+
+        XCTAssertEqual(rawLayer->getTextColor(), propertyValue,
+                       @"Setting textColor to a composite function should update text-color.");
+        XCTAssertEqualObjects(layer.textColor, functionStyleValue,
+                              @"textColor should round-trip composite functions.");                                                                                                          
                               
 
         layer.textColor = nil;
@@ -1724,11 +1837,6 @@
                       @"Unsetting textColor should return text-color to the default value.");
         XCTAssertEqualObjects(layer.textColor, defaultStyleValue,
                               @"textColor should return the default value after being unset.");
-
-        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeIdentity sourceStops:nil attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.textColor = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
-        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeInterval compositeStops:@{@18: constantStyleValue} attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.textColor = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
     }
 
     // text-halo-blur
@@ -1739,7 +1847,7 @@
 
         MGLStyleValue<NSNumber *> *constantStyleValue = [MGLStyleValue<NSNumber *> valueWithRawValue:@0xff];
         layer.textHaloBlur = constantStyleValue;
-        mbgl::style::PropertyValue<float> propertyValue = { 0xff };
+        mbgl::style::DataDrivenPropertyValue<float> propertyValue = { 0xff };
         XCTAssertEqual(rawLayer->getTextHaloBlur(), propertyValue,
                        @"Setting textHaloBlur to a constant value should update text-halo-blur.");
         XCTAssertEqualObjects(layer.textHaloBlur, constantStyleValue,
@@ -1756,6 +1864,29 @@
         XCTAssertEqualObjects(layer.textHaloBlur, functionStyleValue,
                               @"textHaloBlur should round-trip camera functions.");
 
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential sourceStops:@{@18: constantStyleValue} attributeName:@"keyName" options:nil];
+        layer.textHaloBlur = functionStyleValue;
+
+        mbgl::style::ExponentialStops<float> exponentialStops = { {{18, 0xff}}, 1.0 };
+        propertyValue = mbgl::style::SourceFunction<float> { "keyName", exponentialStops };
+
+        XCTAssertEqual(rawLayer->getTextHaloBlur(), propertyValue,
+                       @"Setting textHaloBlur to a source function should update text-halo-blur.");
+        XCTAssertEqualObjects(layer.textHaloBlur, functionStyleValue,
+                              @"textHaloBlur should round-trip source functions.");
+
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential compositeStops:@{@10: @{@18: constantStyleValue}} attributeName:@"keyName" options:nil];
+        layer.textHaloBlur = functionStyleValue;
+
+        std::map<float, float> innerStops { {18, 0xff} };
+        mbgl::style::CompositeExponentialStops<float> compositeStops { { {10.0, innerStops} }, 1.0 };
+
+        propertyValue = mbgl::style::CompositeFunction<float> { "keyName", compositeStops };
+
+        XCTAssertEqual(rawLayer->getTextHaloBlur(), propertyValue,
+                       @"Setting textHaloBlur to a composite function should update text-halo-blur.");
+        XCTAssertEqualObjects(layer.textHaloBlur, functionStyleValue,
+                              @"textHaloBlur should round-trip composite functions.");                                                                                                          
                               
 
         layer.textHaloBlur = nil;
@@ -1763,11 +1894,6 @@
                       @"Unsetting textHaloBlur should return text-halo-blur to the default value.");
         XCTAssertEqualObjects(layer.textHaloBlur, defaultStyleValue,
                               @"textHaloBlur should return the default value after being unset.");
-
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeIdentity sourceStops:nil attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.textHaloBlur = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeInterval compositeStops:@{@18: constantStyleValue} attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.textHaloBlur = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
     }
 
     // text-halo-color
@@ -1778,7 +1904,7 @@
 
         MGLStyleValue<MGLColor *> *constantStyleValue = [MGLStyleValue<MGLColor *> valueWithRawValue:[MGLColor redColor]];
         layer.textHaloColor = constantStyleValue;
-        mbgl::style::PropertyValue<mbgl::Color> propertyValue = { { 1, 0, 0, 1 } };
+        mbgl::style::DataDrivenPropertyValue<mbgl::Color> propertyValue = { { 1, 0, 0, 1 } };
         XCTAssertEqual(rawLayer->getTextHaloColor(), propertyValue,
                        @"Setting textHaloColor to a constant value should update text-halo-color.");
         XCTAssertEqualObjects(layer.textHaloColor, constantStyleValue,
@@ -1795,6 +1921,29 @@
         XCTAssertEqualObjects(layer.textHaloColor, functionStyleValue,
                               @"textHaloColor should round-trip camera functions.");
 
+        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeExponential sourceStops:@{@18: constantStyleValue} attributeName:@"keyName" options:nil];
+        layer.textHaloColor = functionStyleValue;
+
+        mbgl::style::ExponentialStops<mbgl::Color> exponentialStops = { {{18, { 1, 0, 0, 1 }}}, 1.0 };
+        propertyValue = mbgl::style::SourceFunction<mbgl::Color> { "keyName", exponentialStops };
+
+        XCTAssertEqual(rawLayer->getTextHaloColor(), propertyValue,
+                       @"Setting textHaloColor to a source function should update text-halo-color.");
+        XCTAssertEqualObjects(layer.textHaloColor, functionStyleValue,
+                              @"textHaloColor should round-trip source functions.");
+
+        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeExponential compositeStops:@{@10: @{@18: constantStyleValue}} attributeName:@"keyName" options:nil];
+        layer.textHaloColor = functionStyleValue;
+
+        std::map<float, mbgl::Color> innerStops { {18, { 1, 0, 0, 1 }} };
+        mbgl::style::CompositeExponentialStops<mbgl::Color> compositeStops { { {10.0, innerStops} }, 1.0 };
+
+        propertyValue = mbgl::style::CompositeFunction<mbgl::Color> { "keyName", compositeStops };
+
+        XCTAssertEqual(rawLayer->getTextHaloColor(), propertyValue,
+                       @"Setting textHaloColor to a composite function should update text-halo-color.");
+        XCTAssertEqualObjects(layer.textHaloColor, functionStyleValue,
+                              @"textHaloColor should round-trip composite functions.");                                                                                                          
                               
 
         layer.textHaloColor = nil;
@@ -1802,11 +1951,6 @@
                       @"Unsetting textHaloColor should return text-halo-color to the default value.");
         XCTAssertEqualObjects(layer.textHaloColor, defaultStyleValue,
                               @"textHaloColor should return the default value after being unset.");
-
-        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeIdentity sourceStops:nil attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.textHaloColor = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
-        functionStyleValue = [MGLStyleValue<MGLColor *> valueWithInterpolationMode:MGLInterpolationModeInterval compositeStops:@{@18: constantStyleValue} attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.textHaloColor = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
     }
 
     // text-halo-width
@@ -1817,7 +1961,7 @@
 
         MGLStyleValue<NSNumber *> *constantStyleValue = [MGLStyleValue<NSNumber *> valueWithRawValue:@0xff];
         layer.textHaloWidth = constantStyleValue;
-        mbgl::style::PropertyValue<float> propertyValue = { 0xff };
+        mbgl::style::DataDrivenPropertyValue<float> propertyValue = { 0xff };
         XCTAssertEqual(rawLayer->getTextHaloWidth(), propertyValue,
                        @"Setting textHaloWidth to a constant value should update text-halo-width.");
         XCTAssertEqualObjects(layer.textHaloWidth, constantStyleValue,
@@ -1834,6 +1978,29 @@
         XCTAssertEqualObjects(layer.textHaloWidth, functionStyleValue,
                               @"textHaloWidth should round-trip camera functions.");
 
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential sourceStops:@{@18: constantStyleValue} attributeName:@"keyName" options:nil];
+        layer.textHaloWidth = functionStyleValue;
+
+        mbgl::style::ExponentialStops<float> exponentialStops = { {{18, 0xff}}, 1.0 };
+        propertyValue = mbgl::style::SourceFunction<float> { "keyName", exponentialStops };
+
+        XCTAssertEqual(rawLayer->getTextHaloWidth(), propertyValue,
+                       @"Setting textHaloWidth to a source function should update text-halo-width.");
+        XCTAssertEqualObjects(layer.textHaloWidth, functionStyleValue,
+                              @"textHaloWidth should round-trip source functions.");
+
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential compositeStops:@{@10: @{@18: constantStyleValue}} attributeName:@"keyName" options:nil];
+        layer.textHaloWidth = functionStyleValue;
+
+        std::map<float, float> innerStops { {18, 0xff} };
+        mbgl::style::CompositeExponentialStops<float> compositeStops { { {10.0, innerStops} }, 1.0 };
+
+        propertyValue = mbgl::style::CompositeFunction<float> { "keyName", compositeStops };
+
+        XCTAssertEqual(rawLayer->getTextHaloWidth(), propertyValue,
+                       @"Setting textHaloWidth to a composite function should update text-halo-width.");
+        XCTAssertEqualObjects(layer.textHaloWidth, functionStyleValue,
+                              @"textHaloWidth should round-trip composite functions.");                                                                                                          
                               
 
         layer.textHaloWidth = nil;
@@ -1841,11 +2008,6 @@
                       @"Unsetting textHaloWidth should return text-halo-width to the default value.");
         XCTAssertEqualObjects(layer.textHaloWidth, defaultStyleValue,
                               @"textHaloWidth should return the default value after being unset.");
-
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeIdentity sourceStops:nil attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.textHaloWidth = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeInterval compositeStops:@{@18: constantStyleValue} attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.textHaloWidth = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
     }
 
     // text-opacity
@@ -1856,7 +2018,7 @@
 
         MGLStyleValue<NSNumber *> *constantStyleValue = [MGLStyleValue<NSNumber *> valueWithRawValue:@0xff];
         layer.textOpacity = constantStyleValue;
-        mbgl::style::PropertyValue<float> propertyValue = { 0xff };
+        mbgl::style::DataDrivenPropertyValue<float> propertyValue = { 0xff };
         XCTAssertEqual(rawLayer->getTextOpacity(), propertyValue,
                        @"Setting textOpacity to a constant value should update text-opacity.");
         XCTAssertEqualObjects(layer.textOpacity, constantStyleValue,
@@ -1873,6 +2035,29 @@
         XCTAssertEqualObjects(layer.textOpacity, functionStyleValue,
                               @"textOpacity should round-trip camera functions.");
 
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential sourceStops:@{@18: constantStyleValue} attributeName:@"keyName" options:nil];
+        layer.textOpacity = functionStyleValue;
+
+        mbgl::style::ExponentialStops<float> exponentialStops = { {{18, 0xff}}, 1.0 };
+        propertyValue = mbgl::style::SourceFunction<float> { "keyName", exponentialStops };
+
+        XCTAssertEqual(rawLayer->getTextOpacity(), propertyValue,
+                       @"Setting textOpacity to a source function should update text-opacity.");
+        XCTAssertEqualObjects(layer.textOpacity, functionStyleValue,
+                              @"textOpacity should round-trip source functions.");
+
+        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeExponential compositeStops:@{@10: @{@18: constantStyleValue}} attributeName:@"keyName" options:nil];
+        layer.textOpacity = functionStyleValue;
+
+        std::map<float, float> innerStops { {18, 0xff} };
+        mbgl::style::CompositeExponentialStops<float> compositeStops { { {10.0, innerStops} }, 1.0 };
+
+        propertyValue = mbgl::style::CompositeFunction<float> { "keyName", compositeStops };
+
+        XCTAssertEqual(rawLayer->getTextOpacity(), propertyValue,
+                       @"Setting textOpacity to a composite function should update text-opacity.");
+        XCTAssertEqualObjects(layer.textOpacity, functionStyleValue,
+                              @"textOpacity should round-trip composite functions.");                                                                                                          
                               
 
         layer.textOpacity = nil;
@@ -1880,11 +2065,6 @@
                       @"Unsetting textOpacity should return text-opacity to the default value.");
         XCTAssertEqualObjects(layer.textOpacity, defaultStyleValue,
                               @"textOpacity should return the default value after being unset.");
-
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeIdentity sourceStops:nil attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.textOpacity = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
-        functionStyleValue = [MGLStyleValue<NSNumber *> valueWithInterpolationMode:MGLInterpolationModeInterval compositeStops:@{@18: constantStyleValue} attributeName:@"" options:nil];
-        XCTAssertThrowsSpecificNamed(layer.textOpacity = functionStyleValue, NSException, NSInvalidArgumentException, @"MGLStyleValue should raise an exception if it is applied to a property that cannot support it");
     }
 
     // text-translate

scripts/generate-style-code.js

@@ -47,7 +47,20 @@ global.evaluatedType = function (property) {
 };
 
 function attributeType(property, type) {
-    const name = property.name.replace(type + '-', '').replace('-', '_');
+    const attributeNameExceptions = {
+      'text-opacity': 'opacity',
+      'icon-opacity': 'opacity',
+      'text-color': 'fill_color',
+      'icon-color': 'fill_color',
+      'text-halo-color': 'halo_color',
+      'icon-halo-color': 'halo_color',
+      'text-halo-blur': 'halo_blur',
+      'icon-halo-blur': 'halo_blur',
+      'text-halo-width': 'halo_width',
+      'icon-halo-width': 'halo_width'
+    }
+    const name = attributeNameExceptions[property.name] ||
+        property.name.replace(type + '-', '').replace(/-/g, '_');
     return `attributes::a_${name}${name === 'offset' ? '<1>' : ''}`;
 }
 

src/mbgl/layout/symbol_feature.hpp

@@ -8,14 +8,23 @@
 
 namespace mbgl {
 
-class SymbolFeature {
+class SymbolFeature : public GeometryTileFeature {
 public:
-    FeatureType type;
+    SymbolFeature(std::unique_ptr<GeometryTileFeature> feature_) :
+        feature(std::move(feature_)),
+        geometry(feature->getGeometries()) // we need a mutable copy of the geometry for mergeLines()
+    {}
+    
+    FeatureType getType() const override { return feature->getType(); }
+    optional<Value> getValue(const std::string& key) const override { return feature->getValue(key); };
+    std::unordered_map<std::string,Value> getProperties() const override { return feature->getProperties(); };
+    optional<FeatureIdentifier> getID() const override { return feature->getID(); };
+    GeometryCollection getGeometries() const override { return geometry; };
+
+    std::unique_ptr<GeometryTileFeature> feature;
     GeometryCollection geometry;
     optional<std::u16string> text;
     optional<std::string> icon;
-    std::array<float, 2> iconOffset;
-    float iconRotation;
     std::size_t index;
 };
 

src/mbgl/layout/symbol_instance.cpp

@@ -10,7 +10,7 @@ SymbolInstance::SymbolInstance(Anchor& anchor, const GeometryCoordinates& line,
         const SymbolLayoutProperties::Evaluated& layout, const bool addToBuffers, const uint32_t index_,
         const float textBoxScale, const float textPadding, const SymbolPlacementType textPlacement,
         const float iconBoxScale, const float iconPadding, const SymbolPlacementType iconPlacement,
-        const GlyphPositions& face, const IndexedSubfeature& indexedFeature) :
+        const GlyphPositions& face, const IndexedSubfeature& indexedFeature, const std::size_t featureIndex_) :
     point(anchor.point),
     index(index_),
     hasText(shapedTextOrientations.first || shapedTextOrientations.second),
@@ -18,7 +18,8 @@ SymbolInstance::SymbolInstance(Anchor& anchor, const GeometryCoordinates& line,
 
     // Create the collision features that will be used to check whether this symbol instance can be placed
     textCollisionFeature(line, anchor, shapedTextOrientations.second ?: shapedTextOrientations.first, textBoxScale, textPadding, textPlacement, indexedFeature),
-    iconCollisionFeature(line, anchor, shapedIcon, iconBoxScale, iconPadding, iconPlacement, indexedFeature) {
+    iconCollisionFeature(line, anchor, shapedIcon, iconBoxScale, iconPadding, iconPlacement, indexedFeature),
+    featureIndex(featureIndex_) {
 
     // Create the quads used for rendering the icon and glyphs.
     if (addToBuffers) {

src/mbgl/layout/symbol_instance.hpp

@@ -17,7 +17,7 @@ public:
             const style::SymbolLayoutProperties::Evaluated&, const bool inside, const uint32_t index,
             const float textBoxScale, const float textPadding, style::SymbolPlacementType textPlacement,
             const float iconBoxScale, const float iconPadding, style::SymbolPlacementType iconPlacement,
-            const GlyphPositions& face, const IndexedSubfeature& indexedfeature);
+            const GlyphPositions& face, const IndexedSubfeature& indexedfeature, const std::size_t featureIndex);
 
     Point<float> point;
     uint32_t index;
@@ -28,6 +28,7 @@ public:
     CollisionFeature textCollisionFeature;
     CollisionFeature iconCollisionFeature;
     WritingModeType writingModes;
+    std::size_t featureIndex;
 };
 
 } // namespace mbgl

src/mbgl/layout/symbol_layout.cpp

@@ -87,7 +87,10 @@ SymbolLayout::SymbolLayout(const BucketParameters& parameters,
     }
 
     for (const auto& layer : layers) {
-        layerPaintProperties.emplace(layer->getID(), layer->as<SymbolLayer>()->impl->paint.evaluated);
+        layerPaintProperties.emplace(layer->getID(), std::make_pair(
+            layer->as<SymbolLayer>()->impl->iconPaintProperties(),
+            layer->as<SymbolLayer>()->impl->textPaintProperties()
+        ));
     }
 
     // Determine and load glyph ranges
@@ -96,12 +99,13 @@ SymbolLayout::SymbolLayout(const BucketParameters& parameters,
         auto feature = sourceLayer.getFeature(i);
         if (!leader.filter(feature->getType(), feature->getID(), [&] (const auto& key) { return feature->getValue(key); }))
             continue;
+        
+        SymbolFeature ft(std::move(feature));
 
-        SymbolFeature ft;
         ft.index = i;
 
-        auto getValue = [&feature](const std::string& key) -> std::string {
-            auto value = feature->getValue(key);
+        auto getValue = [&ft](const std::string& key) -> std::string {
+            auto value = ft.getValue(key);
             if (!value)
                 return std::string();
             if (value->is<std::string>())
@@ -118,12 +122,12 @@ SymbolLayout::SymbolLayout(const BucketParameters& parameters,
         };
         
         if (hasText) {
-            std::string u8string = layout.evaluate<TextField>(zoom, *feature);
+            std::string u8string = layout.evaluate<TextField>(zoom, ft);
             if (layout.get<TextField>().isConstant()) {
                 u8string = util::replaceTokens(u8string, getValue);
             }
             
-            auto textTransform = layout.evaluate<TextTransform>(zoom, *feature);
+            auto textTransform = layout.evaluate<TextTransform>(zoom, ft);
 
             if (textTransform == TextTransformType::Uppercase) {
                 u8string = platform::uppercase(u8string);
@@ -144,13 +148,9 @@ SymbolLayout::SymbolLayout(const BucketParameters& parameters,
 
         if (hasIcon) {
             ft.icon = util::replaceTokens(layout.get<IconImage>(), getValue);
-            ft.iconOffset = layout.evaluate<IconOffset>(zoom, *feature);
-            ft.iconRotation = layout.evaluate<IconRotate>(zoom, *feature) * util::DEG2RAD;
         }
 
         if (ft.text || ft.icon) {
-            ft.type = feature->getType();
-            ft.geometry = feature->getGeometries();
             features.push_back(std::move(ft));
         }
     }
@@ -229,7 +229,8 @@ void SymbolLayout::prepare(uintptr_t tileUID,
     const bool textAlongLine = layout.get<TextRotationAlignment>() == AlignmentType::Map &&
         layout.get<SymbolPlacement>() == SymbolPlacementType::Line;
 
-    for (const auto& feature : features) {
+    for (auto it = features.begin(); it != features.end(); ++it) {
+        auto& feature = *it;
         if (feature.geometry.empty()) continue;
 
         std::pair<Shaping, Shaping> shapedTextOrientations;
@@ -273,7 +274,9 @@ void SymbolLayout::prepare(uintptr_t tileUID,
         if (feature.icon) {
             auto image = spriteAtlas.getIcon(*feature.icon);
             if (image) {
-                shapedIcon = shapeIcon(*image, feature);
+                shapedIcon = shapeIcon(*image,
+                    layout.evaluate<IconOffset>(zoom, feature),
+                    layout.evaluate<IconRotate>(zoom, feature) * util::DEG2RAD);
                 assert((*image).spriteImage);
                 if ((*image).spriteImage->sdf) {
                     sdfIcons = true;
@@ -288,15 +291,17 @@ void SymbolLayout::prepare(uintptr_t tileUID,
 
         // if either shapedText or icon position is present, add the feature
         if (shapedTextOrientations.first || shapedIcon) {
-            addFeature(feature, shapedTextOrientations, shapedIcon, face);
+            addFeature(std::distance(features.begin(), it), feature, shapedTextOrientations, shapedIcon, face);
         }
+        
+        feature.geometry.clear();
     }
 
-    features.clear();
     compareText.clear();
 }
 
-void SymbolLayout::addFeature(const SymbolFeature& feature,
+void SymbolLayout::addFeature(const std::size_t index,
+                              const SymbolFeature& feature,
                               const std::pair<Shaping, Shaping>& shapedTextOrientations,
                               const PositionedIcon& shapedIcon,
                               const GlyphPositions& face) {
@@ -345,8 +350,10 @@ void SymbolLayout::addFeature(const SymbolFeature& feature,
         symbolInstances.emplace_back(anchor, line, shapedTextOrientations, shapedIcon, layout, addToBuffers, symbolInstances.size(),
                 textBoxScale, textPadding, textPlacement,
                 iconBoxScale, iconPadding, iconPlacement,
-                face, indexedFeature);
+                face, indexedFeature, index);
     };
+    
+    const auto& type = feature.getType();
 
     if (layout.get<SymbolPlacement>() == SymbolPlacementType::Line) {
         auto clippedLines = util::clipLines(feature.geometry, 0, 0, util::EXTENT, util::EXTENT);
@@ -368,7 +375,7 @@ void SymbolLayout::addFeature(const SymbolFeature& feature,
                 }
             }
         }
-    } else if (feature.type == FeatureType::Polygon) {
+    } else if (type == FeatureType::Polygon) {
         for (const auto& polygon : classifyRings(feature.geometry)) {
             Polygon<double> poly;
             for (const auto& ring : polygon) {
@@ -384,12 +391,12 @@ void SymbolLayout::addFeature(const SymbolFeature& feature,
             Anchor anchor(poi.x, poi.y, 0, minScale);
             addSymbolInstance(polygon[0], anchor);
         }
-    } else if (feature.type == FeatureType::LineString) {
+    } else if (type == FeatureType::LineString) {
         for (const auto& line : feature.geometry) {
             Anchor anchor(line[0].x, line[0].y, 0, minScale);
             addSymbolInstance(line, anchor);
         }
-    } else if (feature.type == FeatureType::Point) {
+    } else if (type == FeatureType::Point) {
         for (const auto& points : feature.geometry) {
             for (const auto& point : points) {
                 Anchor anchor(point.x, point.y, 0, minScale);
@@ -503,6 +510,12 @@ std::unique_ptr<SymbolBucket> SymbolLayout::place(CollisionTile& collisionTile)
                     keepUpright, iconPlacement, collisionTile.config.angle, symbolInstance.writingModes);
             }
         }
+        
+        const auto& feature = features.at(symbolInstance.featureIndex);
+        for (auto& pair : bucket->paintPropertyBinders) {
+            pair.second.first.populateVertexVectors(feature, bucket->icon.vertices.vertexSize());
+            pair.second.second.populateVertexVectors(feature, bucket->text.vertices.vertexSize());
+        }
     }
 
     if (collisionTile.config.debug) {

src/mbgl/layout/symbol_layout.hpp

@@ -5,6 +5,7 @@
 #include <mbgl/layout/symbol_feature.hpp>
 #include <mbgl/layout/symbol_instance.hpp>
 #include <mbgl/text/bidi.hpp>
+#include <mbgl/style/layers/symbol_layer_impl.hpp>
 
 #include <memory>
 #include <map>
@@ -51,10 +52,12 @@ public:
 
     State state = Pending;
 
-    std::unordered_map<std::string, style::SymbolPaintProperties::Evaluated> layerPaintProperties;
+    std::unordered_map<std::string,
+        std::pair<style::IconPaintProperties::Evaluated, style::TextPaintProperties::Evaluated>> layerPaintProperties;
 
 private:
-    void addFeature(const SymbolFeature&,
+    void addFeature(const size_t,
+                    const SymbolFeature&,
                     const std::pair<Shaping, Shaping>& shapedTextOrientations,
                     const PositionedIcon& shapedIcon,
                     const GlyphPositions& face);

src/mbgl/programs/attributes.hpp

@@ -64,6 +64,34 @@ struct a_color : gl::Attribute<gl::Normalized<uint8_t>, 4> {
     }
 };
 
+// used in the symbol sdf shader
+struct a_fill_color : gl::Attribute<gl::Normalized<uint8_t>, 4> {
+    static auto name() { return "a_fill_color"; }
+    
+    static Value value(const Color& color) {
+        return {{
+            gl::Normalized<uint8_t>(color.r),
+            gl::Normalized<uint8_t>(color.g),
+            gl::Normalized<uint8_t>(color.b),
+            gl::Normalized<uint8_t>(color.a)
+        }};
+    }
+};
+
+// used in the symbol sdf shader
+struct a_halo_color : gl::Attribute<gl::Normalized<uint8_t>, 4> {
+    static auto name() { return "a_halo_color"; }
+    
+    static Value value(const Color& color) {
+        return {{
+            gl::Normalized<uint8_t>(color.r),
+            gl::Normalized<uint8_t>(color.g),
+            gl::Normalized<uint8_t>(color.b),
+            gl::Normalized<uint8_t>(color.a)
+        }};
+    }
+};
+
 struct a_stroke_color : gl::Attribute<gl::Normalized<uint8_t>, 4> {
     static auto name() { return "a_stroke_color"; }
 
@@ -171,5 +199,23 @@ struct a_offset<1> : gl::Attribute<float, 1> {
     }
 };
 
+struct a_halo_width : gl::Attribute<float, 1> {
+    static auto name() { return "a_halo_width"; }
+    
+    static Value value(float width) {
+        return {{ width }};
+    }
+};
+
+struct a_halo_blur : gl::Attribute<float, 1> {
+    static auto name() { return "a_halo_blur"; }
+    
+    static Value value(float blur) {
+        return {{ blur }};
+    }
+};
+
+
+
 } // namespace attributes
 } // namespace mbgl

src/mbgl/programs/programs.hpp

@@ -40,8 +40,8 @@ public:
     LinePatternProgram linePattern;
     RasterProgram raster;
     SymbolIconProgram symbolIcon;
-    SymbolSDFProgram symbolIconSDF;
-    SymbolSDFProgram symbolGlyph;
+    SymbolSDFIconProgram symbolIconSDF;
+    SymbolSDFTextProgram symbolGlyph;
 
     DebugProgram debug;
     CollisionBoxProgram collisionBox;

src/mbgl/programs/symbol_program.cpp

@@ -2,6 +2,7 @@
 #include <mbgl/renderer/render_tile.hpp>
 #include <mbgl/map/transform_state.hpp>
 #include <mbgl/style/layers/symbol_layer_impl.hpp>
+#include <mbgl/util/enum.hpp>
 
 namespace mbgl {
 
@@ -19,6 +20,7 @@ Values makeValues(const style::SymbolPropertyValues& values,
     std::array<float, 2> extrudeScale;
 
     const float scale = values.paintSize / values.sdfScale;
+    
     if (values.pitchAlignment == AlignmentType::Map) {
         extrudeScale.fill(tile.id.pixelsToTileUnits(1, state.getZoom()) * scale);
     } else {
@@ -27,7 +29,7 @@ Values makeValues(const style::SymbolPropertyValues& values,
             pixelsToGLUnits[1] * scale * state.getCameraToCenterDistance()
         }};
     }
-
+    
     // adjust min/max zooms for variable font sies
     float zoomAdjust = std::log(values.paintSize / values.layoutSize) / std::log(2);
 
@@ -35,7 +37,6 @@ Values makeValues(const style::SymbolPropertyValues& values,
         uniforms::u_matrix::Value{ tile.translatedMatrix(values.translate,
                                    values.translateAnchor,
                                    state) },
-        uniforms::u_opacity::Value{ values.opacity },
         uniforms::u_extrude_scale::Value{ extrudeScale },
         uniforms::u_texsize::Value{ std::array<float, 2> {{ float(texsize.width) / 4, float(texsize.height) / 4 }} },
         uniforms::u_zoom::Value{ float((state.getZoom() - zoomAdjust) * 10) },
@@ -62,84 +63,37 @@ SymbolIconProgram::uniformValues(const style::SymbolPropertyValues& values,
     );
 }
 
-static SymbolSDFProgram::UniformValues makeSDFValues(const style::SymbolPropertyValues& values,
-                                               const Size& texsize,
-                                               const std::array<float, 2>& pixelsToGLUnits,
-                                               const RenderTile& tile,
-                                               const TransformState& state,
-                                               float pixelRatio,
-                                               Color color,
-                                               float buffer,
-                                               float gammaAdjust)
-{
-    // The default gamma value has to be adjust for the current pixelratio so that we're not
-    // drawing blurry font on retina screens.
-    const float gammaBase = 0.105 * values.sdfScale / values.paintSize / pixelRatio;
-    const float gammaScale = (values.pitchAlignment == AlignmentType::Map
-        ? 1.0 / std::cos(state.getPitch())
-        : 1.0) / state.getCameraToCenterDistance();
-
-    return makeValues<SymbolSDFProgram::UniformValues>(
-        values,
-        texsize,
-        pixelsToGLUnits,
-        tile,
-        state,
-        uniforms::u_color::Value{ color },
-        uniforms::u_buffer::Value{ buffer },
-        uniforms::u_gamma::Value{ (gammaBase + gammaAdjust) * gammaScale },
-        uniforms::u_pitch::Value{ state.getPitch() },
-        uniforms::u_bearing::Value{ -1.0f * state.getAngle() },
-        uniforms::u_aspect_ratio::Value{ (state.getSize().width * 1.0f) / (state.getSize().height * 1.0f) },
-        uniforms::u_pitch_with_map::Value{ values.pitchAlignment == AlignmentType::Map }
-    );
-}
-
-SymbolSDFProgram::UniformValues
-SymbolSDFProgram::haloUniformValues(const style::SymbolPropertyValues& values,
+template <class PaintProperties>
+typename SymbolSDFProgram<PaintProperties>::UniformValues SymbolSDFProgram<PaintProperties>::uniformValues(const style::SymbolPropertyValues& values,
                               const Size& texsize,
                               const std::array<float, 2>& pixelsToGLUnits,
                               const RenderTile& tile,
                               const TransformState& state,
-                              float pixelRatio)
+                              const SymbolSDFPart part)
 {
     const float scale = values.paintSize / values.sdfScale;
-    const float sdfPx = 8.0f;
-    const float blurOffset = 1.19f;
-    const float haloOffset = 6.0f;
-
-    return makeSDFValues(
+    
+    const float gammaScale = scale * (values.pitchAlignment == AlignmentType::Map
+                              ? std::cos(state.getPitch())
+                              : 1.0) * state.getCameraToCenterDistance();
+    
+    return makeValues<SymbolSDFProgram<PaintProperties>::UniformValues>(
         values,
         texsize,
         pixelsToGLUnits,
         tile,
         state,
-        pixelRatio,
-        values.haloColor,
-        (haloOffset - values.haloWidth / scale) / sdfPx,
-        values.haloBlur * blurOffset / scale / sdfPx
+        uniforms::u_font_scale::Value{ scale },
+        uniforms::u_gamma_scale::Value{ gammaScale },
+        uniforms::u_pitch::Value{ state.getPitch() },
+        uniforms::u_bearing::Value{ -1.0f * state.getAngle() },
+        uniforms::u_aspect_ratio::Value{ (state.getSize().width * 1.0f) / (state.getSize().height * 1.0f) },
+        uniforms::u_pitch_with_map::Value{ values.pitchAlignment == AlignmentType::Map },
+        uniforms::u_is_halo::Value{ part == SymbolSDFPart::Halo }
     );
 }
 
-SymbolSDFProgram::UniformValues
-SymbolSDFProgram::foregroundUniformValues(const style::SymbolPropertyValues& values,
-                                    const Size& texsize,
-                                    const std::array<float, 2>& pixelsToGLUnits,
-                                    const RenderTile& tile,
-                                    const TransformState& state,
-                                    float pixelRatio)
-{
-    return makeSDFValues(
-        values,
-        texsize,
-        pixelsToGLUnits,
-        tile,
-        state,
-        pixelRatio,
-        values.color,
-        (256.0f - 64.0f) / 256.0f,
-        0
-    );
-}
+template class SymbolSDFProgram<style::IconPaintProperties>;
+template class SymbolSDFProgram<style::TextPaintProperties>;
 
 } // namespace mbgl

src/mbgl/programs/symbol_program.hpp

@@ -8,6 +8,7 @@
 #include <mbgl/util/geometry.hpp>
 #include <mbgl/util/size.hpp>
 #include <mbgl/style/layers/symbol_layer_properties.hpp>
+#include <mbgl/style/layers/symbol_layer_impl.hpp>
 
 #include <cmath>
 #include <array>
@@ -27,9 +28,10 @@ MBGL_DEFINE_UNIFORM_SCALAR(bool, u_rotate_with_map);
 MBGL_DEFINE_UNIFORM_SCALAR(bool, u_pitch_with_map);
 MBGL_DEFINE_UNIFORM_SCALAR(gl::TextureUnit, u_texture);
 MBGL_DEFINE_UNIFORM_SCALAR(gl::TextureUnit, u_fadetexture);
-MBGL_DEFINE_UNIFORM_SCALAR(float, u_buffer);
-MBGL_DEFINE_UNIFORM_SCALAR(float, u_gamma);
 MBGL_DEFINE_UNIFORM_SCALAR(float, u_aspect_ratio);
+MBGL_DEFINE_UNIFORM_SCALAR(bool, u_is_halo);
+MBGL_DEFINE_UNIFORM_SCALAR(float, u_font_scale);
+MBGL_DEFINE_UNIFORM_SCALAR(float, u_gamma_scale);
 } // namespace uniforms
 
 struct SymbolLayoutAttributes : gl::Attributes<
@@ -75,14 +77,13 @@ class SymbolIconProgram : public Program<
     SymbolLayoutAttributes,
     gl::Uniforms<
         uniforms::u_matrix,
-        uniforms::u_opacity,
         uniforms::u_extrude_scale,
         uniforms::u_texsize,
         uniforms::u_zoom,
         uniforms::u_rotate_with_map,
         uniforms::u_texture,
         uniforms::u_fadetexture>,
-    style::SymbolPaintProperties>
+    style::IconPaintProperties>
 {
 public:
     using Program::Program;
@@ -94,47 +95,73 @@ public:
                                        const TransformState&);
 };
 
+enum class SymbolSDFPart {
+    Fill = 1,
+    Halo = 0
+};
+
+template <class PaintProperties>
 class SymbolSDFProgram : public Program<
     shaders::symbol_sdf,
     gl::Triangle,
     SymbolLayoutAttributes,
     gl::Uniforms<
         uniforms::u_matrix,
-        uniforms::u_opacity,
         uniforms::u_extrude_scale,
         uniforms::u_texsize,
         uniforms::u_zoom,
         uniforms::u_rotate_with_map,
         uniforms::u_texture,
         uniforms::u_fadetexture,
-        uniforms::u_color,
-        uniforms::u_buffer,
-        uniforms::u_gamma,
+        uniforms::u_font_scale,
+        uniforms::u_gamma_scale,
         uniforms::u_pitch,
         uniforms::u_bearing,
         uniforms::u_aspect_ratio,
-        uniforms::u_pitch_with_map>,
-    style::SymbolPaintProperties>
+        uniforms::u_pitch_with_map,
+        uniforms::u_is_halo>,
+    PaintProperties>
 {
 public:
-    using Program::Program;
+    using BaseProgram = Program<shaders::symbol_sdf,
+        gl::Triangle,
+        SymbolLayoutAttributes,
+        gl::Uniforms<
+            uniforms::u_matrix,
+            uniforms::u_extrude_scale,
+            uniforms::u_texsize,
+            uniforms::u_zoom,
+            uniforms::u_rotate_with_map,
+            uniforms::u_texture,
+            uniforms::u_fadetexture,
+            uniforms::u_font_scale,
+            uniforms::u_gamma_scale,
+            uniforms::u_pitch,
+            uniforms::u_bearing,
+            uniforms::u_aspect_ratio,
+            uniforms::u_pitch_with_map,
+            uniforms::u_is_halo>,
+        PaintProperties>;
+    
+    using UniformValues = typename BaseProgram::UniformValues;
+    
 
-    static UniformValues haloUniformValues(const style::SymbolPropertyValues&,
-                                           const Size& texsize,
-                                           const std::array<float, 2>& pixelsToGLUnits,
-                                           const RenderTile&,
-                                           const TransformState&,
-                                           float pixelRatio);
+    
+    using BaseProgram::BaseProgram;
 
-    static UniformValues foregroundUniformValues(const style::SymbolPropertyValues&,
-                                                 const Size& texsize,
-                                                 const std::array<float, 2>& pixelsToGLUnits,
-                                                 const RenderTile&,
-                                                 const TransformState&,
-                                                 float pixelRatio);
+    static UniformValues uniformValues(const style::SymbolPropertyValues&,
+                                       const Size& texsize,
+                                       const std::array<float, 2>& pixelsToGLUnits,
+                                       const RenderTile&,
+                                       const TransformState&,
+                                       const SymbolSDFPart);
 };
 
+using SymbolSDFIconProgram = SymbolSDFProgram<style::IconPaintProperties>;
+using SymbolSDFTextProgram = SymbolSDFProgram<style::TextPaintProperties>;
+
 using SymbolLayoutVertex = SymbolLayoutAttributes::Vertex;
-using SymbolAttributes = SymbolIconProgram::Attributes;
+using SymbolIconAttributes = SymbolIconProgram::Attributes;
+using SymbolTextAttributes = SymbolSDFTextProgram::Attributes;
 
 } // namespace mbgl

src/mbgl/renderer/painter_symbol.cpp

@@ -33,7 +33,9 @@ void Painter::renderSymbol(PaintParameters& parameters,
     auto draw = [&] (auto& program,
                      auto&& uniformValues,
                      const auto& buffers,
-                     const SymbolPropertyValues& values_)
+                     const SymbolPropertyValues& values_,
+                     const auto& binders,
+                     const auto& paintProperties)
     {
         // We clip symbols to their tile extent in still mode.
         const bool needsClipping = frame.mapMode == MapMode::Still;
@@ -52,14 +54,15 @@ void Painter::renderSymbol(PaintParameters& parameters,
             *buffers.vertexBuffer,
             *buffers.indexBuffer,
             buffers.segments,
-            bucket.paintPropertyBinders.at(layer.getID()),
-            layer.impl->paint.evaluated,
+            binders,
+            paintProperties,
             state.getZoom()
         );
     };
 
     if (bucket.hasIconData()) {
         auto values = layer.impl->iconPropertyValues(layout);
+        auto paintPropertyValues = layer.impl->iconPaintProperties();
 
         SpriteAtlas& atlas = *layer.impl->spriteAtlas;
         const bool iconScaled = values.paintSize != 1.0f || frame.pixelRatio != atlas.getPixelRatio() || bucket.iconsNeedLinear;
@@ -69,24 +72,30 @@ void Painter::renderSymbol(PaintParameters& parameters,
         const Size texsize = atlas.getSize();
 
         if (bucket.sdfIcons) {
-            if (values.hasHalo()) {
+            if (values.hasHalo) {
                 draw(parameters.programs.symbolIconSDF,
-                     SymbolSDFProgram::haloUniformValues(values, texsize, pixelsToGLUnits, tile, state, frame.pixelRatio),
+                     SymbolSDFIconProgram::uniformValues(values, texsize, pixelsToGLUnits, tile, state, SymbolSDFPart::Halo),
                      bucket.icon,
-                     values);
+                     values,
+                     bucket.paintPropertyBinders.at(layer.getID()).first,
+                     paintPropertyValues);
             }
 
-            if (values.hasForeground()) {
+            if (values.hasFill) {
                 draw(parameters.programs.symbolIconSDF,
-                     SymbolSDFProgram::foregroundUniformValues(values, texsize, pixelsToGLUnits, tile, state, frame.pixelRatio),
+                     SymbolSDFIconProgram::uniformValues(values, texsize, pixelsToGLUnits, tile, state, SymbolSDFPart::Fill),
                      bucket.icon,
-                     values);
+                     values,
+                     bucket.paintPropertyBinders.at(layer.getID()).first,
+                     paintPropertyValues);
             }
         } else {
             draw(parameters.programs.symbolIcon,
                  SymbolIconProgram::uniformValues(values, texsize, pixelsToGLUnits, tile, state),
                  bucket.icon,
-                 values);
+                 values,
+                 bucket.paintPropertyBinders.at(layer.getID()).first,
+                 paintPropertyValues);
         }
     }
 
@@ -94,21 +103,26 @@ void Painter::renderSymbol(PaintParameters& parameters,
         glyphAtlas->bind(context, 0);
 
         auto values = layer.impl->textPropertyValues(layout);
+        auto paintPropertyValues = layer.impl->textPaintProperties();
 
         const Size texsize = glyphAtlas->getSize();
 
-        if (values.hasHalo()) {
+        if (values.hasHalo) {
             draw(parameters.programs.symbolGlyph,
-                 SymbolSDFProgram::haloUniformValues(values, texsize, pixelsToGLUnits, tile, state, frame.pixelRatio),
+                 SymbolSDFTextProgram::uniformValues(values, texsize, pixelsToGLUnits, tile, state, SymbolSDFPart::Halo),
                  bucket.text,
-                 values);
+                 values,
+                 bucket.paintPropertyBinders.at(layer.getID()).second,
+                 paintPropertyValues);
         }
 
-        if (values.hasForeground()) {
+        if (values.hasFill) {
             draw(parameters.programs.symbolGlyph,
-                 SymbolSDFProgram::foregroundUniformValues(values, texsize, pixelsToGLUnits, tile, state, frame.pixelRatio),
+                 SymbolSDFTextProgram::uniformValues(values, texsize, pixelsToGLUnits, tile, state, SymbolSDFPart::Fill),
                  bucket.text,
-                 values);
+                 values,
+                 bucket.paintPropertyBinders.at(layer.getID()).second,
+                 paintPropertyValues);
         }
     }
 

src/mbgl/renderer/symbol_bucket.cpp

@@ -9,7 +9,8 @@ namespace mbgl {
 using namespace style;
 
 SymbolBucket::SymbolBucket(style::SymbolLayoutProperties::Evaluated layout_,
-                           const std::unordered_map<std::string, style::SymbolPaintProperties::Evaluated>& layerPaintProperties,
+                           const std::unordered_map<std::string, std::pair<
+                               style::IconPaintProperties::Evaluated, style::TextPaintProperties::Evaluated>>& layerPaintProperties,
                            float zoom,
                            bool sdfIcons_,
                            bool iconsNeedLinear_)
@@ -17,8 +18,10 @@ SymbolBucket::SymbolBucket(style::SymbolLayoutProperties::Evaluated layout_,
       sdfIcons(sdfIcons_),
       iconsNeedLinear(iconsNeedLinear_) {
     for (const auto& pair : layerPaintProperties) {
-        paintPropertyBinders.emplace(pair.first,
-            SymbolIconProgram::PaintPropertyBinders(pair.second, zoom));
+        paintPropertyBinders.emplace(pair.first, std::make_pair(
+            SymbolIconProgram::PaintPropertyBinders(pair.second.first, zoom),
+            SymbolSDFTextProgram::PaintPropertyBinders(pair.second.second, zoom)
+        ));
     }
 }
 
@@ -39,7 +42,8 @@ void SymbolBucket::upload(gl::Context& context) {
     }
 
     for (auto& pair : paintPropertyBinders) {
-        pair.second.upload(context);
+        pair.second.first.upload(context);
+        pair.second.second.upload(context);
     }
 
     uploaded = true;

src/mbgl/renderer/symbol_bucket.hpp

@@ -17,7 +17,7 @@ namespace mbgl {
 class SymbolBucket : public Bucket {
 public:
     SymbolBucket(style::SymbolLayoutProperties::Evaluated,
-                 const std::unordered_map<std::string, style::SymbolPaintProperties::Evaluated>&,
+                 const std::unordered_map<std::string, std::pair<style::IconPaintProperties::Evaluated, style::TextPaintProperties::Evaluated>>&,
                  float zoom,
                  bool sdfIcons,
                  bool iconsNeedLinear);
@@ -33,12 +33,14 @@ public:
     const bool sdfIcons;
     const bool iconsNeedLinear;
 
-    std::unordered_map<std::string, SymbolIconProgram::PaintPropertyBinders> paintPropertyBinders;
+    std::unordered_map<std::string, std::pair<
+        SymbolIconProgram::PaintPropertyBinders,
+        SymbolSDFTextProgram::PaintPropertyBinders>> paintPropertyBinders;
 
     struct TextBuffer {
         gl::VertexVector<SymbolLayoutVertex> vertices;
         gl::IndexVector<gl::Triangles> triangles;
-        gl::SegmentVector<SymbolAttributes> segments;
+        gl::SegmentVector<SymbolTextAttributes> segments;
 
         optional<gl::VertexBuffer<SymbolLayoutVertex>> vertexBuffer;
         optional<gl::IndexBuffer<gl::Triangles>> indexBuffer;
@@ -47,7 +49,7 @@ public:
     struct IconBuffer {
         gl::VertexVector<SymbolLayoutVertex> vertices;
         gl::IndexVector<gl::Triangles> triangles;
-        gl::SegmentVector<SymbolAttributes> segments;
+        gl::SegmentVector<SymbolIconAttributes> segments;
 
         optional<gl::VertexBuffer<SymbolLayoutVertex>> vertexBuffer;
         optional<gl::IndexBuffer<gl::Triangles>> indexBuffer;

src/mbgl/shaders/symbol_icon.cpp

@@ -66,6 +66,10 @@ attribute vec2 a_offset;
 attribute vec2 a_texture_pos;
 attribute vec4 a_data;
 
+uniform lowp float a_opacity_t;
+attribute lowp float a_opacity_min;
+attribute lowp float a_opacity_max;
+varying lowp float opacity;
 
 // matrix is for the vertex position.
 uniform mat4 u_matrix;
@@ -80,6 +84,8 @@ varying vec2 v_tex;
 varying vec2 v_fade_tex;
 
 void main() {
+    opacity = mix(a_opacity_min, a_opacity_max, a_opacity_t);
+
     vec2 a_tex = a_texture_pos.xy;
     mediump float a_labelminzoom = a_data[0];
     mediump vec2 a_zoom = a_data.pq;
@@ -122,13 +128,16 @@ precision mediump float;
 #endif
 uniform sampler2D u_texture;
 uniform sampler2D u_fadetexture;
-uniform lowp float u_opacity;
+
+varying lowp float opacity;
 
 varying vec2 v_tex;
 varying vec2 v_fade_tex;
 
 void main() {
-    lowp float alpha = texture2D(u_fadetexture, v_fade_tex).a * u_opacity;
+    
+
+    lowp float alpha = texture2D(u_fadetexture, v_fade_tex).a * opacity;
     gl_FragColor = texture2D(u_texture, v_tex) * alpha;
 
 #ifdef OVERDRAW_INSPECTOR

src/mbgl/shaders/symbol_sdf.cpp

@@ -68,6 +68,26 @@ attribute vec2 a_offset;
 attribute vec2 a_texture_pos;
 attribute vec4 a_data;
 
+uniform lowp float a_fill_color_t;
+attribute lowp vec4 a_fill_color_min;
+attribute lowp vec4 a_fill_color_max;
+varying lowp vec4 fill_color;
+uniform lowp float a_halo_color_t;
+attribute lowp vec4 a_halo_color_min;
+attribute lowp vec4 a_halo_color_max;
+varying lowp vec4 halo_color;
+uniform lowp float a_opacity_t;
+attribute lowp float a_opacity_min;
+attribute lowp float a_opacity_max;
+varying lowp float opacity;
+uniform lowp float a_halo_width_t;
+attribute lowp float a_halo_width_min;
+attribute lowp float a_halo_width_max;
+varying lowp float halo_width;
+uniform lowp float a_halo_blur_t;
+attribute lowp float a_halo_blur_min;
+attribute lowp float a_halo_blur_max;
+varying lowp float halo_blur;
 
 // matrix is for the vertex position.
 uniform mat4 u_matrix;
@@ -87,6 +107,12 @@ varying vec2 v_fade_tex;
 varying float v_gamma_scale;
 
 void main() {
+    fill_color = mix(a_fill_color_min, a_fill_color_max, a_fill_color_t);
+    halo_color = mix(a_halo_color_min, a_halo_color_max, a_halo_color_t);
+    opacity = mix(a_opacity_min, a_opacity_max, a_opacity_t);
+    halo_width = mix(a_halo_width_min, a_halo_width_max, a_halo_width_t);
+    halo_blur = mix(a_halo_blur_min, a_halo_blur_max, a_halo_blur_t);
+
     vec2 a_tex = a_texture_pos.xy;
     mediump float a_labelminzoom = a_data[0];
     mediump vec2 a_zoom = a_data.pq;
@@ -163,24 +189,47 @@ precision mediump float;
 #endif
 
 #endif
+#define SDF_PX 8.0
+#define EDGE_GAMMA 0.105/DEVICE_PIXEL_RATIO
+
+uniform bool u_is_halo;
+varying lowp vec4 fill_color;
+varying lowp vec4 halo_color;
+varying lowp float opacity;
+varying lowp float halo_width;
+varying lowp float halo_blur;
+
 uniform sampler2D u_texture;
 uniform sampler2D u_fadetexture;
-uniform lowp vec4 u_color;
-uniform lowp float u_opacity;
-uniform lowp float u_buffer;
-uniform highp float u_gamma;
+uniform lowp float u_font_scale;
+uniform highp float u_gamma_scale;
 
 varying vec2 v_tex;
 varying vec2 v_fade_tex;
 varying float v_gamma_scale;
 
 void main() {
+    
+    
+    
+    
+    
+
+    lowp vec4 color = fill_color;
+    lowp float gamma = EDGE_GAMMA / u_gamma_scale;
+    lowp float buff = (256.0 - 64.0) / 256.0;
+    if (u_is_halo) {
+        color = halo_color;
+        gamma = (halo_blur * 1.19 / SDF_PX + EDGE_GAMMA) / u_gamma_scale;
+        buff = (6.0 - halo_width / u_font_scale) / SDF_PX;
+    }
+
     lowp float dist = texture2D(u_texture, v_tex).a;
     lowp float fade_alpha = texture2D(u_fadetexture, v_fade_tex).a;
-    highp float gamma = u_gamma * v_gamma_scale;
-    highp float alpha = smoothstep(u_buffer - gamma, u_buffer + gamma, dist) * fade_alpha;
+    highp float gamma_scaled = gamma * v_gamma_scale;
+    highp float alpha = smoothstep(buff - gamma_scaled, buff + gamma_scaled, dist) * fade_alpha;
 
-    gl_FragColor = u_color * (alpha * u_opacity);
+    gl_FragColor = color * (alpha * opacity);
 
 #ifdef OVERDRAW_INSPECTOR
     gl_FragColor = vec4(1.0);

src/mbgl/style/layers/symbol_layer.cpp

@@ -542,95 +542,115 @@ void SymbolLayer::setTextOptional(PropertyValue<bool> value) {
 
 // Paint properties
 
-PropertyValue<float> SymbolLayer::getDefaultIconOpacity() {
+DataDrivenPropertyValue<float> SymbolLayer::getDefaultIconOpacity() {
     return { 1 };
 }
 
-PropertyValue<float> SymbolLayer::getIconOpacity(const optional<std::string>& klass) const {
+DataDrivenPropertyValue<float> SymbolLayer::getIconOpacity(const optional<std::string>& klass) const {
     return impl->paint.get<IconOpacity>(klass);
 }
 
-void SymbolLayer::setIconOpacity(PropertyValue<float> value, const optional<std::string>& klass) {
+void SymbolLayer::setIconOpacity(DataDrivenPropertyValue<float> value, const optional<std::string>& klass) {
     if (value == getIconOpacity(klass))
         return;
     impl->paint.set<IconOpacity>(value, klass);
-    impl->observer->onLayerPaintPropertyChanged(*this);
+    if (value.isDataDriven()) {
+        impl->observer->onLayerDataDrivenPaintPropertyChanged(*this);
+    } else {
+        impl->observer->onLayerPaintPropertyChanged(*this);
+    }
 }
 
 void SymbolLayer::setIconOpacityTransition(const TransitionOptions& value, const optional<std::string>& klass) {
     impl->paint.setTransition<IconOpacity>(value, klass);
 }
 
-PropertyValue<Color> SymbolLayer::getDefaultIconColor() {
+DataDrivenPropertyValue<Color> SymbolLayer::getDefaultIconColor() {
     return { Color::black() };
 }
 
-PropertyValue<Color> SymbolLayer::getIconColor(const optional<std::string>& klass) const {
+DataDrivenPropertyValue<Color> SymbolLayer::getIconColor(const optional<std::string>& klass) const {
     return impl->paint.get<IconColor>(klass);
 }
 
-void SymbolLayer::setIconColor(PropertyValue<Color> value, const optional<std::string>& klass) {
+void SymbolLayer::setIconColor(DataDrivenPropertyValue<Color> value, const optional<std::string>& klass) {
     if (value == getIconColor(klass))
         return;
     impl->paint.set<IconColor>(value, klass);
-    impl->observer->onLayerPaintPropertyChanged(*this);
+    if (value.isDataDriven()) {
+        impl->observer->onLayerDataDrivenPaintPropertyChanged(*this);
+    } else {
+        impl->observer->onLayerPaintPropertyChanged(*this);
+    }
 }
 
 void SymbolLayer::setIconColorTransition(const TransitionOptions& value, const optional<std::string>& klass) {
     impl->paint.setTransition<IconColor>(value, klass);
 }
 
-PropertyValue<Color> SymbolLayer::getDefaultIconHaloColor() {
+DataDrivenPropertyValue<Color> SymbolLayer::getDefaultIconHaloColor() {
     return { {} };
 }
 
-PropertyValue<Color> SymbolLayer::getIconHaloColor(const optional<std::string>& klass) const {
+DataDrivenPropertyValue<Color> SymbolLayer::getIconHaloColor(const optional<std::string>& klass) const {
     return impl->paint.get<IconHaloColor>(klass);
 }
 
-void SymbolLayer::setIconHaloColor(PropertyValue<Color> value, const optional<std::string>& klass) {
+void SymbolLayer::setIconHaloColor(DataDrivenPropertyValue<Color> value, const optional<std::string>& klass) {
     if (value == getIconHaloColor(klass))
         return;
     impl->paint.set<IconHaloColor>(value, klass);
-    impl->observer->onLayerPaintPropertyChanged(*this);
+    if (value.isDataDriven()) {
+        impl->observer->onLayerDataDrivenPaintPropertyChanged(*this);
+    } else {
+        impl->observer->onLayerPaintPropertyChanged(*this);
+    }
 }
 
 void SymbolLayer::setIconHaloColorTransition(const TransitionOptions& value, const optional<std::string>& klass) {
     impl->paint.setTransition<IconHaloColor>(value, klass);
 }
 
-PropertyValue<float> SymbolLayer::getDefaultIconHaloWidth() {
+DataDrivenPropertyValue<float> SymbolLayer::getDefaultIconHaloWidth() {
     return { 0 };
 }
 
-PropertyValue<float> SymbolLayer::getIconHaloWidth(const optional<std::string>& klass) const {
+DataDrivenPropertyValue<float> SymbolLayer::getIconHaloWidth(const optional<std::string>& klass) const {
     return impl->paint.get<IconHaloWidth>(klass);
 }
 
-void SymbolLayer::setIconHaloWidth(PropertyValue<float> value, const optional<std::string>& klass) {
+void SymbolLayer::setIconHaloWidth(DataDrivenPropertyValue<float> value, const optional<std::string>& klass) {
     if (value == getIconHaloWidth(klass))
         return;
     impl->paint.set<IconHaloWidth>(value, klass);
-    impl->observer->onLayerPaintPropertyChanged(*this);
+    if (value.isDataDriven()) {
+        impl->observer->onLayerDataDrivenPaintPropertyChanged(*this);
+    } else {
+        impl->observer->onLayerPaintPropertyChanged(*this);
+    }
 }
 
 void SymbolLayer::setIconHaloWidthTransition(const TransitionOptions& value, const optional<std::string>& klass) {
     impl->paint.setTransition<IconHaloWidth>(value, klass);
 }
 
-PropertyValue<float> SymbolLayer::getDefaultIconHaloBlur() {
+DataDrivenPropertyValue<float> SymbolLayer::getDefaultIconHaloBlur() {
     return { 0 };
 }
 
-PropertyValue<float> SymbolLayer::getIconHaloBlur(const optional<std::string>& klass) const {
+DataDrivenPropertyValue<float> SymbolLayer::getIconHaloBlur(const optional<std::string>& klass) const {
     return impl->paint.get<IconHaloBlur>(klass);
 }
 
-void SymbolLayer::setIconHaloBlur(PropertyValue<float> value, const optional<std::string>& klass) {
+void SymbolLayer::setIconHaloBlur(DataDrivenPropertyValue<float> value, const optional<std::string>& klass) {
     if (value == getIconHaloBlur(klass))
         return;
     impl->paint.set<IconHaloBlur>(value, klass);
-    impl->observer->onLayerPaintPropertyChanged(*this);
+    if (value.isDataDriven()) {
+        impl->observer->onLayerDataDrivenPaintPropertyChanged(*this);
+    } else {
+        impl->observer->onLayerPaintPropertyChanged(*this);
+    }
 }
 
 void SymbolLayer::setIconHaloBlurTransition(const TransitionOptions& value, const optional<std::string>& klass) {
@@ -671,99 +691,119 @@ void SymbolLayer::setIconTranslateAnchor(PropertyValue<TranslateAnchorType> valu
     impl->observer->onLayerPaintPropertyChanged(*this);
 }
 
-PropertyValue<float> SymbolLayer::getDefaultTextOpacity() {
-    return { 1 };
-}
-
 void SymbolLayer::setIconTranslateAnchorTransition(const TransitionOptions& value, const optional<std::string>& klass) {
     impl->paint.setTransition<IconTranslateAnchor>(value, klass);
 }
 
-PropertyValue<float> SymbolLayer::getTextOpacity(const optional<std::string>& klass) const {
+DataDrivenPropertyValue<float> SymbolLayer::getDefaultTextOpacity() {
+    return { 1 };
+}
+
+DataDrivenPropertyValue<float> SymbolLayer::getTextOpacity(const optional<std::string>& klass) const {
     return impl->paint.get<TextOpacity>(klass);
 }
 
-void SymbolLayer::setTextOpacity(PropertyValue<float> value, const optional<std::string>& klass) {
+void SymbolLayer::setTextOpacity(DataDrivenPropertyValue<float> value, const optional<std::string>& klass) {
     if (value == getTextOpacity(klass))
         return;
     impl->paint.set<TextOpacity>(value, klass);
-    impl->observer->onLayerPaintPropertyChanged(*this);
-}
-
-PropertyValue<Color> SymbolLayer::getDefaultTextColor() {
-    return { Color::black() };
+    if (value.isDataDriven()) {
+        impl->observer->onLayerDataDrivenPaintPropertyChanged(*this);
+    } else {
+        impl->observer->onLayerPaintPropertyChanged(*this);
+    }
 }
 
 void SymbolLayer::setTextOpacityTransition(const TransitionOptions& value, const optional<std::string>& klass) {
     impl->paint.setTransition<TextOpacity>(value, klass);
 }
 
-PropertyValue<Color> SymbolLayer::getTextColor(const optional<std::string>& klass) const {
+DataDrivenPropertyValue<Color> SymbolLayer::getDefaultTextColor() {
+    return { Color::black() };
+}
+
+DataDrivenPropertyValue<Color> SymbolLayer::getTextColor(const optional<std::string>& klass) const {
     return impl->paint.get<TextColor>(klass);
 }
 
-void SymbolLayer::setTextColor(PropertyValue<Color> value, const optional<std::string>& klass) {
+void SymbolLayer::setTextColor(DataDrivenPropertyValue<Color> value, const optional<std::string>& klass) {
     if (value == getTextColor(klass))
         return;
     impl->paint.set<TextColor>(value, klass);
-    impl->observer->onLayerPaintPropertyChanged(*this);
+    if (value.isDataDriven()) {
+        impl->observer->onLayerDataDrivenPaintPropertyChanged(*this);
+    } else {
+        impl->observer->onLayerPaintPropertyChanged(*this);
+    }
 }
 
 void SymbolLayer::setTextColorTransition(const TransitionOptions& value, const optional<std::string>& klass) {
     impl->paint.setTransition<TextColor>(value, klass);
 }
 
-PropertyValue<Color> SymbolLayer::getDefaultTextHaloColor() {
+DataDrivenPropertyValue<Color> SymbolLayer::getDefaultTextHaloColor() {
     return { {} };
 }
 
-PropertyValue<Color> SymbolLayer::getTextHaloColor(const optional<std::string>& klass) const {
+DataDrivenPropertyValue<Color> SymbolLayer::getTextHaloColor(const optional<std::string>& klass) const {
     return impl->paint.get<TextHaloColor>(klass);
 }
 
-void SymbolLayer::setTextHaloColor(PropertyValue<Color> value, const optional<std::string>& klass) {
+void SymbolLayer::setTextHaloColor(DataDrivenPropertyValue<Color> value, const optional<std::string>& klass) {
     if (value == getTextHaloColor(klass))
         return;
     impl->paint.set<TextHaloColor>(value, klass);
-    impl->observer->onLayerPaintPropertyChanged(*this);
+    if (value.isDataDriven()) {
+        impl->observer->onLayerDataDrivenPaintPropertyChanged(*this);
+    } else {
+        impl->observer->onLayerPaintPropertyChanged(*this);
+    }
 }
 
 void SymbolLayer::setTextHaloColorTransition(const TransitionOptions& value, const optional<std::string>& klass) {
     impl->paint.setTransition<TextHaloColor>(value, klass);
 }
 
-PropertyValue<float> SymbolLayer::getDefaultTextHaloWidth() {
+DataDrivenPropertyValue<float> SymbolLayer::getDefaultTextHaloWidth() {
     return { 0 };
 }
 
-PropertyValue<float> SymbolLayer::getTextHaloWidth(const optional<std::string>& klass) const {
+DataDrivenPropertyValue<float> SymbolLayer::getTextHaloWidth(const optional<std::string>& klass) const {
     return impl->paint.get<TextHaloWidth>(klass);
 }
 
-void SymbolLayer::setTextHaloWidth(PropertyValue<float> value, const optional<std::string>& klass) {
+void SymbolLayer::setTextHaloWidth(DataDrivenPropertyValue<float> value, const optional<std::string>& klass) {
     if (value == getTextHaloWidth(klass))
         return;
     impl->paint.set<TextHaloWidth>(value, klass);
-    impl->observer->onLayerPaintPropertyChanged(*this);
+    if (value.isDataDriven()) {
+        impl->observer->onLayerDataDrivenPaintPropertyChanged(*this);
+    } else {
+        impl->observer->onLayerPaintPropertyChanged(*this);
+    }
 }
 
 void SymbolLayer::setTextHaloWidthTransition(const TransitionOptions& value, const optional<std::string>& klass) {
     impl->paint.setTransition<TextHaloWidth>(value, klass);
 }
 
-PropertyValue<float> SymbolLayer::getDefaultTextHaloBlur() {
+DataDrivenPropertyValue<float> SymbolLayer::getDefaultTextHaloBlur() {
     return { 0 };
 }
 
-PropertyValue<float> SymbolLayer::getTextHaloBlur(const optional<std::string>& klass) const {
+DataDrivenPropertyValue<float> SymbolLayer::getTextHaloBlur(const optional<std::string>& klass) const {
     return impl->paint.get<TextHaloBlur>(klass);
 }
 
-void SymbolLayer::setTextHaloBlur(PropertyValue<float> value, const optional<std::string>& klass) {
+void SymbolLayer::setTextHaloBlur(DataDrivenPropertyValue<float> value, const optional<std::string>& klass) {
     if (value == getTextHaloBlur(klass))
         return;
     impl->paint.set<TextHaloBlur>(value, klass);
-    impl->observer->onLayerPaintPropertyChanged(*this);
+    if (value.isDataDriven()) {
+        impl->observer->onLayerDataDrivenPaintPropertyChanged(*this);
+    } else {
+        impl->observer->onLayerPaintPropertyChanged(*this);
+    }
 }
 
 void SymbolLayer::setTextHaloBlurTransition(const TransitionOptions& value, const optional<std::string>& klass) {

src/mbgl/style/layers/symbol_layer_impl.cpp

@@ -16,9 +16,14 @@ bool SymbolLayer::Impl::evaluate(const PropertyEvaluationParameters& parameters)
     // text-size and icon-size are layout properties but they also need to be evaluated as paint properties:
     iconSize = layout.evaluate<IconSize>(parameters);
     textSize = layout.evaluate<TextSize>(parameters);
-
-    passes = ((paint.evaluated.get<IconOpacity>() > 0 && (paint.evaluated.get<IconColor>().a > 0 || paint.evaluated.get<IconHaloColor>().a > 0) && iconSize > 0)
-           || (paint.evaluated.get<TextOpacity>() > 0 && (paint.evaluated.get<TextColor>().a > 0 || paint.evaluated.get<TextHaloColor>().a > 0) && textSize > 0))
+    
+    auto hasIconOpacity = paint.evaluated.get<IconColor>().constantOr(Color::black()).a > 0 ||
+        paint.evaluated.get<IconHaloColor>().constantOr(Color::black()).a > 0;
+    auto hasTextOpacity = paint.evaluated.get<TextColor>().constantOr(Color::black()).a > 0 ||
+        paint.evaluated.get<TextHaloColor>().constantOr(Color::black()).a > 0;
+    
+    passes = ((paint.evaluated.get<IconOpacity>().constantOr(1) > 0 && hasIconOpacity && iconSize > 0)
+           || (paint.evaluated.get<TextOpacity>().constantOr(1) > 0 && hasTextOpacity && textSize > 0))
         ? RenderPass::Translucent : RenderPass::None;
 
     return paint.hasTransition();
@@ -38,20 +43,43 @@ std::unique_ptr<SymbolLayout> SymbolLayer::Impl::createLayout(const BucketParame
                                           *spriteAtlas);
 }
 
-SymbolPropertyValues SymbolLayer::Impl::iconPropertyValues(const SymbolLayoutProperties::Evaluated& layout_) const {
-    return SymbolPropertyValues {
-        layout_.get<IconRotationAlignment>(), // icon-pitch-alignment is not yet implemented; inherit the rotation alignment
-        layout_.get<IconRotationAlignment>(),
-        layout_.get<IconSize>(),
+IconPaintProperties::Evaluated SymbolLayer::Impl::iconPaintProperties() const {
+    return IconPaintProperties::Evaluated {
         paint.evaluated.get<IconOpacity>(),
         paint.evaluated.get<IconColor>(),
         paint.evaluated.get<IconHaloColor>(),
         paint.evaluated.get<IconHaloWidth>(),
         paint.evaluated.get<IconHaloBlur>(),
         paint.evaluated.get<IconTranslate>(),
+        paint.evaluated.get<IconTranslateAnchor>()
+    };
+}
+
+TextPaintProperties::Evaluated SymbolLayer::Impl::textPaintProperties() const {
+    return TextPaintProperties::Evaluated {
+        paint.evaluated.get<TextOpacity>(),
+        paint.evaluated.get<TextColor>(),
+        paint.evaluated.get<TextHaloColor>(),
+        paint.evaluated.get<TextHaloWidth>(),
+        paint.evaluated.get<TextHaloBlur>(),
+        paint.evaluated.get<TextTranslate>(),
+        paint.evaluated.get<TextTranslateAnchor>()
+    };
+}
+
+
+SymbolPropertyValues SymbolLayer::Impl::iconPropertyValues(const SymbolLayoutProperties::Evaluated& layout_) const {
+    return SymbolPropertyValues {
+        layout_.get<IconRotationAlignment>(), // icon-pitch-alignment is not yet implemented; inherit the rotation alignment
+        layout_.get<IconRotationAlignment>(),
+        layout_.get<IconSize>(),
+        paint.evaluated.get<IconTranslate>(),
         paint.evaluated.get<IconTranslateAnchor>(),
         iconSize,
-        1.0f
+        1.0f,
+        paint.evaluated.get<IconHaloColor>().constantOr(Color::black()).a > 0 &&
+            paint.evaluated.get<IconHaloWidth>().constantOr(1),
+        paint.evaluated.get<IconColor>().constantOr(Color::black()).a > 0
     };
 }
 
@@ -60,15 +88,13 @@ SymbolPropertyValues SymbolLayer::Impl::textPropertyValues(const SymbolLayoutPro
         layout_.get<TextPitchAlignment>(),
         layout_.get<TextRotationAlignment>(),
         layout_.get<TextSize>(),
-        paint.evaluated.get<TextOpacity>(),
-        paint.evaluated.get<TextColor>(),
-        paint.evaluated.get<TextHaloColor>(),
-        paint.evaluated.get<TextHaloWidth>(),
-        paint.evaluated.get<TextHaloBlur>(),
         paint.evaluated.get<TextTranslate>(),
         paint.evaluated.get<TextTranslateAnchor>(),
         textSize,
-        24.0f
+        24.0f,
+        paint.evaluated.get<TextHaloColor>().constantOr(Color::black()).a > 0 &&
+            paint.evaluated.get<TextHaloWidth>().constantOr(1),
+        paint.evaluated.get<TextColor>().constantOr(Color::black()).a > 0
     };
 }
 

src/mbgl/style/layers/symbol_layer_impl.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <mbgl/util/variant.hpp>
 #include <mbgl/style/layer_impl.hpp>
 #include <mbgl/style/layers/symbol_layer.hpp>
 #include <mbgl/style/layers/symbol_layer_properties.hpp>
@@ -10,6 +11,30 @@ class SpriteAtlas;
 class SymbolLayout;
 
 namespace style {
+    
+
+// {icon,text}-specific paint-property packs for use in the symbol Programs.
+// Since each program deals either with icons or text, using a smaller property set
+// lets us avoid unnecessarily binding attributes for properties the program wouldn't use.
+class IconPaintProperties : public PaintProperties<
+    IconOpacity,
+    IconColor,
+    IconHaloColor,
+    IconHaloWidth,
+    IconHaloBlur,
+    IconTranslate,
+    IconTranslateAnchor
+> {};
+    
+class TextPaintProperties : public PaintProperties<
+    TextOpacity,
+    TextColor,
+    TextHaloColor,
+    TextHaloWidth,
+    TextHaloBlur,
+    TextTranslate,
+    TextTranslateAnchor
+> {};
 
 // Repackaging evaluated values from SymbolLayoutProperties + SymbolPaintProperties
 // for genericity over icons vs. text.
@@ -21,24 +46,14 @@ public:
     float layoutSize;
 
     // Paint
-    float opacity;
-    Color color;
-    Color haloColor;
-    float haloWidth;
-    float haloBlur;
     std::array<float, 2> translate;
     TranslateAnchorType translateAnchor;
     float paintSize;
 
     float sdfScale;   // Constant (1.0 or 24.0)
-
-    bool hasHalo() const {
-        return haloColor.a > 0.0f && haloWidth > 0.0f;
-    }
-
-    bool hasForeground() const {
-        return color.a > 0.0f;
-    }
+    
+    bool hasHalo;
+    bool hasFill;    
 };
 
 class SymbolLayer::Impl : public Layer::Impl {
@@ -54,6 +69,9 @@ public:
     std::unique_ptr<SymbolLayout> createLayout(const BucketParameters&, const std::vector<const Layer*>&,
                                                const GeometryTileLayer&) const;
 
+    IconPaintProperties::Evaluated iconPaintProperties() const;
+    TextPaintProperties::Evaluated textPaintProperties() const;
+    
     SymbolPropertyValues iconPropertyValues(const SymbolLayoutProperties::Evaluated&) const;
     SymbolPropertyValues textPropertyValues(const SymbolLayoutProperties::Evaluated&) const;
 

src/mbgl/style/layers/symbol_layer_properties.hpp

@@ -180,23 +180,23 @@ struct TextOptional : LayoutProperty<bool> {
     static bool defaultValue() { return false; }
 };
 
-struct IconOpacity : PaintProperty<float> {
+struct IconOpacity : DataDrivenPaintProperty<float, attributes::a_opacity> {
     static float defaultValue() { return 1; }
 };
 
-struct IconColor : PaintProperty<Color> {
+struct IconColor : DataDrivenPaintProperty<Color, attributes::a_fill_color> {
     static Color defaultValue() { return Color::black(); }
 };
 
-struct IconHaloColor : PaintProperty<Color> {
+struct IconHaloColor : DataDrivenPaintProperty<Color, attributes::a_halo_color> {
     static Color defaultValue() { return {}; }
 };
 
-struct IconHaloWidth : PaintProperty<float> {
+struct IconHaloWidth : DataDrivenPaintProperty<float, attributes::a_halo_width> {
     static float defaultValue() { return 0; }
 };
 
-struct IconHaloBlur : PaintProperty<float> {
+struct IconHaloBlur : DataDrivenPaintProperty<float, attributes::a_halo_blur> {
     static float defaultValue() { return 0; }
 };
 
@@ -208,23 +208,23 @@ struct IconTranslateAnchor : PaintProperty<TranslateAnchorType> {
     static TranslateAnchorType defaultValue() { return TranslateAnchorType::Map; }
 };
 
-struct TextOpacity : PaintProperty<float> {
+struct TextOpacity : DataDrivenPaintProperty<float, attributes::a_opacity> {
     static float defaultValue() { return 1; }
 };
 
-struct TextColor : PaintProperty<Color> {
+struct TextColor : DataDrivenPaintProperty<Color, attributes::a_fill_color> {
     static Color defaultValue() { return Color::black(); }
 };
 
-struct TextHaloColor : PaintProperty<Color> {
+struct TextHaloColor : DataDrivenPaintProperty<Color, attributes::a_halo_color> {
     static Color defaultValue() { return {}; }
 };
 
-struct TextHaloWidth : PaintProperty<float> {
+struct TextHaloWidth : DataDrivenPaintProperty<float, attributes::a_halo_width> {
     static float defaultValue() { return 0; }
 };
 
-struct TextHaloBlur : PaintProperty<float> {
+struct TextHaloBlur : DataDrivenPaintProperty<float, attributes::a_halo_blur> {
     static float defaultValue() { return 0; }
 };
 

src/mbgl/text/shaping.cpp

@@ -3,16 +3,15 @@
 
 namespace mbgl {
 
-PositionedIcon shapeIcon(const SpriteAtlasElement& image,
-                         const SymbolFeature& feature) {
-    float dx = feature.iconOffset[0];
-    float dy = feature.iconOffset[1];
+PositionedIcon shapeIcon(const SpriteAtlasElement& image, const std::array<float, 2>& iconOffset, const float iconRotation) {
+    float dx = iconOffset[0];
+    float dy = iconOffset[1];
     float x1 = dx - image.spriteImage->getWidth() / 2.0f;
     float x2 = x1 + image.spriteImage->getWidth();
     float y1 = dy - image.spriteImage->getHeight() / 2.0f;
     float y2 = y1 + image.spriteImage->getHeight();
 
-    return PositionedIcon(image, y1, y2, x1, x2, feature.iconRotation);
+    return PositionedIcon(image, y1, y2, x1, x2, iconRotation);
 }
 
 } // namespace mbgl

src/mbgl/text/shaping.hpp

@@ -36,7 +36,6 @@ public:
     explicit operator bool() const { return image && (*image).pos.hasArea(); }
 };
 
-PositionedIcon shapeIcon(const SpriteAtlasElement&,
-                         const SymbolFeature&);
+PositionedIcon shapeIcon(const SpriteAtlasElement&, const std::array<float, 2>& iconOffset, const float iconRotation);
 
 } // namespace mbgl

src/mbgl/tile/vector_tile.cpp

@@ -15,9 +15,23 @@ class VectorTileLayer;
 
 using packed_iter_type = protozero::iterator_range<protozero::pbf_reader::const_uint32_iterator>;
 
+struct VectorTileLayerData {
+    VectorTileLayerData(std::shared_ptr<const std::string>);
+    
+    // Hold a reference to the underlying pbf data that backs the lazily-built
+    // components of the owning VectorTileLayer and VectorTileFeature objects
+    std::shared_ptr<const std::string> data;
+    
+    uint32_t version = 1;
+    uint32_t extent = 4096;
+    std::unordered_map<std::string, uint32_t> keysMap;
+    std::vector<std::reference_wrapper<const std::string>> keys;
+    std::vector<Value> values;
+};
+
 class VectorTileFeature : public GeometryTileFeature {
 public:
-    VectorTileFeature(protozero::pbf_reader, const VectorTileLayer&);
+    VectorTileFeature(protozero::pbf_reader, std::shared_ptr<VectorTileLayerData> layerData);
 
     FeatureType getType() const override { return type; }
     optional<Value> getValue(const std::string&) const override;
@@ -26,16 +40,16 @@ public:
     GeometryCollection getGeometries() const override;
 
 private:
-    const VectorTileLayer& layer;
+    std::shared_ptr<VectorTileLayerData> layerData;
     optional<FeatureIdentifier> id;
     FeatureType type = FeatureType::Unknown;
     packed_iter_type tags_iter;
     packed_iter_type geometry_iter;
 };
-
+    
 class VectorTileLayer : public GeometryTileLayer {
 public:
-    VectorTileLayer(protozero::pbf_reader);
+    VectorTileLayer(protozero::pbf_reader, std::shared_ptr<const std::string>);
 
     std::size_t featureCount() const override { return features.size(); }
     std::unique_ptr<GeometryTileFeature> getFeature(std::size_t) const override;
@@ -46,12 +60,8 @@ private:
     friend class VectorTileFeature;
 
     std::string name;
-    uint32_t version = 1;
-    uint32_t extent = 4096;
-    std::unordered_map<std::string, uint32_t> keysMap;
-    std::vector<std::reference_wrapper<const std::string>> keys;
-    std::vector<Value> values;
     std::vector<protozero::pbf_reader> features;
+    std::shared_ptr<VectorTileLayerData> data;
 };
 
 class VectorTileData : public GeometryTileData {
@@ -117,8 +127,8 @@ Value parseValue(protozero::pbf_reader data) {
     return false;
 }
 
-VectorTileFeature::VectorTileFeature(protozero::pbf_reader feature_pbf, const VectorTileLayer& layer_)
-    : layer(layer_) {
+VectorTileFeature::VectorTileFeature(protozero::pbf_reader feature_pbf, std::shared_ptr<VectorTileLayerData> layerData_)
+    : layerData(std::move(layerData_)) {
     while (feature_pbf.next()) {
         switch (feature_pbf.tag()) {
         case 1: // id
@@ -141,8 +151,8 @@ VectorTileFeature::VectorTileFeature(protozero::pbf_reader feature_pbf, const Ve
 }
 
 optional<Value> VectorTileFeature::getValue(const std::string& key) const {
-    auto keyIter = layer.keysMap.find(key);
-    if (keyIter == layer.keysMap.end()) {
+    auto keyIter = layerData->keysMap.find(key);
+    if (keyIter == layerData->keysMap.end()) {
         return optional<Value>();
     }
 
@@ -151,7 +161,7 @@ optional<Value> VectorTileFeature::getValue(const std::string& key) const {
     while (start_itr != end_itr) {
         uint32_t tag_key = static_cast<uint32_t>(*start_itr++);
 
-        if (layer.keysMap.size() <= tag_key) {
+        if (layerData->keysMap.size() <= tag_key) {
             throw std::runtime_error("feature referenced out of range key");
         }
 
@@ -160,12 +170,12 @@ optional<Value> VectorTileFeature::getValue(const std::string& key) const {
         }
 
         uint32_t tag_val = static_cast<uint32_t>(*start_itr++);;
-        if (layer.values.size() <= tag_val) {
+        if (layerData->values.size() <= tag_val) {
             throw std::runtime_error("feature referenced out of range value");
         }
 
         if (tag_key == keyIter->second) {
-            return layer.values[tag_val];
+            return layerData->values[tag_val];
         }
     }
 
@@ -182,7 +192,7 @@ std::unordered_map<std::string,Value> VectorTileFeature::getProperties() const {
             throw std::runtime_error("uneven number of feature tag ids");
         }
         uint32_t tag_val = static_cast<uint32_t>(*start_itr++);
-        properties[layer.keys.at(tag_key)] = layer.values.at(tag_val);
+        properties[layerData->keys.at(tag_key)] = layerData->values.at(tag_val);
     }
     return properties;
 }
@@ -196,7 +206,7 @@ GeometryCollection VectorTileFeature::getGeometries() const {
     uint32_t length = 0;
     int32_t x = 0;
     int32_t y = 0;
-    const float scale = float(util::EXTENT) / layer.extent;
+    const float scale = float(util::EXTENT) / layerData->extent;
 
     GeometryCollection lines;
 
@@ -234,7 +244,7 @@ GeometryCollection VectorTileFeature::getGeometries() const {
         }
     }
 
-    if (layer.version >= 2 || type != FeatureType::Polygon) {
+    if (layerData->version >= 2 || type != FeatureType::Polygon) {
         return lines;
     }
 
@@ -250,7 +260,7 @@ const GeometryTileLayer* VectorTileData::getLayer(const std::string& name) const
         parsed = true;
         protozero::pbf_reader tile_pbf(*data);
         while (tile_pbf.next(3)) {
-            VectorTileLayer layer(tile_pbf.get_message());
+            VectorTileLayer layer(tile_pbf.get_message(), data);
             layers.emplace(layer.name, std::move(layer));
         }
     }
@@ -262,7 +272,13 @@ const GeometryTileLayer* VectorTileData::getLayer(const std::string& name) const
     return nullptr;
 }
 
-VectorTileLayer::VectorTileLayer(protozero::pbf_reader layer_pbf) {
+VectorTileLayerData::VectorTileLayerData(std::shared_ptr<const std::string> pbfData) :
+    data(std::move(pbfData))
+{}
+
+VectorTileLayer::VectorTileLayer(protozero::pbf_reader layer_pbf, std::shared_ptr<const std::string> pbfData)
+    : data(std::make_shared<VectorTileLayerData>(std::move(pbfData)))
+{
     while (layer_pbf.next()) {
         switch (layer_pbf.tag()) {
         case 1: // name
@@ -273,18 +289,18 @@ VectorTileLayer::VectorTileLayer(protozero::pbf_reader layer_pbf) {
             break;
         case 3: // keys
             {
-                auto iter = keysMap.emplace(layer_pbf.get_string(), keysMap.size());
-                keys.emplace_back(std::reference_wrapper<const std::string>(iter.first->first));
+                auto iter = data->keysMap.emplace(layer_pbf.get_string(), data->keysMap.size());
+                data->keys.emplace_back(std::reference_wrapper<const std::string>(iter.first->first));
             }
             break;
         case 4: // values
-            values.emplace_back(parseValue(layer_pbf.get_message()));
+            data->values.emplace_back(parseValue(layer_pbf.get_message()));
             break;
         case 5: // extent
-            extent = layer_pbf.get_uint32();
+            data->extent = layer_pbf.get_uint32();
             break;
         case 15: // version
-            version = layer_pbf.get_uint32();
+            data->version = layer_pbf.get_uint32();
             break;
         default:
             layer_pbf.skip();
@@ -294,7 +310,7 @@ VectorTileLayer::VectorTileLayer(protozero::pbf_reader layer_pbf) {
 }
 
 std::unique_ptr<GeometryTileFeature> VectorTileLayer::getFeature(std::size_t i) const {
-    return std::make_unique<VectorTileFeature>(features.at(i), *this);
+    return std::make_unique<VectorTileFeature>(features.at(i), data);
 }
 
 std::string VectorTileLayer::getName() const {

test/tile/vector_tile.test.cpp

@@ -61,9 +61,11 @@ TEST(VectorTile, Issue7615) {
     style::SymbolLayer symbolLayer("symbol", "source");
     auto symbolBucket = std::make_shared<SymbolBucket>(
         style::SymbolLayoutProperties::Evaluated(),
-        std::unordered_map<std::string, style::SymbolPaintProperties::Evaluated>(),
+        std::unordered_map<
+            std::string,
+            std::pair<style::IconPaintProperties::Evaluated, style::TextPaintProperties::Evaluated>>(),
         0.0f, false, false);
-
+    
     // Simulate placement of a symbol layer.
     tile.onPlacement(GeometryTile::PlacementResult {
         {{

test/util/merge_lines.test.cpp

@@ -8,95 +8,131 @@ const std::u16string bbb = u"b";
 
 using namespace mbgl;
 
+class GeometryTileFeatureStub : public GeometryTileFeature {
+public:
+    GeometryTileFeatureStub(optional<FeatureIdentifier> id_, FeatureType type_, GeometryCollection geometry_,
+                  std::unordered_map<std::string, Value> properties_) :
+        id(id_),
+        type(type_),
+        geometry(geometry_),
+        properties(properties_)
+    {}
+    
+    FeatureType getType() const override { return type; }
+    optional<Value> getValue(const std::string& key) const override {
+        auto it = properties.find(key);
+        if (it != properties.end()) {
+            return it->second;
+        }
+        return {};
+    };
+    std::unordered_map<std::string,Value> getProperties() const override { return properties; };
+    optional<FeatureIdentifier> getID() const override { return id; };
+    GeometryCollection getGeometries() const override { return geometry; };
+    
+    optional<FeatureIdentifier> id;
+    FeatureType type;
+    GeometryCollection geometry;
+    std::unordered_map<std::string,Value> properties;
+};
+
+class SymbolFeatureStub : public SymbolFeature {
+public:
+    SymbolFeatureStub(optional<FeatureIdentifier> id_, FeatureType type_, GeometryCollection geometry_,
+                            std::unordered_map<std::string, Value> properties_, optional<std::u16string> text_,
+                            optional<std::string> icon_, std::size_t index_) :
+        SymbolFeature(std::make_unique<GeometryTileFeatureStub>(id_, type_, geometry_, properties_))
+    {
+        text = text_;
+        icon = icon_;
+        index = index_;
+    }
+};
+
 TEST(MergeLines, SameText) {
     // merges lines with the same text
-    std::vector<mbgl::SymbolFeature> input1 = {
-        { FeatureType::LineString, {{{0, 0}, {1, 0}, {2, 0}}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{{4, 0}, {5, 0}, {6, 0}}}, bbb, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{{8, 0}, {9, 0}}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{{2, 0}, {3, 0}, {4, 0}}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{{6, 0}, {7, 0}, {8, 0}}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{{5, 0}, {6, 0}}}, aaa, {}, {{0, 0}}, 0, 0 }
-    };
+    std::vector<mbgl::SymbolFeature> input1;
+    input1.push_back(SymbolFeatureStub({}, FeatureType::LineString, {{{0, 0}, {1, 0}, {2, 0}}}, {}, aaa, {}, 0));
+    input1.push_back(SymbolFeatureStub({}, FeatureType::LineString, {{{4, 0}, {5, 0}, {6, 0}}}, {}, bbb, {}, 0));
+    input1.push_back(SymbolFeatureStub({}, FeatureType::LineString, {{{8, 0}, {9, 0}}}, {}, aaa, {}, 0));
+    input1.push_back(SymbolFeatureStub({}, FeatureType::LineString, {{{2, 0}, {3, 0}, {4, 0}}}, {}, aaa, {}, 0));
+    input1.push_back(SymbolFeatureStub({}, FeatureType::LineString, {{{6, 0}, {7, 0}, {8, 0}}}, {}, aaa, {}, 0));
+    input1.push_back(SymbolFeatureStub({}, FeatureType::LineString, {{{5, 0}, {6, 0}}}, {}, aaa, {}, 0));
 
-    const std::vector<mbgl::SymbolFeature> expected1 = {
-        { FeatureType::LineString, {{{0, 0}, {1, 0}, {2, 0}, {3, 0}, {4, 0}}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{{4, 0}, {5, 0}, {6, 0}}}, bbb, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{{5, 0}, {6, 0}, {7, 0}, {8, 0}, {9, 0}}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{}}, aaa, {}, {{0, 0}}, 0, 0 }
+    const std::vector<GeometryTileFeatureStub> expected1 = {
+        { {}, FeatureType::LineString, {{{0, 0}, {1, 0}, {2, 0}, {3, 0}, {4, 0}}}, {} },
+        { {}, FeatureType::LineString, {{{4, 0}, {5, 0}, {6, 0}}}, {} },
+        { {}, FeatureType::LineString, {{{5, 0}, {6, 0}, {7, 0}, {8, 0}, {9, 0}}}, {} },
+        { {}, FeatureType::LineString, {{}}, {} },
+        { {}, FeatureType::LineString, {{}}, {} },
+        { {}, FeatureType::LineString, {{}}, {} }
     };
-
+    
     mbgl::util::mergeLines(input1);
 
     for (int i = 0; i < 6; i++) {
-        EXPECT_TRUE(input1[i].geometry == expected1[i].geometry);
+        EXPECT_TRUE(input1[i].geometry == expected1[i].getGeometries());
     }
 }
 
 TEST(MergeLines, BothEnds) {
     // mergeLines handles merge from both ends
-    std::vector<mbgl::SymbolFeature> input2 = {
-        { FeatureType::LineString, {{{0, 0}, {1, 0}, {2, 0}}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{{4, 0}, {5, 0}, {6, 0}}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{{2, 0}, {3, 0}, {4, 0}}}, aaa, {}, {{0, 0}}, 0, 0 }
-    };
+    std::vector<mbgl::SymbolFeature> input2;
+    input2.push_back(SymbolFeatureStub { {}, FeatureType::LineString, {{{0, 0}, {1, 0}, {2, 0}}}, {}, aaa, {}, 0 });
+    input2.push_back(SymbolFeatureStub { {}, FeatureType::LineString, {{{4, 0}, {5, 0}, {6, 0}}}, {}, aaa, {}, 0 });
+    input2.push_back(SymbolFeatureStub { {}, FeatureType::LineString, {{{2, 0}, {3, 0}, {4, 0}}}, {}, aaa, {}, 0 });
 
-    const std::vector<mbgl::SymbolFeature> expected2 = {
-        { FeatureType::LineString, {{{0, 0}, {1, 0}, {2, 0}, {3, 0}, {4, 0}, {5, 0}, {6, 0}}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{}}, aaa, {}, {{0, 0}}, 0, 0 }
+    const std::vector<GeometryTileFeatureStub> expected2 = {
+        { {}, FeatureType::LineString, {{{0, 0}, {1, 0}, {2, 0}, {3, 0}, {4, 0}, {5, 0}, {6, 0}}}, {} },
+        { {}, FeatureType::LineString, {{}}, {} },
+        { {}, FeatureType::LineString, {{}}, {} }
     };
 
     mbgl::util::mergeLines(input2);
 
     for (int i = 0; i < 3; i++) {
-        EXPECT_TRUE(input2[i].geometry == expected2[i].geometry);
+        EXPECT_TRUE(input2[i].geometry == expected2[i].getGeometries());
     }
 }
 
 TEST(MergeLines, CircularLines) {
     // mergeLines handles circular lines
-    std::vector<mbgl::SymbolFeature> input3 = {
-        { FeatureType::LineString, {{{0, 0}, {1, 0}, {2, 0}}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{{2, 0}, {3, 0}, {4, 0}}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{{4, 0}, {0, 0}}}, aaa, {}, {{0, 0}}, 0, 0 }
-    };
+    std::vector<mbgl::SymbolFeature> input3;
+    input3.push_back(SymbolFeatureStub { {}, FeatureType::LineString, {{{0, 0}, {1, 0}, {2, 0}}}, {}, aaa, {}, 0 });
+    input3.push_back(SymbolFeatureStub { {}, FeatureType::LineString, {{{2, 0}, {3, 0}, {4, 0}}}, {}, aaa, {}, 0 });
+    input3.push_back(SymbolFeatureStub { {}, FeatureType::LineString, {{{4, 0}, {0, 0}}}, {}, aaa, {}, 0 });
 
-    const std::vector<mbgl::SymbolFeature> expected3 = {
-        { FeatureType::LineString, {{{0, 0}, {1, 0}, {2, 0}, {3, 0}, {4, 0}, {0, 0}}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{}}, aaa, {}, {{0, 0}}, 0, 0 },
-        { FeatureType::LineString, {{}}, aaa, {}, {{0, 0}}, 0, 0 }
+    const std::vector<GeometryTileFeatureStub> expected3 = {
+        { {}, FeatureType::LineString, {{{0, 0}, {1, 0}, {2, 0}, {3, 0}, {4, 0}, {0, 0}}}, {} },
+        { {}, FeatureType::LineString, {{}}, {} },
+        { {}, FeatureType::LineString, {{}}, {} }
     };
 
     mbgl::util::mergeLines(input3);
 
     for (int i = 0; i < 3; i++) {
-        EXPECT_TRUE(input3[i].geometry == expected3[i].geometry);
+        EXPECT_TRUE(input3[i].geometry == expected3[i].getGeometries());
     }
 }
 
 TEST(MergeLines, EmptyOuterGeometry) {
-    std::vector<mbgl::SymbolFeature> input = {
-        { FeatureType::LineString, {}, aaa, {}, {{0, 0}}, 0, 0 },
-    };
+    std::vector<mbgl::SymbolFeature> input;
+    input.push_back(SymbolFeatureStub { {}, FeatureType::LineString, {}, {}, aaa, {}, 0 });
 
-    const std::vector<mbgl::SymbolFeature> expected = input;
+    const std::vector<GeometryTileFeatureStub> expected = { { {}, FeatureType::LineString, {}, {} } };
 
     mbgl::util::mergeLines(input);
 
-    EXPECT_EQ(expected[0].geometry, input[0].geometry);
+    EXPECT_EQ(input[0].geometry, expected[0].getGeometries());
 }
 
 TEST(MergeLines, EmptyInnerGeometry) {
-    std::vector<mbgl::SymbolFeature> input = {
-        { FeatureType::LineString, {{}}, aaa, {}, {{0, 0}}, 0, 0 },
-    };
+    std::vector<mbgl::SymbolFeature> input;
+    input.push_back(SymbolFeatureStub { {}, FeatureType::LineString, {{}}, {}, aaa, {}, 0 });
 
-    const std::vector<mbgl::SymbolFeature> expected = input;
+    const std::vector<GeometryTileFeatureStub> expected = { { {}, FeatureType::LineString, {{}}, {} } };
 
     mbgl::util::mergeLines(input);
 
-    EXPECT_EQ(expected[0].geometry, input[0].geometry);
+    EXPECT_EQ(input[0].geometry, expected[0].getGeometries());
 }