Single text positioning property

https://github.com/mapbox/mapbox-gl-style-spec/issues/197

include/mbgl/style/style_bucket.hpp

@@ -64,8 +64,7 @@ public:
         float line_height = 1.2f * 24 /* em */;
         float letter_spacing = 0.0f * 24 /* em */;
         TextJustifyType justify = TextJustifyType::Center;
-        TextHorizontalAlignType horizontal_align = TextHorizontalAlignType::Center;
-        TextVerticalAlignType vertical_align = TextVerticalAlignType::Center;
+        TextAnchorType anchor = TextAnchorType::Center;
         float max_angle = 45.0f /* degrees */;
         float rotate = 0.0f;
         float slant = 0.0f;

include/mbgl/style/types.hpp

@@ -152,30 +152,20 @@ MBGL_DEFINE_ENUM_CLASS(TextJustifyTypeClass, TextJustifyType, {
 
 // -------------------------------------------------------------------------------------------------
 
-enum class TextHorizontalAlignType : uint8_t {
+enum class TextAnchorType : uint8_t {
+    Center,
     Left,
-    Center,
     Right,
-};
-
-MBGL_DEFINE_ENUM_CLASS(TextHorizontalAlignTypeClass, TextHorizontalAlignType, {
-    { TextHorizontalAlignType::Left, "left" },
-    { TextHorizontalAlignType::Center, "center" },
-    { TextHorizontalAlignType::Right, "right" },
-});
-
-// -------------------------------------------------------------------------------------------------
-
-enum class TextVerticalAlignType : uint8_t {
     Top,
-    Center,
-    Bottom,
+    Bottom
 };
 
-MBGL_DEFINE_ENUM_CLASS(TextVerticalAlignTypeClass, TextVerticalAlignType, {
-    { TextVerticalAlignType::Top, "top" },
-    { TextVerticalAlignType::Center, "center" },
-    { TextVerticalAlignType::Bottom, "bottom" },
+MBGL_DEFINE_ENUM_CLASS(TextAnchorTypeClass, TextAnchorType, {
+    { TextAnchorType::Center, "center" },
+    { TextAnchorType::Left, "left" },
+    { TextAnchorType::Right, "right" },
+    { TextAnchorType::Top, "top" },
+    { TextAnchorType::Bottom, "bottom" },
 });
 
 // -------------------------------------------------------------------------------------------------

src/renderer/symbol_bucket.cpp

@@ -103,16 +103,24 @@ void SymbolBucket::addFeatures(const VectorTileLayer &layer, const FilterExpress
     const std::vector<SymbolFeature> features = processFeatures(layer, filter, glyphStore, sprite);
 
     float horizontalAlign = 0.5;
-    if (properties.text.horizontal_align == TextHorizontalAlignType::Right)
-        horizontalAlign = 1;
-    else if (properties.text.horizontal_align == TextHorizontalAlignType::Left)
-        horizontalAlign = 0;
-
     float verticalAlign = 0.5;
-    if (properties.text.vertical_align == TextVerticalAlignType::Bottom)
-        verticalAlign = 1;
-    else if (properties.text.vertical_align == TextVerticalAlignType::Top)
-        verticalAlign = 0;
+
+    switch (properties.text.anchor) {
+        case TextAnchorType::Center:
+            break;
+        case TextAnchorType::Right:
+            horizontalAlign = 1;
+            break;
+        case TextAnchorType::Left:
+            horizontalAlign = 0;
+            break;
+        case TextAnchorType::Bottom:
+            verticalAlign = 1;
+            break;
+        case TextAnchorType::Top:
+            verticalAlign = 0;
+            break;
+    }
 
     float justify = 0.5;
     if (properties.text.justify == TextJustifyType::Right) justify = 1;

src/style/style_parser.cpp

@@ -801,8 +801,7 @@ void StyleParser::parseLayout(JSVal value, util::ptr<StyleLayer> &layer) {
             render.text.letter_spacing *= 24; // em
         }
         parseRenderProperty<TextJustifyTypeClass>(value, render.text.justify, "text-justify");
-        parseRenderProperty<TextHorizontalAlignTypeClass>(value, render.text.horizontal_align, "text-horizontal-align");
-        parseRenderProperty<TextVerticalAlignTypeClass>(value, render.text.vertical_align, "text-vertical-align");
+        parseRenderProperty<TextAnchorTypeClass>(value, render.text.anchor, "text-anchor");
         parseRenderProperty(value, render.text.max_angle, "text-max-angle");
         parseRenderProperty(value, render.text.rotate, "text-rotate");
         parseRenderProperty(value, render.text.slant, "text-slant");