[core] Add min and max pitch options

include/mbgl/map/bound_options.hpp

@@ -16,6 +16,16 @@ struct BoundOptions {
     BoundOptions& withMinZoom(double z) { minZoom = z; return *this; }
     /// Sets the maximum zoom level
     BoundOptions& withMaxZoom(double z) { maxZoom = z; return *this; }
+    /// Sets the minimum pitch
+    BoundOptions& withMinPitch(double p) {
+        minPitch = p;
+        return *this;
+    }
+    /// Sets the maximum pitch
+    BoundOptions& withMaxPitch(double p) {
+        maxPitch = p;
+        return *this;
+    }
 
     /// Constrain the center of the camera to be within these bounds.
     optional<LatLngBounds> bounds;
@@ -25,6 +35,12 @@ struct BoundOptions {
 
     /// Minimum zoom level allowed.
     optional<double> minZoom;
+
+    /// Maximum pitch allowed.
+    optional<double> maxPitch;
+
+    /// Minimum pitch allowed.
+    optional<double> minPitch;
 };
 
 }  // namespace mbgl

src/mbgl/map/map.cpp

@@ -306,6 +306,22 @@ void Map::setBounds(const BoundOptions& options) {
         }
     }
 
+    if (options.maxPitch) {
+        impl->transform.setMaxPitch(*options.maxPitch);
+        if (impl->transform.getPitch() > impl->transform.getState().getMaxPitch()) {
+            changeCamera = true;
+            cameraOptions.withPitch(*options.maxPitch);
+        }
+    }
+
+    if (options.minPitch) {
+        impl->transform.setMinPitch(*options.minPitch);
+        if (impl->transform.getPitch() < impl->transform.getState().getMinPitch()) {
+            changeCamera = true;
+            cameraOptions.withPitch(*options.minPitch);
+        }
+    }
+
     if (changeCamera) {
         jumpTo(cameraOptions);
     }
@@ -315,7 +331,9 @@ BoundOptions Map::getBounds() const {
     return BoundOptions()
         .withLatLngBounds(impl->transform.getState().getLatLngBounds())
         .withMinZoom(impl->transform.getState().getMinZoom())
-        .withMaxZoom(impl->transform.getState().getMaxZoom());
+        .withMaxZoom(impl->transform.getState().getMaxZoom())
+        .withMinPitch(impl->transform.getState().getMinPitch())
+        .withMaxPitch(impl->transform.getState().getMaxPitch());
 }
 
 #pragma mark - Map options

src/mbgl/map/transform.cpp

@@ -123,7 +123,7 @@ void Transform::easeTo(const CameraOptions& camera, const AnimationOptions& anim
 
     // Constrain camera options.
     zoom = util::clamp(zoom, state.getMinZoom(), state.getMaxZoom());
-    pitch = util::clamp(pitch, util::PITCH_MIN, util::PITCH_MAX);
+    pitch = util::clamp(pitch, state.getMinPitch(), state.getMaxPitch());
 
     // Minimize rotation by taking the shorter path around the circle.
     bearing = _normalizeAngle(bearing, state.getBearing());
@@ -196,7 +196,7 @@ void Transform::flyTo(const CameraOptions& camera, const AnimationOptions& anima
 
     // Constrain camera options.
     zoom = util::clamp(zoom, state.getMinZoom(), state.getMaxZoom());
-    pitch = util::clamp(pitch, util::PITCH_MIN, util::PITCH_MAX);
+    pitch = util::clamp(pitch, state.getMinPitch(), state.getMaxPitch());
 
     // Minimize rotation by taking the shorter path around the circle.
     bearing = _normalizeAngle(bearing, state.getBearing());
@@ -379,6 +379,26 @@ void Transform::setMaxZoom(const double maxZoom) {
     state.setMaxZoom(maxZoom);
 }
 
+void Transform::setMinPitch(const double minPitch) {
+    if (std::isnan(minPitch)) return;
+    if (minPitch * util::DEG2RAD < util::PITCH_MIN) {
+        Log::Warning(Event::General,
+                     "Trying to set minimum pitch below the limit (%.0f degrees), the value will be clamped.",
+                     util::PITCH_MIN * util::RAD2DEG);
+    }
+    state.setMinPitch(minPitch * util::DEG2RAD);
+}
+
+void Transform::setMaxPitch(const double maxPitch) {
+    if (std::isnan(maxPitch)) return;
+    if (maxPitch * util::DEG2RAD > util::PITCH_MAX) {
+        Log::Warning(Event::General,
+                     "Trying to set maximum pitch above the limit (%.0f degrees), the value will be clamped.",
+                     util::PITCH_MAX * util::RAD2DEG);
+    }
+    state.setMaxPitch(maxPitch * util::DEG2RAD);
+}
+
 #pragma mark - Bearing
 
 void Transform::rotateBy(const ScreenCoordinate& first,

src/mbgl/map/transform.hpp

@@ -59,6 +59,9 @@ public:
     void setMinZoom(double);
     void setMaxZoom(double);
 
+    void setMinPitch(double);
+    void setMaxPitch(double);
+
     // Zoom
 
     /** Returns the zoom level. */

src/mbgl/map/transform_state.cpp

@@ -1,11 +1,12 @@
 #include <mbgl/map/transform_state.hpp>
+#include <mbgl/math/clamp.hpp>
+#include <mbgl/math/log2.hpp>
 #include <mbgl/tile/tile_id.hpp>
 #include <mbgl/util/constants.hpp>
 #include <mbgl/util/interpolate.hpp>
+#include <mbgl/util/logging.hpp>
 #include <mbgl/util/projection.hpp>
 #include <mbgl/util/tile_coordinate.hpp>
-#include <mbgl/math/log2.hpp>
-#include <mbgl/math/clamp.hpp>
 
 namespace mbgl {
 TransformState::TransformState(ConstrainMode constrainMode_, ViewportMode viewportMode_)
@@ -340,6 +341,30 @@ double TransformState::getMaxZoom() const {
     return scaleZoom(max_scale);
 }
 
+void TransformState::setMinPitch(const double pitch_) {
+    if (pitch_ <= maxPitch) {
+        minPitch = util::clamp(pitch_, util::PITCH_MIN, maxPitch);
+    } else {
+        Log::Warning(Event::General, "Trying to set minimum pitch to larger than maximum pitch, no changes made.");
+    }
+}
+
+double TransformState::getMinPitch() const {
+    return minPitch;
+}
+
+void TransformState::setMaxPitch(const double pitch_) {
+    if (pitch_ >= minPitch) {
+        maxPitch = util::clamp(pitch_, minPitch, util::PITCH_MAX);
+    } else {
+        Log::Warning(Event::General, "Trying to set maximum pitch to smaller than minimum pitch, no changes made.");
+    }
+}
+
+double TransformState::getMaxPitch() const {
+    return maxPitch;
+}
+
 #pragma mark - Scale
 double TransformState::getScale() const {
     return scale;

src/mbgl/map/transform_state.hpp

@@ -163,6 +163,10 @@ public:
     double getMinZoom() const;
     void setMaxZoom(double);
     double getMaxZoom() const;
+    void setMinPitch(double);
+    double getMinPitch() const;
+    void setMaxPitch(double);
+    double getMaxPitch() const;
 
     // Rotation
     double getBearing() const;
@@ -225,6 +229,10 @@ private:
     double min_scale = std::pow(2, 0);
     double max_scale = std::pow(2, util::DEFAULT_MAX_ZOOM);
 
+    // Limit the amount of pitch
+    double minPitch = util::PITCH_MIN;
+    double maxPitch = util::PITCH_MAX;
+
     NorthOrientation orientation = NorthOrientation::Upwards;
 
     // logical dimensions