variable FOV seems to work

bin/render.cpp

@@ -33,6 +33,7 @@ int main(int argc, char* argv[]) {
 
     args::ValueFlag<double> lonValue(argumentParser, "degrees", "Longitude", {'x', "lon"});
     args::ValueFlag<double> latValue(argumentParser, "degrees", "Latitude", {'y', "lat"});
+    args::ValueFlag<double> fovValue(argumentParser, "degrees", "FOV", {'f', "fov"});
     args::ValueFlag<double> bearingValue(argumentParser, "degrees", "Bearing", {'b', "bearing"});
     args::ValueFlag<double> pitchValue(argumentParser, "degrees", "Pitch", {'p', "pitch"});
     args::ValueFlag<uint32_t> widthValue(argumentParser, "pixels", "Image width", {'w', "width"});
@@ -56,6 +57,7 @@ int main(int argc, char* argv[]) {
     const double lat = latValue ? args::get(latValue) : 0;
     const double lon = lonValue ? args::get(lonValue) : 0;
     const double zoom = zoomValue ? args::get(zoomValue) : 0;
+    const double fov = fovValue ? args::get(fovValue) : 37;
     const double bearing = bearingValue ? args::get(bearingValue) : 0;
     const double pitch = pitchValue ? args::get(pitchValue) : 0;
     const double pixelRatio = pixelRatioValue ? args::get(pixelRatioValue) : 1;
@@ -97,7 +99,7 @@ int main(int argc, char* argv[]) {
     }
 
     map.getStyle().loadURL(style);
-    map.jumpTo(CameraOptions().withCenter(LatLng{lat, lon}).withZoom(zoom).withBearing(bearing).withPitch(pitch));
+    map.jumpTo(CameraOptions().withCenter(LatLng{lat, lon}).withZoom(zoom).withBearing(bearing).withPitch(pitch).withFov(fov));
 
     if (debug) {
         map.setDebug(debug ? mbgl::MapDebugOptions::TileBorders | mbgl::MapDebugOptions::ParseStatus

include/mbgl/map/camera.hpp

@@ -41,6 +41,10 @@ struct CameraOptions {
         pitch = o;
         return *this;
     }
+    CameraOptions& withFov(const std::optional<double>& o) {
+        fov = o;
+        return *this;
+    }
 
     /** Coordinate at the center of the map. */
     std::optional<LatLng> center;
@@ -63,11 +67,13 @@ struct CameraOptions {
     /** Pitch toward the horizon measured in degrees , with 0 deg resulting in a
         two-dimensional map. */
     std::optional<double> pitch;
+
+    std::optional<double> fov;
 };
 
 constexpr bool operator==(const CameraOptions& a, const CameraOptions& b) {
     return a.center == b.center && a.padding == b.padding && a.anchor == b.anchor && a.zoom == b.zoom &&
-           a.bearing == b.bearing && a.pitch == b.pitch;
+           a.bearing == b.bearing && a.pitch == b.pitch && a.fov == b.fov;
 }
 
 constexpr bool operator!=(const CameraOptions& a, const CameraOptions& b) {

src/mbgl/map/transform.cpp

@@ -97,6 +97,7 @@ void Transform::easeTo(const CameraOptions& camera, const AnimationOptions& anim
     double zoom = camera.zoom.value_or(getZoom());
     double bearing = camera.bearing ? util::deg2rad(-*camera.bearing) : getBearing();
     double pitch = camera.pitch ? util::deg2rad(*camera.pitch) : getPitch();
+    double fov = camera.fov ? util::deg2rad(*camera.fov) : getFieldOfView();
 
     if (std::isnan(zoom) || std::isnan(bearing) || std::isnan(pitch)) {
         if (animation.transitionFinishFn) {
@@ -161,6 +162,7 @@ void Transform::easeTo(const CameraOptions& camera, const AnimationOptions& anim
             if (pitch != startPitch) {
                 state.setPitch(util::interpolate(startPitch, pitch, t));
             }
+            state.setFieldOfView(fov);
         },
         duration);
 }

src/mbgl/map/transform_state.cpp

@@ -48,6 +48,9 @@ void TransformState::setProperties(const TransformStateProperties& properties) {
     if (properties.bearing) {
         setBearing(*properties.bearing);
     }
+    if (properties.fov) {
+        setFieldOfView(*properties.fov);
+    }
     if (properties.pitch) {
         setPitch(*properties.pitch);
     }
@@ -429,7 +432,8 @@ CameraOptions TransformState::getCameraOptions(const std::optional<EdgeInsets>&
         .withPadding(padding ? padding : edgeInsets)
         .withZoom(getZoom())
         .withBearing(util::rad2deg(-bearing))
-        .withPitch(util::rad2deg(pitch));
+        .withPitch(util::rad2deg(pitch))
+        .withFov(util::rad2deg(fov));
 }
 
 // MARK: - EdgeInsets
@@ -590,6 +594,13 @@ float TransformState::getFieldOfView() const {
     return static_cast<float>(fov);
 }
 
+void TransformState::setFieldOfView(double val) {
+    if (fov != val) {
+        fov = val;
+        requestMatricesUpdate = true;
+    }
+}
+
 float TransformState::getCameraToCenterDistance() const {
     return static_cast<float>(0.5 * size.height / std::tan(fov / 2.0));
 }

src/mbgl/map/transform_state.hpp

@@ -33,6 +33,10 @@ struct TransformStateProperties {
         scale = val;
         return *this;
     }
+    TransformStateProperties& withFov(const std::optional<double>& val) {
+        fov = val;
+        return *this;
+    }
     TransformStateProperties& withBearing(const std::optional<double>& val) {
         bearing = val;
         return *this;
@@ -88,6 +92,7 @@ struct TransformStateProperties {
 
     std::optional<double> x;
     std::optional<double> y;
+    std::optional<double> fov;
     std::optional<double> bearing;
     std::optional<double> scale;
     std::optional<double> pitch;
@@ -173,6 +178,7 @@ class TransformState {
     double getBearing() const;
     void setBearing(double);
     float getFieldOfView() const;
+    void setFieldOfView(double);
     float getCameraToCenterDistance() const;
     double getPitch() const;
     void setPitch(double);