[core] Add static getters for property default values (#6124)

src/mbgl/style/layers/circle_layer.cpp

@@ -61,6 +61,10 @@ const Filter& CircleLayer::getFilter() const {
 
 // Paint properties
 
+PropertyValue<float> CircleLayer::getDefaultCircleRadius() {
+    return { 5 };
+}
+
 PropertyValue<float> CircleLayer::getCircleRadius() const {
     return impl->paint.circleRadius.get();
 }
@@ -69,6 +73,10 @@ void CircleLayer::setCircleRadius(PropertyValue<float> value, const optional<std
     impl->paint.circleRadius.set(value, klass);
 }
 
+PropertyValue<Color> CircleLayer::getDefaultCircleColor() {
+    return { Color::black() };
+}
+
 PropertyValue<Color> CircleLayer::getCircleColor() const {
     return impl->paint.circleColor.get();
 }
@@ -77,6 +85,10 @@ void CircleLayer::setCircleColor(PropertyValue<Color> value, const optional<std:
     impl->paint.circleColor.set(value, klass);
 }
 
+PropertyValue<float> CircleLayer::getDefaultCircleBlur() {
+    return { 0 };
+}
+
 PropertyValue<float> CircleLayer::getCircleBlur() const {
     return impl->paint.circleBlur.get();
 }
@@ -85,6 +97,10 @@ void CircleLayer::setCircleBlur(PropertyValue<float> value, const optional<std::
     impl->paint.circleBlur.set(value, klass);
 }
 
+PropertyValue<float> CircleLayer::getDefaultCircleOpacity() {
+    return { 1 };
+}
+
 PropertyValue<float> CircleLayer::getCircleOpacity() const {
     return impl->paint.circleOpacity.get();
 }
@@ -93,6 +109,10 @@ void CircleLayer::setCircleOpacity(PropertyValue<float> value, const optional<st
     impl->paint.circleOpacity.set(value, klass);
 }
 
+PropertyValue<std::array<float, 2>> CircleLayer::getDefaultCircleTranslate() {
+    return { {{ 0, 0 }} };
+}
+
 PropertyValue<std::array<float, 2>> CircleLayer::getCircleTranslate() const {
     return impl->paint.circleTranslate.get();
 }
@@ -101,6 +121,10 @@ void CircleLayer::setCircleTranslate(PropertyValue<std::array<float, 2>> value,
     impl->paint.circleTranslate.set(value, klass);
 }
 
+PropertyValue<TranslateAnchorType> CircleLayer::getDefaultCircleTranslateAnchor() {
+    return { TranslateAnchorType::Map };
+}
+
 PropertyValue<TranslateAnchorType> CircleLayer::getCircleTranslateAnchor() const {
     return impl->paint.circleTranslateAnchor.get();
 }
@@ -109,6 +133,10 @@ void CircleLayer::setCircleTranslateAnchor(PropertyValue<TranslateAnchorType> va
     impl->paint.circleTranslateAnchor.set(value, klass);
 }
 
+PropertyValue<CirclePitchScaleType> CircleLayer::getDefaultCirclePitchScale() {
+    return { CirclePitchScaleType::Map };
+}
+
 PropertyValue<CirclePitchScaleType> CircleLayer::getCirclePitchScale() const {
     return impl->paint.circlePitchScale.get();
 }