[core] draw clipping masks from ClipIDGenerator rather than Sources

src/mbgl/map/source.cpp

@@ -173,14 +173,6 @@ void Source::updateMatrices(const mat4 &projMatrix, const TransformState &transf
     }
 }
 
-void Source::drawClippingMasks(Painter &painter) {
-    for (const auto& pair : tiles) {
-        Tile &tile = *pair.second;
-        MBGL_DEBUG_GROUP(std::string { "mask: " } + std::string(tile.id));
-        painter.drawClippingMask(tile.matrix, tile.clip);
-    }
-}
-
 void Source::finishRender(Painter &painter) {
     for (const auto& pair : tiles) {
         Tile &tile = *pair.second;

src/mbgl/map/source.hpp

@@ -60,7 +60,6 @@ public:
     bool update(const StyleUpdateParameters&);
 
     void updateMatrices(const mat4 &projMatrix, const TransformState &transform);
-    void drawClippingMasks(Painter &painter);
     void finishRender(Painter &painter);
 
     std::forward_list<Tile *> getLoadedTiles() const;

src/mbgl/renderer/painter.cpp

@@ -151,7 +151,7 @@ void Painter::render(const Style& style, const FrameData& frame_, SpriteAtlas& a
             source->updateMatrices(projMatrix, state);
         }
 
-        drawClippingMasks(sources);
+        drawClippingMasks(generator.getStencils());
     }
 
     frameHistory.record(data.getAnimationTime(), state.getZoom());

src/mbgl/renderer/painter.hpp

@@ -93,8 +93,7 @@ public:
     float contrastFactor(float contrast);
     std::array<float, 3> spinWeights(float spin_value);
 
-    void drawClippingMasks(const std::set<Source*>&);
-    void drawClippingMask(const mat4& matrix, const ClipID& clip);
+    void drawClippingMasks(const std::map<TileID, ClipID>&);
 
     bool needsAnimation() const;
 

src/mbgl/renderer/painter_clipping.cpp

@@ -6,31 +6,34 @@
 
 using namespace mbgl;
 
-void Painter::drawClippingMasks(const std::set<Source*>& sources) {
+
+void Painter::drawClippingMasks(const std::map<TileID, ClipID>& stencils) {
     MBGL_DEBUG_GROUP("clipping masks");
 
+    mat4 matrix;
+    const GLuint mask = 0b11111111;
+
     config.program = plainShader->program;
     config.stencilOp.reset();
     config.stencilTest = GL_TRUE;
-    config.depthFunc.reset();
-    config.depthTest = GL_TRUE;
+    config.depthTest = GL_FALSE;
     config.depthMask = GL_FALSE;
     config.colorMask = { GL_FALSE, GL_FALSE, GL_FALSE, GL_FALSE };
-    config.depthRange = { 1.0f, 1.0f };
+    config.stencilMask = mask;
 
     coveringPlainArray.bind(*plainShader, tileStencilBuffer, BUFFER_OFFSET_0);
 
-    for (const auto& source : sources) {
-        source->drawClippingMasks(*this);
+    for (const auto& stencil : stencils) {
+        const auto& id = stencil.first;
+        const auto& clip = stencil.second;
+
+        MBGL_DEBUG_GROUP(std::string{ "mask: " } + std::string(id));
+        state.matrixFor(matrix, id, id.z);
+        matrix::multiply(matrix, projMatrix, matrix);
+        plainShader->u_matrix = matrix;
+
+        const GLint ref = (GLint)(clip.reference.to_ulong());
+        config.stencilFunc = { GL_ALWAYS, ref, mask };
+        MBGL_CHECK_ERROR(glDrawArrays(GL_TRIANGLES, 0, (GLsizei)tileStencilBuffer.index()));
     }
 }
-
-void Painter::drawClippingMask(const mat4& matrix, const ClipID &clip) {
-    plainShader->u_matrix = matrix;
-
-    const GLint ref = (GLint)(clip.reference.to_ulong());
-    const GLuint mask = (GLuint)(clip.mask.to_ulong());
-    config.stencilFunc = { GL_ALWAYS, ref, mask };
-    config.stencilMask = mask;
-    MBGL_CHECK_ERROR(glDrawArrays(GL_TRIANGLES, 0, (GLsizei)tileStencilBuffer.index()));
-}