[core] Make MapDebugOptions::StencilClip a no-op in Release mode

src/mbgl/renderer/painter.cpp

@@ -159,10 +159,12 @@ void Painter::render(const Style& style, const FrameData& frame_, SpriteAtlas& a
         drawClippingMasks(parameters, generator.getStencils());
     }
 
+#if defined(DEBUG)
     if (frame.debugOptions & MapDebugOptions::StencilClip) {
         renderClipMasks();
         return;
     }
+#endif
 
     // Actually render the layers
     if (debug::renderTree) { Log::Info(Event::Render, "{"); indent++; }

src/mbgl/renderer/painter.hpp

@@ -86,7 +86,10 @@ public:
     // Renders the red debug frame around a tile, visualizing its perimeter.
     void renderDebugFrame(const mat4 &matrix);
 
+#if defined(DEBUG)
+    // Renders tile clip boundaries, using stencil buffer to calculate fill color.
     void renderClipMasks();
+#endif
 
     void renderDebugText(Tile&, const mat4&);
     void renderFill(PaintParameters&, FillBucket&, const style::FillLayer&, const RenderTile&);

src/mbgl/renderer/painter_debug.cpp

@@ -87,6 +87,7 @@ void Painter::renderDebugFrame(const mat4 &matrix) {
     MBGL_CHECK_ERROR(glDrawArrays(GL_LINE_STRIP, 0, (GLsizei)tileBorderBuffer.index()));
 }
 
+#if defined(DEBUG)
 void Painter::renderClipMasks() {
     config.stencilTest = GL_FALSE;
     config.depthTest = GL_FALSE;
@@ -122,5 +123,6 @@ void Painter::renderClipMasks() {
     MBGL_CHECK_ERROR(glDrawPixels(fbSize[0], fbSize[1], GL_LUMINANCE, GL_UNSIGNED_BYTE, pixels.get()));
 #endif // GL_ES_VERSION_2_0
 }
+#endif // defined(DEBUG)
 
 } // namespace mbgl