Add ShaderLayer to Flutter compositor

We need this to implement RenderShaderMask properly. See #1155.

sky/compositor/BUILD.gn

@@ -34,6 +34,8 @@ source_set("compositor") {
     "raster_cache.h",
     "performance_overlay_layer.cc",
     "performance_overlay_layer.h",
+    "shader_layer.cc",
+    "shader_layer.h",
     "transform_layer.cc",
     "transform_layer.h",
   ]

sky/compositor/clip_path_layer.cc

@@ -15,10 +15,10 @@ ClipPathLayer::~ClipPathLayer() {
 
 void ClipPathLayer::Paint(PaintContext::ScopedFrame& frame) {
   SkCanvas& canvas = frame.canvas();
+  SkAutoCanvasRestore save(&canvas, false);
   canvas.saveLayer(&clip_path_.getBounds(), nullptr);
   canvas.clipPath(clip_path_);
   PaintChildren(frame);
-  canvas.restore();
 }
 
 }  // namespace compositor

sky/compositor/clip_rect_layer.cc

@@ -15,10 +15,9 @@ ClipRectLayer::~ClipRectLayer() {
 
 void ClipRectLayer::Paint(PaintContext::ScopedFrame& frame) {
   SkCanvas& canvas = frame.canvas();
-  canvas.save();
+  SkAutoCanvasRestore save(&canvas, true);
   canvas.clipRect(clip_rect_);
   PaintChildren(frame);
-  canvas.restore();
 }
 
 }  // namespace compositor

sky/compositor/clip_rrect_layer.cc

@@ -15,10 +15,10 @@ ClipRRectLayer::~ClipRRectLayer() {
 
 void ClipRRectLayer::Paint(PaintContext::ScopedFrame& frame) {
   SkCanvas& canvas = frame.canvas();
+  SkAutoCanvasRestore save(&canvas, false);
   canvas.saveLayer(&clip_rrect_.getBounds(), nullptr);
   canvas.clipRRect(clip_rrect_);
   PaintChildren(frame);
-  canvas.restore();
 }
 
 }  // namespace compositor

sky/compositor/color_filter_layer.cc

@@ -23,10 +23,11 @@ void ColorFilterLayer::Paint(PaintContext::ScopedFrame& frame) {
       adoptRef(SkColorFilter::CreateModeFilter(color_, transfer_mode_));
   SkPaint paint;
   paint.setColorFilter(color_filter.get());
+
   SkCanvas& canvas = frame.canvas();
+  SkAutoCanvasRestore save(&canvas, false);
   canvas.saveLayer(&paint_bounds(), &paint);
   PaintChildren(frame);
-  canvas.restore();
 }
 
 }  // namespace compositor

sky/compositor/opacity_layer.cc

@@ -22,10 +22,11 @@ void OpacityLayer::Paint(PaintContext::ScopedFrame& frame) {
   SkPaint paint;
   paint.setColor(SkColorSetARGB(alpha_, 0, 0, 0));
   paint.setXfermodeMode(SkXfermode::kSrcOver_Mode);
+
   SkCanvas& canvas = frame.canvas();
+  SkAutoCanvasRestore save(&canvas, false);
   canvas.saveLayer(&paint_bounds(), &paint);
   PaintChildren(frame);
-  canvas.restore();
 }
 
 }  // namespace compositor

sky/compositor/shader_layer.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "sky/compositor/shader_layer.h"
+
+namespace sky {
+namespace compositor {
+
+ShaderLayer::ShaderLayer() {
+}
+
+ShaderLayer::~ShaderLayer() {
+}
+
+void ShaderLayer::Preroll(PrerollContext* context, const SkMatrix& matrix) {
+  ContainerLayer::Preroll(context, matrix);
+  set_paint_bounds(context->child_paint_bounds);
+}
+
+void ShaderLayer::Paint(PaintContext::ScopedFrame& frame) {
+  SkPaint paint;
+  paint.setXfermodeMode(transfer_mode_);
+  paint.setShader(shader_.get());
+
+  SkCanvas& canvas = frame.canvas();
+  SkAutoCanvasRestore save(&canvas, false);
+  canvas.saveLayer(&paint_bounds(), &paint);
+  PaintChildren(frame);
+}
+
+}  // namespace compositor
+}  // namespace sky

sky/compositor/shader_layer.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SKY_COMPOSITOR_SHADER_LAYER_H_
+#define SKY_COMPOSITOR_SHADER_LAYER_H_
+
+#include "sky/compositor/container_layer.h"
+
+#include "third_party/skia/include/core/SkShader.h"
+
+namespace sky {
+namespace compositor {
+
+class ShaderLayer : public ContainerLayer {
+ public:
+  ShaderLayer();
+  ~ShaderLayer() override;
+
+  void set_shader(SkShader* shader) { shader_ = shader; }
+
+  void set_transfer_mode(SkXfermode::Mode transfer_mode) {
+    transfer_mode_ = transfer_mode;
+  }
+
+ protected:
+  void Preroll(PrerollContext* context, const SkMatrix& matrix) override;
+  void Paint(PaintContext::ScopedFrame& frame) override;
+
+ private:
+  RefPtr<SkShader> shader_;
+  SkXfermode::Mode transfer_mode_;
+
+  DISALLOW_COPY_AND_ASSIGN(ShaderLayer);
+};
+
+}  // namespace compositor
+}  // namespace sky
+
+#endif  // SKY_COMPOSITOR_SHADER_LAYER_H_

sky/compositor/transform_layer.cc

@@ -22,10 +22,9 @@ void TransformLayer::Preroll(PrerollContext* context, const SkMatrix& matrix) {
 
 void TransformLayer::Paint(PaintContext::ScopedFrame& frame) {
   SkCanvas& canvas = frame.canvas();
-  canvas.save();
+  SkAutoCanvasRestore save(&canvas, true);
   canvas.concat(transform_);
   PaintChildren(frame);
-  canvas.restore();
 }
 
 }  // namespace compositor

sky/engine/core/compositing/SceneBuilder.cpp

@@ -6,6 +6,7 @@
 
 #include "third_party/skia/include/core/SkColorFilter.h"
 #include "sky/engine/core/painting/Matrix.h"
+#include "sky/engine/core/painting/Shader.h"
 #include "sky/compositor/clip_path_layer.h"
 #include "sky/compositor/clip_rect_layer.h"
 #include "sky/compositor/clip_rrect_layer.h"
@@ -14,6 +15,7 @@
 #include "sky/compositor/opacity_layer.h"
 #include "sky/compositor/picture_layer.h"
 #include "sky/compositor/performance_overlay_layer.h"
+#include "sky/compositor/shader_layer.h"
 #include "sky/compositor/transform_layer.h"
 #include "sky/engine/tonic/dart_args.h"
 #include "sky/engine/tonic/dart_binding_macros.h"
@@ -45,6 +47,7 @@ IMPLEMENT_WRAPPERTYPEINFO(ui, SceneBuilder);
   V(SceneBuilder, pushClipPath) \
   V(SceneBuilder, pushOpacity) \
   V(SceneBuilder, pushColorFilter) \
+  V(SceneBuilder, pushShader) \
   V(SceneBuilder, pop) \
   V(SceneBuilder, addPicture) \
   V(SceneBuilder, addPerformanceOverlay) \
@@ -88,28 +91,28 @@ void SceneBuilder::pushClipRect(const Rect& rect)
     addLayer(std::move(layer));
 }
 
-void SceneBuilder::pushClipRRect(const RRect& rrect, const Rect& bounds)
+void SceneBuilder::pushClipRRect(const RRect& rrect)
 {
     std::unique_ptr<sky::compositor::ClipRRectLayer> layer(new sky::compositor::ClipRRectLayer());
     layer->set_clip_rrect(rrect.sk_rrect);
     addLayer(std::move(layer));
 }
 
-void SceneBuilder::pushClipPath(const CanvasPath* path, const Rect& bounds)
+void SceneBuilder::pushClipPath(const CanvasPath* path)
 {
     std::unique_ptr<sky::compositor::ClipPathLayer> layer(new sky::compositor::ClipPathLayer());
     layer->set_clip_path(path->path());
     addLayer(std::move(layer));
 }
 
-void SceneBuilder::pushOpacity(int alpha, const Rect& bounds)
+void SceneBuilder::pushOpacity(int alpha)
 {
     std::unique_ptr<sky::compositor::OpacityLayer> layer(new sky::compositor::OpacityLayer());
     layer->set_alpha(alpha);
     addLayer(std::move(layer));
 }
 
-void SceneBuilder::pushColorFilter(CanvasColor color, TransferMode transferMode, const Rect& bounds)
+void SceneBuilder::pushColorFilter(CanvasColor color, TransferMode transferMode)
 {
     std::unique_ptr<sky::compositor::ColorFilterLayer> layer(new sky::compositor::ColorFilterLayer());
     layer->set_color(color);
@@ -117,6 +120,14 @@ void SceneBuilder::pushColorFilter(CanvasColor color, TransferMode transferMode,
     addLayer(std::move(layer));
 }
 
+void SceneBuilder::pushShader(Shader* shader, TransferMode transferMode)
+{
+    std::unique_ptr<sky::compositor::ShaderLayer> layer(new sky::compositor::ShaderLayer());
+    layer->set_shader(shader->shader());
+    layer->set_transfer_mode(transferMode);
+    addLayer(std::move(layer));
+}
+
 void SceneBuilder::addLayer(std::unique_ptr<sky::compositor::ContainerLayer> layer)
 {
     DCHECK(layer);
@@ -140,7 +151,7 @@ void SceneBuilder::pop()
     m_currentLayer = m_currentLayer->parent();
 }
 
-void SceneBuilder::addPicture(const Offset& offset, Picture* picture, const Rect& paintBounds)
+void SceneBuilder::addPicture(const Offset& offset, Picture* picture)
 {
     if (!m_currentLayer)
         return;

sky/engine/core/compositing/SceneBuilder.h

@@ -37,14 +37,15 @@ public:
 
     void pushTransform(const Float64List& matrix4, ExceptionState&);
     void pushClipRect(const Rect& rect);
-    void pushClipRRect(const RRect& rrect, const Rect& bounds);
-    void pushClipPath(const CanvasPath* path, const Rect& bounds);
-    void pushOpacity(int alpha, const Rect& bounds);
-    void pushColorFilter(CanvasColor color, TransferMode transferMode, const Rect& bounds);
+    void pushClipRRect(const RRect& rrect);
+    void pushClipPath(const CanvasPath* path);
+    void pushOpacity(int alpha);
+    void pushColorFilter(CanvasColor color, TransferMode transferMode);
+    void pushShader(Shader* shader, TransferMode transferMode);
     void pop();
 
-    void addPicture(const Offset& offset, Picture* picture, const Rect& bounds);
     void addPerformanceOverlay(uint64_t enabledOptions, const Rect& bounds);
+    void addPicture(const Offset& offset, Picture* picture);
 
     void setRasterizerTracingThreshold(uint32_t frameInterval);
 

sky/engine/core/dart/compositing.dart

@@ -14,16 +14,34 @@ class SceneBuilder extends NativeFieldWrapperClass2 {
 
   void pushTransform(Float64List matrix4) native "SceneBuilder_pushTransform";
   void pushClipRect(Rect rect) native "SceneBuilder_pushClipRect";
-  void pushClipRRect(RRect rrect, Rect bounds) native "SceneBuilder_pushClipRRect";
-  void pushClipPath(Path path, Rect bounds) native "SceneBuilder_pushClipPath";
-  void pushOpacity(int alpha, Rect bounds) native "SceneBuilder_pushOpacity";
-  void pushColorFilter(Color color, TransferMode transferMode, Rect bounds) native "SceneBuilder_pushColorFilter";
+  void _pushClipRRect(RRect rrect) native "SceneBuilder_pushClipRRect";
+  void _pushClipPath(Path path) native "SceneBuilder_pushClipPath";
+  void _pushOpacity(int alpha) native "SceneBuilder_pushOpacity";
+  void _pushColorFilter(Color color, TransferMode transferMode) native "SceneBuilder_pushColorFilter";
+  void pushShader(Shader shader, TransferMode transferMode) native "SceneBuilder_pushShader";
 
   void pop() native "SceneBuilder_pop";
 
-  void addPicture(Offset offset, Picture picture, Rect bounds) native "SceneBuilder_addPicture";
   void addPerformanceOverlay(int enabledOptions, Rect bounds) native "SceneBuilder_addPerformanceOverlay";
+  void _addPicture(Offset offset, Picture picture) native "SceneBuilder_addPicture";
   void setRasterizerTracingThreshold(int frameInterval) native "SceneBuilder_setRasterizerTracingThreshold";
 
   Scene build() native "SceneBuilder_build";
+
+  // TODO(abarth): Remove these once clients stop passing bounds.
+  void pushClipRRect(RRect rrect, [ Rect bounds ]) {
+    _pushClipRRect(rrect);
+  }
+  void pushClipPath(Path path, [ Rect bounds ]) {
+    _pushClipPath(path);
+  }
+  void pushOpacity(int alpha, [ Rect bounds ]) {
+    _pushOpacity(alpha);
+  }
+  void pushColorFilter(Color color, TransferMode transferMode, [ Rect bounds ]) {
+    _pushColorFilter(color, transferMode);
+  }
+  void addPicture(Offset offset, Picture picture, [ Rect bounds ]) {
+    _addPicture(offset, picture);
+  }
 }