Use sky.SceneBuilder to upload Layer tree to C++

We still use SkPicture as our rasterization backend, but now we're uploading
our layer tree to C++. A future patch will push the layer tree deeper into the
system and we'll eventually switch backends.

sky/engine/core/compositing/Scene.cpp

@@ -0,0 +1,24 @@
+// Copyright 2015 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/engine/core/compositing/Scene.h"
+
+namespace blink {
+
+PassRefPtr<Scene> Scene::create(PassRefPtr<SkPicture> picture)
+{
+    ASSERT(picture);
+    return adoptRef(new Scene(picture));
+}
+
+Scene::Scene(PassRefPtr<SkPicture> picture)
+    : m_picture(picture)
+{
+}
+
+Scene::~Scene()
+{
+}
+
+} // namespace blink

sky/engine/core/compositing/Scene.h

@@ -0,0 +1,33 @@
+// Copyright 2015 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_ENGINE_CORE_COMPOSITING_SCENE_H_
+#define SKY_ENGINE_CORE_COMPOSITING_SCENE_H_
+
+#include "sky/engine/tonic/dart_wrappable.h"
+#include "sky/engine/wtf/PassRefPtr.h"
+#include "sky/engine/wtf/RefCounted.h"
+#include "third_party/skia/include/core/SkPicture.h"
+
+namespace blink {
+
+class Scene : public RefCounted<Scene>, public DartWrappable {
+    DEFINE_WRAPPERTYPEINFO();
+public:
+    ~Scene() override;
+    static PassRefPtr<Scene> create(PassRefPtr<SkPicture> skPicture);
+
+    SkPicture* toSkia() const { return m_picture.get(); }
+
+private:
+    explicit Scene(PassRefPtr<SkPicture> skPicture);
+
+    // While bootstraping the compositing system, we use an SkPicture instead
+    // of a layer tree to back the scene.
+    RefPtr<SkPicture> m_picture;
+};
+
+} // namespace blink
+
+#endif  // SKY_ENGINE_CORE_COMPOSITING_SCENE_H_

sky/engine/core/compositing/Scene.idl

@@ -0,0 +1,7 @@
+// Copyright 2015 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.
+
+// An opaque handle to a composited scene.
+interface Scene {
+};

sky/engine/core/compositing/SceneBuilder.cpp

@@ -0,0 +1,100 @@
+// Copyright 2015 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/engine/core/compositing/SceneBuilder.h"
+
+#include "sky/engine/core/painting/Matrix.h"
+#include "third_party/skia/include/core/SkColorFilter.h"
+
+namespace blink {
+
+SceneBuilder::SceneBuilder(const Rect& bounds)
+{
+    m_canvas = m_pictureRecorder.beginRecording(bounds.sk_rect,
+        &m_rtreeFactory, SkPictureRecorder::kComputeSaveLayerInfo_RecordFlag);
+}
+
+SceneBuilder::~SceneBuilder()
+{
+}
+
+void SceneBuilder::pushTransform(const Float32List& matrix4, ExceptionState& es)
+{
+    SkMatrix sk_matrix = toSkMatrix(matrix4, es);
+    if (es.had_exception())
+        return;
+    m_canvas->save();
+    m_canvas->concat(sk_matrix);
+}
+
+void SceneBuilder::pushClipRect(const Rect& rect)
+{
+    if (!m_canvas)
+        return;
+    m_canvas->save();
+    m_canvas->clipRect(rect.sk_rect);
+}
+
+void SceneBuilder::pushClipRRect(const RRect* rrect, const Rect& bounds)
+{
+    if (!m_canvas)
+        return;
+    m_canvas->saveLayer(&bounds.sk_rect, nullptr);
+    m_canvas->clipRRect(rrect->rrect());
+}
+
+void SceneBuilder::pushClipPath(const CanvasPath* path, const Rect& bounds)
+{
+    if (!m_canvas)
+        return;
+    m_canvas->saveLayer(&bounds.sk_rect, nullptr);
+    m_canvas->clipPath(path->path());
+}
+
+void SceneBuilder::pushOpacity(int alpha, const Rect& bounds)
+{
+    if (!m_canvas)
+        return;
+    SkColor color = SkColorSetARGB(alpha, 0, 0, 0);
+    RefPtr<SkColorFilter> colorFilter = adoptRef(SkColorFilter::CreateModeFilter(color, SkXfermode::kSrcOver_Mode));
+    SkPaint paint;
+    paint.setColorFilter(colorFilter.get());
+    m_canvas->saveLayer(&bounds.sk_rect, &paint);
+}
+
+void SceneBuilder::pushColorFilter(SkColor color, SkXfermode::Mode transferMode, const Rect& bounds)
+{
+    if (!m_canvas)
+        return;
+    RefPtr<SkColorFilter> colorFilter = adoptRef(SkColorFilter::CreateModeFilter(color, transferMode));
+    SkPaint paint;
+    paint.setColorFilter(colorFilter.get());
+    m_canvas->saveLayer(&bounds.sk_rect, &paint);
+}
+
+void SceneBuilder::pop()
+{
+    if (!m_canvas)
+        return;
+    m_canvas->restore();
+}
+
+void SceneBuilder::addPicture(const Offset& offset, Picture* picture, const Rect& paintBounds)
+{
+    if (!m_canvas)
+        return;
+    m_canvas->save();
+    m_canvas->translate(offset.sk_size.width(), offset.sk_size.height());
+    m_canvas->drawPicture(picture->toSkia());
+    m_canvas->restore();
+}
+
+PassRefPtr<Scene> SceneBuilder::build()
+{
+    RefPtr<Scene> scene = Scene::create(adoptRef(m_pictureRecorder.endRecording()));
+    m_canvas = nullptr;
+    return scene.release();
+}
+
+} // namespace blink

sky/engine/core/compositing/SceneBuilder.h

@@ -0,0 +1,57 @@
+// Copyright 2015 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_ENGINE_CORE_COMPOSITING_SCENEBUILDER_H_
+#define SKY_ENGINE_CORE_COMPOSITING_SCENEBUILDER_H_
+
+#include "sky/engine/bindings/exception_state.h"
+#include "sky/engine/core/compositing/Scene.h"
+#include "sky/engine/core/painting/CanvasPath.h"
+#include "sky/engine/core/painting/Offset.h"
+#include "sky/engine/core/painting/Paint.h"
+#include "sky/engine/core/painting/Picture.h"
+#include "sky/engine/core/painting/Point.h"
+#include "sky/engine/core/painting/Rect.h"
+#include "sky/engine/core/painting/RRect.h"
+#include "sky/engine/core/painting/Size.h"
+#include "sky/engine/tonic/dart_wrappable.h"
+#include "sky/engine/tonic/float32_list.h"
+#include "sky/engine/wtf/PassRefPtr.h"
+#include "sky/engine/wtf/RefCounted.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "third_party/skia/include/core/SkPictureRecorder.h"
+
+namespace blink {
+
+class SceneBuilder : public RefCounted<SceneBuilder>, public DartWrappable {
+    DEFINE_WRAPPERTYPEINFO();
+public:
+    static PassRefPtr<SceneBuilder> create(const Rect& bounds) {
+      return adoptRef(new SceneBuilder(bounds));
+    }
+
+    ~SceneBuilder() override;
+
+    void pushTransform(const Float32List& 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(SkColor color, SkXfermode::Mode transferMode, const Rect& bounds);
+    void pop();
+    void addPicture(const Offset& offset, Picture* picture, const Rect& bounds);
+
+    PassRefPtr<Scene> build();
+
+private:
+    explicit SceneBuilder(const Rect& bounds);
+
+    SkRTreeFactory m_rtreeFactory;
+    SkPictureRecorder m_pictureRecorder;
+    SkCanvas* m_canvas;
+};
+
+} // namespace blink
+
+#endif  // SKY_ENGINE_CORE_COMPOSITING_SCENEBUILDER_H_

sky/engine/core/compositing/SceneBuilder.idl

@@ -0,0 +1,19 @@
+// Copyright 2015 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.
+
+[
+  Constructor(Rect bounds),
+] interface SceneBuilder {
+  [RaisesException] void pushTransform(Float32List matrix4);
+  void pushClipRect(Rect rect);
+  void pushClipRRect(RRect rrect, Rect bounds);
+  void pushClipPath(Path path, Rect bounds);
+  void pushOpacity(long alpha, Rect bounds);
+  void pushColorFilter(Color color, TransferMode transferMode, Rect bounds);
+  void pop();
+
+  void addPicture(Offset offset, Picture picture, Rect bounds);
+
+  Scene build();
+};

sky/engine/core/core.gni

@@ -7,6 +7,10 @@ sky_core_output_dir = "$root_gen_dir/sky/core"
 sky_core_files = [
   "Init.cpp",
   "Init.h",
+  "compositing/Scene.cpp",
+  "compositing/Scene.h",
+  "compositing/SceneBuilder.cpp",
+  "compositing/SceneBuilder.h",
   "css/BasicShapeFunctions.cpp",
   "css/BasicShapeFunctions.h",
   "css/BinaryDataFontFaceSource.cpp",
@@ -434,6 +438,8 @@ sky_core_files = [
   "painting/LayoutRoot.h",
   "painting/MaskFilter.cpp",
   "painting/MaskFilter.h",
+  "painting/Matrix.cpp",
+  "painting/Matrix.h",
   "painting/Offset.cpp",
   "painting/Offset.h",
   "painting/Paint.cpp",
@@ -626,6 +632,8 @@ sky_core_files = [
 ]
 
 core_idl_files = get_path_info([
+                                 "compositing/Scene.idl",
+                                 "compositing/SceneBuilder.idl",
                                  "css/CSS.idl",
                                  "css/CSSStyleDeclaration.idl",
                                  "css/MediaQueryList.idl",

sky/engine/core/painting/Canvas.cpp

@@ -9,6 +9,7 @@
 #include "sky/engine/core/dom/Document.h"
 #include "sky/engine/core/dom/Element.h"
 #include "sky/engine/core/painting/CanvasImage.h"
+#include "sky/engine/core/painting/Matrix.h"
 #include "sky/engine/core/painting/PaintingTasks.h"
 #include "sky/engine/platform/geometry/IntRect.h"
 #include "third_party/skia/include/core/SkCanvas.h"
@@ -82,36 +83,6 @@ void Canvas::skew(float sx, float sy)
     m_canvas->skew(sx, sy);
 }
 
-// Mappings from SkMatrix-index to input-index.
-static const int kSkMatrixIndexToMatrix4Index[] = {
-    0, 4, 12,
-    1, 5, 13,
-    3, 7, 15,
-};
-
-SkMatrix toSkMatrix(const Float32List& matrix4, ExceptionState& es)
-{
-    ASSERT(matrix4.data());
-    SkMatrix sk_matrix;
-    if (matrix4.num_elements() != 16) {
-        es.ThrowTypeError("Incorrect number of elements in matrix.");
-        return sk_matrix;
-    }
-
-    for (intptr_t i = 0; i < 9; ++i)
-        sk_matrix[i] = matrix4[kSkMatrixIndexToMatrix4Index[i]];
-    return sk_matrix;
-}
-
-Float32List toMatrix4(const SkMatrix& sk_matrix)
-{
-    Float32List matrix4(Dart_NewTypedData(Dart_TypedData_kFloat32, 16));
-    for (intptr_t i = 0; i < 9; ++i)
-        matrix4[kSkMatrixIndexToMatrix4Index[i]] = sk_matrix[i];
-    matrix4[10] = 1.0; // Identity along the z axis.
-    return matrix4;
-}
-
 void Canvas::concat(const Float32List& matrix4, ExceptionState& es)
 {
     if (!m_canvas)

sky/engine/core/painting/CanvasPath.cpp

@@ -14,4 +14,10 @@ CanvasPath::~CanvasPath()
 {
 }
 
+PassRefPtr<CanvasPath> CanvasPath::shift(const Offset& offset) {
+  RefPtr<CanvasPath> path = CanvasPath::create();
+  m_path.offset(offset.sk_size.width(), offset.sk_size.height(), &path->m_path);
+  return path.release();
+}
+
 } // namespace blink

sky/engine/core/painting/CanvasPath.h

@@ -7,6 +7,7 @@
 
 #include "math.h"
 
+#include "sky/engine/core/painting/Offset.h"
 #include "sky/engine/core/painting/Rect.h"
 #include "sky/engine/tonic/dart_wrappable.h"
 #include "sky/engine/wtf/PassRefPtr.h"
@@ -55,6 +56,8 @@ public:
 
     const SkPath& path() const { return m_path; }
 
+    PassRefPtr<CanvasPath> shift(const Offset& offset);
+
 private:
     CanvasPath();
 

sky/engine/core/painting/Matrix.cpp

@@ -0,0 +1,39 @@
+// Copyright 2015 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/engine/core/painting/Matrix.h"
+
+namespace blink {
+
+// Mappings from SkMatrix-index to input-index.
+static const int kSkMatrixIndexToMatrix4Index[] = {
+    0, 4, 12,
+    1, 5, 13,
+    3, 7, 15,
+};
+
+SkMatrix toSkMatrix(const Float32List& matrix4, ExceptionState& es)
+{
+    ASSERT(matrix4.data());
+    SkMatrix sk_matrix;
+    if (matrix4.num_elements() != 16) {
+        es.ThrowTypeError("Incorrect number of elements in matrix.");
+        return sk_matrix;
+    }
+
+    for (intptr_t i = 0; i < 9; ++i)
+        sk_matrix[i] = matrix4[kSkMatrixIndexToMatrix4Index[i]];
+    return sk_matrix;
+}
+
+Float32List toMatrix4(const SkMatrix& sk_matrix)
+{
+    Float32List matrix4(Dart_NewTypedData(Dart_TypedData_kFloat32, 16));
+    for (intptr_t i = 0; i < 9; ++i)
+        matrix4[kSkMatrixIndexToMatrix4Index[i]] = sk_matrix[i];
+    matrix4[10] = 1.0; // Identity along the z axis.
+    return matrix4;
+}
+
+}  // namespace blink

sky/engine/core/painting/Matrix.h

@@ -0,0 +1,19 @@
+// Copyright 2015 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_ENGINE_CORE_PAINTING_MATRIX_H_
+#define SKY_ENGINE_CORE_PAINTING_MATRIX_H_
+
+#include "sky/engine/bindings/exception_state.h"
+#include "sky/engine/tonic/float32_list.h"
+#include "third_party/skia/include/core/SkMatrix.h"
+
+namespace blink {
+
+SkMatrix toSkMatrix(const Float32List& matrix4, ExceptionState& es);
+Float32List toMatrix4(const SkMatrix& sk_matrix);
+
+}  // namespace blink
+
+#endif  // SKY_ENGINE_CORE_PAINTING_MATRIX_H_

sky/engine/core/painting/Path.idl

@@ -11,4 +11,6 @@
     void arcTo(Rect rect, float startAngle, float sweepAngle, boolean forceMoveTo); // angles in radians
     void addOval(Rect oval);
     void close();
+
+    Path shift(Offset offset);
 };

sky/engine/core/painting/RRect.cpp

@@ -16,7 +16,14 @@ RRect::~RRect()
 
 void RRect::setRectXY(const Rect& rect, float xRad, float yRad)
 {
- 	m_rrect.setRectXY(rect.sk_rect, xRad, yRad);
+    m_rrect.setRectXY(rect.sk_rect, xRad, yRad);
+}
+
+PassRefPtr<RRect> RRect::shift(const Offset& offset) {
+    RefPtr<RRect> rrect = RRect::create();
+    rrect->m_rrect = m_rrect;
+    rrect->m_rrect.offset(offset.sk_size.width(), offset.sk_size.height());
+    return rrect.release();
 }
 
 } // namespace blink

sky/engine/core/painting/RRect.h

@@ -5,6 +5,7 @@
 #ifndef SKY_ENGINE_CORE_PAINTING_RRECT_H_
 #define SKY_ENGINE_CORE_PAINTING_RRECT_H_
 
+#include "sky/engine/core/painting/Offset.h"
 #include "sky/engine/core/painting/Rect.h"
 #include "sky/engine/tonic/dart_wrappable.h"
 #include "sky/engine/wtf/PassRefPtr.h"
@@ -27,6 +28,8 @@ public:
     const SkRRect& rrect() const { return m_rrect; }
     void setRRect(const SkRRect& rrect) { m_rrect = rrect; }
 
+    PassRefPtr<RRect> shift(const Offset& offset);
+
 private:
     RRect();
 

sky/engine/core/painting/RRect.idl

@@ -6,4 +6,6 @@
   Constructor(),
 ] interface RRect {
   void setRectXY(Rect rect, float xRad, float yRad);
+
+  RRect shift(Offset offset);
 };

sky/engine/core/view/View.h

@@ -7,6 +7,7 @@
 
 #include "base/callback.h"
 #include "base/time/time.h"
+#include "sky/engine/core/compositing/Scene.h"
 #include "sky/engine/core/html/VoidCallback.h"
 #include "sky/engine/core/painting/Picture.h"
 #include "sky/engine/core/view/EventCallback.h"
@@ -37,6 +38,9 @@ public:
     Picture* picture() const { return m_picture.get(); }
     void setPicture(Picture* picture) { m_picture = picture; }
 
+    Scene* scene() const { return m_scene.get(); }
+    void setScene(Scene* scene) { m_scene = scene; }
+
     void setEventCallback(PassOwnPtr<EventCallback> callback);
 
     void setMetricsChangedCallback(PassOwnPtr<VoidCallback> callback);
@@ -57,6 +61,7 @@ private:
     OwnPtr<VoidCallback> m_metricsChangedCallback;
     OwnPtr<FrameCallback> m_frameCallback;
     RefPtr<Picture> m_picture;
+    RefPtr<Scene> m_scene;
 };
 
 } // namespace blink

sky/engine/core/view/View.idl

@@ -15,6 +15,7 @@ interface View {
   readonly attribute double height;
 
   attribute Picture picture;
+  attribute Scene scene;
 
   void setEventCallback(EventCallback callback);
   void setMetricsChangedCallback(VoidCallback callback);

sky/engine/public/sky/sky_view.cc

@@ -53,6 +53,8 @@ void SkyView::BeginFrame(base::TimeTicks frame_time) {
 }
 
 PassRefPtr<SkPicture> SkyView::Paint() {
+  if (Scene* scene = view_->scene())
+    return scene->toSkia();
   if (Picture* picture = view_->picture())
     return picture->toSkia();
   return nullptr;

sky/packages/sky/lib/rendering/layer.dart

@@ -5,7 +5,6 @@
 import 'dart:sky' as sky;
 import 'dart:sky' show Point, Offset, Size, Rect, Color, Paint, Path;
 
-import 'package:sky/base/debug.dart';
 import 'package:vector_math/vector_math.dart';
 
 abstract class Layer {
@@ -47,12 +46,7 @@ abstract class Layer {
     _parent = null;
   }
 
-  // The paint() methods are temporary. Eventually, Layers won't have
-  // a paint() method, the entire Layer hierarchy will be handed over
-  // to the C++ side for processing. Until we implement that, though,
-  // we instead have the layers paint themselves into a canvas at
-  // paint time.
-  void paint(sky.Canvas canvas);
+  void addToScene(sky.SceneBuilder builder, Offset layerOffset);
 }
 
 class PictureLayer extends Layer {
@@ -62,24 +56,10 @@ class PictureLayer extends Layer {
   Rect paintBounds;
   sky.Picture picture;
 
-  bool _debugPaintLayerBorder(sky.Canvas canvas) {
-    if (debugPaintLayerBordersEnabled) {
-      Paint border = new Paint()
-        ..color = debugPaintLayerBordersColor
-        ..strokeWidth = 2.0
-        ..setStyle(sky.PaintingStyle.stroke);
-      canvas.drawRect(paintBounds, border);
-    }
-    return true;
+  void addToScene(sky.SceneBuilder builder, Offset layerOffset) {
+    builder.addPicture(offset + layerOffset, picture, paintBounds);
   }
 
-  void paint(sky.Canvas canvas) {
-    assert(picture != null);
-    canvas.translate(offset.dx, offset.dy);
-    canvas.drawPicture(picture);
-    assert(_debugPaintLayerBorder(canvas));
-    canvas.translate(-offset.dx, -offset.dy);
-  }
 }
 
 class ContainerLayer extends Layer {
@@ -182,19 +162,18 @@ class ContainerLayer extends Layer {
     _lastChild = null;
   }
 
-  void paint(sky.Canvas canvas) {
-    canvas.translate(offset.dx, offset.dy);
-    paintChildren(canvas);
-    canvas.translate(-offset.dx, -offset.dy);
+  void addToScene(sky.SceneBuilder builder, Offset layerOffset) {
+    addChildrenToScene(builder, offset + layerOffset);
   }
 
-  void paintChildren(sky.Canvas canvas) {
+  void addChildrenToScene(sky.SceneBuilder builder, Offset layerOffset) {
     Layer child = firstChild;
     while (child != null) {
-      child.paint(canvas);
+      child.addToScene(builder, layerOffset);
       child = child.nextSibling;
     }
   }
+
 }
 
 class ClipRectLayer extends ContainerLayer {
@@ -203,16 +182,13 @@ class ClipRectLayer extends ContainerLayer {
   // clipRect is _not_ affected by given offset
   Rect clipRect;
 
-  void paint(sky.Canvas canvas) {
-    canvas.save();
-    canvas.clipRect(clipRect);
-    canvas.translate(offset.dx, offset.dy);
-    paintChildren(canvas);
-    canvas.restore();
+  void addToScene(sky.SceneBuilder builder, Offset layerOffset) {
+    builder.pushClipRect(clipRect.shift(layerOffset));
+    addChildrenToScene(builder, offset + layerOffset);
+    builder.pop();
   }
-}
 
-final Paint _disableAntialias = new Paint()..isAntiAlias = false;
+}
 
 class ClipRRectLayer extends ContainerLayer {
   ClipRRectLayer({ Offset offset: Offset.zero, this.bounds, this.clipRRect }) : super(offset: offset);
@@ -221,13 +197,12 @@ class ClipRRectLayer extends ContainerLayer {
   Rect bounds;
   sky.RRect clipRRect;
 
-  void paint(sky.Canvas canvas) {
-    canvas.saveLayer(bounds, _disableAntialias);
-    canvas.clipRRect(clipRRect);
-    canvas.translate(offset.dx, offset.dy);
-    paintChildren(canvas);
-    canvas.restore();
+  void addToScene(sky.SceneBuilder builder, Offset layerOffset) {
+    builder.pushClipRRect(clipRRect.shift(layerOffset), bounds.shift(layerOffset));
+    addChildrenToScene(builder, offset + layerOffset);
+    builder.pop();
   }
+
 }
 
 class ClipPathLayer extends ContainerLayer {
@@ -237,13 +212,12 @@ class ClipPathLayer extends ContainerLayer {
   Rect bounds;
   Path clipPath;
 
-  void paint(sky.Canvas canvas) {
-    canvas.saveLayer(bounds, _disableAntialias);
-    canvas.clipPath(clipPath);
-    canvas.translate(offset.dx, offset.dy);
-    paintChildren(canvas);
-    canvas.restore();
+  void addToScene(sky.SceneBuilder builder, Offset layerOffset) {
+    builder.pushClipPath(clipPath.shift(layerOffset), bounds.shift(layerOffset));
+    addChildrenToScene(builder, offset + layerOffset);
+    builder.pop();
   }
+
 }
 
 class TransformLayer extends ContainerLayer {
@@ -251,12 +225,12 @@ class TransformLayer extends ContainerLayer {
 
   Matrix4 transform;
 
-  void paint(sky.Canvas canvas) {
-    canvas.save();
-    canvas.translate(offset.dx, offset.dy);
-    canvas.concat(transform.storage);
-    paintChildren(canvas);
-    canvas.restore();
+  void addToScene(sky.SceneBuilder builder, Offset layerOffset) {
+    Matrix4 offsetTransform = new Matrix4.identity();
+    offsetTransform.translate(offset.dx + layerOffset.dx, offset.dy + layerOffset.dy);
+    builder.pushTransform((offsetTransform * transform).storage);
+    addChildrenToScene(builder, Offset.zero);
+    builder.pop();
   }
 }
 
@@ -267,18 +241,10 @@ class OpacityLayer extends ContainerLayer {
   Rect bounds;
   int alpha;
 
-  static Paint paintForAlpha(int alpha) {
-    return new Paint()
-      ..color = new Color.fromARGB(alpha, 0, 0, 0)
-      ..setTransferMode(sky.TransferMode.srcOver)
-      ..isAntiAlias = false;
-  }
-
-  void paint(sky.Canvas canvas) {
-    canvas.saveLayer(bounds, paintForAlpha(alpha));
-    canvas.translate(offset.dx, offset.dy);
-    paintChildren(canvas);
-    canvas.restore();
+  void addToScene(sky.SceneBuilder builder, Offset layerOffset) {
+    builder.pushOpacity(alpha, bounds == null ? null : bounds.shift(layerOffset));
+    addChildrenToScene(builder, offset + layerOffset);
+    builder.pop();
   }
 }
 
@@ -295,16 +261,9 @@ class ColorFilterLayer extends ContainerLayer {
   Color color;
   sky.TransferMode transferMode;
 
-  static paintForColorFilter(Color color, sky.TransferMode transferMode) {
-    new Paint()
-      ..setColorFilter(new sky.ColorFilter.mode(color, transferMode))
-      ..isAntiAlias = false;
-  }
-
-  void paint(sky.Canvas canvas) {
-    canvas.saveLayer(bounds, paintForColorFilter(color, transferMode));
-    canvas.translate(offset.dx, offset.dy);
-    paintChildren(canvas);
-    canvas.restore();
+  void addToScene(sky.SceneBuilder builder, Offset layerOffset) {
+    builder.pushColorFilter(color, transferMode, bounds.shift(offset));
+    addChildrenToScene(builder, offset + layerOffset);
+    builder.pop();
   }
 }

sky/packages/sky/lib/rendering/view.dart

@@ -98,13 +98,10 @@ class RenderView extends RenderObject with RenderObjectWithChildMixin<RenderBox>
   void compositeFrame() {
     sky.tracing.begin('RenderView.compositeFrame');
     try {
-      // Eventually we will want to pass the entire layer tree to the C++ side.
-      // For now, however, we take the layer tree and paint it into a Canvas,
-      // which we then hand to the C++ side.
-      sky.PictureRecorder recorder = new sky.PictureRecorder();
-      sky.Canvas canvas = new sky.Canvas(recorder, Point.origin & (size * sky.view.devicePixelRatio));
-      layer.paint(canvas);
-      sky.view.picture = recorder.endRecording();
+      Rect bounds = Point.origin & (size * sky.view.devicePixelRatio);
+      sky.SceneBuilder builder = new sky.SceneBuilder(bounds);
+      layer.addToScene(builder, Offset.zero);
+      sky.view.scene = builder.build();
     } finally {
       sky.tracing.end('RenderView.compositeFrame');
     }