Bug 947781 - Part 4: Add ReadbackLayer functionality to ClientLayerManager. r=mattwoodrow

gfx/layers/client/ClientContainerLayer.h

@@ -15,6 +15,8 @@
 #include "nsISupportsUtils.h"           // for NS_ADDREF, NS_RELEASE
 #include "nsRegion.h"                   // for nsIntRegion
 #include "nsTArray.h"                   // for nsAutoTArray
+#include "ReadbackProcessor.h"
+#include "ClientThebesLayer.h"
 
 namespace mozilla {
 namespace layers {
@@ -55,13 +57,20 @@ public:
     nsAutoTArray<Layer*, 12> children;
     SortChildrenBy3DZOrder(children);
 
+    ReadbackProcessor readback;
+    readback.BuildUpdates(this);
+
     for (uint32_t i = 0; i < children.Length(); i++) {
       Layer* child = children.ElementAt(i);
       if (child->GetEffectiveVisibleRegion().IsEmpty()) {
         continue;
       }
 
-      ToClientLayer(child)->RenderLayer();
+      if (child->GetType() != TYPE_THEBES) {
+        ToClientLayer(child)->RenderLayer();
+      } else {
+        static_cast<ClientThebesLayer*>(child)->RenderLayer(&readback);
+      }
 
       if (!ClientManager()->GetRepeatTransaction() &&
           !child->GetInvalidRegion().IsEmpty()) {

gfx/layers/client/ClientLayerManager.cpp

@@ -21,6 +21,7 @@
 #include "mozilla/layers/LayerTransactionChild.h"
 #include "mozilla/layers/TextureClientPool.h" // for TextureClientPool
 #include "mozilla/layers/SimpleTextureClientPool.h" // for SimpleTextureClientPool
+#include "ClientReadbackLayer.h"        // for ClientReadbackLayer
 #include "nsAString.h"
 #include "nsIWidget.h"                  // for nsIWidget
 #include "nsIWidgetListener.h"
@@ -116,6 +117,13 @@ ClientLayerManager::Mutated(Layer* aLayer)
   mForwarder->Mutated(Hold(aLayer));
 }
 
+already_AddRefed<ReadbackLayer>
+ClientLayerManager::CreateReadbackLayer()
+{
+  nsRefPtr<ReadbackLayer> layer = new ClientReadbackLayer(this);
+  return layer.forget();
+}
+
 void
 ClientLayerManager::BeginTransactionWithTarget(gfxContext* aTarget)
 {

gfx/layers/client/ClientLayerManager.h

@@ -88,6 +88,7 @@ public:
   virtual already_AddRefed<ContainerLayer> CreateContainerLayer();
   virtual already_AddRefed<ImageLayer> CreateImageLayer();
   virtual already_AddRefed<CanvasLayer> CreateCanvasLayer();
+  virtual already_AddRefed<ReadbackLayer> CreateReadbackLayer();
   virtual already_AddRefed<ColorLayer> CreateColorLayer();
   virtual already_AddRefed<RefLayer> CreateRefLayer();
 

gfx/layers/client/ClientReadbackLayer.h

@@ -0,0 +1,33 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef GFX_CLIENTREADBACKLAYER_H
+#define GFX_CLIENTREADBACKLAYER_H
+
+#include "ClientLayerManager.h"
+#include "ReadbackLayer.h"
+
+namespace mozilla {
+namespace layers {
+
+class ClientReadbackLayer :
+  public ReadbackLayer,
+  public ClientLayer
+{
+public:
+    ClientReadbackLayer(ClientLayerManager *aManager)
+    : ReadbackLayer(aManager, nullptr)
+  {
+      mImplData = static_cast<ClientLayer*>(this);
+  }
+
+  virtual Layer* AsLayer() { return this; }
+  virtual void RenderLayer() {}
+};
+
+} /* layers */
+} /* mozilla */
+
+#endif /* GFX_CLIENTREADBACKLAYER_H */

gfx/layers/client/ClientThebesLayer.cpp

@@ -24,6 +24,7 @@
 #include "nsISupportsImpl.h"            // for Layer::AddRef, etc
 #include "nsRect.h"                     // for nsIntRect
 #include "gfx2DGlue.h"
+#include "ReadbackProcessor.h"
 
 namespace mozilla {
 namespace layers {
@@ -104,7 +105,7 @@ ClientThebesLayer::PaintThebes()
 }
 
 void
-ClientThebesLayer::RenderLayer()
+ClientThebesLayer::RenderLayer(ReadbackProcessor *aReadback)
 {
   if (GetMaskLayer()) {
     ToClientLayer(GetMaskLayer())->RenderLayer();
@@ -120,9 +121,16 @@ ClientThebesLayer::RenderLayer()
     MOZ_ASSERT(mContentClient->GetForwarder());
   }
 
+  nsTArray<ReadbackProcessor::Update> readbackUpdates;
+  nsIntRegion readbackRegion;
+  if (aReadback && UsedForReadback()) {
+    aReadback->GetThebesLayerUpdates(this, &readbackUpdates);
+  }
+
+  IntPoint origin(mVisibleRegion.GetBounds().x, mVisibleRegion.GetBounds().y);
   mContentClient->BeginPaint();
   PaintThebes();
-  mContentClient->EndPaint();
+  mContentClient->EndPaint(&readbackUpdates);
 }
 
 bool

gfx/layers/client/ClientThebesLayer.h

@@ -69,7 +69,9 @@ public:
     mValidRegion.Sub(mValidRegion, mInvalidRegion);
   }
 
-  virtual void RenderLayer();
+  virtual void RenderLayer() { RenderLayer(nullptr); }
+
+  virtual void RenderLayer(ReadbackProcessor *aReadback);
 
   virtual void ClearCachedResources()
   {

gfx/layers/client/ContentClient.cpp

@@ -36,6 +36,11 @@
 #include "gfxPlatformGtk.h"
 #endif
 #include "gfx2DGlue.h"
+#include "ReadbackLayer.h"
+
+#include <vector>
+
+using namespace std;
 
 namespace mozilla {
 
@@ -101,7 +106,7 @@ ContentClient::CreateContentClient(CompositableForwarder* aForwarder)
 }
 
 void
-ContentClient::EndPaint()
+ContentClient::EndPaint(nsTArray<ReadbackProcessor::Update>* aReadbackUpdates)
 {
   // It is very important that this is called after any overridden EndPaint behaviour,
   // because destroying textures is a three stage process:
@@ -157,6 +162,64 @@ ContentClientRemoteBuffer::DestroyBuffers()
   DestroyFrontBuffer();
 }
 
+class RemoteBufferReadbackProcessor : public TextureReadbackSink
+{
+public:
+  RemoteBufferReadbackProcessor(nsTArray<ReadbackProcessor::Update>* aReadbackUpdates,
+                                const nsIntRect& aBufferRect, const nsIntPoint& aBufferRotation)
+    : mReadbackUpdates(*aReadbackUpdates)
+    , mBufferRect(aBufferRect)
+    , mBufferRotation(aBufferRotation)
+  {
+    for (uint32_t i = 0; i < mReadbackUpdates.Length(); ++i) {
+      mLayerRefs.push_back(mReadbackUpdates[i].mLayer);
+    }
+  }
+
+  virtual void ProcessReadback(gfx::DataSourceSurface *aSourceSurface)
+  {
+    SourceRotatedBuffer rotBuffer(aSourceSurface, nullptr, mBufferRect, mBufferRotation);
+
+    for (uint32_t i = 0; i < mReadbackUpdates.Length(); ++i) {
+      ReadbackProcessor::Update& update = mReadbackUpdates[i];
+      nsIntPoint offset = update.mLayer->GetBackgroundLayerOffset();
+
+      ReadbackSink* sink = update.mLayer->GetSink();
+
+      if (!sink) {
+        continue;
+      }
+
+      if (!aSourceSurface) {
+        sink->SetUnknown(update.mSequenceCounter);
+        continue;
+      }
+
+      nsRefPtr<gfxContext> ctx =
+        sink->BeginUpdate(update.mUpdateRect + offset, update.mSequenceCounter);
+
+      if (!ctx) {
+        continue;
+      }
+
+      DrawTarget* dt = ctx->GetDrawTarget();
+      dt->SetTransform(Matrix::Translation(offset.x, offset.y));
+
+      rotBuffer.DrawBufferWithRotation(dt, RotatedBuffer::BUFFER_BLACK);
+
+      update.mLayer->GetSink()->EndUpdate(ctx, update.mUpdateRect + offset);
+    }
+  }
+
+private:
+  nsTArray<ReadbackProcessor::Update> mReadbackUpdates;
+  // This array is used to keep the layers alive until the callback.
+  vector<RefPtr<Layer>> mLayerRefs;
+
+  nsIntRect mBufferRect;
+  nsIntPoint mBufferRotation;
+};
+
 void
 ContentClientRemoteBuffer::BeginPaint()
 {
@@ -173,8 +236,10 @@ ContentClientRemoteBuffer::BeginPaint()
 }
 
 void
-ContentClientRemoteBuffer::EndPaint()
+ContentClientRemoteBuffer::EndPaint(nsTArray<ReadbackProcessor::Update>* aReadbackUpdates)
 {
+  MOZ_ASSERT(!mTextureClientOnWhite || !aReadbackUpdates || aReadbackUpdates->Length() == 0);
+
   // XXX: We might still not have a texture client if PaintThebes
   // decided we didn't need one yet because the region to draw was empty.
   SetBufferProvider(nullptr);
@@ -187,12 +252,18 @@ ContentClientRemoteBuffer::EndPaint()
   mOldTextures.Clear();
 
   if (mTextureClient && mTextureClient->IsLocked()) {
+    if (aReadbackUpdates->Length() > 0) {
+      RefPtr<TextureReadbackSink> readbackSink = new RemoteBufferReadbackProcessor(aReadbackUpdates, mBufferRect, mBufferRotation);
+
+      mTextureClient->SetReadbackSink(readbackSink);
+    }
+
     mTextureClient->Unlock();
   }
   if (mTextureClientOnWhite && mTextureClientOnWhite->IsLocked()) {
     mTextureClientOnWhite->Unlock();
   }
-  ContentClientRemote::EndPaint();
+  ContentClientRemote::EndPaint(aReadbackUpdates);
 }
 
 void

gfx/layers/client/ContentClient.h

@@ -21,6 +21,7 @@
 #include "mozilla/layers/LayersSurfaces.h"  // for SurfaceDescriptor
 #include "mozilla/layers/TextureClient.h"  // for TextureClient
 #include "mozilla/mozalloc.h"           // for operator delete
+#include "ReadbackProcessor.h"          // For ReadbackProcessor::Update
 #include "nsCOMPtr.h"                   // for already_AddRefed
 #include "nsPoint.h"                    // for nsIntPoint
 #include "nsRect.h"                     // for nsIntRect
@@ -103,7 +104,7 @@ public:
 
   // call before and after painting into this content client
   virtual void BeginPaint() {}
-  virtual void EndPaint();
+  virtual void EndPaint(nsTArray<ReadbackProcessor::Update>* aReadbackUpdates = nullptr);
 };
 
 /**
@@ -231,7 +232,7 @@ public:
    * are affected by mapping/unmapping.
    */
   virtual void BeginPaint() MOZ_OVERRIDE;
-  virtual void EndPaint() MOZ_OVERRIDE;
+  virtual void EndPaint(nsTArray<ReadbackProcessor::Update>* aReadbackUpdates = nullptr) MOZ_OVERRIDE;
 
   virtual void Updated(const nsIntRegion& aRegionToDraw,
                        const nsIntRegion& aVisibleRegion,
@@ -430,7 +431,7 @@ public:
                        const nsIntRegion& aVisibleRegion,
                        bool aDidSelfCopy);
 
-  virtual void EndPaint()
+  virtual void EndPaint(nsTArray<ReadbackProcessor::Update>* aReadbackUpdates = nullptr)
   {
     if (IsSurfaceDescriptorValid(mUpdateDescriptor)) {
       mForwarder->DestroySharedSurface(&mUpdateDescriptor);
@@ -438,7 +439,7 @@ public:
     if (IsSurfaceDescriptorValid(mUpdateDescriptorOnWhite)) {
       mForwarder->DestroySharedSurface(&mUpdateDescriptorOnWhite);
     }
-    ContentClientRemote::EndPaint();
+    ContentClientRemote::EndPaint(aReadbackUpdates);
   }
 
 private: