Bug 1381973 - Lazily create the reference DT in DrawTargetCapture. r=dvander

gfx/2d/2D.h

@@ -1231,14 +1231,6 @@ public:
   virtual already_AddRefed<DrawTarget>
     CreateSimilarDrawTarget(const IntSize &aSize, SurfaceFormat aFormat) const = 0;
 
-  /**
-   * Create a DrawTarget that captures the drawing commands and can be replayed
-   * onto a compatible DrawTarget afterwards.
-   *
-   * @param aSize Size of the area this DT will capture.
-   */
-  virtual already_AddRefed<DrawTargetCapture> CreateCaptureDT(const IntSize& aSize);
-
   /**
    * Create a draw target optimized for drawing a shadow.
    *
@@ -1497,6 +1489,16 @@ public:
   static already_AddRefed<DrawTarget>
     CreateDrawTarget(BackendType aBackend, const IntSize &aSize, SurfaceFormat aFormat);
 
+  /**
+   * Create a DrawTarget that captures the drawing commands and can be replayed
+   * onto a compatible DrawTarget afterwards.
+   *
+   * @param aSize Size of the area this DT will capture.
+   */
+  static already_AddRefed<DrawTargetCapture>
+    CreateCaptureDrawTarget(BackendType aBackend, const IntSize &aSize, SurfaceFormat aFormat);
+
+
   static already_AddRefed<DrawTarget>
     CreateWrapAndRecordDrawTarget(DrawEventRecorder *aRecorder, DrawTarget *aDT);
 

gfx/2d/DrawTarget.cpp

@@ -175,19 +175,6 @@ ComputeLinearRGBLuminanceMask(const uint8_t *aSourceData,
   }
 }
 
-already_AddRefed<DrawTargetCapture>
-DrawTarget::CreateCaptureDT(const IntSize& aSize)
-{
-  RefPtr<DrawTargetCaptureImpl> dt = new DrawTargetCaptureImpl();
-
-  if (!dt->Init(aSize, this)) {
-    gfxWarning() << "Failed to initialize Capture DrawTarget!";
-    return nullptr;
-  }
-
-  return dt.forget();
-}
-
 void
 DrawTarget::DrawCapturedDT(DrawTargetCapture *aCaptureDT,
                            const Matrix& aTransform)

gfx/2d/DrawTargetCapture.cpp

@@ -5,6 +5,7 @@
 
 #include "DrawTargetCapture.h"
 #include "DrawCommand.h"
+#include "gfxPlatform.h"
 
 namespace mozilla {
 namespace gfx {
@@ -22,6 +23,31 @@ DrawTargetCaptureImpl::~DrawTargetCaptureImpl()
   }
 }
 
+DrawTargetCaptureImpl::DrawTargetCaptureImpl(BackendType aBackend,
+                                             const IntSize& aSize,
+                                             SurfaceFormat aFormat)
+  : mSize(aSize)
+{
+  RefPtr<DrawTarget> screenRefDT =
+      gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget();
+
+  if (aBackend == screenRefDT->GetBackendType()) {
+    mRefDT = screenRefDT;
+  } else {
+    // If you got here, we have to create a new ref DT to create
+    // backend specific assets like paths / gradients. Try to
+    // create the same backend type as the screen ref dt.
+    gfxWarning() << "Creating a RefDT in DrawTargetCapture.";
+
+    // Create a 1x1 size ref dt to create assets
+    // If we have to snapshot, we'll just create the real DT
+    IntSize size(1, 1);
+    mRefDT = Factory::CreateDrawTarget(aBackend, size, mFormat);
+  }
+
+  mFormat = aFormat;
+}
+
 bool
 DrawTargetCaptureImpl::Init(const IntSize& aSize, DrawTarget* aRefDT)
 {
@@ -39,7 +65,7 @@ DrawTargetCaptureImpl::Init(const IntSize& aSize, DrawTarget* aRefDT)
 already_AddRefed<SourceSurface>
 DrawTargetCaptureImpl::Snapshot()
 {
-  RefPtr<DrawTarget> dt = mRefDT->CreateSimilarDrawTarget(mSize, mRefDT->GetFormat());
+  RefPtr<DrawTarget> dt = mRefDT->CreateSimilarDrawTarget(mSize, mFormat);
 
   ReplayToDrawTarget(dt, Matrix());
 

gfx/2d/DrawTargetCapture.h

@@ -19,8 +19,7 @@ class DrawingCommand;
 class DrawTargetCaptureImpl : public DrawTargetCapture
 {
 public:
-  DrawTargetCaptureImpl()
+  DrawTargetCaptureImpl(BackendType aBackend, const IntSize& aSize, SurfaceFormat aFormat);
-  {}
 
   bool Init(const IntSize& aSize, DrawTarget* aRefDT);
 
@@ -149,7 +148,7 @@ public:
   bool ContainsOnlyColoredGlyphs(RefPtr<ScaledFont>& aScaledFont, Color& aColor, std::vector<Glyph>& aGlyphs) override;
 
 protected:
-  ~DrawTargetCaptureImpl();
+  virtual ~DrawTargetCaptureImpl();
 
 private:
 
@@ -166,7 +165,6 @@ private:
     return reinterpret_cast<T*>(nextDrawLocation + sizeof(uint32_t));
   }
   RefPtr<DrawTarget> mRefDT;
-
   IntSize mSize;
 
   std::vector<uint8_t> mDrawCommandStorage;

gfx/2d/Factory.cpp

@@ -1,5 +1,5 @@
-/* -*- 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
+/* 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/. */
 
@@ -48,6 +48,7 @@
 #include "mozilla/Mutex.h"
 #endif
 
+#include "DrawTargetCapture.h"
 #include "DrawTargetDual.h"
 #include "DrawTargetTiled.h"
 #include "DrawTargetWrapAndRecord.h"
@@ -418,6 +419,12 @@ Factory::CreateRecordingDrawTarget(DrawEventRecorder *aRecorder, DrawTarget *aDT
   return MakeAndAddRef<DrawTargetRecording>(aRecorder, aDT, aSize);
 }
 
+already_AddRefed<DrawTargetCapture>
+Factory::CreateCaptureDrawTarget(BackendType aBackend, const IntSize& aSize, SurfaceFormat aFormat)
+{
+  return MakeAndAddRef<DrawTargetCaptureImpl>(aBackend, aSize, aFormat);
+}
+
 already_AddRefed<DrawTarget>
 Factory::CreateDrawTargetForData(BackendType aBackend,
                                  unsigned char *aData,

gfx/layers/client/ClientPaintedLayer.cpp

@@ -204,16 +204,14 @@ ClientPaintedLayer::PaintOffMainThread()
       continue;
     }
 
-    RefPtr<DrawTarget> refDT =
-      Factory::CreateDrawTarget(gfxPlatform::GetPlatform()->GetDefaultContentBackend(),
-                                target->GetSize(), target->GetFormat());
-
     // We don't clear the rect here like WRPaintedBlobLayers do
     // because ContentClient already clears the surface for us during BeginPaint.
-    RefPtr<DrawTargetCapture> captureDT = refDT->CreateCaptureDT(target->GetSize());
+    RefPtr<DrawTargetCapture> captureDT =
+      Factory::CreateCaptureDrawTarget(target->GetBackendType(),
+                                       target->GetSize(),
+                                       target->GetFormat());
     captureDT->SetTransform(target->GetTransform());
 
-    SetAntialiasingFlags(this, refDT);
     SetAntialiasingFlags(this, captureDT);
     SetAntialiasingFlags(this, target);
 

layout/generic/nsBulletFrame.cpp

@@ -398,8 +398,12 @@ BulletRenderer::BuildGlyphForText(nsDisplayItem* aItem, bool disableSubpixelAA)
 {
   MOZ_ASSERT(IsTextType());
 
+  RefPtr<DrawTarget> screenTarget = gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget();
   RefPtr<DrawTargetCapture> capture =
-    gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget()->CreateCaptureDT(IntSize());
+    Factory::CreateCaptureDrawTarget(screenTarget->GetBackendType(),
+                                     IntSize(),
+                                     screenTarget->GetFormat());
+
   RefPtr<gfxContext> captureCtx = gfxContext::CreateOrNull(capture);
 
   {

layout/generic/nsTextFrame.cpp

@@ -5119,8 +5119,11 @@ nsDisplayText::nsDisplayText(nsDisplayListBuilder* aBuilder, nsTextFrame* aFrame
 
   if (gfxPrefs::LayersAllowTextLayers() &&
       CanUseAdvancedLayer(aBuilder->GetWidgetLayerManager())) {
+    RefPtr<DrawTarget> screenTarget = gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget();
     RefPtr<DrawTargetCapture> capture =
-      gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget()->CreateCaptureDT(IntSize());
+      Factory::CreateCaptureDrawTarget(screenTarget->GetBackendType(),
+                                       IntSize(),
+                                       screenTarget->GetFormat());
     RefPtr<gfxContext> captureCtx = gfxContext::CreateOrNull(capture);
 
     // TODO: Paint() checks mDisableSubpixelAA, we should too.