gecko-dev/gfx/layers/CopyableCanvasLayer.h

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/* -*- Mode: C++; tab-width: 2; 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_COPYABLECANVASLAYER_H
#define GFX_COPYABLECANVASLAYER_H
#include "Layers.h"
#include "mozilla/layers/CanvasClient.h"
#include "mozilla/Preferences.h"
#include "gfxPlatform.h"
using namespace mozilla::gfx;
namespace mozilla {
namespace layers {
class CanvasClient2D;
class CanvasClientWebGL;
/**
* A shared CanvasLayer implementation that supports copying
* its contents into a gfxASurface using UpdateSurface.
*/
class CopyableCanvasLayer : public CanvasLayer
{
public:
CopyableCanvasLayer(LayerManager* aLayerManager, void *aImplData) :
CanvasLayer(aLayerManager, aImplData)
{
MOZ_COUNT_CTOR(CopyableCanvasLayer);
mForceReadback = Preferences::GetBool("webgl.force-layers-readback", false);
}
virtual ~CopyableCanvasLayer()
{
MOZ_COUNT_DTOR(CopyableCanvasLayer);
}
virtual void Initialize(const Data& aData);
protected:
void PaintWithOpacity(gfxContext* aContext,
float aOpacity,
Layer* aMaskLayer,
gfxContext::GraphicsOperator aOperator = gfxContext::OPERATOR_OVER);
void UpdateSurface(gfxASurface* aDestSurface = nullptr, Layer* aMaskLayer = nullptr);
nsRefPtr<gfxASurface> mSurface;
nsRefPtr<mozilla::gl::GLContext> mGLContext;
mozilla::RefPtr<mozilla::gfx::DrawTarget> mDrawTarget;
uint32_t mCanvasFramebuffer;
bool mIsGLAlphaPremult;
bool mNeedsYFlip;
bool mForceReadback;
nsRefPtr<gfxImageSurface> mCachedTempSurface;
gfxIntSize mCachedSize;
gfxImageFormat mCachedFormat;
gfxImageSurface* GetTempSurface(const gfxIntSize& aSize, const gfxImageFormat aFormat)
{
if (!mCachedTempSurface ||
aSize.width != mCachedSize.width ||
aSize.height != mCachedSize.height ||
aFormat != mCachedFormat)
{
mCachedTempSurface = new gfxImageSurface(aSize, aFormat);
mCachedSize = aSize;
mCachedFormat = aFormat;
}
MOZ_ASSERT(mCachedTempSurface->Stride() == mCachedTempSurface->Width() * 4);
return mCachedTempSurface;
}
void DiscardTempSurface()
{
mCachedTempSurface = nullptr;
}
};
}
}
#endif