/*
 * Copyright (c) 2013, Google Inc. All rights reserved.
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 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
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 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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#ifndef SKY_ENGINE_PLATFORM_GRAPHICS_GPU_WEBGLIMAGEBUFFERSURFACE_H_
#define SKY_ENGINE_PLATFORM_GRAPHICS_GPU_WEBGLIMAGEBUFFERSURFACE_H_

#include "sky/engine/platform/graphics/ImageBufferSurface.h"
#include "sky/engine/wtf/OwnPtr.h"
#include "third_party/skia/include/core/SkBitmap.h"

namespace blink {

class WebGraphicsContext3DProvider;

// This is a GPU backed surface that has no canvas or render target.
class PLATFORM_EXPORT WebGLImageBufferSurface : public ImageBufferSurface {
    WTF_MAKE_NONCOPYABLE(WebGLImageBufferSurface); WTF_MAKE_FAST_ALLOCATED;
public:
    WebGLImageBufferSurface(const IntSize&, OpacityMode = NonOpaque);
    virtual ~WebGLImageBufferSurface();

    virtual SkCanvas* canvas() const override { return 0; }
    virtual const SkBitmap& bitmap() override { return m_bitmap; }
    virtual bool isValid() const override { return m_bitmap.pixelRef(); }
    virtual bool isAccelerated() const override { return true; }
    virtual Platform3DObject getBackingTexture() const override;
    virtual bool cachedBitmapEnabled() const override { return true; }
    virtual const SkBitmap& cachedBitmap() const override { return m_cachedBitmap; }
    virtual void invalidateCachedBitmap() override;
    virtual void updateCachedBitmapIfNeeded() override;

private:
    SkBitmap m_bitmap;
    // This raw-pixel based SkBitmap works as a cache at CPU side to avoid heavy cost
    // on readback from GPU side to CPU side in some cases.
    SkBitmap m_cachedBitmap;
    OwnPtr<WebGraphicsContext3DProvider> m_contextProvider;
};

} // namespace blink

#endif  // SKY_ENGINE_PLATFORM_GRAPHICS_GPU_WEBGLIMAGEBUFFERSURFACE_H_