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/*
* Copyright (c) 2010, Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* 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
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef DrawingBuffer_h
#define DrawingBuffer_h
#include "GraphicsContext3D.h"
#include "GraphicsLayer.h"
#include "GraphicsTypes3D.h"
#include "IntSize.h"
#include <wtf/Noncopyable.h>
#include <wtf/OwnPtr.h>
#include <wtf/PassOwnPtr.h>
#if PLATFORM(MAC)
#include <wtf/RetainPtr.h>
#endif
namespace WebCore {
class GraphicsContext3D;
class ImageData;
#if PLATFORM(CHROMIUM)
class DrawingBufferPrivate;
#endif
// Manages a rendering target (framebuffer + attachment) for a canvas. Can publish its rendering
// results to a PlatformLayer for compositing.
class DrawingBuffer : public RefCounted<DrawingBuffer> {
public:
enum PreserveDrawingBuffer {
Preserve,
Discard
};
enum AlphaRequirement {
Alpha,
Opaque
};
static PassRefPtr<DrawingBuffer> create(GraphicsContext3D*, const IntSize&, PreserveDrawingBuffer, AlphaRequirement);
friend class GraphicsContext3D;
~DrawingBuffer();
// Issues a glClear() on all framebuffers associated with this DrawingBuffer. The caller is responsible for
// making the context current and setting the clear values and masks. Modifies the framebuffer binding.
void clearFramebuffers(GC3Dbitfield clearMask);
// Returns true if the buffer was successfully resized.
bool reset(const IntSize&);
void bind();
IntSize size() const { return m_size; }
Platform3DObject colorBuffer() const { return m_colorBuffer; }
// Clear all resources from this object, as well as context. Called when context is destroyed
// to prevent invalid accesses to the resources.
void clear();
// Create the depth/stencil and multisample buffers, if needed.
void createSecondaryBuffers();
void resizeDepthStencil(int sampleCount);
// Copies the multisample color buffer to the normal color buffer and leaves m_fbo bound
void commit(long x = 0, long y = 0, long width = -1, long height = -1);
// commit should copy the full multisample buffer, and not respect the
// current scissor bounds. Track the state of the scissor test so that it
// can be disabled during calls to commit.
void setScissorEnabled(bool scissorEnabled) { m_scissorEnabled = scissorEnabled; }
// The DrawingBuffer needs to track the texture bound to texture unit 0.
// The bound texture is tracked to avoid costly queries during rendering.
void setTexture2DBinding(Platform3DObject texture) { m_texture2DBinding = texture; }
// The DrawingBuffer needs to track the currently bound framebuffer so it
// restore the binding when needed.
void setFramebufferBinding(Platform3DObject fbo) { m_framebufferBinding = fbo; }
// Bind to the m_framebufferBinding if it's not 0.
void restoreFramebufferBinding();
// Track the currently active texture unit. Texture unit 0 is used as host for a scratch
// texture.
void setActiveTextureUnit(GC3Dint textureUnit) { m_activeTextureUnit = textureUnit; }
bool multisample() const;
Platform3DObject framebuffer() const;
PassRefPtr<ImageData> paintRenderingResultsToImageData();
// Immediately releases ownership of all resources. Call upon loss of the
// graphics context to prevent freeing invalid resources.
void discardResources();
void markContentsChanged() { m_contentsChanged = true; }
#if USE(ACCELERATED_COMPOSITING)
PlatformLayer* platformLayer();
void prepareBackBuffer();
bool requiresCopyFromBackToFrontBuffer() const;
unsigned frontColorBuffer() const;
void paintCompositedResultsToCanvas(ImageBuffer*);
#endif
GraphicsContext3D* graphicsContext3D() const { return m_context.get(); }
private:
DrawingBuffer(GraphicsContext3D*, const IntSize&, bool multisampleExtensionSupported,
bool packedDepthStencilExtensionSupported, PreserveDrawingBuffer, AlphaRequirement);
void initialize(const IntSize&);
PreserveDrawingBuffer m_preserveDrawingBuffer;
AlphaRequirement m_alpha;
bool m_scissorEnabled;
Platform3DObject m_texture2DBinding;
Platform3DObject m_framebufferBinding;
GC3Denum m_activeTextureUnit;
RefPtr<GraphicsContext3D> m_context;
IntSize m_size;
bool m_multisampleExtensionSupported;
bool m_packedDepthStencilExtensionSupported;
Platform3DObject m_fbo;
Platform3DObject m_colorBuffer;
Platform3DObject m_frontColorBuffer;
bool m_separateFrontTexture;
// This is used when we have OES_packed_depth_stencil.
Platform3DObject m_depthStencilBuffer;
// These are used when we don't.
Platform3DObject m_depthBuffer;
Platform3DObject m_stencilBuffer;
// For multisampling
Platform3DObject m_multisampleFBO;
Platform3DObject m_multisampleColorBuffer;
// True if our contents have been modified since the last presentation of this buffer.
bool m_contentsChanged;
#if PLATFORM(CHROMIUM)
OwnPtr<DrawingBufferPrivate> m_private;
#endif
#if PLATFORM(MAC)
RetainPtr<WebGLLayer> m_platformLayer;
#endif
};
} // namespace WebCore
#endif // DrawingBuffer_h
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