LayerRenderer.h   [plain text]

/*
 * Copyright (C) 2010, 2011, 2012, 2013 Research In Motion Limited. All rights reserved.
 * 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
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 */

#ifndef LayerRenderer_h
#define LayerRenderer_h

#if USE(ACCELERATED_COMPOSITING)

#include "Extensions3DOpenGLES.h"
#include "IntRect.h"
#include "LayerData.h"
#include "LayerFilterRenderer.h"
#include "TransformationMatrix.h"

#include <BlackBerryPlatformGLES2Context.h>
#include <BlackBerryPlatformGLES2Program.h>
#include <BlackBerryPlatformIntRectRegion.h>
#include <wtf/HashSet.h>
#include <wtf/Noncopyable.h>
#include <wtf/PassOwnPtr.h>
#include <wtf/Vector.h>

namespace WebCore {

class Color;
class LayerCompositingThread;
class LayerRendererClient;
class LayerRendererSurface;

class LayerRenderingResults {
public:
    LayerRenderingResults() : wasEmpty(true), needsAnimationFrame(false) { }

    static const int NumberOfDirtyRects = 3;
    const IntRect& dirtyRect(int i) const { return m_dirtyRects[i]; }
    void addDirtyRect(const IntRect& dirtyRect);
    bool isEmpty() const;

    bool wasEmpty;

    BlackBerry::Platform::IntRectRegion dirtyRegion;

    bool needsAnimationFrame;

private:
    IntRect m_dirtyRects[NumberOfDirtyRects];
};

// Class that handles drawing of composited render layers using GL.
class LayerRenderer {
    WTF_MAKE_NONCOPYABLE(LayerRenderer);
public:
    static TransformationMatrix orthoMatrix(float left, float right, float bottom, float top, float nearZ, float farZ);

    static PassOwnPtr<LayerRenderer> create(LayerRendererClient*);

    LayerRenderer(LayerRendererClient*);
    ~LayerRenderer();

    LayerRendererClient* client() const { return m_client; }

    void releaseLayerResources();

    // In order to render the layers, you must do the following 3 operations, in order.

    // 1. Upload textures and other operations that should be performed at the beginning of each frame.
    // Note, this call also resets the last rendering results.
    void prepareFrame(double animationTime, LayerCompositingThread* rootLayer);

    // 2. Set the OpenGL viewport and store other viewport-related parameters
    //   viewport is the GL viewport
    //   clipRect is an additional clip rect, if clipping is required beyond the clipping effect of the viewport.
    //   visibleRect is the subrect of the web page that you wish to composite, expressed in content coordinates
    // The last two parameters are required to draw fixed position elements in the right place:
    //   layoutRect is the subrect of the web page that the WebKit thread believes is visible (scroll position, actual visible size).
    //   contentsSize is the contents size of the web page
    void setViewport(const IntRect& viewport, const IntRect& clipRect, const FloatRect& visibleRect, const IntRect& layoutRect, const IntSize& contentsSize);

    // 3. Prepares all the layers for compositing
    // transform is the model-view-project matrix that goes all the way from contents to normalized device coordinates.
    void compositeLayers(const TransformationMatrix&, LayerCompositingThread* rootLayer);
    void compositeBuffer(const TransformationMatrix&, const FloatRect& contents, BlackBerry::Platform::Graphics::Buffer*, bool contentsOpaque, float opacity);
    void drawColor(const TransformationMatrix&, const FloatRect& contents, const Color&);

    // Keep track of layers that need cleanup when the LayerRenderer is destroyed
    void addLayer(LayerCompositingThread*);
    bool removeLayer(LayerCompositingThread*);

    // Keep track of layers that need to release their textures when we swap buffers
    void addLayerToReleaseTextureResourcesList(LayerCompositingThread*);

    bool hardwareCompositing() const { return m_hardwareCompositing; }

    BlackBerry::Platform::Graphics::GLES2Context* context() const;

    const LayerRenderingResults& lastRenderingResults() const { return m_lastRenderingResults; }

    // Schedule a commit on the WebKit thread at the end of rendering
    // Used when a layer discovers during rendering that it needs a commit.
    void setNeedsCommit() { m_needsCommit = true; }

    IntRect toWindowCoordinates(const FloatRect&) const;
    IntRect toPixelViewportCoordinates(const FloatRect&) const;
    IntRect toDocumentViewportCoordinates(const FloatRect&) const;

    // If the layer has already been drawed on a surface.
    bool layerAlreadyOnSurface(LayerCompositingThread*) const;

    void drawDebugBorder(const Vector<FloatPoint>&, const Color&, float borderWidth);

    static GLuint loadShader(GLenum type, const char* shaderSource);
    static GLuint loadShaderProgram(const char* vertexShaderSource, const char* fragmentShaderSource);

private:
    void prepareFrameRecursive(LayerCompositingThread*, double animationTime, bool isContextCurrent);
    void updateLayersRecursive(LayerCompositingThread*, const TransformationMatrix& parentMatrix, const TransformationMatrix& projectionMatrix, Vector<RefPtr<LayerCompositingThread> >& surfaceLayers, float opacity, FloatRect clipRect);
    void compositeLayersRecursive(LayerCompositingThread*, int stencilValue, FloatRect clipRect);
    void updateScissorIfNeeded(const FloatRect& clipRect);

    bool useSurface(LayerRendererSurface*);
    void drawLayersOnSurfaces(const Vector<RefPtr<LayerCompositingThread> >& surfaceLayers);

    void drawDebugBorder(LayerCompositingThread*);
    void drawHolePunchRect(LayerCompositingThread*);

    IntRect toOpenGLWindowCoordinates(const FloatRect&) const;

    bool makeContextCurrent();

    enum ProgramIndex {
        LayerProgramRGBA = LayerData::LayerProgramRGBA,
        LayerProgramBGRA = LayerData::LayerProgramBGRA,

        MaskPrograms,
        LayerMaskProgramRGBA = MaskPrograms + LayerData::LayerProgramRGBA,
        LayerMaskProgramBGRA = MaskPrograms + LayerData::LayerProgramBGRA,

        InternalPrograms,
        ColorProgram = InternalPrograms,

        NumberOfPrograms
    };

    bool createProgram(ProgramIndex);
    const BlackBerry::Platform::Graphics::GLES2Program& useProgram(ProgramIndex);
    const BlackBerry::Platform::Graphics::GLES2Program& useLayerProgram(LayerData::LayerProgram, bool isMask = false);

    LayerRendererClient* m_client;

    BlackBerry::Platform::Graphics::GLES2Program m_programs[NumberOfPrograms];

    // Shader uniform and attribute locations.
#if ENABLE(CSS_FILTERS)
    OwnPtr<LayerFilterRenderer> m_filterRenderer;
#endif

    int m_colorColorLocation;

    // Current draw configuration.
    double m_scale;
    double m_animationTime;
    FloatRect m_visibleRect;
    IntRect m_layoutRect;
    IntSize m_contentsSize;

    IntRect m_viewport; // In render target coordinates
    IntRect m_scissorRect; // In render target coordinates
    FloatRect m_clipRect; // In normalized device coordinates

    unsigned m_fbo;
    LayerRendererSurface* m_currentLayerRendererSurface;

    bool m_hardwareCompositing;

    // Map associating layers with textures ids used by the GL compositor.
    typedef HashSet<LayerCompositingThread*> LayerSet;
    LayerSet m_layers;
    LayerSet m_layersLockingTextureResources;

    bool m_isRobustnessSupported;
    PFNGLGETGRAPHICSRESETSTATUSEXTPROC m_glGetGraphicsResetStatusEXT;

    LayerRenderingResults m_lastRenderingResults;
    bool m_needsCommit;
    bool m_stencilCleared;
};

}

#endif // USE(ACCELERATED_COMPOSITING)

#endif