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      1 /*
      2  * Copyright 2011, The Android Open Source Project
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  *  * Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  *  * Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  *
     13  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
     14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     15  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     16  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
     17  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
     18  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
     19  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
     20  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
     21  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     23  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     24  */
     25 
     26 #ifndef SurfaceBacking_h
     27 #define SurfaceBacking_h
     28 
     29 #include "SkRefCnt.h"
     30 #include "TileGrid.h"
     31 
     32 namespace WebCore {
     33 
     34 class LayerAndroid;
     35 class TexturesResult;
     36 class TilePainter;
     37 
     38 class SurfaceBacking : public SkRefCnt {
     39 // TODO: investigate webkit threadsafe ref counting
     40 public:
     41     SurfaceBacking(bool isBaseSurface);
     42     ~SurfaceBacking();
     43     void prepareGL(GLWebViewState* state, float maxZoomScale,
     44                    const IntRect& prepareArea, const IntRect& fullContentArea,
     45                    TilePainter* painter, bool aggressiveRendering,
     46                    bool updateWithBlit);
     47     bool swapTiles();
     48     void drawGL(const IntRect& visibleContentArea, float opacity,
     49                 const TransformationMatrix* transform, bool aggressiveRendering,
     50                 const Color* background);
     51     void markAsDirty(const SkRegion& dirtyArea);
     52     void computeTexturesAmount(TexturesResult* result,
     53                                const IntRect& visibleContentArea,
     54                                const IntRect& fullContentArea,
     55                                LayerAndroid* layer);
     56     void discardTextures()
     57     {
     58         m_frontTileGrid->discardTextures();
     59         m_backTileGrid->discardTextures();
     60     }
     61     bool isReady()
     62     {
     63         return !m_zooming && m_frontTileGrid->isReady() && m_scale > 0;
     64     }
     65 
     66     bool isDirty()
     67     {
     68         return m_frontTileGrid->isDirty();
     69     }
     70 
     71     bool isMissingContent()
     72     {
     73         return m_zooming || m_frontTileGrid->isMissingContent();
     74     }
     75 
     76     int nbTextures(IntRect& area, float scale)
     77     {
     78         // TODO: consider the zooming case for the backTileGrid
     79         if (!m_frontTileGrid)
     80             return 0;
     81         return m_frontTileGrid->nbTextures(area, scale);
     82     }
     83 
     84 private:
     85     void swapTileGrids();
     86 
     87     // Delay before we schedule a new tile at the new scale factor
     88     static const double s_zoomUpdateDelay = 0.1; // 100 ms
     89 
     90     TileGrid* m_frontTileGrid;
     91     TileGrid* m_backTileGrid;
     92     TileGrid* m_lowResTileGrid;
     93 
     94     float m_scale;
     95     float m_futureScale;
     96     double m_zoomUpdateTime;
     97     bool m_zooming;
     98     float m_maxZoomScale;
     99 };
    100 
    101 } // namespace WebCore
    102 
    103 #endif // SurfaceBacking_h
    104