Add CPU backing store for GrAtlas to reduce texture uploads

src/gpu/GrAtlas.h

 
 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrAtlas_DEFINED
 #define GrAtlas_DEFINED
@@ skipping 22 matching lines @@
 public:
     SK_DECLARE_INTERNAL_LLIST_INTERFACE(GrPlot);
 
     GrTexture* texture() const { return fTexture; }
 
     bool addSubImage(int width, int height, const void*, GrIPoint16*);
 
     GrDrawTarget::DrawToken drawToken() const { return fDrawToken; }
     void setDrawToken(GrDrawTarget::DrawToken draw) { fDrawToken = draw; }
 
+    void uploadToTexture();
+
     void resetRects();
 
 private:
     GrPlot();
     ~GrPlot(); // does not try to delete the fNext field
     void init(GrAtlasMgr* mgr, int offX, int offY, int width, int height, size_t bpp);
 
     // for recycling
     GrDrawTarget::DrawToken fDrawToken;
 
+    unsigned char*          fPlotData;
     GrTexture*              fTexture;
     GrRectanizer*           fRects;
     GrAtlasMgr*             fAtlasMgr;
     GrIPoint16              fOffset;        // the offset of the plot in the backing texture
     size_t                  fBytesPerPixel;
+    SkIRect                 fDirtyRect;
+    bool                    fDirty;
 
     friend class GrAtlasMgr;
 };
 
 typedef SkTInternalLList<GrPlot> GrPlotList;
 
 class GrAtlasMgr {
 public:
     GrAtlasMgr(GrGpu*, GrPixelConfig, const SkISize& backingTextureSize,
                int numPlotsX, int numPlotsY);
     ~GrAtlasMgr();
 
     // add subimage of width, height dimensions to atlas
     // returns the containing GrPlot and location relative to the backing texture
     GrPlot* addToAtlas(GrAtlas*, int width, int height, const void*, GrIPoint16*);
 
     // remove reference to this plot
     bool removePlot(GrAtlas* atlas, const GrPlot* plot);
 
     // get a plot that's not being used by the current draw
     // this allows us to overwrite this plot without flushing
     GrPlot* getUnusedPlot();
 
     GrTexture* getTexture() const {
         return fTexture;
     }
 
+    void uploadPlotsToTexture();
+
 private:
     void moveToHead(GrPlot* plot);
 
     GrGpu*        fGpu;
     GrPixelConfig fPixelConfig;
     GrTexture*    fTexture;
     SkISize       fBackingTextureSize;
     int           fNumPlotsX;
     int           fNumPlotsY;
 
@@ skipping 10 matching lines @@
 
     bool isEmpty() { return 0 == fPlots.count(); }
 
 private:
     SkTDArray<GrPlot*> fPlots;
 
     friend class GrAtlasMgr;
 };
 
 #endif