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      1 
      2 /*
      3  * Copyright 2010 Google Inc.
      4  *
      5  * Use of this source code is governed by a BSD-style license that can be
      6  * found in the LICENSE file.
      7  */
      8 
      9 #ifndef GrAtlas_DEFINED
     10 #define GrAtlas_DEFINED
     11 
     12 
     13 #include "SkPoint.h"
     14 #include "GrTexture.h"
     15 #include "GrDrawTarget.h"
     16 
     17 class GrGpu;
     18 class GrRectanizer;
     19 class GrAtlasMgr;
     20 class GrAtlas;
     21 
     22 // The backing GrTexture for a set of GrAtlases is broken into a spatial grid of GrPlots. When
     23 // a GrAtlas needs space on the texture, it requests a GrPlot. Each GrAtlas can claim one
     24 // or more GrPlots. The GrPlots keep track of subimage placement via their GrRectanizer. Once a
     25 // GrPlot is "full" (i.e. there is no room for the new subimage according to the GrRectanizer), the
     26 // GrAtlas can request a new GrPlot via GrAtlasMgr::addToAtlas().
     27 //
     28 // If all GrPlots are allocated, the replacement strategy is up to the client. The drawToken is
     29 // available to ensure that all draw calls are finished for that particular GrPlot.
     30 // GrAtlasMgr::removeUnusedPlots() will free up any finished plots for a given GrAtlas.
     31 
     32 class GrPlot {
     33 public:
     34     SK_DECLARE_INTERNAL_LLIST_INTERFACE(GrPlot);
     35 
     36     GrTexture* texture() const { return fTexture; }
     37 
     38     bool addSubImage(int width, int height, const void*, SkIPoint16*);
     39 
     40     GrDrawTarget::DrawToken drawToken() const { return fDrawToken; }
     41     void setDrawToken(GrDrawTarget::DrawToken draw) { fDrawToken = draw; }
     42 
     43     void uploadToTexture();
     44 
     45     void resetRects();
     46 
     47 private:
     48     GrPlot();
     49     ~GrPlot(); // does not try to delete the fNext field
     50     void init(GrAtlasMgr* mgr, int offX, int offY, int width, int height, size_t bpp,
     51               bool batchUploads);
     52 
     53     // for recycling
     54     GrDrawTarget::DrawToken fDrawToken;
     55 
     56     unsigned char*          fPlotData;
     57     GrTexture*              fTexture;
     58     GrRectanizer*           fRects;
     59     GrAtlasMgr*             fAtlasMgr;
     60     SkIPoint16              fOffset;        // the offset of the plot in the backing texture
     61     size_t                  fBytesPerPixel;
     62     SkIRect                 fDirtyRect;
     63     bool                    fDirty;
     64     bool                    fBatchUploads;
     65 
     66     friend class GrAtlasMgr;
     67 };
     68 
     69 typedef SkTInternalLList<GrPlot> GrPlotList;
     70 
     71 class GrAtlasMgr {
     72 public:
     73     GrAtlasMgr(GrGpu*, GrPixelConfig, const SkISize& backingTextureSize,
     74                int numPlotsX, int numPlotsY, bool batchUploads);
     75     ~GrAtlasMgr();
     76 
     77     // add subimage of width, height dimensions to atlas
     78     // returns the containing GrPlot and location relative to the backing texture
     79     GrPlot* addToAtlas(GrAtlas*, int width, int height, const void*, SkIPoint16*);
     80 
     81     // remove reference to this plot
     82     bool removePlot(GrAtlas* atlas, const GrPlot* plot);
     83 
     84     // get a plot that's not being used by the current draw
     85     // this allows us to overwrite this plot without flushing
     86     GrPlot* getUnusedPlot();
     87 
     88     GrTexture* getTexture() const {
     89         return fTexture;
     90     }
     91 
     92     void uploadPlotsToTexture();
     93 
     94 private:
     95     void moveToHead(GrPlot* plot);
     96 
     97     GrGpu*        fGpu;
     98     GrPixelConfig fPixelConfig;
     99     GrTexture*    fTexture;
    100     SkISize       fBackingTextureSize;
    101     int           fNumPlotsX;
    102     int           fNumPlotsY;
    103     bool          fBatchUploads;
    104 
    105     // allocated array of GrPlots
    106     GrPlot*       fPlotArray;
    107     // LRU list of GrPlots
    108     GrPlotList    fPlotList;
    109 };
    110 
    111 class GrAtlas {
    112 public:
    113     GrAtlas() { }
    114     ~GrAtlas() { }
    115 
    116     bool isEmpty() { return 0 == fPlots.count(); }
    117 
    118 private:
    119     SkTDArray<GrPlot*> fPlots;
    120 
    121     friend class GrAtlasMgr;
    122 };
    123 
    124 #endif
    125