Add plot-based purging to GrLayerCache

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 63 matching lines @@
 typedef SkTInternalLList<GrPlot> GrPlotList;
 
 class GrAtlas {
 public:
     // This class allows each client to independently track the GrPlots in
     // which its data is stored.
     class ClientPlotUsage {
     public:
         bool isEmpty() const { return 0 == fPlots.count(); }
 
+#ifdef SK_DEBUG
+        bool contains(const GrPlot* plot) const { 
+            return fPlots.contains(const_cast<GrPlot*>(plot)); 
+        }
+#endif
+
     private:
         SkTDArray<GrPlot*> fPlots;
 
         friend class GrAtlas;
     };
 
     GrAtlas(GrGpu*, GrPixelConfig, GrTextureFlags flags, 
             const SkISize& backingTextureSize,
             int numPlotsX, int numPlotsY, bool batchUploads);
     ~GrAtlas();
@@ skipping 11 matching lines @@
     // 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();
 
+    enum IterOrder {
+        kLRUFirst_IterOrder,
+        kMRUFirst_IterOrder
+    };
+
+    typedef GrPlotList::Iter PlotIter;
+    GrPlot* iterInit(PlotIter* iter, IterOrder order) {
+        return iter->init(fPlotList, kLRUFirst_IterOrder == order 
+                                                       ? GrPlotList::Iter::kTail_IterStart
+                                                       : GrPlotList::Iter::kHead_IterStart);
+    }
+
 private:
     void makeMRU(GrPlot* plot);
 
     GrGpu*         fGpu;
     GrPixelConfig  fPixelConfig;
     GrTextureFlags fFlags;
     GrTexture*     fTexture;
     SkISize        fBackingTextureSize;
     int            fNumPlotsX;
     int            fNumPlotsY;
     bool           fBatchUploads;
 
     // allocated array of GrPlots
     GrPlot*       fPlotArray;
     // LRU list of GrPlots (MRU at head - LRU at tail)
     GrPlotList    fPlotList;
 };
 
 #endif