Creation of GrBatchAtlas and Distancefieldpathrenderer batch

src/gpu/GrBatchAtlas.h

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrBatchAtlas_DEFINED
+#define GrBatchAtlas_DEFINED
+
+#include "GrTexture.h"
+#include "SkPoint.h"
+#include "SkTDArray.h"
+#include "SkTInternalLList.h"
+
+class BatchPlot;
+class GrBatchTarget;
+class GrRectanizer;
+
+typedef SkTInternalLList<BatchPlot> GrBatchPlotList;
+
+class GrBatchAtlas {
+public:
+    typedef uint64_t BatchToken;
+    // An AtlasID is an opaque handle which callers can use to determine if the atlas contains
+    // a specific piece of data
+    typedef uint32_t AtlasID;
+
+    // A function pointer for use as a callback during eviction.  Whenever GrBatchAtlas evicts a
+    // specific AtlasID, it will call all of the registered listeners so they can optionally process
+    // the eviction
+    typedef void (*EvictionFunc)(GrBatchAtlas::AtlasID, void*);
+
+    GrBatchAtlas(GrTexture*, int numPlotsX, int numPlotsY);
+    ~GrBatchAtlas();
+
+    // Adds a width x height subimage to the atlas. Upon success it returns
+    // the containing GrPlot and absolute location in the backing texture.
+    // NULL is returned if the subimage cannot fit in the atlas.
+    // If provided, the image data will be written to the CPU-side backing bitmap.
+    bool addToAtlas(AtlasID*, GrBatchTarget*, int width, int height, const void* image,
+                    SkIPoint16* loc);
+
+    GrTexture* getTexture() const { return fTexture; }
+
+    bool hasID(AtlasID id);
+    void setLastRefToken(AtlasID id, BatchToken batchToken);
+    void registerEvictionCallback(EvictionFunc func, void* userData) {
+        EvictionData* data = fEvictionCallbacks.append();
+        data->fFunc = func;
+        data->fData = userData;
+    }
+
+private:
+    int getIndexFromID(AtlasID id) {
+        return id & 0xffff;
+    }
+
+    int getGenerationFromID(AtlasID id) {
+        return (id >> 16) & 0xffff;
+    }
+
+    inline void updatePlot(GrBatchTarget*, AtlasID*, BatchPlot*);
+
+    inline void makeMRU(BatchPlot* plot);
+
+    inline void processEviction(AtlasID);
+
+    GrTexture* fTexture;
+    int fNumPlotsX;
+    int fNumPlotsY;
+    int fPlotWidth;
+    int fPlotHeight;
+    size_t fBPP;
+
+    struct EvictionData {
+        EvictionFunc fFunc;
+        void* fData;
+    };
+
+    SkTDArray<EvictionData> fEvictionCallbacks;
+    // allocated array of GrBatchPlots
+    SkAutoTUnref<BatchPlot>* fPlotArray;
+    // LRU list of GrPlots (MRU at head - LRU at tail)
+    GrBatchPlotList fPlotList;
+};
+
+#endif