Fix bug in layer hoisting transition to SkRecord backend

src/gpu/GrLayerCache.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrLayerCache_DEFINED
 #define GrLayerCache_DEFINED
 
@@ skipping 33 matching lines @@
 // get a ref to the GrTexture in which they reside. In both cases 'fRect' 
 // contains the layer's extent in its texture.
 // Atlased layers also get a pointer to the plot in which they reside.
 // For non-atlased layers, the lock field just corresponds to locking in
 // the resource cache. For atlased layers, it implements an additional level
 // of locking to allow atlased layers to be reused multiple times.
 struct GrCachedLayer {
 public:
     // For SkTDynamicHash
     struct Key {
-        Key(uint32_t pictureID, int start, int stop, const SkMatrix& ctm) 
+        Key(uint32_t pictureID, int start, int stop, const SkIPoint& offset, const SkMatrix& ctm) 
         : fPictureID(pictureID)
         , fStart(start)
         , fStop(stop)
+        , fOffset(offset)
         , fCTM(ctm) {
             fCTM.getType(); // force initialization of type so hashes match
 
             // Key needs to be tightly packed.
             GR_STATIC_ASSERT(sizeof(Key) == sizeof(uint32_t) + 2 * sizeof(int) + 
+                                            2 * sizeof(int32_t) +
                                             9 * sizeof(SkScalar) + sizeof(uint32_t));
         }
 
         bool operator==(const Key& other) const {
             return fPictureID == other.fPictureID &&
                    fStart == other.fStart &&
                    fStop == other.fStop &&
+                   fOffset == other.fOffset &&
                    fCTM.cheapEqualTo(other.fCTM);
         }
 
         uint32_t pictureID() const { return fPictureID; }
         int start() const { return fStart; }
         int stop() const { return fStop; }
+        const SkIPoint& offset() const { return fOffset; }
         const SkMatrix& ctm() const { return fCTM; }
 
     private:
         // ID of the picture of which this layer is a part
         const uint32_t fPictureID;
         // The range of commands in the picture this layer represents
         const int      fStart;
         const int      fStop;
+        // The offset of the layer in device space
+        const SkIPoint fOffset;
         // The CTM applied to this layer in the picture
         SkMatrix       fCTM;
     };
 
     static const Key& GetKey(const GrCachedLayer& layer) { return layer.fKey; }
     static uint32_t Hash(const Key& key) { 
         return SkChecksum::Murmur3(reinterpret_cast<const uint32_t*>(&key), sizeof(Key));
     }
 
     // GrCachedLayer proper
-    GrCachedLayer(uint32_t pictureID, int start, int stop, const SkMatrix& ctm) 
-        : fKey(pictureID, start, stop, ctm)
+    GrCachedLayer(uint32_t pictureID, int start, int stop,
+                  const SkIPoint& offset, const SkMatrix& ctm) 
+        : fKey(pictureID, start, stop, offset, ctm)
         , fTexture(NULL)
         , fRect(GrIRect16::MakeEmpty())
         , fPlot(NULL)
         , fLocked(false) {
         SkASSERT(SK_InvalidGenID != pictureID && start >= 0 && stop >= 0);
     }
 
     ~GrCachedLayer() {
         SkSafeUnref(fTexture);
     }
 
     uint32_t pictureID() const { return fKey.pictureID(); }
     int start() const { return fKey.start(); }
     int stop() const { return fKey.stop(); }
+    const SkIPoint& offset() const { return fKey.offset(); }
     const SkMatrix& ctm() const { return fKey.ctm(); }
 
     void setTexture(GrTexture* texture, const GrIRect16& rect) {
         SkRefCnt_SafeAssign(fTexture, texture);
         fRect = rect;
     }
     GrTexture* texture() { return fTexture; }
     const GrIRect16& rect() const { return fRect; }
 
     void setPlot(GrPlot* plot) {
@@ skipping 44 matching lines @@
 // classes.
 class GrLayerCache {
 public:
     GrLayerCache(GrContext*);
     ~GrLayerCache();
 
     // As a cache, the GrLayerCache can be ordered to free up all its cached
     // elements by the GrContext
     void freeAll();
 
-    GrCachedLayer* findLayer(uint32_t pictureID, int start, int stop, const SkMatrix& ctm);
+    GrCachedLayer* findLayer(uint32_t pictureID, int start, int stop, 
+                             const SkIPoint& offset, const SkMatrix& ctm);
     GrCachedLayer* findLayerOrCreate(uint32_t pictureID,
                                      int start, int stop, 
+                                     const SkIPoint& offset,
                                      const SkMatrix& ctm);
 
     // Inform the cache that layer's cached image is now required. 
     // Return true if the layer must be re-rendered. Return false if the
     // layer was found in the cache and can be reused.
     bool lock(GrCachedLayer* layer, const GrTextureDesc& desc, bool dontAtlas);
 
     // Inform the cache that layer's cached image is not currently required
     void unlock(GrCachedLayer* layer);
 
@@ skipping 33 matching lines @@
 
     // This implements a plot-centric locking mechanism (since the atlas
     // backing texture is always locked). Each layer that is locked (i.e.,
     // needed for the current rendering) in a plot increments the plot lock
     // count for that plot. Similarly, once a rendering is complete all the
     // layers used in it decrement the lock count for the used plots.
     // Plots with a 0 lock count are open for recycling/purging.
     int fPlotLocks[kNumPlotsX * kNumPlotsY];
 
     void initAtlas();
-    GrCachedLayer* createLayer(uint32_t pictureID, int start, int stop, const SkMatrix& ctm);
+    GrCachedLayer* createLayer(uint32_t pictureID, int start, int stop, 
+                               const SkIPoint& offset, const SkMatrix& ctm);
 
-public:
     void purgeAll();
 
     // Remove all the layers (and unlock any resources) associated with 'pictureID'
     void purge(uint32_t pictureID);
 
     static bool PlausiblyAtlasable(int width, int height) {
         return width <= kPlotWidth && height <= kPlotHeight;
     }
 
     void purgePlot(GrPlot* plot);
 
     // Try to find a purgeable plot and clear it out. Return true if a plot
     // was purged; false otherwise.
     bool purgePlot();
 
     // for testing
     friend class TestingAccess;
     int numLayers() const { return fLayerHash.count(); }
 };
 
 #endif