Move offset and CTM from LayerCache Key to per-hoisted-layer info

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 SkIPoint& offset, const SkMatrix& ctm) 
+        // TODO: the key needs to include the clip
+        Key(uint32_t pictureID, int start, const SkMatrix& ctm) 
         : fPictureID(pictureID)
-        , fStart(start)
-        , fStop(stop)
-        , fOffset(offset)
-        , fCTM(ctm) {
-            fCTM.getType(); // force initialization of type so hashes match
-
+        , fStart(start) {
+            fCTM[0] = ctm.getScaleX();
+            fCTM[1] = ctm.getSkewX();
+            fCTM[2] = ctm.getSkewY();
+            fCTM[3] = ctm.getScaleY();
             // 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));
+            GR_STATIC_ASSERT(sizeof(Key) == sizeof(uint32_t) +      // picture ID
+                                            sizeof(int) +           // start index
+                                            4 * sizeof(SkScalar));  // 2x2 from CTM
         }
 
         bool operator==(const Key& other) const {
             return fPictureID == other.fPictureID &&
                    fStart == other.fStart &&
-                   fStop == other.fStop &&
-                   fOffset == other.fOffset &&
-                   fCTM.cheapEqualTo(other.fCTM);
+                   0 == memcmp(fCTM, other.fCTM, sizeof(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
+        // The the index of the saveLayer command in the picture
         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;
+        // The 2x2 portion of the CTM applied to this layer in the picture
+        SkScalar       fCTM[4];
     };
 
     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 SkIPoint& offset, const SkMatrix& ctm,
-                  const SkPaint* paint)
-        : fKey(pictureID, start, stop, offset, ctm)
+                  const SkMatrix& ctm, const SkPaint* paint)
+        : fKey(pictureID, start, ctm)
+        , fStop(stop)
         , fPaint(paint ? SkNEW_ARGS(SkPaint, (*paint)) : NULL)
         , fTexture(NULL)
         , fRect(GrIRect16::MakeEmpty())
         , fPlot(NULL)
         , fLocked(false) {
         SkASSERT(SK_InvalidGenID != pictureID && start >= 0 && stop >= 0);
     }
 
     ~GrCachedLayer() {
         SkSafeUnref(fTexture);
         SkDELETE(fPaint);
     }
 
     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(); }
 
+    int stop() const { return fStop; }
     void setTexture(GrTexture* texture, const GrIRect16& rect) {
         SkRefCnt_SafeAssign(fTexture, texture);
         fRect = rect;
     }
     GrTexture* texture() { return fTexture; }
     const SkPaint* paint() const { return fPaint; }
     const GrIRect16& rect() const { return fRect; }
 
     void setPlot(GrPlot* plot) {
         SkASSERT(NULL == plot || NULL == fPlot);
         fPlot = plot;
     }
     GrPlot* plot() { return fPlot; }
 
     bool isAtlased() const { return SkToBool(fPlot); }
 
     void setLocked(bool locked) { fLocked = locked; }
     bool locked() const { return fLocked; }
 
     SkDEBUGCODE(const GrPlot* plot() const { return fPlot; })
     SkDEBUGCODE(void validate(const GrTexture* backingTexture) const;)
 
 private:
     const Key       fKey;
 
+    // The final "restore" operation index of the cached layer
+    const int       fStop;
+
     // The paint used when dropping the layer down into the owning canvas.
     // Can be NULL. This class makes a copy for itself.
     const SkPaint*  fPaint;
 
     // fTexture is a ref on the atlasing texture for atlased layers and a
     // ref on a GrTexture for non-atlased textures.
     GrTexture*      fTexture;
 
     // For both atlased and non-atlased layers 'fRect' contains the  bound of
     // the layer in whichever texture it resides. It is empty when 'fTexture'
@@ skipping 22 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 SkIPoint& offset, const SkMatrix& ctm);
+    GrCachedLayer* findLayer(uint32_t pictureID, int start, const SkMatrix& ctm);
     GrCachedLayer* findLayerOrCreate(uint32_t pictureID,
                                      int start, int stop, 
-                                     const SkIPoint& offset,
                                      const SkMatrix& ctm,
                                      const SkPaint* paint);
 
     // 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 35 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 SkIPoint& offset, const SkMatrix& ctm,
-                               const SkPaint* paint);
+                               const SkMatrix& ctm, const SkPaint* paint);
 
     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