Begin atlasing

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
 
+#define USE_ATLAS 0
+
 #include "GrAllocPool.h"
 #include "GrAtlas.h"
 #include "GrTHashTable.h"
 #include "GrPictureUtils.h"
 #include "GrRect.h"
 
 class GrGpu;
 class SkPicture;
 
-// GrAtlasLocation captures an atlased item's position in the atlas. This
-// means the plot in which it resides and its bounds inside the plot.
-// TODO: Make GrGlyph use one of these?
-class GrAtlasLocation {
-public:
-    GrAtlasLocation() : fPlot(NULL) {}
-
-    void set(GrPlot* plot, const GrIRect16& bounds) {
-        fPlot = plot;
-        fBounds = bounds;
-    }
-
-    const GrPlot* plot() const {
-        return fPlot;
-    }
-
-    const GrIRect16& bounds() const {
-        return fBounds;
-    }
-
-private:
-    GrPlot*   fPlot;
-    GrIRect16 fBounds;  // only valid is fPlot != NULL
-};
-
 // GrCachedLayer encapsulates the caching information for a single saveLayer.
 //
-// Atlased layers get a ref to their atlas GrTexture and their GrAtlasLocation
-// is filled in.
-// In this case GrCachedLayer is roughly equivalent to a GrGlyph in the font
-// caching system.
+// Atlased layers get a ref to their atlas GrTexture and 'fRect' contains
+// their absolute location in the backing texture.
 //
-// Non-atlased layers get a ref to the GrTexture in which they reside.
+// Non-atlased layers get a ref to the GrTexture in which they reside. Their
+// 'fRect' will be empty.
+//
 // TODO: can we easily reuse the empty space in the non-atlased GrTexture's?
 struct GrCachedLayer {
 public:
+    GrCachedLayer(uint32_t pictureID, int layerID) {
+        fPictureID = pictureID;
+        fLayerID = layerID;
+        fTexture = NULL;
+        fRect = GrIRect16::MakeEmpty();
+    }
+
     uint32_t pictureID() const { return fPictureID; }
     int layerID() const { return fLayerID; }
 
-    void init(uint32_t pictureID, int layerID) {
-        fPictureID = pictureID;
-        fLayerID   = layerID;
-        fTexture   = NULL;
-        fLocation.set(NULL, GrIRect16::MakeEmpty());
-    }
-
     // This call takes over the caller's ref
-    void setTexture(GrTexture* texture) {
+    void setTexture(GrTexture* texture, const GrIRect16& rect) {
         if (NULL != fTexture) {
             fTexture->unref();
         }
 
         fTexture = texture; // just take over caller's ref
+        fRect = rect;
     }
-    GrTexture* getTexture() { return fTexture; }
+    GrTexture* texture() { return fTexture; }
+    const GrIRect16& rect() const { return fRect; }
 
 private:
     uint32_t        fPictureID;
     // fLayerID is only valid when fPicture != kInvalidGenID in which case it
     // is the index of this layer in the picture (one of 0 .. #layers).
     int             fLayerID;
 
     // fTexture is a ref on the atlasing texture for atlased layers and a
     // ref on a GrTexture for non-atlased textures. In both cases, if this is
     // non-NULL, that means that the texture is locked in the texture cache.
     GrTexture*      fTexture;
 
-    GrAtlasLocation fLocation;       // only valid if the layer is atlased
+    // For non-atlased layers 'fRect' is empty otherwise it is the bound of
+    // the layer in the atlas.
+    GrIRect16       fRect;
 };
 
 // The GrLayerCache caches pre-computed saveLayers for later rendering.
 // Non-atlased layers are stored in their own GrTexture while the atlased
 // layers share a single GrTexture.
 // Unlike the GrFontCache, the GrTexture atlas only has one GrAtlas (for 8888)
 // and one GrPlot (for the entire atlas). As such, the GrLayerCache
 // roughly combines the functionality of the GrFontCache and GrTextStrike
 // classes.
 class GrLayerCache {
@@ skipping 10 matching lines @@
     
     // Inform the cache that layer's cached image is now required. Return true
     // if it was found in the ResourceCache and doesn't need to be regenerated.
     // If false is returned the caller should (re)render the layer into the
     // newly acquired texture.
     bool lock(GrCachedLayer* layer, const GrTextureDesc& desc);
 
     // Inform the cache that layer's cached image is not currently required
     void unlock(GrCachedLayer* layer);
 
+    // Remove all the layers (and unlock any resources) associated with 'picture'
+    void purge(const SkPicture* picture);
+
 private:
     GrContext*                fContext;  // pointer back to owning context
     SkAutoTDelete<GrAtlas>    fAtlas;    // TODO: could lazily allocate
     GrAtlas::ClientPlotUsage  fPlotUsage;
 
     class PictureLayerKey;
     GrTHashTable<GrCachedLayer, PictureLayerKey, 7> fLayerHash;
-    GrTAllocPool<GrCachedLayer> fLayerPool;
 
-    void init();
+    void initAtlas();
     GrCachedLayer* createLayer(const SkPicture* picture, int layerID);
+
+    // for testing
+    friend class GetNumLayers;
+    int numLayers() const { return fLayerHash.count(); }
 };
 
 #endif