Cache the GrEffect used for text rendering in GrBitmapTextContext.

R=jvanverth@google.com

Author: bsalomon@google.com

Review URL: https://codereview.chromium.org/338093005

gyp/gpu.gypi

@@ -58,6 +58,7 @@
       '<(skia_src_path)/gpu/GrBlend.h',
       '<(skia_src_path)/gpu/GrBufferAllocPool.cpp',
       '<(skia_src_path)/gpu/GrBufferAllocPool.h',
+      '<(skia_src_path)/gpu/GrCacheable.cpp',
       '<(skia_src_path)/gpu/GrCacheID.cpp',
       '<(skia_src_path)/gpu/GrClipData.cpp',
       '<(skia_src_path)/gpu/GrContext.cpp',

include/gpu/GrCacheable.h

@@ -41,8 +41,17 @@ public:
     void setCacheEntry(GrResourceCacheEntry* cacheEntry) { fCacheEntry = cacheEntry; }
     GrResourceCacheEntry* getCacheEntry() { return fCacheEntry; }
 
+    /**
+     * Gets an id that is unique for this GrCacheable object. It is static in that it does
+     * not change when the content of the GrCacheable object changes. This will never return
+     * 0.
+     */
+    uint32_t getGenerationID() const;
+
 protected:
-    GrCacheable() : fCacheEntry(NULL) {}
+    GrCacheable()
+        : fCacheEntry(NULL)
+        , fGenID(0) {}
 
     bool isInCache() const { return NULL != fCacheEntry; }
 
@@ -55,7 +64,8 @@ protected:
     void didChangeGpuMemorySize() const;
 
 private:
-    GrResourceCacheEntry* fCacheEntry;  // NULL if not in cache
+    GrResourceCacheEntry*   fCacheEntry;  // NULL if not in cache
+    mutable uint32_t        fGenID;
 
     typedef SkRefCnt INHERITED;
 };

src/gpu/GrBitmapTextContext.cpp

@@ -56,6 +56,7 @@ GrBitmapTextContext::GrBitmapTextContext(GrContext* context,
 
     fCurrTexture = NULL;
     fCurrVertex = 0;
+    fEffectTextureGenID = 0;
 
     fVertices = NULL;
     fMaxVertices = 0;
@@ -93,12 +94,17 @@ void GrBitmapTextContext::flushGlyphs() {
         SkASSERT(fCurrTexture);
         GrTextureParams params(SkShader::kRepeat_TileMode, GrTextureParams::kNone_FilterMode);
 
+        uint32_t textureGenID = fCurrTexture->getGenerationID();
+        
+        if (textureGenID != fEffectTextureGenID) {
+            fCachedEffect.reset(GrCustomCoordsTextureEffect::Create(fCurrTexture, params));
+            fEffectTextureGenID = textureGenID;
+        }
+
         // This effect could be stored with one of the cache objects (atlas?)
         int coordsIdx = drawState->hasColorVertexAttribute() ? kGlyphCoordsWithColorAttributeIndex :
                                                                kGlyphCoordsNoColorAttributeIndex;
-        drawState->addCoverageEffect(
-                                GrCustomCoordsTextureEffect::Create(fCurrTexture, params),
-                                coordsIdx)->unref();
+        drawState->addCoverageEffect(fCachedEffect.get(), coordsIdx);
         SkASSERT(NULL != fStrike);
         switch (fStrike->getMaskFormat()) {
             // Color bitmap text

src/gpu/GrBitmapTextContext.h

@@ -45,11 +45,13 @@ private:
         kDefaultRequestedVerts   = kDefaultRequestedGlyphs * 4,
     };
 
-    void*                   fVertices;
-    int32_t                 fMaxVertices;
-    GrTexture*              fCurrTexture;
-    int                     fCurrVertex;
-    SkRect                  fVertexBounds;
+    void*                       fVertices;
+    int32_t                     fMaxVertices;
+    GrTexture*                  fCurrTexture;
+    SkAutoTUnref<GrEffectRef>   fCachedEffect;
+    uint32_t                    fEffectTextureGenID;
+    int                         fCurrVertex;
+    SkRect                      fVertexBounds;
 };
 
 #endif

src/gpu/GrCacheable.cpp

@@ -0,0 +1,17 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#include "GrCacheable.h"
+
+uint32_t GrCacheable::getGenerationID() const {
+    static int32_t gPathRefGenerationID;
+    while (!fGenID) {
+        fGenID = static_cast<uint32_t>(sk_atomic_inc(&gPathRefGenerationID) + 1);
+    }
+    return fGenID;
+}