Implement a persistent uniqueID-based cache for SkImageFilter.

src/gpu/SkGpuDevice.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkGpuDevice.h"
 
 #include "effects/GrBicubicEffect.h"
@@ skipping 22 matching lines @@
 #include "SkPictureRangePlayback.h"
 #include "SkPictureReplacementPlayback.h"
 #include "SkRRect.h"
 #include "SkStroke.h"
 #include "SkSurface.h"
 #include "SkTLazy.h"
 #include "SkUtils.h"
 #include "SkVertState.h"
 #include "SkErrorInternals.h"
 
+enum { kDefaultImageFilterCacheSize = 32 * 1024 * 1024 };
+
 #define CACHE_COMPATIBLE_DEVICE_TEXTURES 1
 
 #if 0
     extern bool (*gShouldDrawProc)();
     #define CHECK_SHOULD_DRAW(draw, forceI)                     \
         do {                                                    \
             if (gShouldDrawProc && !gShouldDrawProc()) return;  \
             this->prepareDraw(draw, forceI);                    \
         } while (0)
 #else
@@ skipping 1364 matching lines @@
 
     SkImageFilter* filter = paint.getImageFilter();
     // This bitmap will own the filtered result as a texture.
     SkBitmap filteredBitmap;
 
     if (NULL != filter) {
         SkIPoint offset = SkIPoint::Make(0, 0);
         SkMatrix matrix(*draw.fMatrix);
         matrix.postTranslate(SkIntToScalar(-left), SkIntToScalar(-top));
         SkIRect clipBounds = SkIRect::MakeWH(bitmap.width(), bitmap.height());
-        SkImageFilter::Cache* cache = SkImageFilter::Cache::Create();
-        SkAutoUnref aur(cache);
+        SkAutoTUnref<SkImageFilter::GenIDCache> cache(getImageFilterCache());

[bsalomon, 2014/07/25 14:11:58]

A comment here about tossing the textures after filtering is completed?

[Stephen White, 2014/07/25 17:34:17]

Done. Also done in SkGpuDevice::drawDevice(), which I realized was 
not properly unref'ing it (whoops).

Note that SkCanvas::internalDrawDevice() also does this in the GPU 
case, but not in the CPU case (which gets a ref on the singleton
instead).

         SkImageFilter::Context ctx(matrix, clipBounds, cache);
         if (filter_texture(this, fContext, texture, filter, w, h, ctx, &filteredBitmap,
                            &offset)) {
             texture = (GrTexture*) filteredBitmap.getTexture();
             w = filteredBitmap.width();
             h = filteredBitmap.height();
             left += offset.x();
             top += offset.y();
         } else {
             return;
@@ skipping 88 matching lines @@
 
     SkImageFilter* filter = paint.getImageFilter();
     // This bitmap will own the filtered result as a texture.
     SkBitmap filteredBitmap;
 
     if (NULL != filter) {
         SkIPoint offset = SkIPoint::Make(0, 0);
         SkMatrix matrix(*draw.fMatrix);
         matrix.postTranslate(SkIntToScalar(-x), SkIntToScalar(-y));
         SkIRect clipBounds = SkIRect::MakeWH(devTex->width(), devTex->height());
-        SkImageFilter::Cache* cache = SkImageFilter::Cache::Create();
-        SkAutoUnref aur(cache);
-        SkImageFilter::Context ctx(matrix, clipBounds, cache);
+        SkImageFilter::Context ctx(matrix, clipBounds, getImageFilterCache());
         if (filter_texture(this, fContext, devTex, filter, w, h, ctx, &filteredBitmap,
                            &offset)) {
             devTex = filteredBitmap.getTexture();
             w = filteredBitmap.width();
             h = filteredBitmap.height();
             x += offset.fX;
             y += offset.fY;
         } else {
             return;
         }
@@ skipping 501 matching lines @@
     playback.draw(canvas, NULL);
 
     // unlock the layers
     for (int i = 0; i < gpuData->numSaveLayers(); ++i) {
         GrCachedLayer* layer = fContext->getLayerCache()->findLayer(picture, i);
         fContext->getLayerCache()->unlock(layer);
     }
 
     return true;
 }
+
+SkImageFilter::GenIDCache* SkGpuDevice::getImageFilterCache() {
+    // We always return a transient cache, so it is freed after each
+    // filter traversal.
+    return SkImageFilter::GenIDCache::Create(kDefaultImageFilterCacheSize);
+}