Cache blur mask for rects which can not break into nine-patch

src/core/SkMaskFilter.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkMaskFilter.h"
 #include "SkBlitter.h"
 #include "SkDraw.h"
+#include "SkMaskCache.h"
 #include "SkRasterClip.h"
 #include "SkRRect.h"
 #include "SkTypes.h"
 
 #if SK_SUPPORT_GPU
 #include "GrTexture.h"
 #include "SkGr.h"
 #include "SkGrPixelRef.h"
 #endif
 
@@ skipping 233 matching lines @@
 
     SkMask  srcM, dstM;
 
     if (!SkDraw::DrawToMask(devPath, &clip.getBounds(), this, &matrix, &srcM,
                             SkMask::kComputeBoundsAndRenderImage_CreateMode,
                             style)) {
         return false;
     }
     SkAutoMaskFreeImage autoSrc(srcM.fImage);
 
-    if (!this->filterMask(&dstM, srcM, matrix, NULL)) {
-        return false;
+    BlurRec rec;
+    if (this->asABlur(&rec) && rectCount) {
+        SkScalar scaledSigma = matrix.mapRadius(rec.fSigma);
+        if (!SkMaskCache::FindAndCopy(scaledSigma, rec.fStyle, rec.fQuality,

[reed1, 2015/01/08 15:51:21]

I think it will be easier to read if we change this from 

if (!...

to

if (...

so we can see the code that handles a cache-hit right below the FindAndCopy

[qiankun, 2015/01/12 04:36:26]

Done.

+                                      rects, rectCount, &dstM)) {
+            if (!this->filterMask(&dstM, srcM, matrix, NULL)) {
+                return false;
+            }
+            SkMaskCache::AddAndCopy(scaledSigma, rec.fStyle, rec.fQuality, rects, rectCount, dstM);
+        } else {
+            // Compute the correct bounds of dst mask if dst mask is got from cache.
+            SkMask tmpSrc, tmpDst;
+            tmpSrc = srcM;
+            tmpSrc.fImage = NULL;
+            if (!this->filterMask(&tmpDst, tmpSrc, matrix, NULL)) {
+                return false;
+            }
+
+            // Fallback to original calculation if size of bounds is different with

[reed1, 2015/01/08 15:51:21]

I'm afraid I still don't understand the scenario this is catching. We have a
cache "hit", but we can't use it, so we have to delete the copied answer?

[qiankun, 2015/01/12 04:36:26]

It was used to handle clipping bounds. Now, the new CL don't search the cache
for clipped dst bounds.

+            // size of the cached mask.
+            if (dstM.fBounds.width() != tmpDst.fBounds.width() ||
+                dstM.fBounds.height() != tmpDst.fBounds.height()) {
+                SkMask::FreeImage(dstM.fImage);
+                if (!this->filterMask(&dstM, srcM, matrix, NULL)) {
+                    return false;
+                }
+            } else {
+                dstM.fBounds = tmpDst.fBounds;
+            }
+        }
+    } else {
+        if (!this->filterMask(&dstM, srcM, matrix, NULL)) {
+            return false;
+        }
     }
+
     SkAutoMaskFreeImage autoDst(dstM.fImage);
 
     // if we get here, we need to (possibly) resolve the clip and blitter
     SkAAClipBlitterWrapper wrapper(clip, blitter);
     blitter = wrapper.getBlitter();
 
     SkRegion::Cliperator clipper(wrapper.getRgn(), dstM.fBounds);
 
     if (!clipper.done()) {
         const SkIRect& cr = clipper.rect();
@@ skipping 64 matching lines @@
     srcM.fRowBytes = 0;
     srcM.fFormat = SkMask::kA8_Format;
 
     SkIPoint margin;    // ignored
     if (this->filterMask(&dstM, srcM, SkMatrix::I(), &margin)) {
         dst->set(dstM.fBounds);
     } else {
         dst->set(srcM.fBounds);
     }
 }