Optimize CSS box-shadow performance

src/effects/SkBlurMaskFilter.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 "SkBlurMaskFilter.h"
 #include "SkBlurMask.h"
 #include "SkGpuBlurUtils.h"
 #include "SkReadBuffer.h"
 #include "SkWriteBuffer.h"
+#include "SkMaskCache.h"
 #include "SkMaskFilter.h"
 #include "SkRRect.h"
 #include "SkRTConf.h"
 #include "SkStringUtils.h"
 #include "SkStrokeRec.h"
 
 #if SK_SUPPORT_GPU
 #include "GrContext.h"
 #include "GrTexture.h"
 #include "GrEffect.h"
@@ skipping 35 matching lines @@
     virtual bool filterMaskGPU(GrTexture* src,
                                const SkMatrix& ctm,
                                const SkRect& maskRect,
                                GrTexture** result,
                                bool canOverwriteSrc) const SK_OVERRIDE;
 #endif
 
     virtual void computeFastBounds(const SkRect&, SkRect*) const SK_OVERRIDE;
     virtual bool asABlur(BlurRec*) const SK_OVERRIDE;
 
+    static bool getCachedBlurMask(SkScalar sigma,
+                                  unsigned rectCount,
+                                  const SkRect rects[],
+                                  SkCachedMask &mask);
+    static bool getCachedBlurMask(SkScalar sigma,
+                                  const SkRRect rrect,
+                                  SkCachedMask &mask);
+
     SK_TO_STRING_OVERRIDE()
     SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkBlurMaskFilterImpl)
 
 protected:
     virtual FilterReturn filterRectsToNine(const SkRect[], int count, const SkMatrix&,
                                            const SkIRect& clipBounds,
                                            NinePatch*) const SK_OVERRIDE;
 
     virtual FilterReturn filterRRectToNine(const SkRRect&, const SkMatrix&,
                                            const SkIRect& clipBounds,
@@ skipping 29 matching lines @@
         return SkMinScalar(xformedSigma, kMAX_BLUR_SIGMA);
     }
 
     friend class SkBlurMaskFilter;
 
     typedef SkMaskFilter INHERITED;
 };
 
 const SkScalar SkBlurMaskFilterImpl::kMAX_BLUR_SIGMA = SkIntToScalar(128);
 
+bool SkBlurMaskFilterImpl::getCachedBlurMask(SkScalar sigma,

[reed1, 2014/08/25 11:58:42]

Do we really need these helper methods? The caller has to track the cacheID and
remember to unlock it anway, so I think it may be clearer to just have them call
FindAndLock.

[qiankun, 2014/08/26 08:36:33]

Done.

+                                             const SkRRect rrect,
+                                             SkCachedMask &mask) {

[reed1, 2014/08/25 11:58:42]

skia's convention is to only use reference-parameters when they are const (with
the one exception of ReadBuffer). Please pass mask as a ptr.

[qiankun, 2014/08/26 08:36:33]

Done.

+    SkMaskCache::ID* cacheId = SkMaskCache::FindAndLock(sigma, rrect, &mask.fMask);
+    mask.fCacheId = cacheId;

[reed1, 2014/08/25 11:58:42]

Skia's convention is to not set the result fields if we're going to return
false. e.g. mask.fMask should also not be modified if this fails.

[qiankun, 2014/08/26 08:36:33]

Done.

+    return cacheId ? true : false;
+}
+
+bool SkBlurMaskFilterImpl::getCachedBlurMask(SkScalar sigma,
+                                             unsigned rectCount,
+                                             const SkRect rects[],
+                                             SkCachedMask &mask) {
+    SkMaskCache::ID* cacheId = SkMaskCache::FindAndLock(sigma, rectCount, rects, &mask.fMask);
+    mask.fCacheId = cacheId;
+    return cacheId ? true : false;
+}
+
 SkMaskFilter* SkBlurMaskFilter::Create(SkBlurStyle style, SkScalar sigma, uint32_t flags) {
     if (!SkScalarIsFinite(sigma) || sigma <= 0) {
         return NULL;
     }
     if ((unsigned)style > (unsigned)kLastEnum_SkBlurStyle) {
         return NULL;
     }
     if (flags > SkBlurMaskFilter::kAll_BlurFlag) {
         return NULL;
     }
@@ skipping 233 matching lines @@
     SkRect smallR = SkRect::MakeWH(totalSmallWidth, totalSmallHeight);
 
     SkRRect smallRR;
     SkVector radii[4];
     radii[SkRRect::kUpperLeft_Corner] = UL;
     radii[SkRRect::kUpperRight_Corner] = UR;
     radii[SkRRect::kLowerRight_Corner] = LR;
     radii[SkRRect::kLowerLeft_Corner] = LL;
     smallRR.setRectRadii(smallR, radii);
 
+    SkScalar sigma = this->computeXformedSigma(matrix);
+    SkCachedMask cachedBlurMask;
+    cachedBlurMask.fCacheId = NULL;
+    if (getCachedBlurMask(sigma, rrect, cachedBlurMask)) {
+        patch->fCachedMask = cachedBlurMask;
+        patch->fOuterRect = dstM.fBounds;
+        patch->fCenter.fX = SkScalarCeilToInt(leftUnstretched) + 1;
+        patch->fCenter.fY = SkScalarCeilToInt(topUnstretched) + 1;
+        return kTrue_FilterReturn;
+    }
+
     bool analyticBlurWorked = false;
     if (c_analyticBlurRRect) {
         analyticBlurWorked =
-            this->filterRRectMask(&patch->fMask, smallRR, matrix, &margin,
+            this->filterRRectMask(&(patch->fCachedMask.fMask), smallRR, matrix, &margin,
                                   SkMask::kComputeBoundsAndRenderImage_CreateMode);
     }
 
     if (!analyticBlurWorked) {
         if (!draw_rrect_into_mask(smallRR, &srcM)) {
             return kFalse_FilterReturn;
         }
 
         SkAutoMaskFreeImage amf(srcM.fImage);
 
-        if (!this->filterMask(&patch->fMask, srcM, matrix, &margin)) {
+        if (!this->filterMask(&(patch->fCachedMask.fMask), srcM, matrix, &margin)) {
             return kFalse_FilterReturn;
         }
     }
 
-    patch->fMask.fBounds.offsetTo(0, 0);
+    patch->fCachedMask.fMask.fBounds.offsetTo(0, 0);
     patch->fOuterRect = dstM.fBounds;
     patch->fCenter.fX = SkScalarCeilToInt(leftUnstretched) + 1;
     patch->fCenter.fY = SkScalarCeilToInt(topUnstretched) + 1;
+    if (!cachedBlurMask.fCacheId) {
+        patch->fCachedMask.fCacheId = SkMaskCache::AddAndLock(sigma, rrect,
+                                                              patch->fCachedMask.fMask);
+    }
+
     return kTrue_FilterReturn;
 }
 
 SK_CONF_DECLARE( bool, c_analyticBlurNinepatch, "mask.filter.analyticNinePatch", true, "Use the faster analytic blur approach for ninepatch rects" );
 
 SkMaskFilter::FilterReturn
 SkBlurMaskFilterImpl::filterRectsToNine(const SkRect rects[], int count,
                                         const SkMatrix& matrix,
                                         const SkIRect& clipBounds,
                                         NinePatch* patch) const {
@@ skipping 59 matching lines @@
     if (1 == count) {
         innerIR = srcM.fBounds;
         center.set(smallW, smallH);
     } else {
         SkASSERT(2 == count);
         rects[1].roundIn(&innerIR);
         center.set(smallW + (innerIR.left() - srcM.fBounds.left()),
                    smallH + (innerIR.top() - srcM.fBounds.top()));
     }
 
+    SkScalar sigma = this->computeXformedSigma(matrix);
+    SkCachedMask cachedBlurMask;
+    cachedBlurMask.fCacheId = NULL;
+    if (getCachedBlurMask(sigma, count, rects, cachedBlurMask)) {
+        patch->fCachedMask = cachedBlurMask;
+        patch->fOuterRect = dstM.fBounds;
+        patch->fCenter = center;
+        return kTrue_FilterReturn;
+    }
+
     // +1 so we get a clean, stretchable, center row/col
     smallW += 1;
     smallH += 1;
 
     // we want the inset amounts to be integral, so we don't change any
     // fractional phase on the fRight or fBottom of our smallR.
     const SkScalar dx = SkIntToScalar(innerIR.width() - smallW);
     const SkScalar dy = SkIntToScalar(innerIR.height() - smallH);
     if (dx < 0 || dy < 0) {
         // we're too small, relative to our blur, to break into nine-patch,
         // so we ask to have our normal filterMask() be called.
         return kUnimplemented_FilterReturn;
     }
 
     smallR[0].set(rects[0].left(), rects[0].top(), rects[0].right() - dx, rects[0].bottom() - dy);
     if (smallR[0].width() < 2 || smallR[0].height() < 2) {
         return kUnimplemented_FilterReturn;
     }
     if (2 == count) {
         smallR[1].set(rects[1].left(), rects[1].top(),
                       rects[1].right() - dx, rects[1].bottom() - dy);
         SkASSERT(!smallR[1].isEmpty());
     }
 
     if (count > 1 || !c_analyticBlurNinepatch) {
         if (!draw_rects_into_mask(smallR, count, &srcM)) {
             return kFalse_FilterReturn;
         }
-
         SkAutoMaskFreeImage amf(srcM.fImage);
 
-        if (!this->filterMask(&patch->fMask, srcM, matrix, &margin)) {
+        if (!this->filterMask(&patch->fCachedMask.fMask, srcM, matrix, &margin)) {
             return kFalse_FilterReturn;
         }
     } else {
-        if (!this->filterRectMask(&patch->fMask, smallR[0], matrix, &margin,
+        if (!this->filterRectMask(&patch->fCachedMask.fMask, smallR[0], matrix, &margin,
                                   SkMask::kComputeBoundsAndRenderImage_CreateMode)) {
             return kFalse_FilterReturn;
         }
     }
-    patch->fMask.fBounds.offsetTo(0, 0);
+    patch->fCachedMask.fMask.fBounds.offsetTo(0, 0);
     patch->fOuterRect = dstM.fBounds;
     patch->fCenter = center;
+    if (!cachedBlurMask.fCacheId) {
+        patch->fCachedMask.fCacheId = SkMaskCache::AddAndLock(sigma, count, rects,
+                                                              patch->fCachedMask.fMask);
+    }
+
     return kTrue_FilterReturn;
 }
 
 void SkBlurMaskFilterImpl::computeFastBounds(const SkRect& src,
                                              SkRect* dst) const {
     SkScalar pad = 3.0f * fSigma;
 
     dst->set(src.fLeft  - pad, src.fTop    - pad,
              src.fRight + pad, src.fBottom + pad);
 }
@@ skipping 693 matching lines @@
     } else {
         str->append("None");
     }
     str->append("))");
 }
 #endif
 
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkBlurMaskFilter)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkBlurMaskFilterImpl)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END