Optimize CSS box-shadow performance

include/core/SkMaskFilter.h

Index: include/core/SkMaskFilter.h
diff --git a/include/core/SkMaskFilter.h b/include/core/SkMaskFilter.h
index 026ef40cb1e8f93d8733be6703e9af9ad04a1746..7aa46a5ecff3163f1c730d2d70b5b348b0c8fed8 100644
--- a/include/core/SkMaskFilter.h
+++ b/include/core/SkMaskFilter.h
@@ -11,6 +11,7 @@
 #define SkMaskFilter_DEFINED
 
 #include "SkBlurTypes.h"
+#include "SkCachedData.h"

[reed1, 2014/10/21 21:47:05]

SkCachedData.h is a private header, and so cannot be included here. You should
be able to forward-declare it instead...

 #include "SkFlattenable.h"
 #include "SkMask.h"
 #include "SkPaint.h"
@@ -59,7 +60,7 @@ public:
         @return true if the dst mask was correctly created.
     */
     virtual bool filterMask(SkMask* dst, const SkMask& src, const SkMatrix&,
-                            SkIPoint* margin) const;
+                            SkIPoint* margin, SkCachedData** data) const;

[reed1, 2014/10/21 21:29:49]

What is the contract with the caller? If they pass a non-null for data, must it
always be used/returned-as-a-cached-data?

Perhaps, since we're changing the virtual API anyway, would it help/simplify
things to have this (or variants of it) be non-virtual, and introduce a new
onFilterMask virtual? That might allow the non-virtual code to check that data
has been properly allocated if present. I'm still trying to understand the
contract, so perhaps this suggestion is misguided.

 
 #if SK_SUPPORT_GPU
     /**
@@ -165,9 +166,10 @@ protected:
     };
 
     struct NinePatch {
-        SkMask      fMask;      // fBounds must have [0,0] in its top-left
-        SkIRect     fOuterRect; // width/height must be >= fMask.fBounds'
-        SkIPoint    fCenter;    // identifies center row/col for stretching
+        SkMask         fMask;      // fBounds must have [0,0] in its top-left
+        SkCachedData*  fData;
+        SkIRect        fOuterRect; // width/height must be >= fMask.fBounds'
+        SkIPoint       fCenter;    // identifies center row/col for stretching
     };
 
     /**