Refactor bitmap scaler to make it easier to migrate rest of chrome to use it

Previously, the set of platform-specific function pointers to do fast convolution (e.g., neon, SSE) were passed in a structure to the scaler.

I refactored this so that the scaler fills in these function pointers after it's called, so the caller doesn't have to worry about it.

R=mtklein@google.com
TBR=mtklein
NOTRY=True

Author: humper@google.com

Review URL: https://codereview.chromium.org/354193002

src/core/SkBitmapProcState.cpp

@@ -172,16 +172,11 @@ bool SkBitmapProcState::possiblyScaleImage() {
 
             // All the criteria are met; let's make a new bitmap.
 
-            SkConvolutionProcs simd;
-            sk_bzero(&simd, sizeof(simd));
-            this->platformConvolutionProcs(&simd);
-
             if (!SkBitmapScaler::Resize(&fScaledBitmap,
                                         fOrigBitmap,
                                         SkBitmapScaler::RESIZE_BEST,
                                         dest_width,
                                         dest_height,
-                                        simd,
                                         SkScaledImageCache::GetAllocator())) {
                 // we failed to create fScaledBitmap, so just return and let
                 // the scanline proc handle it.

src/core/SkBitmapProcState.h

@@ -33,7 +33,6 @@
 #endif
 
 class SkPaint;
-struct SkConvolutionProcs;
 
 struct SkBitmapProcState {
 
@@ -104,12 +103,6 @@ struct SkBitmapProcState {
      */
     void platformProcs();
 
-    /** Platforms can also optionally overwrite the convolution functions
-        if we have SIMD versions of them.
-      */
-
-    void platformConvolutionProcs(SkConvolutionProcs*);
-
     /** Given the byte size of the index buffer to be passed to the matrix proc,
         return the maximum number of resulting pixels that can be computed
         (i.e. the number of SkPMColor values to be written by the sample proc).

src/core/SkBitmapScaler.cpp

@@ -246,9 +246,11 @@ bool SkBitmapScaler::Resize(SkBitmap* resultPtr,
                             const SkBitmap& source,
                             ResizeMethod method,
                             float destWidth, float destHeight,
-                            const SkConvolutionProcs& convolveProcs,
                             SkBitmap::Allocator* allocator) {
 
+  SkConvolutionProcs convolveProcs= { 0, NULL, NULL, NULL, NULL };
+  PlatformConvolutionProcs(&convolveProcs);
+
   SkRect destSubset = { 0, 0, destWidth, destHeight };
 
   // Ensure that the ResizeMethod enumeration is sound.

src/core/SkBitmapScaler.h

@@ -83,8 +83,13 @@ public:
                        const SkBitmap& source,
                        ResizeMethod method,
                        float dest_width, float dest_height,
-                       const SkConvolutionProcs&,
                        SkBitmap::Allocator* allocator = NULL);
+
+     /** Platforms can also optionally overwrite the convolution functions
+        if we have SIMD versions of them.
+      */
+
+    static void PlatformConvolutionProcs(SkConvolutionProcs*);
 };
 
 #endif

src/opts/SkBitmapProcState_opts_arm.cpp

@@ -6,6 +6,7 @@
  */
 
 
+#include "SkBitmapScaler.h"
 #include "SkBitmapProcState.h"
 #include "SkColorPriv.h"
 #include "SkPaint.h"
@@ -229,6 +230,6 @@ extern void platformConvolutionProcs_arm_neon(SkConvolutionProcs* procs);
 void platformConvolutionProcs_arm(SkConvolutionProcs* procs) {
 }
 
-void SkBitmapProcState::platformConvolutionProcs(SkConvolutionProcs* procs) {
+void SkBitmapScaler::PlatformConvolutionProcs(SkConvolutionProcs* procs) {
     SK_ARM_NEON_WRAP(platformConvolutionProcs_arm)(procs);
 }

src/opts/SkBitmapProcState_opts_none.cpp

@@ -5,6 +5,8 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
+
+#include "SkBitmapScaler.h"
 #include "SkBitmapProcState.h"
 
 /*  A platform may optionally overwrite any of these with accelerated
@@ -23,4 +25,4 @@
 void SkBitmapProcState::platformProcs() {}
 
 // empty implementation just uses default supplied function pointers
-void SkBitmapProcState::platformConvolutionProcs(SkConvolutionProcs*) {}
+void SkBitmapScaler::PlatformConvolutionProcs(SkConvolutionProcs*) {}

src/opts/opts_check_x86.cpp

@@ -8,6 +8,7 @@
 #include "SkBitmapFilter_opts_SSE2.h"
 #include "SkBitmapProcState_opts_SSE2.h"
 #include "SkBitmapProcState_opts_SSSE3.h"
+#include "SkBitmapScaler.h"
 #include "SkBlitMask.h"
 #include "SkBlitRect_opts_SSE2.h"
 #include "SkBlitRow.h"
@@ -123,7 +124,7 @@ static inline bool supports_simd(int minLevel) {
 
 SK_CONF_DECLARE( bool, c_hqfilter_sse, "bitmap.filter.highQualitySSE", false, "Use SSE optimized version of high quality image filters");
 
-void SkBitmapProcState::platformConvolutionProcs(SkConvolutionProcs* procs) {
+void SkBitmapScaler::PlatformConvolutionProcs(SkConvolutionProcs* procs) {
     if (supports_simd(SK_CPU_SSE_LEVEL_SSE2)) {
         procs->fExtraHorizontalReads = 3;
         procs->fConvolveVertically = &convolveVertically_SSE2;