simplify/unify xferproc api

src/core/SkSpriteBlitter4f.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkSpriteBlitter.h"
 #include "SkSpanProcs.h"
 #include "SkTemplates.h"
 #include "SkXfermode.h"
 
 class Sprite_4f : public SkSpriteBlitter {
 public:
     Sprite_4f(const SkPixmap& src, const SkPaint& paint) : INHERITED(src) {
+        fXfer = paint.getXfermode();
         fLoader = SkLoadSpanProc_Choose(src.info());
         fFilter = SkFilterSpanProc_Choose(paint);
         fBuffer.reset(src.width());
     }
     
 protected:
+    SkXfermode*             fXfer;
     SkLoadSpanProc          fLoader;
     SkFilterSpanProc        fFilter;
     SkAutoTMalloc<SkPM4f>   fBuffer;
     
 private:
     typedef SkSpriteBlitter INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
-static SkXfermode::Mode get_mode(const SkXfermode* xfer) {
-    SkXfermode::Mode mode;
-    if (!SkXfermode::AsMode(xfer, &mode)) {
-        mode = SkXfermode::kSrcOver_Mode;
-    }
-    return mode;
-}
-
 class Sprite_F16 : public Sprite_4f {
 public:
     Sprite_F16(const SkPixmap& src, const SkPaint& paint) : INHERITED(src, paint) {
-        fState = { paint.getXfermode(), SkXfermode::kDstIsFloat16_U64Flag };
+        uint32_t flags = SkXfermode::kDstIsFloat16_D64Flag;
         if (src.isOpaque()) {
-            fState.fFlags |= SkXfermode::kSrcIsOpaque_U64Flag;
+            flags |= SkXfermode::kSrcIsOpaque_D64Flag;
         }
-        fXfer = SkXfermode::GetU64ProcN(get_mode(fState.fXfer), fState.fFlags);
+        fWriter = SkXfermode::GetD64Proc(fXfer, flags);
     }
 
     void blitRect(int x, int y, int width, int height) override {
         SkASSERT(width > 0 && height > 0);
         uint64_t* SK_RESTRICT dst = fDst.writable_addr64(x, y);
         size_t dstRB = fDst.rowBytes();
 
         for (int bottom = y + height; y < bottom; ++y) {
             fLoader(fSource, x - fLeft, y - fTop, fBuffer, width);
             fFilter(*fPaint, fBuffer, width);
-            fXfer(fState, dst, fBuffer, width, nullptr);
+            fWriter(fXfer, dst, fBuffer, width, nullptr);
             dst = (uint64_t* SK_RESTRICT)((char*)dst + dstRB);
         }
     }
     
 private:
-    SkXfermode::U64State    fState;
-    SkXfermode::U64ProcN    fXfer;
+    SkXfermode::D64Proc fWriter;
 
     typedef Sprite_4f INHERITED;
 };
 
 
 SkSpriteBlitter* SkSpriteBlitter::ChooseF16(const SkPixmap& source, const SkPaint& paint,
                                             SkTBlitterAllocator* allocator) {
     SkASSERT(allocator != nullptr);
 
     if (paint.getMaskFilter() != nullptr) {
         return nullptr;
     }
 
     switch (source.colorType()) {
         case kN32_SkColorType:
         case kRGBA_F16_SkColorType:
             return allocator->createT<Sprite_F16>(source, paint);
         default:
             return nullptr;
     }
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
 class Sprite_sRGB : public Sprite_4f {
 public:
     Sprite_sRGB(const SkPixmap& src, const SkPaint& paint) : INHERITED(src, paint) {
-        fState = { paint.getXfermode(), SkXfermode::kDstIsSRGB_PM4fFlag };
+        uint32_t flags = SkXfermode::kDstIsSRGB_D32Flag;
         if (src.isOpaque()) {
-            fState.fFlags |= SkXfermode::kSrcIsOpaque_PM4fFlag;
+            flags |= SkXfermode::kSrcIsOpaque_D32Flag;
         }
-        fXfer = SkXfermode::GetPM4fProcN(get_mode(fState.fXfer), fState.fFlags);
+        fWriter = SkXfermode::GetD32Proc(fXfer, flags);
     }
     
     void blitRect(int x, int y, int width, int height) override {
         SkASSERT(width > 0 && height > 0);
         uint32_t* SK_RESTRICT dst = fDst.writable_addr32(x, y);
         size_t dstRB = fDst.rowBytes();
         
         for (int bottom = y + height; y < bottom; ++y) {
             fLoader(fSource, x - fLeft, y - fTop, fBuffer, width);
             fFilter(*fPaint, fBuffer, width);
-            fXfer(fState, dst, fBuffer, width, nullptr);
+            fWriter(fXfer, dst, fBuffer, width, nullptr);
             dst = (uint32_t* SK_RESTRICT)((char*)dst + dstRB);
         }
     }
     
 protected:
-    SkXfermode::PM4fState   fState;
-    SkXfermode::PM4fProcN   fXfer;
+    SkXfermode::D32Proc fWriter;
     
 private:
     typedef Sprite_4f INHERITED;
 };
 
 
 SkSpriteBlitter* SkSpriteBlitter::ChooseS32(const SkPixmap& source, const SkPaint& paint,
                                             SkTBlitterAllocator* allocator) {
     SkASSERT(allocator != nullptr);
     
     if (paint.getMaskFilter() != nullptr) {
         return nullptr;
     }
     
     switch (source.colorType()) {
         case kN32_SkColorType:
         case kRGBA_F16_SkColorType:
             return allocator->createT<Sprite_sRGB>(source, paint);
         default:
             return nullptr;
     }
 }