spriteblitter for memcpy case (for all configs)

include/core/SkImageInfo.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkImageInfo_DEFINED
 #define SkImageInfo_DEFINED
 
@@ skipping 87 matching lines @@
         1,  // kGray_8
         8,  // kRGBA_F16
     };
     static_assert(SK_ARRAY_COUNT(gSize) == (size_t)(kLastEnum_SkColorType + 1),
                   "size_mismatch_with_SkColorType_enum");
 
     SkASSERT((size_t)ct < SK_ARRAY_COUNT(gSize));
     return gSize[ct];
 }
 
+static int SkColorTypeShiftPerPixel(SkColorType ct) {
+    static const uint8_t gShift[] = {
+        0,  // Unknown
+        0,  // Alpha_8
+        1,  // RGB_565
+        1,  // ARGB_4444
+        2,  // RGBA_8888
+        2,  // BGRA_8888
+        0,  // kIndex_8
+        0,  // kGray_8
+        3,  // kRGBA_F16
+    };
+    static_assert(SK_ARRAY_COUNT(gShift) == (size_t)(kLastEnum_SkColorType + 1),
+                  "size_mismatch_with_SkColorType_enum");
+    
+    SkASSERT((size_t)ct < SK_ARRAY_COUNT(gShift));
+    return gShift[ct];
+}
+
 static inline size_t SkColorTypeMinRowBytes(SkColorType ct, int width) {
     return width * SkColorTypeBytesPerPixel(ct);
 }
 
 static inline bool SkColorTypeIsValid(unsigned value) {
     return value <= kLastEnum_SkColorType;
 }
 
 static inline size_t SkColorTypeComputeOffset(SkColorType ct, int x, int y, size_t rowBytes) {
-    int shift = 0;
-    switch (SkColorTypeBytesPerPixel(ct)) {
-        case 8: shift = 3; break;
-        case 4: shift = 2; break;
-        case 2: shift = 1; break;
-        case 1: shift = 0; break;
-        default: return 0;
+    if (kUnknown_SkColorType == ct) {
+        return 0;
     }
-    return y * rowBytes + (x << shift);
+    return y * rowBytes + (x << SkColorTypeShiftPerPixel(ct));
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 
 /**
  *  Return true if alphaType is supported by colorType. If there is a canonical
  *  alphaType for this colorType, return it in canonical.
  */
 bool SkColorTypeValidateAlphaType(SkColorType colorType, SkAlphaType alphaType,
                                   SkAlphaType* canonical = NULL);
@@ skipping 109 matching lines @@
     }
 
     SkImageInfo makeAlphaType(SkAlphaType newAlphaType) const {
         return SkImageInfo::Make(fWidth, fHeight, fColorType, newAlphaType, fProfileType);
     }
     
     SkImageInfo makeColorType(SkColorType newColorType) const {
         return SkImageInfo::Make(fWidth, fHeight, newColorType, fAlphaType, fProfileType);
     }
 
-    int bytesPerPixel() const {
-        return SkColorTypeBytesPerPixel(fColorType);
-    }
+    int bytesPerPixel() const { return SkColorTypeBytesPerPixel(fColorType); }
+
+    int shiftPerPixel() const { return SkColorTypeShiftPerPixel(fColorType); }
 
     uint64_t minRowBytes64() const {
         return sk_64_mul(fWidth, this->bytesPerPixel());
     }
 
     size_t minRowBytes() const {
         return (size_t)this->minRowBytes64();
     }
 
     size_t computeOffset(int x, int y, size_t rowBytes) const {
@@ skipping 54 matching lines @@
 
 static inline bool SkColorAndProfileAreGammaCorrect(SkColorType ct, SkColorProfileType pt) {
     return kSRGB_SkColorProfileType == pt || kRGBA_F16_SkColorType == ct;
 }
 
 static inline bool SkImageInfoIsGammaCorrect(const SkImageInfo& info) {
     return SkColorAndProfileAreGammaCorrect(info.colorType(), info.profileType());
 }
 
 #endif