Support the non-native (RGBA/BGRA) swizzle

src/codec/SkCodecPriv.h

 /*
  * Copyright 2015 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.
  */
 
 #ifndef SkCodecPriv_DEFINED
 #define SkCodecPriv_DEFINED
 
@@ skipping 110 matching lines @@
     // will treat the encoded data as linear regardless of what the client
     // requests.
 
     // Ensure the alpha type is valid
     if (!valid_alpha(dst.alphaType(), src.alphaType())) {
         return false;
     }
 
     // Check for supported color types
     switch (dst.colorType()) {
-        case kN32_SkColorType:
+        case kRGBA_8888_SkColorType:
+        case kBGRA_8888_SkColorType:
             return true;
         case kRGB_565_SkColorType:
             return kOpaque_SkAlphaType == dst.alphaType();
         case kGray_8_SkColorType:
             if (kOpaque_SkAlphaType != dst.alphaType()) {
                 return false;
             }
             // Fall through
         default:
             return dst.colorType() == src.colorType();
     }
 }
 
 /*
  * If there is a color table, get a pointer to the colors, otherwise return nullptr
  */
 inline const SkPMColor* get_color_ptr(SkColorTable* colorTable) {
      return nullptr != colorTable ? colorTable->readColors() : nullptr;
 }
 
 /*
  * Given that the encoded image uses a color table, return the fill value
  */
 inline uint32_t get_color_table_fill_value(SkColorType colorType, const SkPMColor* colorPtr,
         uint8_t fillIndex) {
     SkASSERT(nullptr != colorPtr);
     switch (colorType) {
-        case kN32_SkColorType:
+        case kRGBA_8888_SkColorType:
+        case kBGRA_8888_SkColorType:
             return colorPtr[fillIndex];
         case kRGB_565_SkColorType:
             return SkPixel32ToPixel16(colorPtr[fillIndex]);
         case kIndex_8_SkColorType:
             return fillIndex;
         default:
             SkASSERT(false);
             return 0;
     }
 }
@@ skipping 94 matching lines @@
 }
 
 inline uint16_t get_endian_short(const uint8_t* data, bool littleEndian) {
     if (littleEndian) {
         return (data[1] << 8) | (data[0]);
     }
 
     return (data[0] << 8) | (data[1]);
 }
 
+inline SkPMColor premultiply_argb_as_rgba(U8CPU a, U8CPU r, U8CPU g, U8CPU b) {
+    if (a != 255) {
+        r = SkMulDiv255Round(r, a);
+        g = SkMulDiv255Round(g, a);
+        b = SkMulDiv255Round(b, a);
+    }
+
+    return SkPackARGB_as_RGBA(a, r, g, b);
+}
+
+inline SkPMColor premultiply_argb_as_bgra(U8CPU a, U8CPU r, U8CPU g, U8CPU b) {
+    if (a != 255) {
+        r = SkMulDiv255Round(r, a);
+        g = SkMulDiv255Round(g, a);
+        b = SkMulDiv255Round(b, a);
+    }
+
+    return SkPackARGB_as_BGRA(a, r, g, b);
+}
+
+inline bool is_rgba(SkColorType colorType) {
+#ifdef SK_PMCOLOR_IS_RGBA
+    return (kBGRA_8888_SkColorType != colorType);
+#else
+    return (kRGBA_8888_SkColorType == colorType);
+#endif
+}
+
+// Method for coverting to a 32 bit pixel.
+typedef uint32_t (*PackColorProc)(U8CPU a, U8CPU r, U8CPU g, U8CPU b);
+
+inline PackColorProc choose_pack_color_proc(bool isPremul, SkColorType colorType) {
+    bool isRGBA = is_rgba(colorType);
+    if (isPremul) {
+        if (isRGBA) {
+            return &premultiply_argb_as_rgba;
+        } else {
+            return &premultiply_argb_as_bgra;
+        }
+    } else {
+        if (isRGBA) {
+            return &SkPackARGB_as_RGBA;
+        } else {
+            return &SkPackARGB_as_BGRA;
+        }
+    }
+}
+
 #endif // SkCodecPriv_DEFINED