Adjust the alpha type for pixelRefs.
Move SkBitmap's validate_alphaType to SkImageInfo, with the new
name SkColorTypeValidateAlphaType. Use it in SkPixelRef's constructors,
as well as in SkDecodingImageGenerator. This fixes a bug where an
SkPixelRef's SkAlphaType could get out of sync with its SkBitmap,
when both were assigned the same SkAlphaType.
R=reed@google.com, halcanary@google.com
Author: scroggo@google.com
Review URL: https://codereview.chromium.org/346593003
diff --git a/src/core/SkImageInfo.cpp b/src/core/SkImageInfo.cpp
index 27c4573..e61cd7d 100644
--- a/src/core/SkImageInfo.cpp
+++ b/src/core/SkImageInfo.cpp
@@ -38,3 +38,34 @@
uint32_t packed = (fAlphaType << 8) | fColorType;
buffer.write32(packed);
}
+
+bool SkColorTypeValidateAlphaType(SkColorType colorType, SkAlphaType alphaType,
+ SkAlphaType* canonical) {
+ switch (colorType) {
+ case kUnknown_SkColorType:
+ alphaType = kIgnore_SkAlphaType;
+ break;
+ case kAlpha_8_SkColorType:
+ if (kUnpremul_SkAlphaType == alphaType) {
+ alphaType = kPremul_SkAlphaType;
+ }
+ // fall-through
+ case kIndex_8_SkColorType:
+ case kARGB_4444_SkColorType:
+ case kRGBA_8888_SkColorType:
+ case kBGRA_8888_SkColorType:
+ if (kIgnore_SkAlphaType == alphaType) {
+ return false;
+ }
+ break;
+ case kRGB_565_SkColorType:
+ alphaType = kOpaque_SkAlphaType;
+ break;
+ default:
+ return false;
+ }
+ if (canonical) {
+ *canonical = alphaType;
+ }
+ return true;
+}