Split SkBmpCodec into three separate classes
Will regress behavior on gold on test32bfv4.bmp, where we
will no longer fix transparent decodes.
TODO: Start fixing transparent decodes again, or decide
that we don't want to fix them and remove isTransparent
from SkSwizzler. I think this may become more clear when I
start implementing the scanline decoder.
BUG=skia:
Review URL: https://codereview.chromium.org/1258863008
diff --git a/src/codec/SkCodecPriv.h b/src/codec/SkCodecPriv.h
index 0c45fdd..2596787 100644
--- a/src/codec/SkCodecPriv.h
+++ b/src/codec/SkCodecPriv.h
@@ -30,6 +30,28 @@
#define COMPUTE_RESULT_ALPHA \
SkSwizzler::GetResult(zeroAlpha, maxAlpha);
+static inline bool valid_alpha(SkAlphaType dstAlpha, SkAlphaType srcAlpha) {
+ // Check for supported alpha types
+ if (srcAlpha != dstAlpha) {
+ if (kOpaque_SkAlphaType == srcAlpha) {
+ // If the source is opaque, we must decode to opaque
+ return false;
+ }
+
+ // The source is not opaque
+ switch (dstAlpha) {
+ case kPremul_SkAlphaType:
+ case kUnpremul_SkAlphaType:
+ // The source is not opaque, so either of these is okay
+ break;
+ default:
+ // We cannot decode a non-opaque image to opaque (or unknown)
+ return false;
+ }
+ }
+ return true;
+}
+
/*
* If there is a color table, get a pointer to the colors, otherwise return NULL
*/
@@ -40,7 +62,6 @@
/*
*
* Copy the codec color table back to the client when kIndex8 color type is requested
- *
*/
static inline void copy_color_table(const SkImageInfo& dstInfo, SkColorTable* colorTable,
SkPMColor* inputColorPtr, int* inputColorCount) {
@@ -53,27 +74,21 @@
}
/*
- *
* Compute row bytes for an image using pixels per byte
- *
*/
static inline size_t compute_row_bytes_ppb(int width, uint32_t pixelsPerByte) {
return (width + pixelsPerByte - 1) / pixelsPerByte;
}
/*
- *
* Compute row bytes for an image using bytes per pixel
- *
*/
static inline size_t compute_row_bytes_bpp(int width, uint32_t bytesPerPixel) {
return width * bytesPerPixel;
}
/*
- *
* Compute row bytes for an image
- *
*/
static inline size_t compute_row_bytes(int width, uint32_t bitsPerPixel) {
if (bitsPerPixel < 16) {
@@ -88,20 +103,16 @@
}
/*
- *
* Get a byte from a buffer
* This method is unsafe, the caller is responsible for performing a check
- *
*/
static inline uint8_t get_byte(uint8_t* buffer, uint32_t i) {
return buffer[i];
}
/*
- *
* Get a short from a buffer
* This method is unsafe, the caller is responsible for performing a check
- *
*/
static inline uint16_t get_short(uint8_t* buffer, uint32_t i) {
uint16_t result;
@@ -114,10 +125,8 @@
}
/*
- *
* Get an int from a buffer
* This method is unsafe, the caller is responsible for performing a check
- *
*/
static inline uint32_t get_int(uint8_t* buffer, uint32_t i) {
uint32_t result;