void computeMD5HashStringForContext(CGContextRef bitmapContext, char hashString[33])
{
ASSERT(CGBitmapContextGetBitsPerPixel(bitmapContext) == 32); // ImageDiff assumes 32 bit RGBA, we must as well.
size_t pixelsHigh = CGBitmapContextGetHeight(bitmapContext);
size_t pixelsWide = CGBitmapContextGetWidth(bitmapContext);
size_t bytesPerRow = CGBitmapContextGetBytesPerRow(bitmapContext);
// We need to swap the bytes to ensure consistent hashes independently of endianness
MD5 md5;
unsigned char* bitmapData = static_cast<unsigned char*>(CGBitmapContextGetData(bitmapContext));
#if PLATFORM(MAC)
if ((CGBitmapContextGetBitmapInfo(bitmapContext) & kCGBitmapByteOrderMask) == kCGBitmapByteOrder32Big) {
for (unsigned row = 0; row < pixelsHigh; row++) {
Vector<uint8_t> buffer(4 * pixelsWide);
for (unsigned column = 0; column < pixelsWide; column++)
buffer[column] = OSReadLittleInt32(bitmapData, 4 * column);
md5.addBytes(buffer);
bitmapData += bytesPerRow;
}
} else
#endif
{
for (unsigned row = 0; row < pixelsHigh; row++) {
md5.addBytes(bitmapData, 4 * pixelsWide);
bitmapData += bytesPerRow;
}
}
Vector<uint8_t, 16> hash;
md5.checksum(hash);
hashString[0] = '\0';
for (int i = 0; i < 16; i++)
snprintf(hashString, 33, "%s%02x", hashString, hash[i]);
}
CGBitmapInfo myCGContextGetBitmapInfo(CGContextRef c)
{
if(&CGBitmapContextGetBitmapInfo != NULL)
return CGBitmapContextGetBitmapInfo(c);
else
return CGBitmapContextGetAlphaInfo(c);
}
static cairo_status_t
_cairo_quartz_surface_acquire_source_image(void *abstract_surface,
cairo_image_surface_t **image_out,
void **image_extra)
{
cairo_quartz_surface_t *surface = abstract_surface;
if (CGBitmapContextGetBitmapInfo (surface->context) != 0) {
/* XXX: We can create an image out of the bitmap here */
}
return CAIRO_INT_STATUS_UNSUPPORTED;
}
