Merge pull request #310 from dgelessus/fix_plMipmap_JPEG_alpha_color_channel

zrax · web-flow · commit b76cecc855fd · 2025-10-08T15:54:07.000-07:00
Fix `plMipmap` JPEG decompression using the wrong channel for JPEG alpha
diff --git a/core/PRP/Surface/plMipmap.cpp b/core/PRP/Surface/plMipmap.cpp
@@ -701,7 +701,7 @@ void plMipmap::DecompressImage(size_t level, void* dest, size_t size) const
             unsigned int* dp = (unsigned int*)dest;
             unsigned int* sp = (unsigned int*)jbuffer;
             for (size_t i=0; i<(size/4); i++)
-                dp[i] = (dp[i] & 0x00FFFFFF) | ((sp[i] << 24) & 0xFF000000);
+                dp[i] = (dp[i] & 0x00FFFFFF) | ((sp[i] << 8) & 0xFF000000);
         }
 
         free_aligned(jbuffer);

Original file line number	Diff line number	Diff line change
`@@ -701,7 +701,7 @@ void plMipmap::DecompressImage(size_t level, void* dest, size_t size) const`
`701`	`701`	`unsigned int* dp = (unsigned int*)dest;`
`702`	`702`	`unsigned int* sp = (unsigned int*)jbuffer;`
`703`	`703`	`for (size_t i=0; i<(size/4); i++)`
`704`		`- dp[i] = (dp[i] & 0x00FFFFFF) \| ((sp[i] << 24) & 0xFF000000);`
	`704`	`+ dp[i] = (dp[i] & 0x00FFFFFF) \| ((sp[i] << 8) & 0xFF000000);`
`705`	`705`	`}`
`706`	`706`
`707`	`707`	`free_aligned(jbuffer);`