Allow detection of PNG images without necessarily being able to dynam…

…ically load the PNG library.
libsdl-org · Jul 18, 2007 · 0592c6c · 0592c6c
1 parent 3be31d5
commit 0592c6c
Showing 1 changed file with 6 additions and 5 deletions.
diff --git a/IMG_png.c b/IMG_png.c
@@ -270,18 +270,19 @@ int IMG_isPNG(SDL_RWops *src)
 	int is_PNG;
 	unsigned char buf[PNG_BYTES_TO_CHECK];
 
-	if ( IMG_InitPNG() < 0 ) {
-		return 0;
-	}
 	if ( !src )
 		return 0;
 	start = SDL_RWtell(src);
 	is_PNG = 0;
 	if ( SDL_RWread(src, buf, 1, PNG_BYTES_TO_CHECK) == PNG_BYTES_TO_CHECK ) {
-		is_PNG = (lib.png_sig_cmp(buf, (png_size_t)0, PNG_BYTES_TO_CHECK) == 0);
+                if ( buf[0] == 0x89 &&
+                     buf[1] == 'P' &&
+                     buf[2] == 'N' &&
+                     buf[3] == 'G' ) {
+			is_PNG = 1;
+		}
 	}
 	SDL_RWseek(src, start, SEEK_SET);
-	IMG_QuitPNG();
 	return(is_PNG);
 }