fixed a bug with png loading on x86_64 platforms caused by libpng retardedness (it...

git-svn-id: svn://svn.icculus.org/twilight/trunk/darkplaces@6849 d7cf8633-e32d-0410-b094-e92efae38249

diff --git a/image_png.c b/image_png.c
index d9d7a5004f844dfe13aacdfc444493507b56e6d4..084fb1c8e8268693c30f320abafe5f132e8a3f24 100644 (file)
--- a/image_png.c
+++ b/image_png.c
@@ -50,7 +50,7 @@ static unsigned int           (*qpng_get_valid)                       (void*, void*, unsigned int);
 static unsigned int            (*qpng_get_rowbytes)            (void*, void*);
 static unsigned char   (*qpng_get_channels)            (void*, void*);
 static unsigned char   (*qpng_get_bit_depth)           (void*, void*);
-static unsigned int            (*qpng_get_IHDR)                        (void*, void*, unsigned int*, unsigned int*, int *, int *, int *, int *, int *);
+static unsigned int            (*qpng_get_IHDR)                        (void*, void*, unsigned long*, unsigned long*, int *, int *, int *, int *, int *);
 static char*                   (*qpng_get_libpng_ver)          (void*);
 
 static dllfunction_t pngfuncs[] =
@@ -189,8 +189,8 @@ static struct
        int             BitDepth;
        int             BytesPerPixel;
        int             ColorType;
-       unsigned int    Height;
-       unsigned int    Width;
+       unsigned long   Height; // retarded libpng 1.2 pngconf.h uses long (64bit/32bit depending on arch)
+       unsigned long   Width; // retarded libpng 1.2 pngconf.h uses long (64bit/32bit depending on arch)
        int             Interlace;
        int             Compression;
        int             Filter;
@@ -288,7 +288,21 @@ unsigned char *PNG_LoadImage (const unsigned char *raw, int filesize, int matchw
        qpng_set_read_fn(png, ioBuffer, (void *)PNG_fReadData);
        qpng_read_info(png, pnginfo);
        qpng_get_IHDR(png, pnginfo, &my_png.Width, &my_png.Height,&my_png.BitDepth, &my_png.ColorType, &my_png.Interlace, &my_png.Compression, &my_png.Filter);
-       if ((matchwidth && my_png.Width != (unsigned int)matchwidth) || (matchheight && my_png.Height != (unsigned int)matchheight))
+
+       // this check guards against pngconf.h with unsigned int *width/height parameters on big endian systems by detecting the strange values and shifting them down 32bits
+       // (if it's little endian the unwritten bytes are the most significant
+       //  ones and we don't worry about that)
+       //
+       // this is only necessary because of retarded 64bit png_uint_32 types in libpng 1.2, which can (conceivably) vary by platform
+#if LONG_MAX > 4000000000
+       if (my_png.Width > LONG_MAX || my_png.Height > LONG_MAX)
+       {
+               my_png.Width >>= 32;
+               my_png.Height >>= 32;
+       }
+#endif
+
+if ((matchwidth && my_png.Width != (unsigned long)matchwidth) || (matchheight && my_png.Height != (unsigned long)matchheight))
        {
                qpng_destroy_read_struct(&png, &pnginfo, 0);
                return NULL;
@@ -336,8 +350,8 @@ unsigned char *PNG_LoadImage (const unsigned char *raw, int filesize, int matchw
        qpng_read_end(png, pnginfo);
        qpng_destroy_read_struct(&png, &pnginfo, 0);
 
-       image_width = my_png.Width;
-       image_height = my_png.Height;
+       image_width = (int)my_png.Width;
+       image_height = (int)my_png.Height;
        imagedata = my_png.Data;
 
        if (my_png.BitDepth != 8)