mesa: fix rgtc snorm decoding

The codeword must be unsigned (otherwise will shift in 1's from above when
merging low/high parts so some texels decode wrong).
This also affects gallium's util/u_format_rgtc.

Reviewed-by: Jose Fonseca <jfonseca@vmware.com>
Reviewed-by: Zack Rusin <zackr@vmware.com>
This commit is contained in:
Roland Scheidegger 2013-07-22 21:02:56 +02:00
parent 0acf3a8407
commit bceb5f36ec

View file

@ -37,9 +37,9 @@ static void TAG(fetch_texel_rgtc)(unsigned srcRowStride, const TYPE *pixdata,
const TYPE alpha0 = blksrc[0];
const TYPE alpha1 = blksrc[1];
const char bit_pos = ((j&3) * 4 + (i&3)) * 3;
const TYPE acodelow = blksrc[2 + bit_pos / 8];
const TYPE acodehigh = (3 + bit_pos / 8) < 8 ? blksrc[3 + bit_pos / 8] : 0;
const TYPE code = (acodelow >> (bit_pos & 0x7) |
const unsigned char acodelow = blksrc[2 + bit_pos / 8];
const unsigned char acodehigh = (3 + bit_pos / 8) < 8 ? blksrc[3 + bit_pos / 8] : 0;
const unsigned char code = (acodelow >> (bit_pos & 0x7) |
(acodehigh << (8 - (bit_pos & 0x7)))) & 0x7;
if (code == 0)