diff options
Diffstat (limited to 'src/mesa/main/texcompress_rgtc_tmp.h')
| -rw-r--r-- | src/mesa/main/texcompress_rgtc_tmp.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/src/mesa/main/texcompress_rgtc_tmp.h b/src/mesa/main/texcompress_rgtc_tmp.h index 9377a6bd3b..404f7fe3fd 100644 --- a/src/mesa/main/texcompress_rgtc_tmp.h +++ b/src/mesa/main/texcompress_rgtc_tmp.h @@ -29,6 +29,35 @@ /* included by texcompress_rgtc to define byte/ubyte compressors */ +static void TAG(fetch_texel_rgtc)(unsigned srcRowStride, const TYPE *pixdata, + unsigned i, unsigned j, TYPE *value, unsigned comps) +{ + TYPE decode; + const TYPE *blksrc = (pixdata + ((srcRowStride + 3) / 4 * (j / 4) + (i / 4)) * 8 * comps); + 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) | + (acodehigh << (8 - (bit_pos & 0x7)))) & 0x7; + + if (code == 0) + decode = alpha0; + else if (code == 1) + decode = alpha1; + else if (alpha0 > alpha1) + decode = ((alpha0 * (8 - code) + (alpha1 * (code - 1))) / 7); + else if (code < 6) + decode = ((alpha0 * (6 - code) + (alpha1 * (code - 1))) / 5); + else if (code == 6) + decode = T_MIN; + else + decode = T_MAX; + + *value = decode; +} + static void TAG(write_rgtc_encoded_channel)(TYPE *blkaddr, TYPE alphabase1, TYPE alphabase2, |