-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Am 2015-03-09 um 16:53 schrieb Stefan Dösinger: > I did test if LATC_UNORM and LATC_SNORM still work after my fix. > LATC_SNORM is unchanged (broken in the same way as RGTC_SNORM) and > LATC_UNORM now has the proper precision like RGTC_UNORM. I think the reason why _SNORM is broken is that the way the driver tries to emulate them is conceptually broken. It handles them like the _UNORM variant, but afterwards does a red = red > 0.5 ? red * 2 - 2 : red * 2.
That may work for an uncompressed signed format, but it doesn't take into account the block decompression of RGTC1. For example consider a block that has red1 = 0x7f and red2 = 0x80. As an unsigned value, red2 is the bigger value(127 vs 128). If it is a signed value, red1 is bigger (127 vs -128). The only way this will work is if the driver adds +128 to red1 and red2 for each block before loading (sucks if it's in a PBO) and after sampling does red = red * 2.0 - 1.0. And I'm not even sure if that will work. It will at least break exact zeros. Note that I don't care about the signed RGTC formats. Wine on this card will only ever need the unsigned ones, as they match ATI1N and ATI2N in d3d. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBAgAGBQJU/cYcAAoJEN0/YqbEcdMwdygQAIlgA+nSg42o/7xAOogeOHeq IUf/3WKz0GVAhlA+wbli4UoxZgALUHf5PxWgshBvEZZgpzoEYAqpfTVLQm3cUXDd p3eQkDyGucttgnt1zC5q1jNjkP2io114XRqcTwbMHmMJRfZavzNRK805UBuy1Jd4 sOuxsRT7cTnI+iCkbfqHBdyHo2OSegJ0FDpj35aGzpsc3cDQH9oW/jchryoQJo6V luf3KvdyP5QQlmglp8I2V28n7uBypwVZywAxKg4jR00IalZXCXt/vj2SFBojDQal z2Xr9xSz0ccoV+yFutbRwe8wuoUwTBpOFrpnZnx1PQ1RoG34plpgdLg5AVn/t8+A 5UJv5Op51y0KmWqDGadlGV+8RlpdDWCCV6dOdDsOJbrS1/gOJj3Z+VI8rdrrb4Tt n/eY45OWoF3E0v73aMRLdr220wjgFWcgv7Je16xiER4oSemkCfSsl3kKD7RNy8rS oNhd6VL18UcefgrssVLptWYI/M7M1Zs6tbtPmh6WIFjFFpikzIjX51UBrIppCIxr YKZQ0HtML5PJ9JtdHJR6kjqCFKpNO5ZMZtY5HFOuSD+SAu0jnYpTqe/X0etrCy9r PAKwuCLaOqciqANkhYQBq9quwvv9HwDa9huI0GxSk5xkEd5J4eTqxeKPAURkGx4Y SBzv2N9WDEDhnGuzYgs9 =8Wzg -----END PGP SIGNATURE----- _______________________________________________ mesa-dev mailing list mesa-dev@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/mesa-dev
