years ago i thought the radeon 8500 was a pretty sweet card. now it seems just... well... quirky. ;)

there was one problem where it would amuse itself by dropping random textures and substituting the color white.

maybe this was considered a great driver optimization. :) at one point i did a lot of work to ensure

textures get allocated in a nice order to speed up an nvidia card and that seemed to also mollify the 8500 so i

don't lose sleep over this one any more.

there's another problem though that still creeps up on me occasionally. the 8500 has an interesting hardware

limitation which is that it can't represent the number 0 in a pixel shader constant. 0 actually ends up as a

small negative number. when you feed that to a lerp you get quite unexpected results. a lot of hardware and

driver bugs are easy to work around (for example sometimes you need to set render states in a particular order

or avoid using some feature) but a general fix for this one is much more involved. i manually munge some

constants right now for problematic shaders, but if it sneaks up on me one more time i think i'll need to start

tracking all constants that are used as lerp inputs and munge them automatically just to please the 8500. uy.