[GEM-dev] same patch different machines different outcome

[IOhannes m zmoelnig]

Erich Berger wrote:
> hi,
> 
> since two days i m pondering on this problem.
> 
> i have 2 machines:
> 
> 1) debian testing with old mach64 and experimental dri drivers
> 2) debian testing with nvidia GF4200Ti drivers 1.0-7174 headers installed
>    and gem compiled with them
> 
> both run latest gem-cvs
> 
> the attached patch is a texture feedback with pix_alpha
> in a manner that black becomes alpha.
> 
> this works fine on the mach64, but not on the nvidia.
> see scrrenshots at:
> http://randomseed.org/mach64.gif
> http://randomseed.org/nvidia.gif
> 
> if u exchange pix_snap with pix_snap2tex then everything works
> as desired except on can not use pix_alpha anymore as the
> captured image is already textured.
> 
> anybody an idea what could be the reason ?

the problem is with with rectangle-textures which are supported by the 
new nvidia card but not by the old mach64.
as a work-around (since i guess it is really a bug which should be fixed 
"upstream") try sending a "mode 0" message to [pix_texture] before doing 
the first snap to enforce the use of normalized textures.

i know that the texture is 256x256 (thus: normalized), but Gem still 
assumes that it is "rectangle" in order to benefit from some faster 
transmissions.


mfg.asdr
IOhannes