2008/6/23 Roderick Colenbrander thunderbird2k@gmx.net:
Hi,
I don't think we should implement it this way. For instance on GeforceFX
cards blending is performed in software. Not too long ago (before 1.0) I also sent a patch for this e.g. by doing an extension check. I think I checked for ARB_color_buffer_float in combination with half pixel support.
The format already requires ARB_HALF_FLOAT_PIXEL, which is supported by GF FX. The format also requires ARB_TEXTURE_FLOAT to work properly, which as far as I can see from the list at Delphi3D isn't supported by GF FX. The next patch adds this extension check. Wrt ARB_COLOR_BUFFER_FLOAT, I'm not sure how it would imply post ps blending support?
The extension itself doesn't imply it but since it isn't supported on hardware like the GeforceFX which doesn't offer it. Further Ati offers blending on Radeon >= 9500 GPUs and offers the extension ARB_COLOR_BUFFER_FLOAT. Not sure if they offer half pixel though.
Roderick