[Mesa-dev] [PATCH] gallium/tgsi: add offset to TXF

[Brian Paul]

On 08/26/2011 04:50 AM, Dave Airlie wrote:
> From: Dave Airlie<airlied at redhat.com>
>
> In order to implement the GLSL texelFetchOffset I needed to modify TXF
> (which wasn't defined anyways). It now corresponds to the NV_gpu_shader4.
>
> I've limited things to a u8, since hw can only do about 4-5 bits, since
> that is what DX specifies, TGSI passes stuff in an immediate so its not a
> problem there, if we need to change the tgsi_exec/driver interface later
> it isn't a major problem.

With OpenGL you can query the range of supported offsets with
GL_MIN_PROGRAM_TEXEL_OFFSET and GL_MAX_PROGRAM_TEXEL_OFFSET.  Maybe we 
should add new PIPE_CAP_MIN/MAX_TEXEL_OFFSETS right away...

-Brian