[Mesa-dev] [PATCH] tgsi: update documents with some info on texture lookup

[Brian Paul]

On 12/19/2011 09:40 AM, Dave Airlie wrote:
> From: Dave Airlie<airlied at redhat.com>
>
> this mentions which channels are used for slice and depth comparison values.
>
> Signed-off-by: Dave Airlie<airlied at redhat.com>
> ---
>   src/gallium/docs/source/tgsi.rst |   11 +++++++++++
>   1 files changed, 11 insertions(+), 0 deletions(-)
>
> diff --git a/src/gallium/docs/source/tgsi.rst b/src/gallium/docs/source/tgsi.rst
> index d7f50b1..45af528 100644
> --- a/src/gallium/docs/source/tgsi.rst
> +++ b/src/gallium/docs/source/tgsi.rst
> @@ -585,6 +585,17 @@ This instruction replicates its result.
>
>     dst = texture_sample(unit, coord, bias)
>
> +  for array textures src0.y contains the slice for 1D,
> +  and src0.z contain the slice for 2D.
> +  for shadow textures with no arrays, src0.z contains
> +  the reference value.
> +  for shadow textures with arrays, src0.z contains
> +  the reference value for 1D arrays, and src0.w contains
> +  the reference value for 2D arrays.
> +  There is no way to pass a bias in the .w value for
> +  shadow arrays, and GLSL doesn't allow this.
> +  GLSL does allow cube shadows maps to take a bias value,
> +  and we have to determine how this will look in TGSI.
>
>   .. opcode:: TXD - Texture Lookup with Derivatives
>

Thanks!

Reviewed-by: Brian Paul <brianp at vmware.com>