Mesa (master): gallium/docs: add more info about TXF and MSAA textures

[Brian Paul]

Module: Mesa
Branch: master
Commit: 426673e27149576aac6285da47582a90cf8fe213
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=426673e27149576aac6285da47582a90cf8fe213

Author: Brian Paul <brianp at vmware.com>
Date:   Wed Aug  2 11:06:28 2017 -0600

gallium/docs: add more info about TXF and MSAA textures

If the texture is multisampled, the coord.w component indicates which
sample to fetch.

Reviewed-by: Roland Scheidegger <sroland at vmware.com>

---

 src/gallium/docs/source/tgsi.rst | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/gallium/docs/source/tgsi.rst b/src/gallium/docs/source/tgsi.rst
index d7817cc9d0..d1e7c88905 100644
--- a/src/gallium/docs/source/tgsi.rst
+++ b/src/gallium/docs/source/tgsi.rst
@@ -951,7 +951,9 @@ XXX doesn't look like most of the opcodes really belong here.
   image or PIPE_BUFFER resource. The source sampler may not be a CUBE or
   SHADOW.  src 0 is a
   four-component signed integer vector used to identify the single texel
-  accessed. 3 components + level.  Just like texture instructions, an optional
+  accessed. 3 components + level.  If the texture is multisampled, then
+  the fourth component indicates the sample, not the mipmap level.
+  Just like texture instructions, an optional
   offset vector is provided, which is subject to various driver restrictions
   (regarding range, source of offsets). This instruction ignores the sampler
   state.