[Mesa-dev] [PATCH 3/3] mesa/st: implement ARB_stencil_texturing

[Ilia Mirkin]

If StencilSampling is enabled on the texture object, pass in an
equivalent stencil-only format.

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>
---

This replaces my earlier series, based on a suggestion from Michel Dänzer on
IRC. Much simpler, and enables it for pretty much all gallium drivers.

 src/mesa/state_tracker/st_atom_texture.c | 4 ++++
 src/mesa/state_tracker/st_extensions.c   | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/src/mesa/state_tracker/st_atom_texture.c b/src/mesa/state_tracker/st_atom_texture.c
index afc6d9d..928a4ff 100644
--- a/src/mesa/state_tracker/st_atom_texture.c
+++ b/src/mesa/state_tracker/st_atom_texture.c
@@ -271,6 +271,10 @@ st_get_texture_sampler_view_from_stobj(struct st_context *st,
 
    sv = st_texture_get_sampler_view(st, stObj);
 
+   if (stObj->base.StencilSampling &&
+       util_format_is_depth_and_stencil(format))
+      format = util_format_stencil_only(format);
+
    /* if sampler view has changed dereference it */
    if (*sv) {
       if (check_sampler_swizzle(stObj, *sv) ||
diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index 33cd129..12ba82d 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -507,6 +507,11 @@ void st_init_extensions(struct st_context *st)
 
       { { o(OES_compressed_ETC1_RGB8_texture) },
         { PIPE_FORMAT_ETC1_RGB8 } },
+
+      { { o(ARB_stencil_texturing) },
+        { PIPE_FORMAT_X24S8_UINT,
+          PIPE_FORMAT_S8X24_UINT },
+        GL_TRUE }, /* at least one format must be supported */
    };
 
    /* Required: vertex fetch support. */
-- 
1.8.3.2