[Mesa-dev] [PATCH 3/3] st/mesa: add support for GL_ARB_texture_buffer_range

[Christoph Bumiller]

---
 src/mesa/state_tracker/st_atom_texture.c |   15 ++++++++++++++-
 src/mesa/state_tracker/st_extensions.c   |    6 ++++++
 2 files changed, 20 insertions(+), 1 deletions(-)

diff --git a/src/mesa/state_tracker/st_atom_texture.c b/src/mesa/state_tracker/st_atom_texture.c
index dba1d82..bd2135f 100644
--- a/src/mesa/state_tracker/st_atom_texture.c
+++ b/src/mesa/state_tracker/st_atom_texture.c
@@ -152,7 +152,20 @@ st_create_texture_sampler_view_from_stobj(struct pipe_context *pipe,
    u_sampler_view_default_template(&templ,
                                    stObj->pt,
                                    format);
-   templ.u.tex.first_level = stObj->base.BaseLevel;
+
+   if (stObj->pt->target == PIPE_BUFFER) {
+      unsigned f, n;
+      const struct util_format_description *desc
+         = util_format_description(templ.format);
+
+      f = (stObj->base.BufferOffset * 8 / desc->block.bits) * desc->block.width;
+      n = (stObj->base.BufferSize * 8 / desc->block.bits) * desc->block.width;
+
+      templ.u.buf.first_element = f;
+      templ.u.buf.last_element = f + (n ? (n - 1) : 0);
+   } else {
+      templ.u.tex.first_level = stObj->base.BaseLevel;
+   }
 
    if (swizzle != SWIZZLE_NOOP) {
       templ.swizzle_r = GET_SWZ(swizzle, 0);
diff --git a/src/mesa/state_tracker/st_extensions.c b/src/mesa/state_tracker/st_extensions.c
index 262cc3d..60db753 100644
--- a/src/mesa/state_tracker/st_extensions.c
+++ b/src/mesa/state_tracker/st_extensions.c
@@ -670,7 +670,13 @@ void st_init_extensions(struct st_context *st)
       ctx->Extensions.ARB_map_buffer_alignment = GL_TRUE;
    }
    if (screen->get_param(screen, PIPE_CAP_TEXTURE_BUFFER_OBJECTS)) {
+      ctx->Const.TextureBufferOffsetAlignment =
+         screen->get_param(screen, PIPE_CAP_TEXTURE_BUFFER_OFFSET_ALIGNMENT);
+
       ctx->Extensions.ARB_texture_buffer_object = GL_TRUE;
+      if (ctx->Const.TextureBufferOffsetAlignment)
+         ctx->Extensions.ARB_texture_buffer_range = GL_TRUE;
+
       init_format_extensions(st, tbo_rgb32, Elements(tbo_rgb32),
                              PIPE_BUFFER, PIPE_BIND_SAMPLER_VIEW);
    }
-- 
1.7.3.4