Mesa (master): mesa: Fix extension dependency for half-float TexBOs

[Eric Anholt]

Module: Mesa
Branch: master
Commit: 6d6a29018119fd414973ad051fc2271c784ef0f1
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=6d6a29018119fd414973ad051fc2271c784ef0f1

Author: Ian Romanick <ian.d.romanick at intel.com>
Date:   Mon Jan 13 15:18:23 2014 -0800

mesa: Fix extension dependency for half-float TexBOs

Half-float TexBOs should require both GL_ARB_half_float_pixel and
GL_ARB_texture_float.  This doesn't matter much in practice.  Every
driver that supports GL_ARB_texture_buffer_object already supports
GL_ARB_half_float_pixel.  We only expose the TexBO extension in core
profiles, and those require GL_ARB_texture_float.

Signed-off-by: Ian Romanick <ian.d.romanick at intel.com>
Reviewed-by: Eric Anholt <eric at anholt.net>

---

 src/mesa/main/teximage.c |   13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/mesa/main/teximage.c b/src/mesa/main/teximage.c
index 4d635fe..07ac1e1 100644
--- a/src/mesa/main/teximage.c
+++ b/src/mesa/main/teximage.c
@@ -4186,7 +4186,18 @@ _mesa_validate_texbuffer_format(const struct gl_context *ctx,
    if (datatype == GL_FLOAT && !ctx->Extensions.ARB_texture_float)
       return MESA_FORMAT_NONE;
 
-   if (datatype == GL_HALF_FLOAT && !ctx->Extensions.ARB_half_float_pixel)
+   /* The GL_ARB_texture_buffer_object spec says:
+    *
+    *     "If ARB_texture_float is not supported, references to the
+    *     floating-point internal formats provided by that extension should be
+    *     removed, and such formats may not be passed to TexBufferARB."
+    *
+    * As a result, GL_HALF_FLOAT internal format depends on both
+    * GL_ARB_texture_float and GL_ARB_half_float_pixel.
+    */
+   if (datatype == GL_HALF_FLOAT &&
+       !(ctx->Extensions.ARB_half_float_pixel
+         && ctx->Extensions.ARB_texture_float))
       return MESA_FORMAT_NONE;
 
    if (!ctx->Extensions.ARB_texture_rg) {