[Mesa-dev] [PATCH 14/17] i965: Disable rendering to integer GL_RGB textures.

[Eric Anholt]

We can't really do this because we don't have support for forcing the
alpha to 1 when it gets used for other purposes (readpixels,
texturing).

Fixes the last failure in EXT_texture_integer/fbo-blending

NOTE: This is a candidate for the 8.0 branch.
---
 src/mesa/drivers/dri/i965/brw_wm_surface_state.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
index f203f98..b1be5e8 100644
--- a/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
+++ b/src/mesa/drivers/dri/i965/brw_wm_surface_state.c
@@ -599,6 +599,13 @@ brw_render_target_supported(struct intel_context *intel,
    struct brw_context *brw = brw_context(&intel->ctx);
    gl_format format = rb->Format;
 
+   /* Our GL_RGB formats are promoted to RGBA, but we can't use the alpha
+    * blending trick to force alpha to one like we do for normalized surfaces,
+    * since the hardware can't do blending to integer render targets.
+    */
+   if (rb->_BaseFormat == GL_RGB && _mesa_is_format_integer_color(rb->Format))
+      return false;
+
    return brw->format_supported_as_render_target[format];
 }
 
-- 
1.7.7.3