i965/vs: Move compute_clip_distance() out of emit_urb_writes().

Legacy user clipping (using gl_Position or gl_ClipVertex) is handled by
turning those into the modern gl_ClipDistance equivalents.

This is unnecessary in Core Profile: if user clipping is enabled, but
the shader doesn't write the corresponding gl_ClipDistance entry,
results are undefined.  Hence, it is also unnecessary for geometry
shaders.

This patch moves the call up to run_vs().  This is equivalent for VS,
but removes the need to pass clip distances into emit_urb_writes().

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Jason Ekstrand <jason.ekstrand@intel.com>
Reviewed-by: Chris Forbes <chrisf@ijw.co.nz>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 4292aa6..8658554 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -3816,7 +3816,9 @@ fs_visitor::run_vs(gl_clip_plane *clip_planes)
    if (failed)
       return false;
 
-   emit_urb_writes(clip_planes);
+   compute_clip_distance(clip_planes);
+
+   emit_urb_writes();
 
    if (shader_time_index >= 0)
       emit_shader_time_end();