[Mesa-dev] [PATCH] glsl: Only force varyings to be flat when varying packing.

[Kenneth Graunke]

Varying packing would like to mark certain variables as flat.
This works as long as both sides of the interfaces are changed
accordingly.

For tessellation shaders, we disable varying packing, so this
requirement doesn't exist.  Several CTS tests use separable TCS
and TES programs, and this ends up marking the TES input as flat,
while leaving the TCS output alone.

Fixes CTS tests:
*.tessellation_shader.tessellation_control_to_tessellation_evaluation.gl_MaxPatchVertices_Position_PointSize

Also fixes Piglit's spec/oes_geometry_shader/sso_validation:
- user-defined-gs-input-not-in-block.shader_test
- user-defined-gs-input-in-block.shader_test

Signed-off-by: Kenneth Graunke <kenneth at whitecape.org>
---
 src/compiler/glsl/link_varyings.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/compiler/glsl/link_varyings.cpp b/src/compiler/glsl/link_varyings.cpp
index 1bce3e0..1fad310 100644
--- a/src/compiler/glsl/link_varyings.cpp
+++ b/src/compiler/glsl/link_varyings.cpp
@@ -1390,8 +1390,9 @@ varying_matches::record(ir_variable *producer_var, ir_variable *consumer_var)
       (producer_var->type->contains_integer() ||
        producer_var->type->contains_double());
 
-   if (needs_flat_qualifier ||
-       (consumer_stage != -1 && consumer_stage != MESA_SHADER_FRAGMENT)) {
+   if (!disable_varying_packing &&
+       (needs_flat_qualifier ||
+        (consumer_stage != -1 && consumer_stage != MESA_SHADER_FRAGMENT))) {
       /* Since this varying is not being consumed by the fragment shader, its
        * interpolation type varying cannot possibly affect rendering.
        * Also, this variable is non-flat and is (or contains) an integer
-- 
2.9.3