mesa: validate sampler uniforms during gluniform calls

Patch fixes 'glsl-2types-of-textures-on-same-unit' in WebGL conformance
test suite. No Piglit regressions, fixes gl-2.0-active-sampler-conflict.

To avoid adding potentially heavy check during draw (valid_to_render),
check is done during uniform updates by inspecting TexturesUsed mask.

A new boolean variable is introduced to cache validation state.

v2: take into account case where 2 uniforms use same unit (curro)
    also do the check only when SSO is not in use, SSO has own
    path for sampler validation.

Signed-off-by: Tapani Pälli <tapani.palli@intel.com>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>

1 files changed, 9 insertions, 35 deletions

diff --git a/src/mesa/main/uniform_query.cpp b/src/mesa/main/uniform_query.cpp
index 1592c9b..c2776c0 100644
--- a/src/mesa/main/uniform_query.cpp
+++ b/src/mesa/main/uniform_query.cpp
@@ -1064,42 +1064,16 @@ extern "C" bool
 _mesa_sampler_uniforms_are_valid(const struct gl_shader_program *shProg,
 				 char *errMsg, size_t errMsgLength)
 {
-   const glsl_type *unit_types[MAX_COMBINED_TEXTURE_IMAGE_UNITS];
-
-   memset(unit_types, 0, sizeof(unit_types));
-
-   for (unsigned i = 0; i < shProg->NumUserUniformStorage; i++) {
-      const struct gl_uniform_storage *const storage =
-	 &shProg->UniformStorage[i];
-      const glsl_type *const t = (storage->type->is_array())
-	 ? storage->type->fields.array : storage->type;
-
-      if (!t->is_sampler())
-	 continue;
-
-      const unsigned count = MAX2(1, storage->type->array_size());
-      for (unsigned j = 0; j < count; j++) {
-	 const unsigned unit = storage->storage[j].i;
-
-	 /* The types of the samplers associated with a particular texture
-	  * unit must be an exact match.  Page 74 (page 89 of the PDF) of the
-	  * OpenGL 3.3 core spec says:
-	  *
-	  *     "It is not allowed to have variables of different sampler
-	  *     types pointing to the same texture image unit within a program
-	  *     object."
-	  */
-	 if (unit_types[unit] == NULL) {
-	    unit_types[unit] = t;
-	 } else if (unit_types[unit] != t) {
-	    _mesa_snprintf(errMsg, errMsgLength,
-			   "Texture unit %d is accessed both as %s and %s",
-			   unit, unit_types[unit]->name, t->name);
-	    return false;
-	 }
-      }
+   /* Shader does not have samplers. */
+   if (shProg->NumUserUniformStorage == 0)
+      return true;
+
+   if (!shProg->SamplersValidated) {
+      _mesa_snprintf(errMsg, errMsgLength,
+                     "active samplers with a different type "
+                     "refer to the same texture image unit");
+      return false;
    }
-
    return true;
 }