Mesa (master): glsl: create helper to remove outer vertex index array used by some stages

[Timothy Arceri]

Module: Mesa
Branch: master
Commit: 5907a02ab6fbe20b4ba58eb00bf93261129798d5
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=5907a02ab6fbe20b4ba58eb00bf93261129798d5

Author: Timothy Arceri <timothy.arceri at collabora.com>
Date:   Fri Dec 18 13:53:27 2015 +1100

glsl: create helper to remove outer vertex index array used by some stages

This will be used in the following patch for calculating array sizes correctly
when reserving explicit varying locations.

Reviewed-by: Anuj Phogat <anuj.phogat at gmail.com>
Reviewed-by: Edward O'Callaghan <eocallaghan at alterapraxis.com>

---

 src/glsl/link_varyings.cpp |   36 ++++++++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 10 deletions(-)

diff --git a/src/glsl/link_varyings.cpp b/src/glsl/link_varyings.cpp
index a80a1b5..863a399 100644
--- a/src/glsl/link_varyings.cpp
+++ b/src/glsl/link_varyings.cpp
@@ -41,6 +41,29 @@
 
 
 /**
+ * Get the varying type stripped of the outermost array if we're processing
+ * a stage whose varyings are arrays indexed by a vertex number (such as
+ * geometry shader inputs).
+ */
+static const glsl_type *
+get_varying_type(const ir_variable *var, gl_shader_stage stage)
+{
+   const glsl_type *type = var->type;
+
+   if (!var->data.patch &&
+       ((var->data.mode == ir_var_shader_out &&
+         stage == MESA_SHADER_TESS_CTRL) ||
+        (var->data.mode == ir_var_shader_in &&
+         (stage == MESA_SHADER_TESS_CTRL || stage == MESA_SHADER_TESS_EVAL ||
+          stage == MESA_SHADER_GEOMETRY)))) {
+      assert(type->is_array());
+      type = type->fields.array;
+   }
+
+   return type;
+}
+
+/**
  * Validate the types and qualifiers of an output from one stage against the
  * matching input to another stage.
  */
@@ -981,18 +1004,11 @@ varying_matches::record(ir_variable *producer_var, ir_variable *consumer_var)
    this->matches[this->num_matches].packing_order
       = this->compute_packing_order(var);
    if (this->disable_varying_packing) {
-      const struct glsl_type *type = var->type;
       unsigned slots;
+      gl_shader_stage stage =
+         (producer_var != NULL) ? producer_stage : consumer_stage;
 
-      /* Some shader stages have 2-dimensional varyings. Use the inner type. */
-      if (!var->data.patch &&
-          ((var == producer_var && producer_stage == MESA_SHADER_TESS_CTRL) ||
-           (var == consumer_var && (consumer_stage == MESA_SHADER_TESS_CTRL ||
-                                    consumer_stage == MESA_SHADER_TESS_EVAL ||
-                                    consumer_stage == MESA_SHADER_GEOMETRY)))) {
-         assert(type->is_array());
-         type = type->fields.array;
-      }
+      const glsl_type *type = get_varying_type(var, stage);
 
       slots = type->count_attribute_slots(false);
       this->matches[this->num_matches].num_components = slots * 4;