[Mesa-dev] [PATCH 09/25] glsl: Add support for image binding qualifiers.

[Francisco Jerez]

Support for binding an image to an image unit explicitly in the shader
source is required by both GLSL 4.2 and GLSL ES 3.1, but not by the
original ARB_shader_image_load_store extension.
---
 src/glsl/ast_to_hir.cpp                | 12 +++++++++++-
 src/glsl/link_uniform_initializers.cpp | 24 +++++++++++++++++-------
 2 files changed, 28 insertions(+), 8 deletions(-)

diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
index 06cd6a5..0bf7a1f 100644
--- a/src/glsl/ast_to_hir.cpp
+++ b/src/glsl/ast_to_hir.cpp
@@ -2181,10 +2181,20 @@ validate_binding_qualifier(struct _mesa_glsl_parse_state *state,
 
          return false;
       }
+   } else if (state->is_version(420, 310) &&
+              var->type->without_array()->is_image()) {
+      assert(ctx->Const.MaxImageUnits <= MAX_IMAGE_UNITS);
+      if (max_index >= ctx->Const.MaxImageUnits) {
+         _mesa_glsl_error(loc, state, "Image binding %d exceeds the "
+                          " maximum number of image units (%d)", max_index,
+                          ctx->Const.MaxImageUnits);
+         return false;
+      }
+
    } else {
       _mesa_glsl_error(loc, state,
                        "the \"binding\" qualifier only applies to uniform "
-                       "blocks, samplers, atomic counters, or arrays thereof");
+                       "blocks, opaque variables, or arrays thereof");
       return false;
    }
 
diff --git a/src/glsl/link_uniform_initializers.cpp b/src/glsl/link_uniform_initializers.cpp
index d61ae91..7c6269b 100644
--- a/src/glsl/link_uniform_initializers.cpp
+++ b/src/glsl/link_uniform_initializers.cpp
@@ -101,7 +101,7 @@ copy_constant_to_storage(union gl_constant_value *storage,
 }
 
 void
-set_sampler_binding(gl_shader_program *prog, const char *name, int binding)
+set_opaque_binding(gl_shader_program *prog, const char *name, int binding)
 {
    struct gl_uniform_storage *const storage =
       get_storage(prog->UniformStorage, prog->NumUniformStorage, name);
@@ -127,11 +127,20 @@ set_sampler_binding(gl_shader_program *prog, const char *name, int binding)
    for (int sh = 0; sh < MESA_SHADER_STAGES; sh++) {
       gl_shader *shader = prog->_LinkedShaders[sh];
 
-      if (shader && storage->sampler[sh].active) {
-         for (unsigned i = 0; i < elements; i++) {
-            unsigned index = storage->sampler[sh].index + i;
+      if (shader) {
+         if (storage->type->base_type == GLSL_TYPE_SAMPLER &&
+             storage->sampler[sh].active) {
+            for (unsigned i = 0; i < elements; i++) {
+               const unsigned index = storage->sampler[sh].index + i;
+               shader->SamplerUnits[index] = storage->storage[i].i;
+            }
 
-            shader->SamplerUnits[index] = storage->storage[i].i;
+         } else if (storage->type->base_type == GLSL_TYPE_IMAGE &&
+                    storage->image[sh].active) {
+            for (unsigned i = 0; i < elements; i++) {
+               const unsigned index = storage->image[sh].index + i;
+               shader->ImageUnits[index] = storage->storage[i].i;
+            }
          }
       }
    }
@@ -267,8 +276,9 @@ link_set_uniform_initializers(struct gl_shader_program *prog,
          if (var->data.explicit_binding) {
             const glsl_type *const type = var->type;
 
-            if (type->without_array()->is_sampler()) {
-               linker::set_sampler_binding(prog, var->name, var->data.binding);
+            if (type->without_array()->is_sampler() ||
+                type->without_array()->is_image()) {
+               linker::set_opaque_binding(prog, var->name, var->data.binding);
             } else if (var->is_in_buffer_block()) {
                const glsl_type *const iface_type = var->get_interface_type();
 
-- 
2.4.6