mesa: Add support for ARB_shader_atomic_counters.

This patch implements the common support code required for the
ARB_shader_atomic_counters extension.  It defines the necessary data
structures for tracking atomic counter buffer objects (from now on
"ABOs") associated with some specific context or shader program, it
implements support for binding buffers to an ABO binding point and
querying the existing atomic counters and buffers declared by GLSL
shaders.

v2: Fix extension checks.  Drop unused MAX_ATOMIC_BUFFERS constant.

Acked-by: Paul Berry <stereotype441@gmail.com>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>

1 files changed, 61 insertions, 1 deletions

diff --git a/src/mesa/main/uniforms.c b/src/mesa/main/uniforms.c
index 07e7ea3..2e847fe 100644
--- a/src/mesa/main/uniforms.c
+++ b/src/mesa/main/uniforms.c
@@ -535,7 +535,8 @@ _mesa_GetUniformLocation(GLhandleARB programObj, const GLcharARB *name)
     *      with a named uniform block, or if <name> starts with the reserved
     *      prefix "gl_"."
     */
-   if (shProg->UniformStorage[index].block_index != -1)
+   if (shProg->UniformStorage[index].block_index != -1 ||
+       shProg->UniformStorage[index].atomic_buffer_index != -1)
       return -1;
 
    return _mesa_uniform_merge_location_offset(shProg, index, offset);
@@ -849,4 +850,63 @@ void GLAPIENTRY
 _mesa_GetActiveAtomicCounterBufferiv(GLuint program, GLuint bufferIndex,
                                      GLenum pname, GLint *params)
 {
+   GET_CURRENT_CONTEXT(ctx);
+   struct gl_shader_program *shProg;
+   struct gl_active_atomic_buffer *ab;
+   int i;
+
+   if (!ctx->Extensions.ARB_shader_atomic_counters) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "glGetActiveAtomicCounterBufferiv");
+      return;
+   }
+
+   shProg = _mesa_lookup_shader_program_err(ctx, program,
+                                            "glGetActiveAtomicCounterBufferiv");
+   if (!shProg)
+      return;
+
+   if (bufferIndex >= shProg->NumAtomicBuffers) {
+      _mesa_error(ctx, GL_INVALID_VALUE,
+                  "glGetActiveAtomicCounterBufferiv(bufferIndex)");
+      return;
+   }
+
+   ab = &shProg->AtomicBuffers[bufferIndex];
+
+   switch (pname) {
+   case GL_ATOMIC_COUNTER_BUFFER_BINDING:
+      params[0] = ab->Binding;
+      return;
+   case GL_ATOMIC_COUNTER_BUFFER_DATA_SIZE:
+      params[0] = ab->MinimumSize;
+      return;
+   case GL_ATOMIC_COUNTER_BUFFER_ACTIVE_ATOMIC_COUNTERS:
+      params[0] = ab->NumUniforms;
+      return;
+   case GL_ATOMIC_COUNTER_BUFFER_ACTIVE_ATOMIC_COUNTER_INDICES:
+      for (i = 0; i < ab->NumUniforms; ++i)
+         params[i] = ab->Uniforms[i];
+      return;
+   case GL_ATOMIC_COUNTER_BUFFER_REFERENCED_BY_VERTEX_SHADER:
+      params[0] = ab->StageReferences[MESA_SHADER_VERTEX];
+      return;
+   case GL_ATOMIC_COUNTER_BUFFER_REFERENCED_BY_GEOMETRY_SHADER:
+      params[0] = ab->StageReferences[MESA_SHADER_GEOMETRY];
+      return;
+   case GL_ATOMIC_COUNTER_BUFFER_REFERENCED_BY_FRAGMENT_SHADER:
+      params[0] = ab->StageReferences[MESA_SHADER_FRAGMENT];
+      return;
+   case GL_ATOMIC_COUNTER_BUFFER_REFERENCED_BY_TESS_CONTROL_SHADER:
+      params[0] = GL_FALSE;
+      return;
+   case GL_ATOMIC_COUNTER_BUFFER_REFERENCED_BY_TESS_EVALUATION_SHADER:
+      params[0] = GL_FALSE;
+      return;
+   default:
+      _mesa_error(ctx, GL_INVALID_ENUM,
+                  "glGetActiveAtomicCounterBufferiv(pname 0x%x (%s))",
+                  pname, _mesa_lookup_enum_by_nr(pname));
+      return;
+   }
 }