mesa/sso: replace Shader binding point with _Shader

To avoid NULL pointer check a default pipeline object is installed in
_Shader when no program is current

The spec say that UseProgram/UseShaderProgramEXT/ActiveProgramEXT got an
higher priority over the pipeline object. When default program is
uninstall, the pipeline is used if any was bound.

Note: A careful rename need to be done now...

V2: formating improvement

V3 (idr):
* Build fix.  The original patch added calls to _mesa_use_shader_program
  with 4 parameters, but the fourth parameter isn't added to that
  function until a much later patch.  Just drop that parameter for now.
* Trivial reformatting.
* Updated comment of gl_context::_Shader

v4 (idr): Reformat spec quotations to look like spec quotations.  Update
comments describing what gl_context::_Shader can point to.  Bot
suggested by Eric.

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>

1 files changed, 8 insertions, 0 deletions

diff --git a/src/mesa/main/pipelineobj.c b/src/mesa/main/pipelineobj.c
index 27012df..849c781 100644
--- a/src/mesa/main/pipelineobj.c
+++ b/src/mesa/main/pipelineobj.c
@@ -94,6 +94,10 @@ _mesa_init_pipeline(struct gl_context *ctx)
    ctx->Pipeline.Objects = _mesa_NewHashTable();
 
    ctx->Pipeline.Current = NULL;
+
+   /* Install a default Pipeline */
+   ctx->Pipeline.Default = _mesa_new_pipeline_object(ctx, 0);
+   _mesa_reference_pipeline_object(ctx, &ctx->_Shader, ctx->Pipeline.Default);
 }
 
 
@@ -117,6 +121,10 @@ _mesa_free_pipeline_data(struct gl_context *ctx)
 {
    _mesa_HashDeleteAll(ctx->Pipeline.Objects, delete_pipelineobj_cb, ctx);
    _mesa_DeleteHashTable(ctx->Pipeline.Objects);
+
+   _mesa_reference_pipeline_object(ctx, &ctx->_Shader, NULL);
+   _mesa_delete_pipeline_object(ctx, ctx->Pipeline.Default);
+
 }
 
 /**