[Mesa-dev] [PATCHi V2] mesa: add KHR_no_error support for glUseProgram

[Timothy Arceri]

V2: use CALL_ dispatch macro to select no_error variant of
    BindProgramPipeline rather than a custom USE_PROGRAM
    macro.
---
 
 I'm actually not to sure if using the CALL_ macro is any better
 than just a no error check to select the correct function. It
 seems like it should be, but either way it feels a bit cleaner
 this way.
  

 src/mapi/glapi/gen/gl_API.xml |  2 +-
 src/mesa/main/shaderapi.c     | 75 +++++++++++++++++++++++++++++--------------
 src/mesa/main/shaderapi.h     |  2 ++
 3 files changed, 54 insertions(+), 25 deletions(-)

diff --git a/src/mapi/glapi/gen/gl_API.xml b/src/mapi/glapi/gen/gl_API.xml
index 83f4c01..c271887 100644
--- a/src/mapi/glapi/gen/gl_API.xml
+++ b/src/mapi/glapi/gen/gl_API.xml
@@ -5493,21 +5493,21 @@
     </function>
 
     <function name="ShaderSource" es2="2.0" marshal="custom">
         <param name="shader" type="GLuint"/>
         <param name="count" type="GLsizei"/>
         <param name="string" type="const GLchar * const *"/>
         <param name="length" type="const GLint *"/>
         <glx ignore="true"/>
     </function>
 
-    <function name="UseProgram" es2="2.0">
+    <function name="UseProgram" es2="2.0" no_error="true">
         <param name="program" type="GLuint"/>
         <glx ignore="true"/>
     </function>
 
     <function name="Uniform1f" es2="2.0">
         <param name="location" type="GLint"/>
         <param name="v0" type="GLfloat"/>
         <glx ignore="true"/>
     </function>
     <function name="Uniform2f" es2="2.0">
diff --git a/src/mesa/main/shaderapi.c b/src/mesa/main/shaderapi.c
index eb75a3e..6a35815 100644
--- a/src/mesa/main/shaderapi.c
+++ b/src/mesa/main/shaderapi.c
@@ -1841,20 +1841,70 @@ _mesa_ShaderSource(GLuint shaderObj, GLsizei count,
       free(source);
       source = replacement;
    }
 #endif /* ENABLE_SHADER_CACHE */
 
    shader_source(sh, source);
 
    free(offsets);
 }
 
+/* The ARB_separate_shader_object spec says:
+ *
+ *     "The executable code for an individual shader stage is taken from
+ *     the current program for that stage.  If there is a current program
+ *     object established by UseProgram, that program is considered current
+ *     for all stages.  Otherwise, if there is a bound program pipeline
+ *     object (section 2.14.PPO), the program bound to the appropriate
+ *     stage of the pipeline object is considered current."
+ */
+static void
+reference_pipeline_and_use_program(struct gl_context *ctx,
+                                   struct gl_shader_program *shProg)
+{
+   if (shProg) {
+      /* Attach shader state to the binding point */
+      _mesa_reference_pipeline_object(ctx, &ctx->_Shader, &ctx->Shader);
+      /* Update the program */
+      _mesa_use_shader_program(ctx, shProg);
+   } else {
+      /* Must be done first: detach the progam */
+      _mesa_use_shader_program(ctx, shProg);
+      /* Unattach shader_state binding point */
+      _mesa_reference_pipeline_object(ctx, &ctx->_Shader,
+                                      ctx->Pipeline.Default);
+      /* If a pipeline was bound, rebind it */
+      if (ctx->Pipeline.Current) {
+         /* The CALL_ macro will automatically select the no_error variant if
+          * applicable.
+          */
+         CALL_BindProgramPipeline(GET_DISPATCH(),
+                                  (ctx->Pipeline.Current->Name));
+      }
+   }
+}
+
+                                                                      \
+
+void GLAPIENTRY
+_mesa_UseProgram_no_error(GLuint program)
+{
+   GET_CURRENT_CONTEXT(ctx);
+   struct gl_shader_program *shProg = NULL;
+
+   if (program) {
+      shProg = _mesa_lookup_shader_program(ctx, program);
+   }
+
+   reference_pipeline_and_use_program(ctx, shProg);
+}
+
 
 void GLAPIENTRY
 _mesa_UseProgram(GLuint program)
 {
    GET_CURRENT_CONTEXT(ctx);
    struct gl_shader_program *shProg = NULL;
 
    if (MESA_VERBOSE & VERBOSE_API)
       _mesa_debug(ctx, "glUseProgram %u\n", program);
 
@@ -1875,44 +1925,21 @@ _mesa_UseProgram(GLuint program)
          return;
       }
 
 #ifdef DEBUG
       if (ctx->_Shader->Flags & GLSL_USE_PROG) {
          print_shader_info(shProg);
       }
 #endif
    }
 
-   /* The ARB_separate_shader_object spec says:
-    *
-    *     "The executable code for an individual shader stage is taken from
-    *     the current program for that stage.  If there is a current program
-    *     object established by UseProgram, that program is considered current
-    *     for all stages.  Otherwise, if there is a bound program pipeline
-    *     object (section 2.14.PPO), the program bound to the appropriate
-    *     stage of the pipeline object is considered current."
-    */
-   if (program) {
-      /* Attach shader state to the binding point */
-      _mesa_reference_pipeline_object(ctx, &ctx->_Shader, &ctx->Shader);
-      /* Update the program */
-      _mesa_use_shader_program(ctx, shProg);
-   } else {
-      /* Must be done first: detach the progam */
-      _mesa_use_shader_program(ctx, shProg);
-      /* Unattach shader_state binding point */
-      _mesa_reference_pipeline_object(ctx, &ctx->_Shader, ctx->Pipeline.Default);
-      /* If a pipeline was bound, rebind it */
-      if (ctx->Pipeline.Current) {
-         _mesa_BindProgramPipeline(ctx->Pipeline.Current->Name);
-      }
-   }
+   reference_pipeline_and_use_program(ctx, shProg);
 }
 
 
 void GLAPIENTRY
 _mesa_ValidateProgram(GLuint program)
 {
    GET_CURRENT_CONTEXT(ctx);
    validate_program(ctx, program);
 }
 
diff --git a/src/mesa/main/shaderapi.h b/src/mesa/main/shaderapi.h
index 99b4fe8..0a28185 100644
--- a/src/mesa/main/shaderapi.h
+++ b/src/mesa/main/shaderapi.h
@@ -120,20 +120,22 @@ _mesa_IsProgram(GLuint name);
 
 extern GLboolean GLAPIENTRY
 _mesa_IsShader(GLuint name);
 
 extern void GLAPIENTRY
 _mesa_LinkProgram(GLuint programObj);
 
 extern void GLAPIENTRY
 _mesa_ShaderSource(GLuint, GLsizei, const GLchar* const *, const GLint *);
 
+void GLAPIENTRY
+_mesa_UseProgram_no_error(GLuint);
 extern void GLAPIENTRY
 _mesa_UseProgram(GLuint);
 
 extern void GLAPIENTRY
 _mesa_ValidateProgram(GLuint);
 
 
 extern void GLAPIENTRY
 _mesa_BindAttribLocation(GLuint program, GLuint, const GLchar *);
 
-- 
2.9.3