mesa: added _mesa_nop_vertex/fragment_program()

For debug/test purposes.

src/mesa/shader/programopt.c

@@ -573,3 +573,94 @@ _mesa_remove_output_reads(struct gl_program *prog, gl_register_file type)
       }
    }
 }
+
+
+/**
+ * Make the given fragment program into a "no-op" shader.
+ * Actually, just copy the incoming fragment color (or texcoord)
+ * to the output color.
+ * This is for debug/test purposes.
+ */
+void
+_mesa_nop_fragment_program(GLcontext *ctx, struct gl_fragment_program *prog)
+{
+   struct prog_instruction *inst;
+   GLuint inputAttr;
+
+   inst = _mesa_alloc_instructions(2);
+   if (!inst) {
+      _mesa_error(ctx, GL_OUT_OF_MEMORY, "_mesa_nop_fragment_program");
+      return;
+   }
+
+   _mesa_init_instructions(inst, 2);
+
+   inst[0].Opcode = OPCODE_MOV;
+   inst[0].DstReg.File = PROGRAM_OUTPUT;
+   inst[0].DstReg.Index = FRAG_RESULT_COLOR;
+   inst[0].SrcReg[0].File = PROGRAM_INPUT;
+   if (prog->Base.InputsRead & FRAG_BIT_COL0)
+      inputAttr = FRAG_ATTRIB_COL0;
+   else
+      inputAttr = FRAG_ATTRIB_TEX0;
+   inst[0].SrcReg[0].Index = inputAttr;
+
+   inst[1].Opcode = OPCODE_END;
+
+   _mesa_free_instructions(prog->Base.Instructions,
+                           prog->Base.NumInstructions);
+
+   prog->Base.Instructions = inst;
+   prog->Base.NumInstructions = 2;
+   prog->Base.InputsRead = 1 << inputAttr;
+   prog->Base.OutputsWritten = 1 << FRAG_RESULT_COLOR;
+}
+
+
+/**
+ * \sa _mesa_nop_fragment_program
+ * Replace the given vertex program with a "no-op" program that just
+ * transforms vertex position and emits color.
+ */
+void
+_mesa_nop_vertex_program(GLcontext *ctx, struct gl_vertex_program *prog)
+{
+   struct prog_instruction *inst;
+   GLuint inputAttr;
+
+   /*
+    * Start with a simple vertex program that emits color.
+    */
+   inst = _mesa_alloc_instructions(2);
+   if (!inst) {
+      _mesa_error(ctx, GL_OUT_OF_MEMORY, "_mesa_nop_vertex_program");
+      return;
+   }
+
+   _mesa_init_instructions(inst, 2);
+
+   inst[0].Opcode = OPCODE_MOV;
+   inst[0].DstReg.File = PROGRAM_OUTPUT;
+   inst[0].DstReg.Index = VERT_RESULT_COL0;
+   inst[0].SrcReg[0].File = PROGRAM_INPUT;
+   if (prog->Base.InputsRead & VERT_BIT_COLOR0)
+      inputAttr = VERT_ATTRIB_COLOR0;
+   else
+      inputAttr = VERT_ATTRIB_TEX0;
+   inst[0].SrcReg[0].Index = inputAttr;
+
+   inst[1].Opcode = OPCODE_END;
+
+   _mesa_free_instructions(prog->Base.Instructions,
+                           prog->Base.NumInstructions);
+
+   prog->Base.Instructions = inst;
+   prog->Base.NumInstructions = 2;
+   prog->Base.InputsRead = 1 << inputAttr;
+   prog->Base.OutputsWritten = 1 << VERT_RESULT_COL0;
+
+   /*
+    * Now insert code to do standard modelview/projection transformation.
+    */
+   _mesa_insert_mvp_code(ctx, prog);
+}

src/mesa/shader/programopt.h

@@ -42,4 +42,11 @@ _mesa_count_texture_instructions(struct gl_program *prog);
 extern void
 _mesa_remove_output_reads(struct gl_program *prog, gl_register_file type);
 
+extern void
+_mesa_nop_fragment_program(GLcontext *ctx, struct gl_fragment_program *prog);
+
+extern void
+_mesa_nop_vertex_program(GLcontext *ctx, struct gl_vertex_program *prog);
+
+
 #endif /* PROGRAMOPT_H */