Merge commit 'origin/gallium-0.1'

[mesa.git] / src / mesa / drivers / dri / r300 / radeon_program_alu.c

diff --git a/src/mesa/drivers/dri/r300/radeon_program_alu.c b/src/mesa/drivers/dri/r300/radeon_program_alu.c
index e0a2bd0e9348ffbda4cccb29c5b31dc1c6945b72..1ef71e74dcf27c4c956d7b06cae73a1b8231985d 100644 (file)
--- a/src/mesa/drivers/dri/r300/radeon_program_alu.c
+++ b/src/mesa/drivers/dri/r300/radeon_program_alu.c
@@ -629,3 +629,30 @@ GLboolean radeonTransformTrigScale(struct radeon_transform_context* t,
 
        return GL_TRUE;
 }
+
+/**
+ * Rewrite DDX/DDY instructions to properly work with r5xx shaders.
+ * The r5xx MDH/MDV instruction provides per-quad partial derivatives.
+ * It takes the form A*B+C. A and C are set by setting src0. B should be -1.
+ *
+ * @warning This explicitly changes the form of DDX and DDY!
+ */
+
+GLboolean radeonTransformDeriv(struct radeon_transform_context* t,
+       struct prog_instruction* inst,
+       void* unused)
+{
+       if (inst->Opcode != OPCODE_DDX && inst->Opcode != OPCODE_DDY)
+               return GL_FALSE;
+
+       struct prog_src_register B = inst->SrcReg[1];
+
+       B.Swizzle = MAKE_SWIZZLE4(SWIZZLE_ONE, SWIZZLE_ONE,
+                                               SWIZZLE_ONE, SWIZZLE_ONE);
+       B.NegateBase = NEGATE_XYZW;
+
+       emit2(t->Program, inst->Opcode, inst->SaturateMode, inst->DstReg,
+               inst->SrcReg[0], B);
+
+       return GL_TRUE;
+}