Resuscitate some of the DDX,DDY code.
Only works for program input registers at this time.
Good enough for the common case of texcoords, though.
diff --git a/src/mesa/shader/prog_execute.h b/src/mesa/shader/prog_execute.h
index 47845e9..be29ece 100644
--- a/src/mesa/shader/prog_execute.h
+++ b/src/mesa/shader/prog_execute.h
@@ -48,6 +48,9 @@
/** Fragment Input attributes */
GLfloat (*Attribs)[MAX_WIDTH][4];
+ GLfloat (*DerivX)[4];
+ GLfloat (*DerivY)[4];
+ GLuint NumDeriv; /**< Max index into DerivX/Y arrays */
GLuint CurElement; /**< Index into Attribs arrays */
/** Vertex Input attribs */