only setup varying vars that will be used

1 files changed, 26 insertions, 22 deletions

diff --git a/src/mesa/swrast/s_linetemp.h b/src/mesa/swrast/s_linetemp.h
index 61c338ac69a..b7b434771ee 100644
--- a/src/mesa/swrast/s_linetemp.h
+++ b/src/mesa/swrast/s_linetemp.h
@@ -1,8 +1,8 @@
 /*
  * Mesa 3-D graphics library
- * Version:  6.5
+ * Version:  6.5.3
  *
- * Copyright (C) 1999-2005  Brian Paul   All Rights Reserved.
+ * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
@@ -336,29 +336,33 @@ NAME( GLcontext *ctx, const SWvertex *vert0, const SWvertex *vert1 )
 #endif
 #ifdef INTERP_VARYING
    interpFlags |= SPAN_VARYING;
-   { /* XXX review this */
+   {
       const GLfloat invLen = 1.0F / numPixels;
+      const GLbitfield inputsUsed = ctx->FragmentProgram._Current ?
+         ctx->FragmentProgram._Current->Base.InputsRead : 0x0;
+      const GLfloat invw0 = vert0->win[3];
+      const GLfloat invw1 = vert1->win[3];
       GLuint v;
       for (v = 0; v < MAX_VARYING; v++) {
-         const GLfloat invw0 = vert0->win[3];
-         const GLfloat invw1 = vert1->win[3];
-         GLfloat ds, dt, dr, dq;
-         span.var[v][0] = invw0 * vert0->varying[v][0];
-         span.var[v][1] = invw0 * vert0->varying[v][1];
-         span.var[v][2] = invw0 * vert0->varying[v][2];
-         span.var[v][3] = invw0 * vert0->varying[v][3];
-         ds = (invw1 * vert1->varying[v][0]) - span.var[v][0];
-         dt = (invw1 * vert1->varying[v][1]) - span.var[v][1];
-         dr = (invw1 * vert1->varying[v][2]) - span.var[v][2];
-         dq = (invw1 * vert1->varying[v][3]) - span.var[v][3];
-         span.varStepX[v][0] = ds * invLen;
-         span.varStepX[v][1] = dt * invLen;
-         span.varStepX[v][2] = dr * invLen;
-         span.varStepX[v][3] = dq * invLen;
-         span.varStepY[v][0] = 0.0F;
-         span.varStepY[v][1] = 0.0F;
-         span.varStepY[v][2] = 0.0F;
-         span.varStepY[v][3] = 0.0F;
+         if (inputsUsed & FRAG_BIT_VAR(v)) {
+            GLfloat ds, dt, dr, dq;
+            span.var[v][0] = invw0 * vert0->varying[v][0];
+            span.var[v][1] = invw0 * vert0->varying[v][1];
+            span.var[v][2] = invw0 * vert0->varying[v][2];
+            span.var[v][3] = invw0 * vert0->varying[v][3];
+            ds = (invw1 * vert1->varying[v][0]) - span.var[v][0];
+            dt = (invw1 * vert1->varying[v][1]) - span.var[v][1];
+            dr = (invw1 * vert1->varying[v][2]) - span.var[v][2];
+            dq = (invw1 * vert1->varying[v][3]) - span.var[v][3];
+            span.varStepX[v][0] = ds * invLen;
+            span.varStepX[v][1] = dt * invLen;
+            span.varStepX[v][2] = dr * invLen;
+            span.varStepX[v][3] = dq * invLen;
+            span.varStepY[v][0] = 0.0F;
+            span.varStepY[v][1] = 0.0F;
+            span.varStepY[v][2] = 0.0F;
+            span.varStepY[v][3] = 0.0F;
+         }
       }
    }
 #endif