mesa/main: set PREFER_DP4 to match position_invarient code

This is a quick fix for z fighting in quake4 caused by the mismatch
between vertex transformation here and in the position_invarient code.
Full fix would be to make this driver-tunable and adjust both
position_invarient and ffvertex_prog.c code to respect driver
preferences.

diff --git a/src/mesa/main/ffvertex_prog.c b/src/mesa/main/ffvertex_prog.c
index 1ce5685af45ebda2f1c3d87f992748af77ba80ae..82e1c4af665c2a0a2cfc2473870b34b57981d1fb 100644 (file)
--- a/src/mesa/main/ffvertex_prog.c
+++ b/src/mesa/main/ffvertex_prog.c
@@ -319,7 +319,7 @@ static void make_state_key( GLcontext *ctx, struct state_key *key )
  * multiplications with DP4's or with MUL/MAD's?  SSE works better
  * with the latter, drivers may differ.
  */
-#define PREFER_DP4 0
+#define PREFER_DP4 1
 
 
 /* Use uregs to represent registers internally, translate to Mesa's