From: Daniel Borca <dborca@users.sourceforge.net>
Date: Fri, 12 Dec 2003 08:19:20 +0000 (+0000)
Subject: small bug wrt culling
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=e01d671668a2f618de689e72cce5caf21f57d4a0;p=mesa.git

small bug wrt culling
---

diff --git a/src/mesa/drivers/glide/fxtris.c b/src/mesa/drivers/glide/fxtris.c
index 9be2e1a88f8..56563fc4123 100644
--- a/src/mesa/drivers/glide/fxtris.c
+++ b/src/mesa/drivers/glide/fxtris.c
@@ -389,9 +389,17 @@ static struct {
 #define VERT_X(_v) _v->x
 #define VERT_Y(_v) _v->y
 #define VERT_Z(_v) _v->ooz
-#define AREA_IS_CCW( a ) IS_NEGATIVE(a) /*(a < 0)*/
 #define GET_VERTEX(e) (fxMesa->verts + e)
 
+#ifdef USE_IEEE
+/* type-punning, keep -fstrict-aliasing happy */
+typedef union { GLfloat f; GLuint u; } fu_type;
+/* 0/1 value, to allow XOR'ing with other booleans */
+#define AREA_IS_CCW( a ) (((fu_type *)&(a))->u >> 31)
+#else
+#define AREA_IS_CCW( a ) (a < 0)
+#endif
+
 #define VERT_SET_RGBA( dst, f )			\
 do {						\
    UNCLAMPED_FLOAT_TO_UBYTE(dst->pargb[2], f[0]);\