fix STATE_HALF_VECTOR value (bug 10987)

[mesa.git] / src / mesa / shader / prog_statevars.c

diff --git a/src/mesa/shader/prog_statevars.c b/src/mesa/shader/prog_statevars.c
index 953fbb9b9f78fd932fe78c5aef3cf708d8fc79d5..975a617ac898202ccd0181b182f6c37ac0cf75da 100644 (file)
--- a/src/mesa/shader/prog_statevars.c
+++ b/src/mesa/shader/prog_statevars.c
@@ -1,6 +1,6 @@
 /*
  * Mesa 3-D graphics library
- * Version:  6.5.3
+ * Version:  7.0
  *
  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
  *
@@ -121,17 +121,17 @@ _mesa_fetch_state(GLcontext *ctx, const gl_state_index state[],
             return;
          case STATE_HALF_VECTOR:
             {
-               GLfloat eye_z[] = {0, 0, 1};
-                                       
+               static const GLfloat eye_z[] = {0, 0, 1};
+               GLfloat p[3];
                /* Compute infinite half angle vector:
-                *   half-vector = light_position + (0, 0, 1) 
-                * and then normalize.  w = 0
-               *
+                *   halfVector = normalize(normalize(lightPos) + (0, 0, 1))
                * light.EyePosition.w should be 0 for infinite lights.
                 */
-              ADD_3V(value, eye_z, ctx->Light.Light[ln].EyePosition);
+               COPY_3V(p, ctx->Light.Light[ln].EyePosition);
+               NORMALIZE_3FV(p);
+              ADD_3V(value, p, eye_z);
               NORMALIZE_3FV(value);
-              value[3] = 0;
+              value[3] = 1.0;
             }                                            
             return;
         case STATE_POSITION_NORMALIZED: