Working on the SnapPlane() issue.

- Adding EXPERIMENTAL_SNAP_PLANE_FIX #define to	q3map2.h, it's now set to 1,
but will be set	to 0 if	and when we merge into trunk.

- SnapPlaneImproved() no longer	takes the center argument but still
fixes the snap distance	(only snap when	normal is axial).

- Adding SnapPlaneImprovedWithCenter() that takes the center argument.
Basically renamed SnapPlaneImproved() from previous commit to
SnapPlaneImprovedWithCenter().

- Adding EXPERIMENTAL_SNAP_PLANE_FIX code block	to FindFloatPlane() that
uses the experimental SnapPlane().

This is	very much a work in progress, many more	things to look at.


git-svn-id: svn://svn.icculus.org/gtkradiant/GtkRadiant/branches/Rambetter-math-fix-experiments@401 8a3a26a2-13c4-0310-b231-cf6edde360e5

tools/quake3/q3map2/map.c

@@ -293,7 +293,29 @@ void SnapPlane( vec3_t normal, vec_t *dist )
 SnapPlaneImproved()
 snaps a plane to normal/distance epsilons, improved code
 */
-void SnapPlaneImproved(vec3_t normal, vec_t *dist, vec3_t center)
+void SnapPlaneImproved(vec3_t normal, vec_t *dist)
+{
+	vec_t	distNearestInt;
+
+	SnapNormal(normal);
+
+	if (VectorIsOnAxis(normal))
+	{
+		// Only snap distance if the normal is an axis.  Otherwise there
+		// is nothing "natural" about snapping the distance to an integer.
+		distNearestInt = Q_rint(*dist);
+		if (-distanceEpsilon < *dist - distNearestInt && *dist - distNearestInt < distanceEpsilon)
+		{
+			*dist = distNearestInt;
+		}
+	}
+}
+
+/*
+SnapPlaneImprovedWithCenter()
+snaps a plane to normal/distance epsilons, improved code uses center
+*/
+void SnapPlaneImprovedWithCenter(vec3_t normal, vec_t *dist, const vec3_t center)
 {
 	vec_t	distNearestInt;
 
@@ -331,8 +353,27 @@ int FindFloatPlane( vec3_t normal, vec_t dist, int numPoints, vec3_t *points )
 	vec_t	d;
 	
 	
-	/* hash the plane */
+#if EXPERIMENTAL_SNAP_PLANE_FIX
+	vec3_t	center;
+
+	if (numPoints > 0)
+	{
+		VectorClear(center);
+		for (i = 0; i < numPoints; i++)
+		{
+			VectorAdd(center, points[i], center);
+		}
+		for (j = 0; j < 3; j++) { center[j] = center[j] / numPoints; }
+		SnapPlaneImprovedWithCenter(normal, &dist, center);
+	}
+	else
+	{
+		SnapPlaneImproved(normal, &dist);
+	}
+#else
 	SnapPlane( normal, &dist );
+#endif
+	/* hash the plane */
 	hash = (PLANE_HASHES - 1) & (int) fabs( dist );
 	
 	/* search the border bins as well */

tools/quake3/q3map2/q3map2.h

@@ -125,6 +125,7 @@ constants
 /* temporary hacks and tests (please keep off in SVN to prevent anyone's legacy map from screwing up) */
 #define EXPERIMENTAL_HIGH_PRECISION_MATH_Q3MAP2_FIXES	1
 #define EXPERIMENTAL_SNAP_NORMAL_FIX			1
+#define EXPERIMENTAL_SNAP_PLANE_FIX			1
 
 /* general */
 #define MAX_QPATH				64