audit all uses of ClipWindingEpsilon and choose the strict variant or not, and explai...

[xonotic/netradiant.git] / tools / quake3 / q3map2 / surface.c

diff --git a/tools/quake3/q3map2/surface.c b/tools/quake3/q3map2/surface.c
index 5914c40f307d479dcd74daa89d9707f3852f7680..e2ec89093b9155fd5946a38e1dc80e2987887e39 100644 (file)
--- a/tools/quake3/q3map2/surface.c
+++ b/tools/quake3/q3map2/surface.c
@@ -1356,7 +1356,7 @@ static void SubdivideFace_r( entity_t *e, brush_t *brush, side_t *side, winding_
                if( (subCeil - subFloor) > subdivisions )
                {
                        /* clip the winding */
-                       ClipWindingEpsilon( w, planeNormal, d, epsilon, &frontWinding, &backWinding );
+                       ClipWindingEpsilon( w, planeNormal, d, epsilon, &frontWinding, &backWinding ); /* not strict; we assume we always keep a winding */
 
                        /* the clip may not produce two polygons if it was epsilon close */
                        if( frontWinding == NULL )
@@ -1498,8 +1498,14 @@ void ClipSideIntoTree_r( winding_t *w, side_t *side, node_t *node )
                }
 
                plane = &mapplanes[ node->planenum ];
-               ClipWindingEpsilon ( w, plane->normal, plane->dist,
-                               ON_EPSILON, &front, &back );
+               ClipWindingEpsilonStrict ( w, plane->normal, plane->dist,
+                               ON_EPSILON, &front, &back ); /* strict, we handle the "winding disappeared" case */
+               if(!front && !back)
+               {
+                       /* in doubt, register it in both nodes */
+                       front = CopyWinding(w);
+                       back = CopyWinding(w);
+               }
                FreeWinding( w );
 
                ClipSideIntoTree_r( front, side, node->children[0] );
@@ -2108,7 +2114,7 @@ int FilterWindingIntoTree_r( winding_t *w, mapDrawSurface_t *ds, node_t *node )
                }
                
                /* clip the winding by this plane */
-               ClipWindingEpsilonStrict( w, plane1, plane1[ 3 ], ON_EPSILON, &front, &back );
+               ClipWindingEpsilonStrict( w, plane1, plane1[ 3 ], ON_EPSILON, &front, &back ); /* strict; we handle the "winding disappeared" case */
                
                /* filter by this plane */
                refs = 0;