BuildTriangleNeighbors now detects edges shared by three triangles, fixes weird shado...

[xonotic/darkplaces.git] / model_shared.c

diff --git a/model_shared.c b/model_shared.c
index 591d8ac15d97a8525fea665701613562b69c444a..323931dc4a54c45ab0ef8fd84327422c2e22d2d0 100644 (file)
--- a/model_shared.c
+++ b/model_shared.c
@@ -384,19 +384,30 @@ static void Mod_Print (void)
                        Con_Printf ("%4iK %s\n", mod->mempool ? (mod->mempool->totalsize + 1023) / 1024 : 0, mod->name);
 }
 
-int Mod_FindTriangleWithEdge(const int *elements, int numtriangles, int start, int end)
+int Mod_FindTriangleWithEdge(const int *elements, int numtriangles, int start, int end, int ignore)
 {
-       int i;
+       int i, match, count;
+       count = 0;
+       match = -1;
        for (i = 0;i < numtriangles;i++, elements += 3)
        {
-               if (elements[0] == start && elements[1] == end)
-                       return i;
-               if (elements[1] == start && elements[2] == end)
-                       return i;
-               if (elements[2] == start && elements[0] == end)
-                       return i;
+                    if ((elements[0] == start && elements[1] == end)
+                     || (elements[1] == start && elements[2] == end)
+                     || (elements[2] == start && elements[0] == end))
+               {
+                       if (i != ignore)
+                               match = i;
+                       count++;
+               }
+               else if ((elements[1] == start && elements[0] == end)
+                     || (elements[2] == start && elements[1] == end)
+                     || (elements[0] == start && elements[2] == end))
+                       count++;
        }
-       return -1;
+       // detect edges shared by three triangles and make them seams
+       if (count > 2)
+               match = -1;
+       return match;
 }
 
 void Mod_BuildTriangleNeighbors(int *neighbors, const int *elements, int numtriangles)
@@ -405,9 +416,9 @@ void Mod_BuildTriangleNeighbors(int *neighbors, const int *elements, int numtria
        const int *e;
        for (i = 0, e = elements, n = neighbors;i < numtriangles;i++, e += 3, n += 3)
        {
-               n[0] = Mod_FindTriangleWithEdge(elements, numtriangles, e[1], e[0]);
-               n[1] = Mod_FindTriangleWithEdge(elements, numtriangles, e[2], e[1]);
-               n[2] = Mod_FindTriangleWithEdge(elements, numtriangles, e[0], e[2]);
+               n[0] = Mod_FindTriangleWithEdge(elements, numtriangles, e[1], e[0], i);
+               n[1] = Mod_FindTriangleWithEdge(elements, numtriangles, e[2], e[1], i);
+               n[2] = Mod_FindTriangleWithEdge(elements, numtriangles, e[0], e[2], i);
        }
 }