the new partial-update entity compression protocol now works for the first time ever

[xonotic/darkplaces.git] / model_shared.c

diff --git a/model_shared.c b/model_shared.c
index 393e7bb3baa8375e3fb7555625130a289ac8fc79..2d519e2ce504ee19a04d9af2f3c5acf40aef5a49 100644 (file)
--- a/model_shared.c
+++ b/model_shared.c
@@ -1039,4 +1039,30 @@ int Mod_CountSkinFiles(skinfile_t *skinfile)
        return i;
 }
 
+int Mod_RemoveDegenerateTriangles(int numtriangles, const int *inelement3i, int *outelement3i, const float *vertex3f)
+{
+       int i, outtriangles;
+       float d, edgedir[3], temp[3];
+       // a degenerate triangle is one with no width (thickness, surface area)
+       // these are characterized by having all 3 points colinear (along a line)
+       // or having two points identical
+       for (i = 0, outtriangles = 0;i < numtriangles;i++, inelement3i += 3)
+       {
+               // calculate first edge
+               VectorSubtract(vertex3f + inelement3i[1] * 3, vertex3f + inelement3i[0] * 3, edgedir);
+               if (VectorLength2(edgedir) < 0.0001f)
+                       continue; // degenerate first edge (no length)
+               VectorNormalize(edgedir);
+               // check if third point is on the edge (colinear)
+               d = -DotProduct(vertex3f + inelement3i[2] * 3, edgedir);
+               VectorMA(vertex3f + inelement3i[2] * 3, d, edgedir, temp);
+               if (VectorLength2(temp) < 0.0001f)
+                       continue; // third point colinear with first edge
+               // valid triangle (no colinear points, no duplicate points)
+               VectorCopy(inelement3i, outelement3i);
+               outelement3i += 3;
+               outtriangles++;
+       }
+       return outtriangles;
+}