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31 ** Author: Eric Veach, July 1994.
38 /* __gl_meshTessellateMonoRegion( face ) tessellates a monotone region
39 * (what else would it do??) The region must consist of a single
40 * loop of half-edges (see mesh.h) oriented CCW. "Monotone" in this
41 * case means that any vertical line intersects the interior of the
42 * region in a single interval.
44 * Tessellation consists of adding interior edges (actually pairs of
45 * half-edges), to split the region into non-overlapping triangles.
47 * __gl_meshTessellateInterior( mesh ) tessellates each region of
48 * the mesh which is marked "inside" the polygon. Each such region
51 * __gl_meshDiscardExterior( mesh ) zaps (ie. sets to NULL) all faces
52 * which are not marked "inside" the polygon. Since further mesh operations
53 * on NULL faces are not allowed, the main purpose is to clean up the
54 * mesh so that exterior loops are not represented in the data structure.
56 * __gl_meshSetWindingNumber( mesh, value, keepOnlyBoundary ) resets the
57 * winding numbers on all edges so that regions marked "inside" the
58 * polygon have a winding number of "value", and regions outside
59 * have a winding number of 0.
61 * If keepOnlyBoundary is TRUE, it also deletes all edges which do not
62 * separate an interior region from an exterior one.
65 int __gl_meshTessellateMonoRegion( GLUface *face );
66 int __gl_meshTessellateInterior( GLUmesh *mesh );
67 void __gl_meshDiscardExterior( GLUmesh *mesh );
68 int __gl_meshSetWindingNumber( GLUmesh *mesh, int value,
69 GLboolean keepOnlyBoundary );