// Remove the nonessential diagonals
public static List <MeshPolygon> RemoveNonEssentialDiagonals(List <MeshPolygon> triangles)
{
MeshPolygon poly2 = null;
int i21 = 0, i22 = 0;
// Loop through the triangles
int currentPoly = 0;
while (currentPoly < triangles.Count)
{
var poly1 = triangles[currentPoly];
int i11;
for (i11 = 0; i11 < poly1.GetVerticesCount(); i11++)
{
// Get the first line in the polygon
var d1 = poly1.GetPoint(i11);
var i12 = i11 + 1;
var d2 = poly1.GetPoint(i12);
// Find another polygon who shares this line
var isDiagonal = false;
for (int j1 = currentPoly; j1 < triangles.Count; j1++)
{
poly2 = triangles[j1];
if (poly1 == poly2)
{
continue;
}
// Find a common line with the next polygon to determine if it is a diagonal
for (i21 = 0; i21 < poly2.GetVerticesCount(); i21++)
{
if ((d2.x != poly2.GetPoint(i21).x) || (d2.y != poly2.GetPoint(i21).y))
{
continue;
}
i22 = i21 + 1;
if ((d1.x != poly2.GetPoint(i22).x) || (d1.y != poly2.GetPoint(i22).y))
{
continue;
}
// The line is found in an adjacent polygon
isDiagonal = true;
break;
}
if (isDiagonal)
{
break;
}
}
// If no diagonal has been found between the current polygon and all the others then move to the next
if (!isDiagonal)
{
continue;
}
// First point of the diagonal
var p2 = poly1.GetPoint(i11);
// Get the previous vertex
var i13 = i11 - 1;
var p1 = poly1.GetPoint(i13);
// Get the next vertex on the other polygon
var i23 = i22 + 1;
var p3 = poly2.GetPoint(i23);
// If the formed angle is reflex then the diagonal is essential
if (GeometryHelper.IsReflex(p1, p2, p3))
{
continue;
}
// Get vertex on the other end of the diagonal
p2 = poly1.GetPoint(i12);
// Get the next vertex on the first polygon
i13 = i12 + 1;
p3 = poly1.GetPoint(i13);
// Get the previous vertex on the other polygon
i23 = i21 - 1;
p1 = poly2.GetPoint(i23);
// If the formed angle is reflex then the diagonal is essential
if (GeometryHelper.IsReflex(p1, p2, p3))
{
continue;
}
var newPoly = new MeshPolygon();
int j;
for (j = i12; j != i11; j = (j + 1) % (poly1.GetVerticesCount()))
{
newPoly.AddPoint(poly1.GetPoint(j));
}
for (j = i22; j != i21; j = (j + 1) % (poly2.GetVerticesCount()))
{
newPoly.AddPoint(poly2.GetPoint(j));
}
triangles.Remove(poly2);
poly1 = newPoly;
triangles[currentPoly] = poly1;
i11 = -1;
}
currentPoly++;
}
return(triangles);
}
// Build NavMesh connections
public static void BuildNavMesh(List <MeshPolygon> navMeshPolygons)
{
MeshPolygon poly2 = null;
int i21 = 0;
// Loop through the polygons
int currentPoly = 0;
while (currentPoly < navMeshPolygons.Count)
{
var poly1 = navMeshPolygons[currentPoly];
int i11;
for (i11 = 0; i11 < poly1.GetVerticesCount(); i11++)
{
// Get the first line in the polygon
var d1 = poly1.GetPoint(i11);
var i12 = i11 + 1;
var d2 = poly1.GetPoint(i12);
// Find another polygon who shares this line
var isDiagonal = false;
for (int j1 = currentPoly; j1 < navMeshPolygons.Count; j1++)
{
poly2 = navMeshPolygons[j1];
if (poly1 == poly2)
{
continue;
}
// Find a common line with the next polygon to determine if it is a diagonal
for (i21 = 0; i21 < poly2.GetVerticesCount(); i21++)
{
if ((d2.x != poly2.GetPoint(i21).x) || (d2.y != poly2.GetPoint(i21).y))
{
continue;
}
var i22 = i21 + 1;
if ((d1.x != poly2.GetPoint(i22).x) || (d1.y != poly2.GetPoint(i22).y))
{
continue;
}
// The line is found in an adjacent polygon
isDiagonal = true;
break;
}
if (isDiagonal)
{
break;
}
}
// If no diagonal has been found between the current polygon and all the others then move to the next
if (!isDiagonal)
{
continue;
}
poly1.AddNeighborPolygon(poly2, i11);
poly2.AddNeighborPolygon(poly1, i21);
}
currentPoly++;
}
}
