public void GetDiagonalOfNeighbor(MeshPolygon nearbyPolygon, out Vector2 left, out Vector2 right)
{
int key = m_NeighborPolygons.KeyByValue(nearbyPolygon);
left = GetPoint(key);
right = GetPoint(key + 1);
}
// Get the mid point of the diagonal between two polygons
public Vector2 GetMidPointOfDiagonalNeighbor(MeshPolygon nearbyPolygon)
{
Vector2 left, right;
GetDiagonalOfNeighbor(nearbyPolygon, out left, out right);
return(new Vector2((left.x + right.x) / 2f, (left.y + right.y) / 2f));
}
// Add a neighbor polygon to this polygon on the NavMesh
public void AddNeighborPolygon(MeshPolygon poly, int vertexIndex)
{
if (m_NeighborPolygons == null)
{
m_NeighborPolygons = new Dictionary <int, MeshPolygon>();
}
m_NeighborPolygons.Add(vertexIndex, poly);
}
// Return a list of triangles with the vertices
public static List <MeshPolygon> Triangulate(Polygon polygon)
{
List <MeshPolygon> triangles = new List <MeshPolygon>();
MeshPolygon triangle;
int earIndex = 0;
polygon.ReverseWindingOrder();
// No ears
if (polygon.GetVerticesCount() < 3)
{
return(triangles);
}
// Set the values for the vertices
for (int i = 0; i < polygon.GetVerticesCount(); i++)
{
UpdateVertex(i, polygon);
}
// Start clipping the ears
while (polygon.GetVerticesCount() > 3)
{
var earFound = false;
// find the most extruded ear
for (int j = 0; j < polygon.GetVerticesCount(); j++)
{
if (!polygon.GetVertex(j).isEar)
{
continue;
}
if (!earFound)
{
earFound = true;
earIndex = j;
}
else
{
float vAngle = GeometryHelper.GetAngle(polygon.GetPoint(j - 1), polygon.GetPoint(j),
polygon.GetPoint(j + 1));
float earAngle = GeometryHelper.GetAngle(polygon.GetPoint(earIndex - 1),
polygon.GetPoint(earIndex),
polygon.GetPoint(earIndex + 1));
if (vAngle > earAngle)
{
earIndex = j;
}
}
}
if (!earFound)
{
return(triangles);
}
triangle = new MeshPolygon();
triangle.AddPoint(polygon.GetPoint(earIndex - 1));
triangle.AddPoint(polygon.GetPoint(earIndex));
triangle.AddPoint(polygon.GetPoint(earIndex + 1));
triangles.Add(triangle);
// Clip the ear
polygon.RemovePoint(earIndex);
// Update the adjacent vertices
UpdateVertex(earIndex - 1, polygon);
UpdateVertex(earIndex, polygon);
}
// Add the last ear
if (polygon.GetVerticesCount() == 3)
{
triangle = new MeshPolygon();
triangle.AddPoint(polygon.GetPoint(0));
triangle.AddPoint(polygon.GetPoint(1));
triangle.AddPoint(polygon.GetPoint(2));
triangles.Add(triangle);
return(triangles);
}
return(triangles);
}
public void SetPreviousPolygon(MeshPolygon prev)
{
m_previousPolygon = prev;
}
// 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++;
}
}
