private SectorPolygon EarClip(List <Vector2> polygon)
{
SectorPolygon output = new SectorPolygon();
// Early out for convex polygons
int conv = IsConvex(polygon);
if (conv != 0)
{
if (conv == -1)
{
polygon.Reverse();
}
output.points = polygon;
for (int t = 0; t < polygon.Count - 2; t++)
{
output.triangles.Add(0);
output.triangles.Add(t + 1);
output.triangles.Add(t + 2);
}
return(output);
}
// Make it clockwise because consistent direction is necessary
List <int> clippedIndexes = new List <int>();
int polygonCount = polygon.Count;
int i = 0;
int i1, i2, i3;
int safe = 500;
while (clippedIndexes.Count < polygonCount - 2 && safe >= 0) // be careful!!!
{
safe -= 1;
i1 = i % polygonCount;
while (clippedIndexes.Contains(i1))
{
i1 = (i1 + 1) % polygonCount;
}
i2 = (i1 + 1) % polygonCount;
while (clippedIndexes.Contains(i2) || i2 == i1)
{
i2 = (i2 + 1) % polygonCount;
}
i3 = (i2 + 1) % polygonCount;
while (clippedIndexes.Contains(i3) || i3 == i2)
{
i3 = (i3 + 1) % polygonCount;
}
bool clipped = false;
bool intersects = false;
bool straightLine = false;
if (polygon[i1].y == polygon[i2].y && polygon[i1].y == polygon[i3].y)
{
straightLine = true;
}
if (straightLine == false)
{
for (int j = 0; j < polygonCount; j++)
{
int j1 = (j + 1) % polygonCount;
if (!Vector2.Equals(polygon[i1], polygon[j]) &&
!Vector2.Equals(polygon[i3], polygon[j]) &&
!Vector2.Equals(polygon[i1], polygon[j1]) &&
!Vector2.Equals(polygon[i3], polygon[j1]) &&
LinesIntersect(polygon, i1, i3, j, j1))
{
intersects = true;
break;
}
}
}
//Debug.Log(intersects);
if (intersects == false && straightLine == false)
{
Vector2 midpoint = new Vector2((polygon[i3].x + polygon[i1].x) / 2f, (polygon[i3].y + polygon[i1].y) / 2f);
if (PointInPolygon(midpoint, polygon))
{
// Clippit!!!
clippedIndexes.Add(i2);
output.triangles.Add(i1);
output.triangles.Add(i2);
output.triangles.Add(i3);
clipped = true;
}
}
if (clipped == false)
{
i += 1;
}
}
if (safe <= 0)
{
Debug.LogWarning("EarClip: while loop broke safety net. Clipped Indexes :" + clippedIndexes.Count + " polygonCount: " + polygonCount);
}
if (!IsClockwise(polygon))
{
output.triangles.Reverse();
}
output.points = polygon;
return(output);
}
public List <SectorPolygon> Triangulate(int sector, bool benchmark = false)
{
float time = 0f;
if (benchmark)
{
time = Time.realtimeSinceStartup;
}
int i;
// Trace sector lines
List <List <Vector2> > polygons = TraceLines(sector);
//Debug.Log("Polygons: " + polygons.Count);
// Determine islands
if (polygons.Count == 0)
{
return(null);
}
List <SectorIsland> islands = BuildIslands(polygons);
// Cut islands
List <List <Vector2> > cutPolygons = new List <List <Vector2> >();
for (i = 0; i < islands.Count; i++)
{
List <Vector2> cut = islands[i].Cut();
if (cut != null)
{
cutPolygons.Add(cut);
}
}
// Ear clip
List <SectorPolygon> output = new List <SectorPolygon>();
for (i = 0; i < cutPolygons.Count; i++)
{
SectorPolygon sp = EarClip(cutPolygons[i]);
if (sp != null)
{
output.Add(EarClip(cutPolygons[i]));
}
}
// for (i = 0; i < cutPolygons.Count; i++) {
// int conv = IsConvex(cutPolygons[i]);
// if (conv != 0) {
// if (conv == -1) cutPolygons[i].Reverse();
// output.AddRange(cutPolygons[i]);
// }
// }
// Output
if (benchmark)
{
Debug.Log("Triangulation time: " + (Time.realtimeSinceStartup - time));
}
return(output);
}
