public Mesh Build(Func <Vertex2D, Vector3> coord)
{
var mesh = new Mesh();
var vertices = P.Select(p => {
return(coord(p));
}).ToArray();
var triangles = new List <int>();
for (int i = 0, n = T.Count; i < n; i++)
{
var t = T[i];
int a = P.IndexOf(t.a), b = P.IndexOf(t.b), c = P.IndexOf(t.c);
if (a < 0 || b < 0 || c < 0)
{
// Debug.Log(a + " : " + b + " : " + c);
continue;
}
if (Utils2D.LeftSide(t.a.Coordinate, t.b.Coordinate, t.c.Coordinate))
{
triangles.Add(a); triangles.Add(c); triangles.Add(b);
}
else
{
triangles.Add(a); triangles.Add(b); triangles.Add(c);
}
}
mesh.vertices = vertices;
mesh.SetTriangles(triangles.ToArray(), 0);
mesh.RecalculateNormals();
return(mesh);
}
bool CheckUnique()
{
var flag = false;
for (int i = 0, n = P.Count; i < n; i++)
{
var v0 = P[i];
for (int j = i + 1; j < n; j++)
{
var v1 = P[j];
if (Utils2D.CheckEqual(v0, v1))
{
Debug.LogWarning("vertex " + i + " equals " + j);
flag = true;
}
}
}
for (int i = 0, n = E.Count; i < n; i++)
{
var s0 = E[i];
for (int j = i + 1; j < n; j++)
{
var s1 = E[j];
if (Utils2D.CheckEqual(s0, s1))
{
Debug.LogWarning("segment " + i + " equals " + j);
flag = true;
}
}
}
for (int i = 0, n = T.Count; i < n; i++)
{
var t0 = T[i];
for (int j = i + 1; j < n; j++)
{
var t1 = T[j];
if (Utils2D.CheckEqual(t0, t1))
{
Debug.LogWarning("triangle " + i + " equals " + j);
flag = true;
}
}
}
for (int i = 0, n = T.Count; i < n; i++)
{
var t = T[i];
if (Utils2D.CheckEqual(t.s0, t.s1) || Utils2D.CheckEqual(t.s0, t.s2) || Utils2D.CheckEqual(t.s1, t.s2))
{
Debug.LogWarning("triangle " + i + " has duplicated segments");
flag = true;
}
}
return(flag);
}
/*
* slow incremental approach
* O(n * log(n))
*/
public static Polygon2D ConvexHull(Vector2[] points)
{
var ordered = points.ToList().OrderBy(p => p.x).ToList();
var upper = new List <Vector2>();
upper.Add(ordered[0]);
upper.Add(ordered[1]);
for (int i = 2, n = ordered.Count; i < n; i++)
{
upper.Add(ordered[i]);
int l = upper.Count;
if (l > 2)
{
var p = upper[l - 3];
var r = upper[l - 2];
var q = upper[l - 1];
if (Utils2D.LeftSide(p, q, r)) // r is left side of pq
{
upper.RemoveAt(l - 2);
}
}
}
var lower = new List <Vector2>();
lower.Add(ordered[ordered.Count - 1]);
lower.Add(ordered[ordered.Count - 2]);
for (int i = ordered.Count - 3; i >= 0; i--)
{
lower.Add(ordered[i]);
int l = lower.Count;
if (l > 2)
{
var p = lower[l - 3];
var r = lower[l - 2];
var q = lower[l - 1];
if (Utils2D.LeftSide(p, q, r)) // r is left side of pq
{
lower.RemoveAt(l - 2);
}
}
}
lower.RemoveAt(lower.Count - 1);
lower.RemoveAt(0);
upper.AddRange(lower);
return(new Polygon2D(upper.ToArray()));
}
// Disable to intersect more than two edges
static List <HalfEdge2D> SplitEdges(List <HalfEdge2D> edges)
{
HalfEdge2D start = edges[0];
HalfEdge2D cur = start;
while (true)
{
HalfEdge2D from = cur, to = from.to;
HalfEdge2D from2 = to.to, to2 = from2.to;
int intersections = 0;
while (to2 != from.from)
{
if (Utils2D.Intersect(from.p, to.p, from2.p, to2.p))
{
intersections++;
if (intersections >= 2)
{
break;
}
}
// next
from2 = from2.to;
to2 = to2.to;
}
if (intersections >= 2)
{
edges.Add(cur.Split());
}
else
{
// next
cur = cur.to;
if (cur == start)
{
break;
}
}
}
return(edges);
}
public Mesh Build()
{
var mesh = new Mesh();
var vertices = P.Select(p => {
var xy = p.Coordinate;
var v = new Vector3(xy.x, xy.y, 0f);
return(v);
}).ToArray();
var triangles = new int[T.Count * 3];
for (int i = 0, n = T.Count; i < n; i++)
{
var t = T[i];
var i3 = i * 3;
int a = P.IndexOf(t.a), b = P.IndexOf(t.b), c = P.IndexOf(t.c);
if (Utils2D.LeftSide(t.a.Coordinate, t.b.Coordinate, t.c.Coordinate))
{
triangles[i3] = a;
triangles[i3 + 1] = c;
triangles[i3 + 2] = b;
}
else
{
triangles[i3] = a;
triangles[i3 + 1] = b;
triangles[i3 + 2] = c;
}
}
mesh.vertices = vertices;
mesh.SetTriangles(triangles, 0);
mesh.RecalculateNormals();
return(mesh);
}
public static Polygon2D Contour(Vector2[] points)
{
var n = points.Length;
var edges = new List <HalfEdge2D>();
for (int i = 0; i < n; i++)
{
edges.Add(new HalfEdge2D(points[i]));
}
for (int i = 0; i < n; i++)
{
var e = edges[i];
e.from = edges[(i == 0) ? (n - 1) : (i - 1)];
e.to = edges[(i + 1) % n];
}
edges = Polygon2D.SplitEdges(edges);
var result = new List <Vector2>();
HalfEdge2D start = edges[0];
result.Add(start.p);
HalfEdge2D current = start;
while (true)
{
HalfEdge2D from = current, to = current.to;
HalfEdge2D from2 = to.to, to2 = from2.to;
bool flag = false;
while (from2 != start && to2 != from)
{
if (flag = Utils2D.Intersect(from.p, to.p, from2.p, to2.p))
{
break;
}
from2 = to2;
to2 = to2.to;
}
if (!flag)
{
result.Add(to.p);
current = to; // step to next
}
else
{
result.Add(from2.p);
// reconnect
from.to = from2;
from2.to = from; // invert this edge later
to.from = to2;
to.Invert();
to2.from = to;
HalfEdge2D e = from2;
while (e != to)
{
e.Invert();
e = e.to;
}
current = from2;
}
if (current == start)
{
break;
}
}
result.RemoveAt(result.Count - 1); // remove last
return(new Polygon2D(result.ToArray()));
}
public bool Contains(Vector2 p)
{
return(Utils2D.Contains(p, vertices));
}
bool ExternalPSLG(Vector2 p)
{
return(!Utils2D.Contains(p, V));
}
