protected bool Intersect(int Vertex1Ind, int Vertex2Ind, int Vertex3Ind)
{
double S1, S2, S3;
Vertex1Ind %= VertexCount;
Vertex2Ind %= VertexCount;
Vertex3Ind %= VertexCount;
for (int i = 0; i < VertexCount; i++)
{
if ((i == Vertex1Ind) || (i == Vertex2Ind) || (i == Vertex3Ind))
{
continue;
}
S1 = Geom2d.Square(Vertexes[Vertex1Ind], Vertexes[Vertex2Ind], Vertexes[i]);
S2 = Geom2d.Square(Vertexes[Vertex2Ind], Vertexes[Vertex3Ind], Vertexes[i]);
if (((S1 < 0) && (S2 > 0)) || ((S1 > 0) && (S2 < 0)))
{
continue;
}
S3 = Geom2d.Square(Vertexes[Vertex3Ind], Vertexes[Vertex1Ind], Vertexes[i]);
if (((S3 >= 0) && (S2 >= 0)) || ((S3 <= 0) && (S2 <= 0)))
{
return(true);
}
}
return(false);
}
public void UpdatePolygon()
{
if (VertexCount >= 3)
{
int i;
convexity = 1;
square2 = Geom2d.Square(Vertexes[VertexCount - 1], Vertexes[0], Vertexes[1]);
double S;
for (i = 0; i <= VertexCount - 3; i++)
{
S = Geom2d.Square(Vertexes[i], Vertexes[i + 1], Vertexes[i + 2]);
if (((square2 < 0) && (S > 0)) || ((square2 > 0) && (S < 0)))
{
convexity = -1;
}
else
if ((S == 0) && (square2 == 0))
{
convexity = 0;
}
square2 += S;
}
S = Geom2d.Square(Vertexes[VertexCount - 2], Vertexes[VertexCount - 1], Vertexes[0]);
if (((square2 < 0) && (S > 0)) || ((square2 > 0) && (S < 0)))
{
convexity = -1;
}
else
if ((S == 0) && (square2 == 0))
{
convexity = 0;
}
square2 += S;
/*int High = VertexCount - 1;
* PointD O = new PointD();
* for (i = 0; i < High; i++)
* for (int j = i + 2; j < High; j++)
* if (Geom2d.Intersection(Vertexes[i], Vertexes[i + 1], Vertexes[j], Vertexes[j + 1], out O) == 1)
* {
* self_intersection = 1;
* break;
* }
* if (self_intersection != 1)
* for (i = 1; i < High - 1; i++)
* if (Geom2d.Intersection(Vertexes[i], Vertexes[i + 1], Vertexes[High], Vertexes[0], out O) == 1)
* self_intersection = 1;*/
}
else
{
square2 = 0;
convexity = 0;
self_intersection = 0;
}
}
public void ConvexDivide(bool Triangulation)
{
PointDArray TempPolygon = new PointDArray(this);
ConvPolygons = new List <List <PointD> >();
int CPH = -1;
int begin_ind = 0;
int cur_ind;
//if (Square(TempPolygon) < 0)
// TempPolygon.Reverse();
while (TempPolygon.Count >= 3)
{
while ((Geom2d.Square(TempPolygon[begin_ind], TempPolygon[begin_ind + 1], TempPolygon[begin_ind + 2]) < 0) ||
(Intersect(begin_ind, begin_ind + 1, begin_ind + 2) == true))
{
begin_ind++;
}
cur_ind = begin_ind + 1;
ConvPolygons.Add(new List <PointD>());
CPH++;
ConvPolygons[CPH].Add(TempPolygon[begin_ind]);
ConvPolygons[CPH].Add(TempPolygon[cur_ind]);
ConvPolygons[CPH].Add(TempPolygon[begin_ind + 2]);
if (Triangulation == false)
{
while ((Geom2d.Square(TempPolygon[cur_ind], TempPolygon[cur_ind + 1], TempPolygon[cur_ind + 2]) > 0) && (cur_ind + 2 != begin_ind))
{
if ((Intersect(begin_ind, cur_ind + 1, cur_ind + 2) == true) ||
(Geom2d.Square(TempPolygon[begin_ind], TempPolygon[begin_ind + 1], TempPolygon[cur_ind + 2]) < 0))
{
break;
}
ConvPolygons[CPH].Add(TempPolygon[cur_ind + 2]);
cur_ind++;
}
}
TempPolygon.RemoveRange(begin_ind, cur_ind);
begin_ind++;
}
}
protected void UpdateSCS()
{
if (VertexCount == 3)
{
convexity = 1;
self_intersection = -1;
square2 = Geom2d.Square(Vertexes[0], Vertexes[1], Vertexes[2]);
}
else
if (VertexCount > 3)
{
double S = Geom2d.Square(Vertexes[VertexCount - 2], Vertexes[VertexCount - 1], Vertexes[0]);
if (((S < 0) && (square2 > 0)) || ((S > 0) && (square2 < 0)))
{
convexity = -1;
}
else
if ((S == 0) && (square2 == 0))
{
convexity = 0;
}
square2 += S;
PointD O;
for (int i = 1; i <= VertexCount - 3; i++)
{
if (Geom2d.Intersection(Vertexes[i], Vertexes[i + 1], Vertexes[VertexCount - 1], Vertexes[0], out O) == 1)
{
self_intersection = 1;
break;
}
}
/*perimeter -= Geom2d.Distance(Vertexes[VertexCount - 1], Vertexes[0]);
* perimeter += Geom2d.Distance(Vertexes[VertexCount - 1], Vertexes[VertexCount]);
* perimeter += Geom2d.Distance(Vertexes[VertexCount], Vertexes[0]);*/
}
}