void SupportingLine(PointF s, Polygon p, PointToEdgeRelation side)
{
Rotation rotation = side == PointToEdgeRelation.Right ? Rotation.Clockwise : Rotation.Counterclockwise;
Vertex a = p.V;
Vertex b = p.Neighbour(rotation);
PointToEdgeRelation rel = b.Point.Classify(s, a.Point);
while (rel == side || rel == PointToEdgeRelation.Beyond || rel == PointToEdgeRelation.Between)
{
p.Advance(rotation);
a = p.V;
b = p.Neighbour(rotation);
rel = b.Point.Classify(s, a.Point);
}
}
bool PointInConvexPolygon(PointF s, Polygon p)
{
if (p.Size == 1)
{
return(s.X == p.Point.X && s.Y == p.Point.Y);
}
; //(Math.Abs(s.X - p.Point.X) < 0.0001) && (Math.Abs(s.Y - p.Point.Y) < 0.0001);
if (p.Size == 2)
{
PointToEdgeRelation rel = s.Classify(p.Point, p.Next.Point);
return(rel == PointToEdgeRelation.Between ||
rel == PointToEdgeRelation.Origin ||
rel == PointToEdgeRelation.Destination);
}
Vertex start = p.V;
int intersectsCnt = 0;
int vertexIntersects = 0;
for (int i = 0; i < p.Size; ++i)
{
var classification = s.Classify(p.Point, p.Next.Point);
if (classification == PointToEdgeRelation.Destination || classification == PointToEdgeRelation.Origin ||
classification == PointToEdgeRelation.Between)
{
p.SetV(start);
return(true);
}
if (LinesIntersect(p.Point, p.Next.Point, s, new PointF(pictureBox1.Width - 1, s.Y))
== IntersectionType.Intersects)
{
++intersectsCnt;
}
else if (LinesIntersect(p.Point, p.Next.Point, s, new PointF(pictureBox1.Width - 1, s.Y))
== IntersectionType.VertexIntersects)
{
++vertexIntersects;
}
p.Advance(Rotation.Clockwise);
}
p.SetV(start);
intersectsCnt += vertexIntersects / 2;
return(intersectsCnt % 2 != 0);
}
