public Triangle(Vertex v1, Vertex v2, Vertex v3)
{
V1 = v1;
V2 = v2;
V3 = v3;
// Boundary box.
float b1x = Math.Min(Math.Min(v1.Position.X, v2.Position.X), v3.Position.X);
float b1y = Math.Min(Math.Min(v1.Position.Y, v2.Position.Y), v3.Position.Y);
float b2x = Math.Max(Math.Max(v1.Position.X, v2.Position.X), v3.Position.X);
float b2y = Math.Max(Math.Max(v1.Position.Y, v2.Position.Y), v3.Position.Y);
B1 = new Vector2(b1x, b1y);
B2 = new Vector2(b2x, b2y);
}
private static bool CheckPointToSegment(Vertex sA, Vertex sB, Vertex point)
{
if ((sA.Position.Y < point.Position.Y && sB.Position.Y >= point.Position.Y) ||
(sB.Position.Y < point.Position.Y && sA.Position.Y >= point.Position.Y))
{
float x =
sA.Position.X +
(point.Position.Y - sA.Position.Y) /
(sB.Position.Y - sA.Position.Y) *
(sB.Position.X - sA.Position.X);
if (x < point.Position.X)
return true;
}
return false;
}
public bool ContainsPoint(Vertex point)
{
if (B1.X <= point.Position.X && point.Position.X <= B2.X
&& B1.Y <= point.Position.Y && point.Position.Y <= B2.Y)
{
bool oddNodes = false;
if (CheckPointToSegment(V3, V1, point))
oddNodes = !oddNodes;
if (CheckPointToSegment(V1, V2, point))
oddNodes = !oddNodes;
if (CheckPointToSegment(V2, V3, point))
oddNodes = !oddNodes;
return oddNodes;
}
return false;
}
public bool Equals(Vertex obj)
{
// Duplicate vertexes are now allowed, so no need to check index.
return obj.Position.Equals(Position);
}
public bool HavePoint(Vertex point)
{
return V1.Equals(point) || V2.Equals(point) || V3.Equals(point);
}