private void HandleLeftEdgeClick(Point mousePoint)
{
Point middle = State.ClickedEdge.EdgeMiddle;
LineFunction pLine = State.ClickedEdge.function.GetPLine(middle);
Point newPoint;
if (State.ClickedEdge.ends.left.vPoint.X == State.ClickedEdge.ends.right.vPoint.X)
{
newPoint = new Point(middle.X - 20, middle.Y);
}
else if (State.ClickedEdge.ends.left.vPoint.Y == State.ClickedEdge.ends.right.vPoint.Y)
{
newPoint = new Point(middle.X, middle.Y - 20);
}
else
{
newPoint = FindLengthPoint(mousePoint, middle, pLine, 40).Value;
}
Vertex newVertex = new Vertex(newPoint.X, newPoint.Y);
Edge left = new Edge((State.ClickedEdge.ends.left, newVertex));
Edge right = new Edge((newVertex, State.ClickedEdge.ends.right));
State.ClickedEdge.ends.left.edges = (State.ClickedEdge.ends.left.edges.left, left);
State.ClickedEdge.ends.right.edges = (right, State.ClickedEdge.ends.right.edges.right);
newVertex.edges = (left, right);
State.CurrentPolygon.Edges.Remove(State.ClickedEdge);
State.ClickedEdge = null;
State.CurrentPolygon.Edges.Add(left);
State.CurrentPolygon.Edges.Add(right);
State.CurrentPolygon.Vertices.Add(newVertex);
}
public Point?FindLengthPoint(Point p1, Point p2, LineFunction function, double length)
{
int x2 = p2.X;
int y2 = p2.Y;
int x1 = p1.X;
int y1 = p1.Y;
if (function.B == 0)
{
return(y2 < y1 ? new Point(x2, (int)(y2 + length)) : new Point(x2, (int)(y2 - length)));
}
double a = -function.A;
double b = -function.C;
double a2 = a * a;
double b2 = b * b;
double A = a2 + 1;
double B = 2 * a * b - 2 * y2 * a - 2 * x2;
double C = x2 * x2 + y2 * y2 - 2 * y2 * b + b2 - length * length;
double delta = B * B - 4 * A * C;
int xR1 = (int)Math.Round((-B - Math.Sqrt(delta)) / (2 * A));
int yR1 = (int)Math.Round(a * (-B - Math.Sqrt(delta)) / (2 * A) + b);
int xR2 = (int)Math.Round((-B + Math.Sqrt(delta)) / (2 * A));
int yR2 = (int)Math.Round(a * (-B + Math.Sqrt(delta)) / (2 * A) + b);
double dist1 = Math.Sqrt(Math.Pow(x1 - xR1, 2) + Math.Pow(y1 - yR1, 2));
double dist2 = Math.Sqrt(Math.Pow(x1 - xR2, 2) + Math.Pow(y1 - yR2, 2));
return(dist1 <= dist2 ? new Point(xR1, yR1) : new Point(xR2, yR2));
}
public LineFunction GetPLine(Point p)
{
LineFunction pLine = new LineFunction
{
A = -1 / A,
B = 1
};
pLine.C = -(p.Y - pLine.a * p.X);
return(pLine);
}