public void MovePoint(int pointIndx, Point newPos)
{
Point oldP = points[pointIndx];
for (int i = 0; i < edges.Count; i++)
{
if (edges[i].p == oldP)
{
MyEdge temp = edges[i];
edges.RemoveAt(i);
edges.Insert(i, new MyEdge(newPos, temp.q, temp.color));
}
else if (edges[i].q == oldP)
{
MyEdge temp = edges[i];
edges.RemoveAt(i);
edges.Insert(i, new MyEdge(temp.p, newPos, temp.color));
}
}
for (int i = 0; i < points.Count; i++)
{
if (points[i] == oldP)
{
points.RemoveAt(i);
points.Insert(i, newPos);
}
}
}
private MyEdge CyrusBeck(MyEdge line, Vector[] normal, List <Point> figurePoints)
{
int n = normal.Length;
Vector P1_P0 = new Vector(line.q.X - line.p.X, line.q.Y - line.p.Y);
Vector[] PEi_P0 = new Vector[n];
for (int i = 0; i < n; i++)
{
PEi_P0[i].X = figurePoints[i].X - line.p.X;
PEi_P0[i].Y = figurePoints[i].Y - line.p.Y;
}
int[] numerator = new int[n];
int[] denominator = new int[n];
for (int i = 0; i < n; i++)
{
numerator[i] = dot(normal[i], PEi_P0[i]);
denominator[i] = dot(normal[i], P1_P0);
}
double[] t = new double[n];
List <double> tE = new List <double>();
List <double> tL = new List <double>();
for (int i = 0; i < n; i++)
{
t[i] = (double)numerator[i] / denominator[i];
if (denominator[i] > 0)
{
tE.Add(t[i]);
}
else
{
tL.Add(t[i]);
}
}
double tEMax, tLMin;
tE.Add(0);
tL.Add(1);
tEMax = tE.Max();
tLMin = tL.Min();
if (tEMax > tLMin)
{
return(null);
}
Point p = new Point(line.p.X + P1_P0.X * tEMax, line.p.Y + P1_P0.Y * tEMax);
Point q = new Point(line.p.X + P1_P0.X * tLMin, line.p.Y + P1_P0.Y * tLMin);
return(new MyEdge(p, q, cllipedColor));
}
public void Clipping()
{
clippedLines = new List <MyEdge>();
// clipping only for convex polygons
if (!clippingPolygon.CheckIfConvex())
{
return;
}
if (clipToRectangle)
{
if (clippingRectangle != null)
{
// calculate normals
int nOfPoints = clippingRectangle.points.Count;
Vector[] normal = new Vector[nOfPoints];
for (int i = 0; i < nOfPoints; i++)
{
normal[i].X = clippingRectangle.points[i].Y - clippingRectangle.points[(i + 1) % nOfPoints].Y;
normal[i].Y = clippingRectangle.points[(i + 1) % nOfPoints].X - clippingRectangle.points[i].X;
}
foreach (var edge in edges)
{
MyEdge result = this.CyrusBeck(edge, normal, clippingRectangle.points);
if (result != null)
{
clippedLines.Add(result);
}
}
}
else
{
clipToRectangle = false;
}
}
else if (clipToPolygon)
{
if (clippingPolygon != null)
{
int nOfPoints = clippingPolygon.points.Count - 1;
Vector[] normal = new Vector[nOfPoints];
for (int i = 0; i < nOfPoints; i++)
{
normal[i].X = clippingPolygon.points[i].Y - clippingPolygon.points[(i + 1) % nOfPoints].Y;
normal[i].Y = clippingPolygon.points[(i + 1) % nOfPoints].X - clippingPolygon.points[i].X;
}
foreach (var edge in edges)
{
MyEdge result = this.CyrusBeck(edge, normal, clippingPolygon.points);
if (result != null)
{
clippedLines.Add(result);
}
}
}
else
{
clipToPolygon = false;
}
}
}
