/// <summary>
/// Clip a line to the shape
/// </summary>
/// <param name="sourcePoint">The source of the line</param>
/// <returns>The point which clips at the boundary</returns>
internal override PointF ClipLine(PointF sourcePoint)
{
PointF intersect;
if (GraphUtils.IntersectLine(sourcePoint, this.Center,
new PointF(Boundary.Left, Boundary.Top),
new PointF(Boundary.Left, Boundary.Bottom), out intersect))
{
return(intersect);
}
if (GraphUtils.IntersectLine(sourcePoint, this.Center,
new PointF(Boundary.Left, Boundary.Top),
new PointF(Boundary.Right, Boundary.Top), out intersect))
{
return(intersect);
}
if (GraphUtils.IntersectLine(sourcePoint, this.Center,
new PointF(Boundary.Left, Boundary.Bottom),
new PointF(Boundary.Right, Boundary.Bottom), out intersect))
{
return(intersect);
}
if (GraphUtils.IntersectLine(sourcePoint, this.Center,
new PointF(Boundary.Right, Boundary.Top),
new PointF(Boundary.Right, Boundary.Bottom), out intersect))
{
return(intersect);
}
return(Center);
}
/// <summary>
/// Intersect a line with a rectangle, returns the first intersecting point
/// </summary>
/// <param name="boundary">The rectangle boundary</param>
/// <param name="sourcePoint">The source point of the line</param>
/// <param name="destPoint">The destination point of the line</param>
/// <param name="intersect">Parameter to store the intersection point if found</param>
/// <returns>True if the line intersected at least one side of the rectangle</returns>
public static bool IntersectRectangle(RectangleF boundary, PointF sourcePoint, PointF destPoint, out PointF intersect)
{
if (IntersectLine(sourcePoint, destPoint,
new PointF(boundary.Left, boundary.Top),
new PointF(boundary.Left, boundary.Bottom), out intersect))
{
return(true);
}
if (GraphUtils.IntersectLine(sourcePoint, destPoint,
new PointF(boundary.Left, boundary.Top),
new PointF(boundary.Right, boundary.Top), out intersect))
{
return(true);
}
if (GraphUtils.IntersectLine(sourcePoint, destPoint,
new PointF(boundary.Left, boundary.Bottom),
new PointF(boundary.Right, boundary.Bottom), out intersect))
{
return(true);
}
if (GraphUtils.IntersectLine(sourcePoint, destPoint,
new PointF(boundary.Right, boundary.Top),
new PointF(boundary.Right, boundary.Bottom), out intersect))
{
return(true);
}
return(false);
}
/// <summary>
/// Clip the line, defaults to flattening the path and intersecting every line.
/// If a more efficient method is available it can be overridden
/// </summary>
/// <param name="sourcePoint"></param>
/// <returns></returns>
internal virtual PointF ClipLine(PointF sourcePoint)
{
PointF intersect = Center;
float distance = GraphUtils.CalculateDistance(sourcePoint, Center);
using (GraphicsPath path = GetPath())
{
path.Flatten();
if (path.PointCount > 0)
{
PointF lastPoint = path.GetLastPoint();
// Intersect all the lines in the path with our line and choose the closest
for (int i = 0; i < path.PointCount; ++i)
{
PointF currIntersect;
if (GraphUtils.IntersectLine(sourcePoint, this.Center,
lastPoint, path.PathPoints[i], out currIntersect))
{
float newDistance = GraphUtils.CalculateDistance(sourcePoint, currIntersect);
if (newDistance < distance)
{
distance = newDistance;
intersect = currIntersect;
}
}
lastPoint = path.PathPoints[i];
}
}
}
return(intersect);
}
