public Shape2D FindIntersection(Shape2D shape)
{
// ensure that 'this' is less or as primative as shape
if (Type > shape.Type)
{
return(shape.FindIntersection(this));
}
// find intersection
if (this.Type == ShapeType2D.Point)
{
return(shape.Contains((Point2D)this) ? this : null);
}
else if (this.Type == ShapeType2D.Line)
{
if (shape.Type == ShapeType2D.Line)
{
return(((Line2D)this).FindLineIntersection((Line2D)shape));
}
}
throw new System.NotImplementedException("Intersection between " + shape.Type + " and " + Type + " not implemented.");
}
public Shape2D FindIntersection(Shape2D shape)
{
// ensure that 'this' is less or as primative as shape
if (Type > shape.Type)
return shape.FindIntersection(this);
// find intersection
if (this.Type == ShapeType2D.Point)
return shape.Contains((Point2D)this) ? this : null;
else if (this.Type == ShapeType2D.Line) {
if (shape.Type == ShapeType2D.Line)
return ((Line2D)this).FindLineIntersection((Line2D)shape);
else if (shape.Type == ShapeType2D.Triangle) {
var line = (Line2D)this;
var triangle = (Triangle2D)shape;
var abLine = new Line2D(triangle.A, triangle.B);
var abIntersection = line.FindIntersection(abLine);
var bcLine = new Line2D(triangle.B, triangle.C);
var bcIntersection = line.FindIntersection(bcLine);
var caLine = new Line2D(triangle.C, triangle.A);
var caIntersection = line.FindIntersection(caLine);
var abIntersectionLine = abIntersection as Line2D;
var bcIntersectionLine = bcIntersection as Line2D;
var caIntersectionLine = caIntersection as Line2D;
var intersectionLine = abIntersectionLine ?? bcIntersectionLine ?? caIntersectionLine;
if (intersectionLine != null) {
return intersectionLine;
} else {
var points = new List<Point2D>();
if (abIntersection != null) {
var abIntersectionPoint = (Point2D)abIntersection;
var t = abLine.NearestT(abIntersectionPoint);
if (0 <= t && t <= 1) {
points.Add(abIntersectionPoint);
}
Console.WriteLine(t);
}
if (bcIntersection != null) {
var bcIntersectionPoint = (Point2D)bcIntersection;
var t = bcLine.NearestT(bcIntersectionPoint);
if (0 <= t && t <= 1) {
points.Add(bcIntersectionPoint);
}
Console.WriteLine(t);
}
if (caIntersection != null) {
var caIntersectionPoint = (Point2D)caIntersection;
var t = caLine.NearestT(caIntersectionPoint);
if (0 <= t && t <= 1) {
points.Add(caIntersectionPoint);
}
Console.WriteLine(t);
}
if (points.Count == 0) {
return null;
} else if (points.Count == 1) {
return points.First();
} else {
Console.WriteLine(points.Count);
Trace.Assert(points.Count == 2);
var pointCollection = new PointCollection2D(points.ToArray());
return pointCollection;
}
}
}
}
throw new System.NotImplementedException("Intersection between " + shape.Type + " and " + Type + " not implemented.");
}