public IIntersection Intersects(ILine3 ray2)
{
try
{
var result = new Intersection3();
var ptOut = new Vector2();
if (SlopeXY == ray2.SlopeXY)
{
result.Intersects = false;
}
else
{
double denom = (Point1.X - Point2.X) * (ray2.Point1.Y - ray2.Point2.Y)
- (ray2.Point1.X - ray2.Point2.X) * (Point1.Y - Point2.Y);
double xOut = 0;
double yOut = 0;
double line1Det = Point1.X * Point2.Y - Point2.X * Point1.Y;
double line2Det = ray2.Point1.X * ray2.Point2.Y - ray2.Point2.X * ray2.Point1.Y;
xOut = (line1Det * (ray2.Point1.X - ray2.Point2.X) - line2Det * (Point1.X - Point2.X)) / denom;
yOut = (line1Det * (ray2.Point1.Y - ray2.Point2.Y) - line2Det * (Point1.Y - Point2.Y)) / denom;
result = new Intersection3(new Vector3(xOut, yOut, 0), true);
}
return(result);
}
catch (Exception)
{
throw;
}
}
public IIntersection Intersects(ILine3 ray2)
{
try
{
IIntersection result = new Intersection3();
Vector3 Point1;
Intersection3 ir = new Intersection3();
//transform arc and line to center arc at origin
IVector3 trans = new Vector3(-1 * Center.X, -1 * Center.Y, 0);
IArc arcT = Translate(trans);
ILine3 lineT = ray2.Translate(trans);
//parameterize line
double dy = lineT.Point2.Y - lineT.Point1.Y;
double dx = lineT.Point2.X - lineT.Point1.X;
//calc quadratic solution
double a = Math.Pow(dx, 2) + Math.Pow(dy, 2);
double b = 2 * (dx) * (lineT.Point1.X - arcT.Center.X) + 2 * (dy) * (lineT.Point1.Y - arcT.Center.Y);
double c = Math.Pow(lineT.Point1.X - arcT.Center.X, 2) + Math.Pow(lineT.Point1.Y - arcT.Center.Y, 2) - Math.Pow(arcT.Radius, 2);
double discrim = Math.Pow(b, 2) - 4 * a * c;
if (discrim >= 0)//check solution is real
{
double tPos = (-b + Math.Sqrt(discrim)) / (2 * a);
double tNeg = (-b - Math.Sqrt(discrim)) / (2 * a);
double xpos = dx * tPos + lineT.Point1.X;
double ypos = dy * tPos + lineT.Point1.Y;
double xneg = dx * tNeg + lineT.Point1.X;
double yneg = dy * tNeg + lineT.Point1.Y;
double angneg = Math.Atan2(yneg, xneg);
double angpos = Math.Atan2(ypos, xpos);
if (angneg < 0)
{
angneg += 2 * Math.PI;
}
if (angpos < 0)
{
angpos += 2 * Math.PI;
}
//transform point back before returning
if ((angneg >= arcT.StartAngleRad) && (angneg <= arcT.EndAngleRad))
{
Point1 = new Vector3(xneg, yneg, 0);
var pt = Point1.Translate(new Vector3(Center.X, Center.Y, 0.0));
result = new Intersection3(pt, true);
result.Intersects = true;
}
if ((angpos >= arcT.StartAngleRad) && (angpos <= arcT.EndAngleRad))
{
Point1 = new Vector3(xpos, ypos, 0);
var pt = Point1.Translate(new Vector3(Center.X, Center.Y, 0.0));
result = new Intersection3(pt, true);
result.Intersects = true;
}
}
return(result);
}
catch (Exception)
{
throw;
}
}
