public IPointCyl Translate(IVector3 translation)
{
IVector3 ptXYZ = new Vector3(this);
IVector3 ptTrans = ptXYZ.Translate(translation);
PointCyl ptCylTrans = new PointCyl(ptTrans);
ptCylTrans.Col = Col;
return(ptCylTrans);
}
/// <summary>
/// returns true if infinite ray and arc intersect, stores intersection(s) in result
/// </summary>
/// <param name="arcIn"></param>
/// <param name="lineIn"></param>
/// <param name="result"></param>
/// <returns></returns>
public static IntersectionRecord RayArcXYIntersect(Arc arcIn, Line lineIn)
{
try
{
IntersectionRecord result = new IntersectionRecord();
Vector3 Point1;
IntersectionRecord ir = new IntersectionRecord();
//transform arc and line to center arc at origin
Arc arcT = arcIn.Translate(new Vector3(-1 * arcIn.Center.X, -1 * arcIn.Center.Y, 0));
Line lineT = lineIn.Translate(new Vector3(-1 * arcIn.Center.X, -1 * arcIn.Center.Y, 0));
//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);
result = (IntersectionRecord)Point1.Translate(new Vector3(arcIn.Center.X, arcIn.Center.Y, 0.0));
result.Intersects = true;
}
if ((angpos >= arcT.StartAngleRad) && (angpos <= arcT.EndAngleRad))
{
Point1 = new Vector3(xpos, ypos, 0);
result = (IntersectionRecord)Point1.Translate(new Vector3(arcIn.Center.X, arcIn.Center.Y, 0.0));
result.Intersects = true;
}
}
return(result);
}
catch (Exception)
{
throw;
}
}