/// <summary>
/// return true if 2d coplanar line segments intersect and stores intersection in result
/// </summary>
/// <param name="line1In"></param>
/// <param name="line2In"></param>
/// <param name="result"></param>
/// <returns></returns>
public static IntersectionRecord2 LineLineXYIntersect(Line2 line1In, Line2 line2In)
{
try
{
IntersectionRecord2 result = new IntersectionRecord2();
double x2min = Math.Min(line2In.Point1.X, line2In.Point2.X);
double y2min = Math.Min(line2In.Point1.Y, line2In.Point2.Y);
double x2max = Math.Max(line2In.Point1.X, line2In.Point2.X);
double y2max = Math.Max(line2In.Point1.Y, line2In.Point2.Y);
double x1min = Math.Min(line1In.Point1.X, line1In.Point2.X);
double y1min = Math.Min(line1In.Point1.Y, line1In.Point2.Y);
double x1max = Math.Max(line1In.Point1.X, line1In.Point2.X);
double y1max = Math.Max(line1In.Point1.Y, line1In.Point2.Y);
result = RayRayXYIntersect(line1In, line2In);
if (result.Intersects)
{
if ((result.X <= x1max) && (result.X >= x1min) && (result.X <= x2max) && (result.X >= x2min) &&
(result.Y <= y1max) && (result.Y >= y1min) && (result.Y <= y2max) && (result.Y >= y2min))
{
result.Intersects = true;
}
}
return(result);
}
catch (Exception)
{
throw;
}
}
/// <summary>
/// returns true if 2D coplanar infinite rays intersect and stores intersection in result
/// </summary>
/// <param name="ray1"></param>
/// <param name="ray2"></param>
/// <param name="result"></param>
/// <returns></returns>
public static IntersectionRecord2 RayRayXYIntersect(Line2 ray1, Line2 ray2)
{
try
{
IntersectionRecord2 result = new IntersectionRecord2();
Vector2 ptOut = new Vector2();
if (ray1.SlopeXY == ray2.SlopeXY)
{
double yt = (ray1.Point1.X - ray2.Point1.X) * (ray2.Point2.Y - ray2.Point1.Y);
double yt2 = (ray2.Point2.X - ray2.Point1.X) * (ray2.Point1.Y - ray1.Point1.Y);
if ((yt2 - yt) > float.Epsilon)
{
result.Intersects = false;
}
else
{
result = new IntersectionRecord2(new Vector2(ray2.Point1.X, ray2.Point1.Y), true);
}
}
else
{
double denom = (ray1.Point1.X - ray1.Point2.X) * (ray2.Point1.Y - ray2.Point2.Y) - (ray2.Point1.X - ray2.Point2.X) * (ray1.Point1.Y - ray1.Point2.Y);
double xOut = 0;
double yOut = 0;
double line1Det = ray1.Point1.X * ray1.Point2.Y - ray1.Point2.X * ray1.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 * (ray1.Point1.X - ray1.Point2.X)) / denom;
yOut = (line1Det * (ray2.Point1.Y - ray2.Point2.Y) - line2Det * (ray1.Point1.Y - ray1.Point2.Y)) / denom;
result = new IntersectionRecord2(new Vector2(xOut, yOut), true);
}
return(result);
}
catch (Exception)
{
throw;
}
}
/// <summary>
/// returns true if ray and line segment intersect and stores intersection in result
/// </summary>
/// <param name="RayIn"></param>
/// <param name="line2In"></param>
/// <param name="result"></param>
/// <returns></returns>
public static IntersectionRecord2 RayLineXYIntersect(Line2 rayIn, Line2 line2In)
{
try
{
double x2min = Math.Min(line2In.Point1.X, line2In.Point2.X);
double y2min = Math.Min(line2In.Point1.Y, line2In.Point2.Y);
double x2max = Math.Max(line2In.Point1.X, line2In.Point2.X);
double y2max = Math.Max(line2In.Point1.Y, line2In.Point2.Y);
IntersectionRecord2 result = RayRayXYIntersect(rayIn, line2In);
if (result.Intersects)
{
if ((result.X > x2max) || (result.X < x2min) || (result.Y > y2max) || (result.Y < y2min))
{
result.Intersects = false;
}
}
return(result);
}
catch (Exception)
{
throw;
}
}
