public bool Find()
{
if (Result != IntersectionResult.NotComputed)
{
return(Result == IntersectionResult.Intersects);
}
// [RMS] if either segment direction is not a normalized vector,
// results are garbage, so fail query
if (line.Direction.IsNormalized == false || segment.Direction.IsNormalized == false)
{
Type = IntersectionType.Empty;
Result = IntersectionResult.InvalidQuery;
return(false);
}
Vector2d s = Vector2d.Zero;
Type = IntrLine2Line2.Classify(line.Origin, line.Direction,
segment.Center, segment.Direction,
dotThresh, ref s);
if (Type == IntersectionType.Point)
{
// Test whether the line-line intersection is on the segment.
if (Math.Abs(s[1]) <= segment.Extent + intervalThresh)
{
Quantity = 1;
Point = line.Origin + s[0] * line.Direction;
Parameter = s[0];
}
else
{
Quantity = 0;
Type = IntersectionType.Empty;
}
}
else if (Type == IntersectionType.Line)
{
Type = IntersectionType.Segment;
Quantity = int.MaxValue;
}
else
{
Quantity = 0;
}
Result = (Type != IntersectionType.Empty) ?
IntersectionResult.Intersects : IntersectionResult.NoIntersection;
return(Result == IntersectionResult.Intersects);
}
public bool Find()
{
if (Result != IntersectionResult.NotComputed)
{
return(Result == IntersectionResult.Intersects);
}
// [RMS] if either segment direction is not a normalized vector,
// results are garbage, so fail query
if (segment1.Direction.IsNormalized == false || segment2.Direction.IsNormalized == false)
{
Type = IntersectionType.Empty;
Result = IntersectionResult.InvalidQuery;
return(false);
}
Vector2d s = Vector2d.Zero;
Type = IntrLine2Line2.Classify(segment1.Center, segment1.Direction,
segment2.Center, segment2.Direction,
dotThresh, ref s);
if (Type == IntersectionType.Point)
{
// Test whether the line-line intersection is on the segments.
if (Math.Abs(s[0]) <= segment1.Extent + intervalThresh &&
Math.Abs(s[1]) <= segment2.Extent + intervalThresh)
{
Quantity = 1;
Point0 = segment1.Center + s[0] * segment1.Direction;
Parameter0 = s[0];
}
else
{
Quantity = 0;
Type = IntersectionType.Empty;
}
}
else if (Type == IntersectionType.Line)
{
// Compute the location of segment1 endpoints relative to segment0.
Vector2d diff = segment2.Center - segment1.Center;
double t1 = segment1.Direction.Dot(diff);
double tmin = t1 - segment2.Extent;
double tmax = t1 + segment2.Extent;
var calc = new Intersector1(-segment1.Extent, segment1.Extent, tmin, tmax);
calc.Find();
Quantity = calc.NumIntersections;
if (Quantity == 2)
{
Type = IntersectionType.Segment;
Parameter0 = calc.GetIntersection(0);
Point0 = segment1.Center +
Parameter0 * segment1.Direction;
Parameter1 = calc.GetIntersection(1);
Point1 = segment1.Center +
Parameter1 * segment1.Direction;
}
else if (Quantity == 1)
{
Type = IntersectionType.Point;
Parameter0 = calc.GetIntersection(0);
Point0 = segment1.Center +
Parameter0 * segment1.Direction;
}
else
{
Type = IntersectionType.Empty;
}
}
else
{
Quantity = 0;
}
Result = (Type != IntersectionType.Empty) ?
IntersectionResult.Intersects : IntersectionResult.NoIntersection;
// [RMS] for debugging...
//sanity_check();
return(Result == IntersectionResult.Intersects);
}