public bool Find()
{
if (Result != IntersectionResult.NotComputed)
{
return(Result == IntersectionResult.Intersects);
}
// [RMS] if either line direction is not a normalized vector,
// results are garbage, so fail query
if (segment.Direction.IsNormalized == false)
{
Type = IntersectionType.Empty;
Result = IntersectionResult.InvalidQuery;
return(false);
}
Vector3D dist = Vector3D.Zero;
Vector3i sign = Vector3i.Zero;
int positive = 0, negative = 0, zero = 0;
IntrLine2Triangle2.TriangleLineRelations(segment.Center, segment.Direction, triangle,
ref dist, ref sign, ref positive, ref negative, ref zero);
if (positive == 3 || negative == 3)
{
// No intersections.
Quantity = 0;
Type = IntersectionType.Empty;
}
else
{
Vector2D param = Vector2D.Zero;
IntrLine2Triangle2.GetInterval(segment.Center, segment.Direction, triangle, dist, sign, ref param);
Intersector1 intr = new Intersector1(param[0], param[1], -segment.Extent, +segment.Extent);
intr.Find();
Quantity = intr.NumIntersections;
if (Quantity == 2)
{
// Segment intersection.
Type = IntersectionType.Segment;
Param0 = intr.GetIntersection(0);
Point0 = segment.Center + Param0 * segment.Direction;
Param1 = intr.GetIntersection(1);
Point1 = segment.Center + Param1 * segment.Direction;
}
else if (Quantity == 1)
{
// Point intersection.
Type = IntersectionType.Point;
Param0 = intr.GetIntersection(0);
Point0 = segment.Center + Param0 * segment.Direction;
}
else
{
// No intersections.
Type = IntersectionType.Empty;
}
}
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;
Intersector1 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);
}