/*
* INTERSECT: (LCurve, LCurve)
* - both curves are supposed to be NON-DEGENERATED
*/
public static bool IntersectLL(LCurve lrsA, LCurve lrsB,
out InfoInters inters)
{
inters = null;
if ((lrsA.IsDegen) || (lrsB.IsDegen))
{
throw new ExceptionGMath("Intersect", "IntersectLL(lrs,lrs)", null);
}
VecD a0 = lrsA.Start;
VecD a1 = lrsA.End;
VecD b0 = lrsB.Start;
VecD b1 = lrsB.End;
VecD dirA = lrsA.DirTang;
VecD dirB = lrsB.DirTang;
double det = dirA.Cross(dirB);
// lrsA and lrsB are not parallel
if (Math.Abs(det) > MConsts.EPS_DEC)
{
double lenA = (a1 - a0).Norm;
double lenB = (b1 - b0).Norm;
VecD diff = b0 - a0;
Param parA = (diff.Cross(dirB)) / (det * lenA);
Param parB = (diff.Cross(dirA)) / (det * lenB);
if (lrsA.IsEvaluableStrict(parA) && lrsB.IsEvaluableStrict(parB))
{
VecD pnt = 0.5 * (lrsA.Evaluate(parA) + lrsB.Evaluate(parB));
inters = new IntersD0(parA, parB, pnt, false);
}
return(true);
}
// lrsA and lrsB are parallel
LineD lineB = new LineD(lrsB);
Param paramBInvA0, paramBInvA1;
VecD pntProjA0, pntProjA1;
a0.Project(lineB, out paramBInvA0, out pntProjA0);
a1.Project(lineB, out paramBInvA1, out pntProjA1);
double distA0 = a0.Dist(pntProjA0);
double distA1 = a1.Dist(pntProjA1);
if ((distA0 < MConsts.EPS_DEC) || (distA1 < MConsts.EPS_DEC))
{
// lrsA and lrsB are colinear
Param.TypeParam typeA0 = lrsB.ParamClassify(paramBInvA0);
Param.TypeParam typeA1 = lrsB.ParamClassify(paramBInvA1);
int mult = (int)typeA0 * (int)typeA1;
if (mult == 4)
{
return(true);
}
else if (mult == 1)
{
throw new ExceptionGMath("Intersect", "IntersectLL(lrs,lrs)", null); // lrsA is degenerated
//return false;
}
else if (mult == 2)
{
if ((typeA0 == Param.TypeParam.Start) &&
(typeA1 == Param.TypeParam.Before))
{
inters = new IntersD0(0, 0, a0, false);
}
if ((typeA0 == Param.TypeParam.Before) &&
(typeA1 == Param.TypeParam.Start))
{
inters = new IntersD0(1, 0, a1, false);
}
if ((typeA0 == Param.TypeParam.End) &&
(typeA1 == Param.TypeParam.After))
{
inters = new IntersD0(0, 1, a0, false);
}
if ((typeA0 == Param.TypeParam.After) &&
(typeA1 == Param.TypeParam.End))
{
inters = new IntersD0(1, 1, a1, false);
}
return(true);
}
else if (mult <= 0)
{
return(Inters.RefineIntersLLD1(lrsA, lrsB, out inters));
}
}
return(true);
}
public static bool RefineIntersLLD1(LCurve lrsA, LCurve lrsB,
out InfoInters inters)
{
inters = null;
if ((lrsA is SegD) && (lrsB is SegD))
{
BCurve curveA = lrsA as BCurve;
BCurve curveB = lrsB as BCurve;
return(Inters.RefineIntersBBD1(curveA, curveB, out inters));
}
if (lrsA.LComplexity > lrsB.LComplexity)
{
bool res = Inters.RefineIntersLLD1(lrsB, lrsA, out inters);
if (inters != null)
{
inters.ParamSwap();
}
return(res);
}
VecD a0 = lrsA.Start;
VecD a1 = lrsA.End;
VecD b0 = lrsB.Start;
VecD b1 = lrsB.End;
Param paramBInvA0, paramBInvA1;
bool isOn;
if ((!a0.InverseOn(lrsB, out isOn, out paramBInvA0)) || (!isOn))
{
return(false);
}
if ((!a1.InverseOn(lrsB, out isOn, out paramBInvA1)) || (!isOn))
{
return(false);
}
Param paramAInvB0, paramAInvB1;
if ((!b0.InverseOn(lrsA, out isOn, out paramAInvB0)) || (!isOn))
{
return(false);
}
if ((!b1.InverseOn(lrsA, out isOn, out paramAInvB1)) || (!isOn))
{
return(false);
}
bool areCoDirected = (paramBInvA1.Val >= paramBInvA0.Val);
if (!areCoDirected)
{
if (lrsA is LineD)
{
if (lrsB is LineD)
{
paramAInvB0 = (areCoDirected)? -Param.Infinity: Param.Infinity;
paramAInvB1 = (areCoDirected)? Param.Infinity: -Param.Infinity;
inters = new IntersD1(paramAInvB0, -Param.Infinity,
paramAInvB1, Param.Infinity, lrsB, false);
return(true);
}
if (lrsB is RayD)
{
paramAInvB1 = (areCoDirected)? Param.Infinity: -Param.Infinity;
inters = new IntersD1(paramAInvB0, 0,
paramAInvB1, Param.Infinity, lrsB, false);
return(true);
}
if (lrsB is SegD)
{
inters = new IntersD1(paramAInvB0, 0,
paramAInvB1, 1, lrsB, false);
return(true);
}
}
if (lrsA is RayD)
{
if (lrsB is RayD)
{
if (areCoDirected)
{
if (paramAInvB0 > 0)
{
inters = new IntersD1(paramAInvB0, 0,
Param.Infinity, Param.Infinity, lrsB, false);
return(true);
}
else
{
inters = new IntersD1(0, paramBInvA0,
Param.Infinity, Param.Infinity, lrsA, false);
return(true);
}
}
else
{
if (paramAInvB0 > 0)
{
inters = new IntersD1(0, paramBInvA0,
paramAInvB0, 0, new SegD(a0, b0), false);
return(true);
}
}
}
if (lrsB is SegD)
{
// intersection is known to have dimension D1 !!!
if ((paramBInvA0 >= 1) || (paramBInvA0 <= 0))
{
inters = new IntersD1(paramAInvB0, 0,
paramAInvB1, 1, new SegD(b0, b1), false);
return(true);
}
if ((0 < paramBInvA0) && (paramBInvA1 < 1))
{
if (areCoDirected)
{
inters = new IntersD1(0, paramBInvA0,
paramAInvB1, 1, new SegD(a0, b1), false);
return(true);
}
else
{
inters = new IntersD1(0, paramBInvA0,
paramAInvB0, 0, new SegD(a0, b0), false);
return(true);
}
}
}
}
}
throw new ExceptionGMath("Intersect", "RefineIntersLLD1", null);
//return false;
}