/*
* METHODS
*/
public bool IsSeg(out Param parM)
{
/*
* MEANING: NON_DEGENERATED, PARAMETRIC segment
* (implies, that the Bezier is not
* self-intersecting)
*/
parM=null;
if (this.IsDegen)
return false;
if (this.cp[0]==this.cp[2])
return false; // S/I bezier
if (this.cp[0]==this.cp[1])
{
parM=new Param(0);
return true;
}
if (this.cp[1]==this.cp[2])
{
parM=new Param(1);
return true;
}
SegD seg=new SegD(this.cp[0], this.cp[2]);
LineD line=new LineD(seg);
VecD pnt;
Param par;
this.cp[1].Project(line,out par,out pnt);
if (this.cp[1].Dist(pnt)>MConsts.EPS_DEC)
return false;
if (!seg.IsEvaluableStrict(par))
return false;
parM=par;
if (Math.Abs(parM.Val-0.5)<MConsts.EPS_DEC)
{
parM.Val=0.5;
}
return true;
}
public bool IsSelfInters(out Param parM)
{
/*
* RETURN VALUE: true if Self-Intersecting; false otherwise
*/
parM=null;
if (this.IsDegen)
return false;
Param parSeg;
if (this.IsSeg(out parSeg))
return false;
SegD seg=new SegD(this.cp[0], this.cp[2]);
if (seg.IsDegen)
{
parM=Param.Infinity;
return true;
}
LineD line=new LineD(seg);
VecD pnt;
this.cp[1].Project(line,out parM,out pnt);
if (this.cp[1].Dist(pnt)>MConsts.EPS_DEC)
return false;
return true;
}
/*
* 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;
}
/*
* 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);
}
/*
* INTERSECTIONS: (BCurve,LCurve)
* - lcurve is required non-degenerated
*
* NOTES: - Curves are maximally reduced in AuxIntersectBL
* - Self/intersecting Bezier is NOT a reduction
* from bezier
*/
public static bool AuxIntersectBL(DegenD degen, LCurve lrs, ListInfoInters linters)
{
// IMPORTANT (TODO):
// such intersection is NOT VALID for computation of ray's parity
if (linters==null)
{
throw new ExceptionGMath("Intersect","AuxIntersectBL(degen,lrs)","Null argument");
}
if (lrs.IsDegen)
{
throw new ExceptionGMath("Intersect","AuxIntersectBL(degen,lrs)",null);
}
if (lrs is SegD)
{
return Inters.AuxIntersectBB(degen, lrs as SegD, null, null, linters);
}
LineD line=new LineD(lrs);
Param param;
VecD pnt;
if (!degen.Cp.Project(line,out param,out pnt))
return false;
if (degen.Cp.Dist(pnt)<MConsts.EPS_DEC)
{
if (lrs.IsEvaluableStrict(param))
{
IntersD0 inters=new IntersD0(Param.Degen, param, pnt, false);
linters.Add(inters);
}
}
return true;
}
