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csg2d - better check for spline overlapping

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This commit is contained in:
Matthias Hochsteger 2020-08-28 14:26:57 +02:00
parent f559cdef16
commit 1c825ebddf
1 changed files with 18 additions and 6 deletions
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20
libsrc/geom2d/csg2d.cpp
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@ -332,27 +332,39 @@ bool IsOverlapping( Spline p, Spline s, double & alpha, double & beta, Intersect
double lam0 = -1e3*EPSILON;
double lam1 = -1e3*EPSILON;
double lam2 = -1e3*EPSILON;
double lam3 = -1e3*EPSILON;
alpha=-1e8;
beta=-1e8;
double alpha_mid=-1e8;
double beta_mid=-1e8;
// Check if s.p0 lies on p and vice versa, also check if tangents are in same direction (TODO: TEST)
// If so, assume overlapping splines
// TODO: Better checks! False positives could happen here!
IntersectSplineSegment1( p, s.StartPI(), p_mid, lam0, alpha );
IntersectSplineSegment1( s, p.StartPI(), s_mid, lam1, beta );
// Also check if midpoints lie on other spline
IntersectSplineSegment1( p, s.GetPoint(0.5), p_mid, lam2, alpha_mid );
IntersectSplineSegment1( s, p.GetPoint(0.5), s_mid, lam3, beta_mid );
auto tang0 = s.GetTangent(0.);
auto tang1 = p.GetTangent(alpha);
double err = tang0*tang1;
err*=err;
err *= 1.0/(tang0.Length2()*tang1.Length2());
if(fabs(lam0) < 1e3*EPSILON && fabs(lam1) < 1e3*EPSILON /*&& err < EPSILON*/)
{
double constexpr eps = 1e3*EPSILON;
if(fabs(lam0)>eps) return false;
if(fabs(lam1)>eps) return false;
if(fabs(lam2)>eps) return false;
if(fabs(lam3)>eps) return false;
if(fabs(1.0-err)>eps) return false;
type = ClassifyOverlappingIntersection( alpha, beta );
return true;
}
return false;
}
bool IsInsideTrig( const array<Point<2>,3> & t, Point<2> r )
{