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add a double version of alpha computation 

generated using Herbie
This commit is contained in:
Sébastien Loriot 2022-03-18 08:39:55 +01:00
parent 6c92061772
commit f58073aa01
1 changed files with 50 additions and 7 deletions
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57
Intersections_2/include/CGAL/Intersections_2/Segment_2_Segment_2.h
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@ -353,6 +353,55 @@ protected:
mutable typename K::Point_2 _intersection_point, _other_point;
};
// code generated using Herbie https://herbie.uwplse.org/
inline
double s2s2_interpt(double x0, double y0,
double x1, double y1,
double x2, double y2,
double x3, double y3)
{
double tmp;
if (x1 <= -9.794158788366665e-11) {
tmp = -(x1 / (x0 - x1));
} else {
double t_0 = (y1 - y3) / (y1 - y0);
double tmp_1;
if (x1 <= -1.7579125018815487e-296) {
tmp_1 = t_0;
} else if (x1 <= 1.7250761038378636e-206) {
tmp_1 = x2 / ((fma(x2, y0, fma(y3, x0, (x1 * y2))) - fma(x2, y1, fma(y3, x1, (x0 * y2)))) / (y3 - y1));
} else if (x1 <= 3.6888389969707494e-205) {
tmp_1 = t_0;
} else if (x1 <= 1.4339509931401463e-80) {
tmp_1 = (fma(x1, y2, fma(y1, x3, (y3 * x2))) - fma(x2, y1, fma(x1, y3, (y2 * x3)))) / fma((x3 - x2), (y1 - y0), ((x0 - x1) * (y3 - y2)));
} else if (x1 <= 1.72960576050945e+52) {
tmp_1 = (y1 - y2) / (y1 - y0);
} else if (x1 <= 2.145089573601479e+104) {
tmp_1 = (x1 - x3) / (x1 - x0);
} else {
tmp_1 = (x1 - x2) / (x1 - x0);
}
tmp = tmp_1;
}
return tmp;
}
template <class FT>
FT s2s2_interpt(const FT& x0, const FT& y0,
const FT& x1, const FT& y1,
const FT& x2, const FT& y2,
const FT& x3, const FT& y3)
{
FT s1_dx = x0 - x1,
s1_dy = y0 - y1,
s2_dx = x3 - x2,
s2_dy = y3 - y2,
lx = x3 - x1,
ly = y3 - y1;
return (lx*s2_dy-ly*s2_dx)/(s1_dx*s2_dy-s1_dy*s2_dx);
}
template <class K>
typename Segment_2_Segment_2_pair<K>::Intersection_results
Segment_2_Segment_2_pair<K>::intersection_type() const
@ -400,14 +449,8 @@ Segment_2_Segment_2_pair<K>::intersection_type() const
: CGAL::make_array( _seg2->point(s2s2_id[c][2]), _seg2->point(s2s2_id[c][3]),
_seg1->point(s2s2_id[c][0]), _seg1->point(s2s2_id[c][1]) );
typename K::FT s1_dx = pts[0].x() - pts[1].x(),
s1_dy = pts[0].y() - pts[1].y(),
s2_dx = pts[3].x() - pts[2].x(),
s2_dy = pts[3].y() - pts[2].y(),
lx = pts[3].x() - pts[1].x(),
ly = pts[3].y() - pts[1].y();
typename K::FT alpha = s2s2_interpt(pts[0].x(), pts[0].y(), pts[1].x(), pts[1].y(), pts[2].x(), pts[2].y(), pts[3].x(), pts[3].y());
typename K::FT alpha = (lx*s2_dy-ly*s2_dx)/(s1_dx*s2_dy-s1_dy*s2_dx);
_intersection_point = K().construct_barycenter_2_object()(pts[0], alpha, pts[1]);
return _result;