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Simplify dichotomy + add proper error check

This commit is contained in:
Mael Rouxel-Labbé 2024-02-24 00:15:09 +01:00
parent 440122c1f6
commit 6e463a0f69
1 changed files with 13 additions and 18 deletions
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31
Isosurfacing_3/include/CGAL/Isosurfacing_3/edge_intersection_oracles_3.h
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@ -72,17 +72,17 @@ struct Dichotomy_edge_intersection
auto z_coord = domain.geom_traits().compute_z_3_object(); auto z_coord = domain.geom_traits().compute_z_3_object();
auto point = domain.geom_traits().construct_point_3_object(); auto point = domain.geom_traits().construct_point_3_object();
if((val_0 <= isovalue) == (val_1 <= isovalue)) const bool sl = (val_0 <= isovalue);
const bool sr = (val_1 <= isovalue);
if(sl == sr)
return false; return false;
Point_3 pl = p_0; Point_3 pl = p_0;
Point_3 pr = p_1; Point_3 pr = p_1;
FT val_l = val_0;
FT val_r = val_1;
// @todo max iter choice
unsigned int dichotomy_iterations = 10, iter = 0; unsigned int dichotomy_iterations = 10, iter = 0;
const FT eps = (std::max)(FT(1e-7), std::abs(isovalue) * FT(1e-7));
do do
{ {
p = point((x_coord(pl) + x_coord(pr)) / FT(2), p = point((x_coord(pl) + x_coord(pr)) / FT(2),
@ -90,22 +90,17 @@ struct Dichotomy_edge_intersection
(z_coord(pl) + z_coord(pr)) / FT(2)); (z_coord(pl) + z_coord(pr)) / FT(2));
const FT val_p = domain.value(p); const FT val_p = domain.value(p);
const bool sp = (val_p <= isovalue);
if((val_l <= isovalue) != (val_p <= isovalue)) if(sl == sp)
{
pr = p;
val_r = val_p;
}
else
{
pl = p; pl = p;
val_l = val_p; else if(sp == sr)
} pr = p;
else
// @todo something like 1e-10 * isovalue?
// see also https://stats.stackexchange.com/questions/86708/how-to-calculate-relative-error-when-the-true-value-is-zero
if(is_zero(val_l - val_r))
break; break;
if(std::abs(val_p - isovalue) < eps)
return true;
} }
while(++iter < dichotomy_iterations); while(++iter < dichotomy_iterations);