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Avoid needless loss of precision with BBox_3 usage

This commit is contained in:
Mael Rouxel-Labbé 2020-05-06 12:11:03 +02:00
parent 6fe47eddbe
commit c2f7b46c06
1 changed files with 27 additions and 13 deletions
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40
Optimal_bounding_box/include/CGAL/Optimal_bounding_box/oriented_bounding_box.h
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@ -23,7 +23,6 @@
#include <CGAL/boost/graph/named_params_helper.h>
#include <CGAL/assertions.h>
#include <CGAL/Bbox_3.h>
#include <CGAL/boost/graph/helpers.h>
#include <CGAL/convex_hull_3.h>
#include <CGAL/Convex_hull_traits_3.h>
@ -64,25 +63,40 @@ void construct_oriented_bounding_box(const PointRange& points,
std::array<typename Traits::Point_3, 8>& obb_points,
const Traits& traits)
{
typedef typename Traits::FT FT;
typedef typename Traits::Point_3 Point;
CGAL_precondition(!points.empty());
// Construct the bbox of the transformed point set
CGAL::Bbox_3 bbox;
for(const Point& pt : points)
typename PointRange::const_iterator pit = std::begin(points);
const Point& first_pt = *pit++;
const Point first_rot_pt = transformation.transform(first_pt);
FT xmin = first_rot_pt.x(), xmax = first_rot_pt.x();
FT ymin = first_rot_pt.y(), ymax = first_rot_pt.y();
FT zmin = first_rot_pt.z(), zmax = first_rot_pt.z();
for(typename PointRange::const_iterator end=std::end(points); pit!=end; ++pit)
{
const Point rotated_pt = transformation.transform(pt);
bbox += traits.construct_bbox_3_object()(rotated_pt);
const Point rot_pt = transformation.transform(*pit);
xmin = (std::min)(rot_pt.x(), xmin);
ymin = (std::min)(rot_pt.y(), ymin);
zmin = (std::min)(rot_pt.z(), zmin);
xmax = (std::max)(rot_pt.x(), xmax);
ymax = (std::max)(rot_pt.y(), ymax);
zmax = (std::max)(rot_pt.z(), zmax);
}
obb_points[0] = Point(bbox.xmin(), bbox.ymin(), bbox.zmin());
obb_points[1] = Point(bbox.xmax(), bbox.ymin(), bbox.zmin());
obb_points[2] = Point(bbox.xmax(), bbox.ymax(), bbox.zmin());
obb_points[3] = Point(bbox.xmin(), bbox.ymax(), bbox.zmin());
obb_points[0] = Point(xmin, ymin, zmin);
obb_points[1] = Point(xmax, ymin, zmin);
obb_points[2] = Point(xmax, ymax, zmin);
obb_points[3] = Point(xmin, ymax, zmin);
obb_points[4] = Point(bbox.xmin(), bbox.ymax(), bbox.zmax()); // see order in make_hexahedron()...
obb_points[5] = Point(bbox.xmin(), bbox.ymin(), bbox.zmax());
obb_points[6] = Point(bbox.xmax(), bbox.ymin(), bbox.zmax());
obb_points[7] = Point(bbox.xmax(), bbox.ymax(), bbox.zmax());
obb_points[4] = Point(xmin, ymax, zmax); // see order in make_hexahedron()...
obb_points[5] = Point(xmin, ymin, zmax);
obb_points[6] = Point(xmax, ymin, zmax);
obb_points[7] = Point(xmax, ymax, zmax);
// Apply the inverse rotation to the rotated axis aligned bounding box
for(std::size_t i=0; i<8; ++i)