2012-01-16 16:46:00 +00:00
|
|
|
// Begin License:
|
2014-06-27 09:38:58 +00:00
|
|
|
// Copyright (C) 2006-2014 Tobias Sargeant (tobias.sargeant@gmail.com).
|
2012-01-16 16:46:00 +00:00
|
|
|
// All rights reserved.
|
|
|
|
//
|
|
|
|
// This file is part of the Carve CSG Library (http://carve-csg.com/)
|
|
|
|
//
|
2014-06-27 09:38:58 +00:00
|
|
|
// This file may be used under the terms of either the GNU General
|
|
|
|
// Public License version 2 or 3 (at your option) as published by the
|
|
|
|
// Free Software Foundation and appearing in the files LICENSE.GPL2
|
|
|
|
// and LICENSE.GPL3 included in the packaging of this file.
|
2012-01-16 16:46:00 +00:00
|
|
|
//
|
|
|
|
// This file is provided "AS IS" with NO WARRANTY OF ANY KIND,
|
|
|
|
// INCLUDING THE WARRANTIES OF DESIGN, MERCHANTABILITY AND FITNESS FOR
|
|
|
|
// A PARTICULAR PURPOSE.
|
|
|
|
// End:
|
|
|
|
|
|
|
|
|
|
|
|
#if defined(HAVE_CONFIG_H)
|
|
|
|
# include <carve_config.h>
|
|
|
|
#endif
|
|
|
|
|
|
|
|
#include <carve/csg.hpp>
|
|
|
|
#include <carve/convex_hull.hpp>
|
|
|
|
|
|
|
|
#include <algorithm>
|
|
|
|
|
|
|
|
namespace {
|
|
|
|
|
|
|
|
bool grahamScan(const std::vector<carve::geom2d::P2> &points,
|
|
|
|
int vpp, int vp,
|
|
|
|
const std::vector<int> &ordered,
|
|
|
|
int start,
|
|
|
|
std::vector<int> &result, int _i = 0) {
|
|
|
|
carve::geom2d::P2 v1 = points[vp] - points[vpp];
|
|
|
|
if (start == (int)ordered.size()) return true;
|
|
|
|
|
|
|
|
for (int i = start; i < (int)ordered.size(); ++i) {
|
|
|
|
int v = ordered[i];
|
|
|
|
carve::geom2d::P2 v2 = points[v] - points[vp];
|
|
|
|
|
|
|
|
double cp = v1.x * v2.y - v2.x * v1.y;
|
|
|
|
if (cp < 0) return false;
|
|
|
|
|
|
|
|
int j = i + 1;
|
|
|
|
while (j < (int)ordered.size() && points[ordered[j]] == points[v]) j++;
|
|
|
|
|
|
|
|
result.push_back(v);
|
|
|
|
if (grahamScan(points, vp, v, ordered, j, result, _i + 1)) return true;
|
|
|
|
result.pop_back();
|
|
|
|
}
|
|
|
|
|
|
|
|
return false;
|
|
|
|
}
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
namespace carve {
|
|
|
|
namespace geom {
|
|
|
|
|
|
|
|
std::vector<int> convexHull(const std::vector<carve::geom2d::P2> &points) {
|
|
|
|
double max_x = points[0].x;
|
|
|
|
unsigned max_v = 0;
|
|
|
|
|
|
|
|
for (unsigned i = 1; i < points.size(); ++i) {
|
|
|
|
if (points[i].x > max_x) {
|
|
|
|
max_x = points[i].x;
|
|
|
|
max_v = i;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
std::vector<std::pair<double, double> > angle_dist;
|
|
|
|
std::vector<int> ordered;
|
|
|
|
angle_dist.reserve(points.size());
|
|
|
|
ordered.reserve(points.size() - 1);
|
|
|
|
for (unsigned i = 0; i < points.size(); ++i) {
|
|
|
|
if (i == max_v) continue;
|
|
|
|
angle_dist[i] = std::make_pair(carve::math::ANG(carve::geom2d::atan2(points[i] - points[max_v])), distance2(points[i], points[max_v]));
|
|
|
|
ordered.push_back(i);
|
|
|
|
}
|
|
|
|
|
|
|
|
std::sort(ordered.begin(),
|
|
|
|
ordered.end(),
|
|
|
|
make_index_sort(angle_dist.begin()));
|
|
|
|
|
|
|
|
std::vector<int> result;
|
|
|
|
result.push_back(max_v);
|
|
|
|
result.push_back(ordered[0]);
|
|
|
|
|
|
|
|
if (!grahamScan(points, max_v, ordered[0], ordered, 1, result)) {
|
|
|
|
result.clear();
|
|
|
|
throw carve::exception("convex hull failed!");
|
|
|
|
}
|
|
|
|
|
|
|
|
return result;
|
|
|
|
}
|
|
|
|
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
|