86 lines
2.9 KiB
C++
86 lines
2.9 KiB
C++
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// This file is part of libigl, a simple c++ geometry processing library.
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//
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// Copyright (C) 2016 Qingnan Zhou <qnzhou@gmail.com>
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//
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// This Source Code Form is subject to the terms of the Mozilla Public License
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// v. 2.0. If a copy of the MPL was not distributed with this file, You can
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// obtain one at http://mozilla.org/MPL/2.0/.
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#include "delaunay_triangulation.h"
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#include "flip_edge.h"
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#include "lexicographic_triangulation.h"
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#include "unique_edge_map.h"
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#include <vector>
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#include <sstream>
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template<
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typename DerivedV,
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typename Orient2D,
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typename InCircle,
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typename DerivedF>
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IGL_INLINE void igl::delaunay_triangulation(
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const Eigen::PlainObjectBase<DerivedV>& V,
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Orient2D orient2D,
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InCircle incircle,
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Eigen::PlainObjectBase<DerivedF>& F)
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{
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assert(V.cols() == 2);
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typedef typename DerivedF::Scalar Index;
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typedef typename DerivedV::Scalar Scalar;
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igl::lexicographic_triangulation(V, orient2D, F);
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const size_t num_faces = F.rows();
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if (num_faces == 0) {
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// Input points are degenerate. No faces will be generated.
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return;
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}
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assert(F.cols() == 3);
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Eigen::MatrixXi E;
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Eigen::MatrixXi uE;
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Eigen::VectorXi EMAP;
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std::vector<std::vector<Index> > uE2E;
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igl::unique_edge_map(F, E, uE, EMAP, uE2E);
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auto is_delaunay = [&V,&F,&uE2E,num_faces,&incircle](size_t uei) {
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auto& half_edges = uE2E[uei];
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if (half_edges.size() != 2) {
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throw "Cannot flip non-manifold or boundary edge";
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}
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const size_t f1 = half_edges[0] % num_faces;
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const size_t f2 = half_edges[1] % num_faces;
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const size_t c1 = half_edges[0] / num_faces;
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const size_t c2 = half_edges[1] / num_faces;
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assert(c1 < 3);
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assert(c2 < 3);
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assert(f1 != f2);
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const size_t v1 = F(f1, (c1+1)%3);
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const size_t v2 = F(f1, (c1+2)%3);
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const size_t v4 = F(f1, c1);
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const size_t v3 = F(f2, c2);
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const Scalar p1[] = {V(v1, 0), V(v1, 1)};
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const Scalar p2[] = {V(v2, 0), V(v2, 1)};
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const Scalar p3[] = {V(v3, 0), V(v3, 1)};
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const Scalar p4[] = {V(v4, 0), V(v4, 1)};
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auto orientation = incircle(p1, p2, p4, p3);
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return orientation <= 0;
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};
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bool all_delaunay = false;
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while(!all_delaunay) {
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all_delaunay = true;
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for (size_t i=0; i<uE2E.size(); i++) {
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if (uE2E[i].size() == 2) {
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if (!is_delaunay(i)) {
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all_delaunay = false;
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flip_edge(F, E, uE, EMAP, uE2E, i);
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}
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}
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}
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}
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}
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#ifdef IGL_STATIC_LIBRARY
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template void igl::delaunay_triangulation<Eigen::Matrix<double, -1, -1, 0, -1, -1>, short (*)(double const*, double const*, double const*), short (*)(double const*, double const*, double const*, double const*), Eigen::Matrix<int, -1, -1, 0, -1, -1> >(Eigen::PlainObjectBase<Eigen::Matrix<double, -1, -1, 0, -1, -1> > const&, short (*)(double const*, double const*, double const*), short (*)(double const*, double const*, double const*, double const*), Eigen::PlainObjectBase<Eigen::Matrix<int, -1, -1, 0, -1, -1> >&);
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#endif
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