79 lines
2.0 KiB
C++
79 lines
2.0 KiB
C++
/*
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* p2d_offset.cpp - Simple offsetting (without dogbones)
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*
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* Written 2012 by Werner Almesberger
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* Copyright 2012 by Werner Almesberger
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*/
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/*
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* References:
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* http://www.cgal.org/Manual/latest/examples/Straight_skeleton_2/
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* Create_saop_from_polygon_with_holes_2.cpp
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* http://www.cgal.org/Manual/latest/examples/Straight_skeleton_2/print.h
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*/
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extern "C" {
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#include <assert.h>
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#include "poly2d.h"
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}
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#include "cgal_helper.h"
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#include <vector>
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#include <boost/shared_ptr.hpp>
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#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
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#include <CGAL/Polygon_with_holes_2.h>
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#include <CGAL/create_offset_polygons_from_polygon_with_holes_2.h>
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typedef CGAL::Exact_predicates_inexact_constructions_kernel K;
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typedef CGAL::Polygon_2<K> Polygon_2;
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typedef CGAL::Polygon_with_holes_2<K> Polygon_with_holes;
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typedef boost::shared_ptr<Polygon_2> PolygonPtr;
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typedef std::vector<PolygonPtr> PolygonPtrVector;
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extern "C" struct p2d *p2d_offset_holes(const struct p2d *p,
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const struct p2d *holes, double off)
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{
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const struct p2d *h;
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struct p2d *res = NULL, **last = &res;
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assert(p2d_is_closed(p));
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Polygon_with_holes poly(p2d_to_P2(p, 1));
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for (h = holes; h; h = h->next) {
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assert(p2d_is_closed(h));
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poly.add_hole(p2d_to_P2(h, 0));
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}
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PolygonPtrVector tmp = off > 0 ?
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CGAL::create_exterior_skeleton_and_offset_polygons_2(off,
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poly.outer_boundary()) :
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CGAL::create_interior_skeleton_and_offset_polygons_2(-off, poly);
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for (PolygonPtrVector::const_iterator pit = tmp.begin();
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pit != tmp.end(); ++pit) {
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*last = P2_to_p2d(**pit);
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last = &(*last)->next;
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}
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return res;
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}
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extern "C" struct p2d *p2d_offset(const struct p2d *p, double off)
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{
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return p2d_offset_holes(p, NULL, off);
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}
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