#ifndef GEOM_CONVEX_COVER_H #define GEOM_CONVEX_COVER_H /** * \file * \brief \todo brief description * * Copyright 2006 Nathan Hurst <njh@mail.csse.monash.edu.au> * Copyright 2006 Michael G. Sloan <mgsloan@gmail.com> * * This library is free software; you can redistribute it and/or * modify it either under the terms of the GNU Lesser General Public * License version 2.1 as published by the Free Software Foundation * (the "LGPL") or, at your option, under the terms of the Mozilla * Public License Version 1.1 (the "MPL"). If you do not alter this * notice, a recipient may use your version of this file under either * the MPL or the LGPL. * * You should have received a copy of the LGPL along with this library * in the file COPYING-LGPL-2.1; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * You should have received a copy of the MPL along with this library * in the file COPYING-MPL-1.1 * * The contents of this file are subject to the Mozilla Public License * Version 1.1 (the "License"); you may not use this file except in * compliance with the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY * OF ANY KIND, either express or implied. See the LGPL or the MPL for * the specific language governing rights and limitations. * */ /** A convex cover is a sequence of convex polygons that completely cover the path. For now a * convex hull class is included here (the convex-hull header is wrong) */ #include <2geom/point.h> #include <vector> namespace Geom{ /** ConvexHull * A convexhull is a convex region - every point between two points in the convex hull is also in * the convex hull. It is defined by a set of points travelling in a clockwise direction. We require the first point to be top most, and of the topmost, leftmost. * An empty hull has no points, we allow a single point or two points degenerate cases. * We could provide the centroid as a member for efficient direction determination. We can update the * centroid with all operations with the same time complexity as the operation. */ 00055 class ConvexHull{ public: // XXX: should be private :) // extracts the convex hull of boundary. internal use only void find_pivot(); void angle_sort(); void graham_scan(); void graham(); public: std::vector<Point> boundary; //Point centroid; void merge(Point p); bool contains_point(Point p); bool strict_contains_point(Point p); inline Point operator[](int i) const { int l = boundary.size(); if(l == 0) return Point(); return boundary[i >= 0 ? i % l : (i % l) + l]; } /*inline Point &operator[](unsigned i) { int l = boundary.size(); if(l == 0) return Point(); return boundary[i >= 0 ? i % l : i % l + l]; }*/ public: ConvexHull() {} ConvexHull(std::vector<Point> const & points) { boundary = points; graham(); } template <typename T> ConvexHull(T b, T e) :boundary(b,e) {} ~ConvexHull() { } public: /** Is the convex hull clockwise? We use the definition of clockwise from point.h **/ bool is_clockwise() const; bool no_colinear_points() const; bool top_point_first() const; bool meets_invariants() const; // contains no points bool empty() const { return boundary.empty();} // contains exactly one point bool singular() const { return boundary.size() == 1;} // all points are on a line bool linear() const { return boundary.size() == 2;} bool is_degenerate() const; // area of the convex hull double centroid_and_area(Geom::Point& centroid) const; double area() const { Point tmp; return centroid_and_area(tmp); } // furthest point in a direction (lg time) Point const * furthest(Point direction) const; bool is_left(Point p, int n); bool is_strict_left(Point p, int n); int find_left(Point p); int find_strict_left(Point p); double narrowest_diameter(Point &a, Point &b, Point &c); }; // do two convex hulls intersect? bool intersectp(ConvexHull a, ConvexHull b); std::vector<Point> bridge_points(ConvexHull a, ConvexHull b); // find the convex hull intersection ConvexHull intersection(ConvexHull a, ConvexHull b); ConvexHull sweepline_intersection(ConvexHull const &a, ConvexHull const &b); // find the convex hull of a set of convex hulls ConvexHull merge(ConvexHull a, ConvexHull b); // naive approach ConvexHull graham_merge(ConvexHull a, ConvexHull b); unsigned find_bottom_right(ConvexHull const &a); /*** Arbitrary transform operator. * Take a convex hull and apply an arbitrary convexity preserving transform. * we should be concerned about singular tranforms here. */ template <class T> ConvexHull operator*(ConvexHull const &p, T const &m) { ConvexHull pr; pr.boundary.reserve(p.boundary.size()); for(unsigned i = 0; i < p.boundary.size(); i++) { pr.boundary.push_back(p.boundary[i]*m); } return pr; } ConvexHull clip(ConvexHull const & ch, Point n, double d); //TODO: reinstate /*class ConvexCover{ public: Path const* path; std::vector<ConvexHull> cc; ConvexCover(Path const &sp); };*/ }; #endif //2GEOM_CONVEX_COVER_H /* Local Variables: mode:c++ c-file-style:"stroustrup" c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +)) indent-tabs-mode:nil fill-column:99 End: */ // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :