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/*
* hatching.h -- ePiX hatched region data structures
*
* This file is part of ePiX, a C++ library for creating high-quality
* figures in LaTeX
*
* Version 1.1.13
* Last Change: August 29, 2007
*/
/*
* Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007
* Andrew D. Hwang <rot 13 nujnat at zngupf dot ubylpebff dot rqh>
* Department of Mathematics and Computer Science
* College of the Holy Cross
* Worcester, MA, 01610-2395, USA
*/
/*
* ePiX is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* ePiX is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
* License for more details.
*
* You should have received a copy of the GNU General Public License
* along with ePiX; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef EPIX_HATCHING
#define EPIX_HATCHING
#include <list>
#include <vector>
#include "pairs.h"
#include "edge_data.h"
namespace ePiX {
// edge, endpoint heights, orientation (+/-1 = up/down)
class bd_edge {
public:
bd_edge(const edge2d&, double, double, int);
pair tail() const;
pair head() const;
pair dir() const;
double lo() const;
double hi() const;
int orient() const;
private:
edge2d m_edge;
double m_lo;
double m_hi;
int m_orient;
};
// location where scan line crosses bd_edge
class cut {
public:
cut(pair loc, int sign);
pair loc() const;
int sign() const;
private:
pair m_loc; // location
int m_sign; // orientation
};
// ax + by + c = 0
class scan_line {
public:
scan_line(const pair& t, const pair& h);
void add_cut(const cut&);
// store what we find in value
void draw(std::vector<edge2d>& value) const;
private:
pair m_perp; // (a, b)
double m_ht; // c
std::list<cut> m_cuts;
}; // end of class scan_line
// ctor converts a list of edge2d into a (large) vector of scan lines
class hatch_data {
public:
// components of hatch direction, scanline separation, polygon to fill
hatch_data(double, double,
double sep, const std::list<edge2d>&);
// angle, scanline separation, polygon to fill
hatch_data(double th, double sep, const std::list<edge2d>&);
std::vector<edge2d> data() const;
private:
std::list<bd_edge> m_edges;
std::vector<scan_line> m_scans;
// convert polygon to scan lines parallel to dir, common to both ctors
void hatch_init(const pair& dir,
double sep,
std::list<edge2d> polygon);
}; // end of class hatch_data
} // end of namespace
#endif /* EPIX_HATCHING */
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