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/*
* affine.h -- ePiX::affine class (affine screen maps)
*
* This file is part of ePiX, a C++ library for creating high-quality
* figures in LaTeX
*
* Version 1.1.21
* Last Change: September 23, 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
*/
/*
* An affine map is constructed from the images of the "standard
* triple" (0,0), (1,0), and (0,1).
*
* An affine map may be (post)-composed with translation, rotation,
* reflection, scaling along either or both coordinate axes, shearing,
* and may be inverted. An optional pair argument, defaulting to
* (0,0), gives the center of the operation (if appropriate).
*
* An affine map may be post-composed via member function, and
* pre-composed with operator syntax. The evaluation operator
* returns the image of the argument.
*/
#ifndef EPIX_AFFINE
#define EPIX_AFFINE
#include "pairs.h"
#include "triples.h"
namespace ePiX {
class affine {
public:
// the identity map
affine();
// images of (1,0), (0,1), (0,0)
affine(const pair&, const pair&, const pair& loc=pair(0,0));
affine(const P&, const P&, const P& loc=P(0,0));
// post-operations
// translate by arg
affine& shift(const pair& arg);
affine& shift(const P& arg);
// rotate by theta about ctr
affine& rotate(double theta, const pair& ctr = pair(0,0));
affine& rotate(double theta, const P& ctr);
// reflect in angle-theta line through ctr
affine& reflect(double theta, const pair& ctr = pair(0,0));
affine& reflect(double theta, const P& ctr);
// scale coord direction(s) fixing ctr
affine& h_scale(double, const pair& ctr=pair(0,0));
affine& v_scale(double, const pair& ctr=pair(0,0));
affine& scale(double, const pair& ctr=pair(0,0));
affine& h_scale(double, const P& ctr);
affine& v_scale(double, const P& ctr);
affine& scale(double, const P& ctr);
// shear, fixing ctr
affine& h_shear(double, const pair& ctr=pair(0,0));
affine& v_shear(double, const pair& ctr=pair(0,0));
affine& h_shear(double, const P& ctr);
affine& v_shear(double, const P& ctr);
// post-compose
affine& postcomp(const affine&);
affine& invert();
// evaluation
pair operator() (const pair&) const;
pair operator() (const P&) const;
// pre-compose
affine operator() (const affine&) const;
bool reverses_orientation() const;
private:
pair m_00;
pair m_10;
pair m_01;
};
} // end of ePiX namespace
#endif /* EPIX_AFFINE */
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