bezier-utils.h revision 8001ba81cb851b38d86650a2fef5817facffb763
#ifndef __SP_BEZIER_UTILS_H__
#define __SP_BEZIER_UTILS_H__
/*
* An Algorithm for Automatically Fitting Digitized Curves
* by Philip J. Schneider
* from "Graphics Gems", Academic Press, 1990
*
* Authors:
* Philip J. Schneider
* Lauris Kaplinski <lauris@ximian.com>
*
* Copyright (C) 1990 Philip J. Schneider
* Copyright (C) 2001 Lauris Kaplinski and Ximian, Inc.
*
* 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.
*
*/
#include <2geom/point.h>
namespace Geom{
/* Bezier approximation utils */
Point bezier_pt(unsigned degree, Point const V[], double t);
int bezier_fit_cubic(Point bezier[], Point const data[], int len, double error);
int bezier_fit_cubic_r(Point bezier[], Point const data[], int len, double error,
unsigned max_beziers);
int bezier_fit_cubic_full(Point bezier[], int split_points[], Point const data[], int len,
Point const &tHat1, Point const &tHat2,
double error, unsigned max_beziers);
Point darray_left_tangent(Point const d[], unsigned const len);
Point darray_left_tangent(Point const d[], unsigned const len, double const tolerance_sq);
Point darray_right_tangent(Point const d[], unsigned const length, double const tolerance_sq);
template <typename iterator>
static void
cubic_bezier_poly_coeff(iterator b, Point *pc) {
double c[10] = {1,
-3, 3,
3, -6, 3,
-1, 3, -3, 1};
int cp = 0;
for(int i = 0; i < 4; i++) {
pc[i] = Point(0,0);
++b;
}
for(int i = 0; i < 4; i++) {
--b;
for(int j = 0; j <= i; j++) {
pc[3 - j] += c[cp]*(*b);
cp++;
}
}
}
}
#endif /* __SP_BEZIER_UTILS_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 :