mirror of https://github.com/CGAL/cgal
97 lines
3.3 KiB
C++
97 lines
3.3 KiB
C++
// Copyright (c) 2002-2004 INRIA Sophia-Antipolis (France).
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// All rights reserved.
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//
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// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
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// modify it under the terms of the GNU Lesser General Public License as
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// published by the Free Software Foundation; either version 3 of the License,
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// or (at your option) any later version.
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//
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// Licensees holding a valid commercial license may use this file in
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// accordance with the commercial license agreement provided with the software.
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//
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// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
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// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
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//
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// $URL$
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// $Id$
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//
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//
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// Author(s) : Radu Ursu
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#ifndef CGAL_QT_WIDGET_CONIC_2_H
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#define CGAL_QT_WIDGET_CONIC_2_H
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#include <CGAL/IO/Qt_widget.h>
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#include <CGAL/Conic_2.h>
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#include <CGAL/Simple_cartesian.h>
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namespace CGAL{
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template< class R >
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Qt_widget&
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operator << ( Qt_widget& ws, const CGAL::Conic_2<R>& c)
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{
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// pixel dimensions of window
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int dim = (std::max)( ws.width(), ws.height());
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// length of a pixel in window-coordinates
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double pixel_x = (ws.x_max() - ws.x_min())/dim;
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double pixel_y = (ws.y_max() - ws.y_min())/dim;
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// pixel coordinates, stored for faster output
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typedef CGAL::Simple_cartesian<double>::Point_2 Point;
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std::vector<Point> vcoordinates;
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// conic coordinates
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double r = CGAL::to_double (c.r()),
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s = CGAL::to_double (c.s()),
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t = CGAL::to_double (c.t()),
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u = CGAL::to_double (c.u()),
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v = CGAL::to_double (c.v()),
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w = CGAL::to_double (c.w());
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// Phase I (drawing in x-direction)
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// solve conic equation for y
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if (s != 0.0)
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for (double x = ws.x_min(); x <= ws.x_max(); x+=pixel_x) {
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double discr = (t*t-4.0*r*s)*(x*x) + (2.0*t*v-4.0*s*u)*x +
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v*v - 4.0*s*w;
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if (discr >= 0.0) {
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double y1 = (-t*x - v - CGAL::sqrt(discr))/(2.0*s);
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double y2 = (-t*x - v + CGAL::sqrt(discr))/(2.0*s);
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vcoordinates.push_back(Point(x, y1));
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vcoordinates.push_back(Point(x, y2));} }
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else
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for (double x = ws.x_min(); x <= ws.x_max(); x+=pixel_x) {
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double denom = t*x + v;
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if (denom != 0.0) {
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double y = -(r*x*x + u*x + w)/denom;
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vcoordinates.push_back(Point(x, y)); } }
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// Phase II (drawing in y-direction)
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// solve conic equation for x
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if (r != 0.0)
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for (double y = ws.y_min(); y <= ws.y_max(); y+=pixel_y) {
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double discr = (t*t-4.0*r*s)*(y*y) + (2.0*t*u-4.0*r*v)*y +
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u*u - 4.0*r*w;
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if (discr >= 0.0) {
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double x1 = (-t*y - u - CGAL::sqrt(discr))/(2.0*r);
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double x2 = (-t*y - u + CGAL::sqrt(discr))/(2.0*r);
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vcoordinates.push_back(Point(x1, y));
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vcoordinates.push_back(Point(x2, y));} }
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else
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for (double y = ws.y_min(); y <= ws.y_max(); y+=pixel_y) {
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double denom = t*y + u;
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if (denom != 0.0) {
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double x = -(s*y*y + v*y + w)/denom;
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vcoordinates.push_back(Point(x, y));} }
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typedef typename std::vector<Point>::const_iterator CIT;
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for(CIT it1 = vcoordinates.begin(); it1!= vcoordinates.end(); ++it1)
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ws << *it1;
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return ws;
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}
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}//end namespace CGAL
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#endif
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