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/*
* KSeg
* Copyright (C) 1999-2006 Ilya Baran
*
* This program 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.
*
* This program 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 this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Send comments and/or bug reports to:
* ibaran@mit.edu
*/
#include "G_line.H"
#include "G_drawstyle.H"
#include "KSegView.H"
//drawing:
void G_line::draw(QPainter &p, const G_drawstyle &d, bool selected)
{
QRect r = p.window();
G_point x = getNearestPoint(G_point(0, 0));
if(SQR(x - G_point(r.center())) > DRAW_MAX * DRAW_MAX) return;
G_segment(x - dir * DRAW_MAX, x + dir * DRAW_MAX).draw(p, d, selected);
return;
}
//the mapping is via the tangent function. So when p = 0, the location is -inf and when p = 1 it's inf.
G_point G_line::getPointOnCurve(double p) const
{
double c;
// c = (p - 0.5) * M_PI / (1 + SMALL);
c = (p - 0.5) * 2;
if(c >= 0) c = pow(c, 1./81.) / 2.;
else c = -pow(-c, 1./81.) / 2.;
c = c * M_PI / (1 + SMALL);
return p1 + tan(c) * dir;
}
double G_line::getParamFromPoint(const G_point &p) const
{
double c;
c = atan((p - p1).length()) * SIGN((p - p1) * dir);
// return c / M_PI * (1 + SMALL) + 0.5;
return CUBE(CUBE(CUBE(CUBE(c / M_PI * (1 + SMALL) * 2.)))) / 2. + 0.5;
}
G_point G_line::getNearestPoint(const G_point &p) const
{
return p1 + ((p - p1) * dir) * dir;
}
bool G_line::inRect(const QRect &r) const
{
//a point is in the rectangle only if at least one pair of opposite vertices
//are on opposite sides of the line.
double d1 = (G_point(r.topLeft()) - p1) % dir;
double d2 = (G_point(r.bottomRight()) - p1) % dir;
double d3 = (G_point(r.topRight()) - p1) % dir;
double d4 = (G_point(r.bottomLeft()) - p1) % dir;
return ((d1 < 0) != (d2 < 0)) || ((d3 < 0) != (d4 < 0));
}
G_point G_line::getIntersection(const G_curve *c, int which) const
{
if(c->getType() == G_LINE) {
G_line *l = (G_line *)c;
double r, tmp;
tmp = dir % l->dir;
if(fabs(tmp) < SMALL) return G_point::inValid();
r = ((p1.getY() - l->p1.getY()) * (l->dir.getX()) -
(p1.getX() - l->p1.getX()) * (l->dir.getY())) / tmp;
if((p1 + r * dir).length() > 20000000)
return G_point::inValid();
return p1 + r * dir;
}
else return c->getIntersection(this, which);
}
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