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/*
Copyright (C) 2003 Nikolas Zimmermann <wildfox@kde.org>
This file is part of the KDE project
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public License
aint with this library; see the file COPYING.LIB. If not, write to
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.
*/
#include <math.h>
#include "Point.h"
#include "BezierPathLibart.h"
#include <kdebug.h>
#include <libart_lgpl/art_bpath.h>
#include <libart_lgpl/art_vpath.h>
#include <libart_lgpl/art_vpath_bpath.h>
using namespace T2P;
BezierPathLibart::BezierPathLibart() : BezierPath()
{
m_array.resize(0);
m_length = -1;
}
BezierPathLibart::BezierPathLibart(ArtBpath *other) : BezierPath()
{
int i = 0;
for(;other[i].code != ART_END; i++)
{
ensureSpace(m_array, i)
m_array[i] = other[i];
}
ensureSpace(m_array, i)
m_array[i].code = ART_END;
}
BezierPathLibart::~BezierPathLibart()
{
}
double BezierPathLibart::length(double t)
{
if(m_length < 0.0)
{
double total = 0.0;
// We cheat a bit...
ArtVpath *vpath = art_bez_path_to_vec(m_array.data(), 0.25);
double x = 0.0, y = 0.0;
for(int i = 0; vpath[i].code != ART_END; i++)
{
if(vpath[i].code == ART_MOVETO)
{
x = vpath[i].x;
y = vpath[i].y;
}
else if(vpath[i].code == ART_LINETO)
{
double dx = x, dy = y;
x = vpath[i].x;
y = vpath[i].y;
dx = x - dx;
dy = y - dy;
total += sqrt(pow(dx, 2) + pow(dy, 2));
}
}
art_free(vpath);
return total * t;
}
else
return m_length * t;
}
void BezierPathLibart::pointTangentNormalAt(double t, Point *p, Point *tn, Point *n)
{
double totallen = length(t);
// We cheat a bit...
ArtVpath *vpath = art_bez_path_to_vec(m_array.data(), 0.25);
double total = 0.0;
double x = 0.0, y = 0.0;
for(int i = 0; vpath[i].code != ART_END; i++)
{
if(vpath[i].code == ART_MOVETO)
{
x = vpath[i].x;
y = vpath[i].y;
}
else if(vpath[i].code == ART_LINETO)
{
double dx = x, dy = y;
x = vpath[i].x;
y = vpath[i].y;
dx = x - dx;
dy = y - dy;
double seg_len = sqrt(pow(dx, 2) + pow(dy, 2));
total += seg_len;
if(total >= totallen)
{
double fract = 1 - (totallen - (total - seg_len)) / seg_len;
if(p)
{
p->setX(x - dx * fract);
p->setY(y - dy * fract);
}
// Calculate tangent
if(tn)
{
tn->setX(dx);
tn->setY(dy);
}
// Calculate normal vector.
if(n)
{
// Calculate vector product of "binormal" x tangent
// (0,0,1) x (dx,dy,0), which is simply (dy,-dx,0).
n->setX(dy);
n->setY(-dx);
}
return;
}
}
}
art_free(vpath);
}
void BezierPathLibart::boundingBox(Point *topLeft, Point *bottomRight)
{
if(m_array.count() > 0)
{
// We cheat a bit...
ArtVpath *vpath = art_bez_path_to_vec(m_array.data(), 0.25);
ArtDRect rect;
art_vpath_bbox_drect(vpath, &rect);
art_free(vpath);
*topLeft = Point(rect.x0, rect.y0);
*bottomRight = Point(rect.x1, rect.y1);
}
else
{
*topLeft = Point(0, 0);
*bottomRight = Point(0, 0);
}
}
// vim:ts=4:noet
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