path.cpp revision e6bdf746e2d9e775704a475a29cc1bb167ec271c
/*
* Path - Series of continuous curves
*
* Copyright 2007 MenTaLguY <mental@rydia.net>
*
* 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 "path.h"
#include "ord.h"
namespace Geom {
int CurveHelpers::root_winding(Curve const &c, Point p) {
std::vector<double> ts = c.roots(p[Y], Y);
if(ts.empty()) return 0;
double const fudge = 0.01; //fudge factor used on first and last
std::sort(ts.begin(), ts.end());
// winding determined by crossings at roots
int wind=0;
// previous time
double pt = ts.front() - fudge;
for ( std::vector<double>::iterator ti = ts.begin()
; ti != ts.end()
; ++ti )
{
double t = *ti;
if ( t <= 0. || t >= 1. ) continue; //skip endpoint roots
if ( c.valueAt(t, X) > p[X] ) { // root is ray intersection
// Get t of next:
std::vector<double>::iterator next = ti;
next++;
double nt;
if(next == ts.end()) nt = t + fudge; else nt = *next;
// Check before in time and after in time for positions
// Currently we're using the average times between next and previous segs
Cmp after_to_ray = cmp(c.valueAt((t + nt) / 2, Y), p[Y]);
Cmp before_to_ray = cmp(c.valueAt((t + pt) / 2, Y), p[Y]);
// if y is included, these will have opposite values, giving order.
Cmp dt = cmp(after_to_ray, before_to_ray);
if(dt != EQUAL_TO) //Should always be true, but yah never know..
wind += dt;
pt = t;
}
}
return wind;
}
void Path::swap(Path &other) {
std::swap(curves_, other.curves_);
std::swap(closed_, other.closed_);
std::swap(*final_, *other.final_);
curves_[curves_.size()-1] = final_;
other.curves_[other.curves_.size()-1] = other.final_;
}
Rect Path::boundsFast() const {
Rect bounds=front().boundsFast();
for ( const_iterator iter=++begin(); iter != end() ; ++iter ) {
bounds.unionWith(iter->boundsFast());
}
return bounds;
}
Rect Path::boundsExact() const {
Rect bounds=front().boundsExact();
for ( const_iterator iter=++begin(); iter != end() ; ++iter ) {
bounds.unionWith(iter->boundsExact());
}
return bounds;
}
template<typename iter>
iter inc(iter const &x, unsigned n) {
iter ret = x;
for(unsigned i = 0; i < n; i++)
ret++;
return ret;
}
//This assumes that you can't be perfect in your t-vals, and as such, tweaks the start
void Path::appendPortionTo(Path &ret, double from, double to) const {
assert(from >= 0 && to >= 0);
if(to == 0) to = size()+0.999999;
if(from == to) { return; }
double fi, ti;
double ff = modf(from, &fi), tf = modf(to, &ti);
if(tf == 0) { ti--; tf = 1; }
const_iterator fromi = inc(begin(), (unsigned)fi);
if(fi == ti && from < to) {
Curve *v = fromi->portion(ff, tf);
ret.append(*v);
delete v;
return;
}
const_iterator toi = inc(begin(), (unsigned)ti);
if(ff != 1.) {
Curve *fromv = fromi->portion(ff, 1.);
//fromv->setInitial(ret.finalPoint());
ret.append(*fromv);
delete fromv;
}
if(from >= to) {
const_iterator ender = end();
if(ender->initialPoint() == ender->finalPoint()) ender++;
ret.insert(ret.end(), ++fromi, ender);
ret.insert(ret.end(), begin(), toi);
} else {
ret.insert(ret.end(), ++fromi, toi);
}
Curve *tov = toi->portion(0., tf);
ret.append(*tov);
delete tov;
}
const double eps = .1;
void Path::append(Curve const &curve) {
if ( curves_.front() != final_ && !are_near(curve.initialPoint(), (*final_)[0], eps) ) {
throw ContinuityError();
}
do_append(curve.duplicate());
}
void Path::append(D2<SBasis> const &curve) {
if ( curves_.front() != final_ ) {
for ( int i = 0 ; i < 2 ; ++i ) {
if ( !are_near(curve[i][0][0], (*final_)[0][i], eps) ) {
throw ContinuityError();
}
}
}
do_append(new SBasisCurve(curve));
}
void Path::do_update(Sequence::iterator first_replaced,
Sequence::iterator last_replaced,
Sequence::iterator first,
Sequence::iterator last)
{
// note: modifies the contents of [first,last)
check_continuity(first_replaced, last_replaced, first, last);
delete_range(first_replaced, last_replaced);
if ( ( last - first ) == ( last_replaced - first_replaced ) ) {
std::copy(first, last, first_replaced);
} else {
// this approach depends on std::vector's behavior WRT iterator stability
curves_.erase(first_replaced, last_replaced);
curves_.insert(first_replaced, first, last);
}
if ( curves_.front() != final_ ) {
final_->setPoint(0, back().finalPoint());
final_->setPoint(1, front().initialPoint());
}
}
void Path::do_append(Curve *curve) {
if ( curves_.front() == final_ ) {
final_->setPoint(1, curve->initialPoint());
}
curves_.insert(curves_.end()-1, curve);
final_->setPoint(0, curve->finalPoint());
}
void Path::delete_range(Sequence::iterator first, Sequence::iterator last) {
for ( Sequence::iterator iter=first ; iter != last ; ++iter ) {
delete *iter;
}
}
void Path::check_continuity(Sequence::iterator first_replaced,
Sequence::iterator last_replaced,
Sequence::iterator first,
Sequence::iterator last)
{
if ( first != last ) {
if ( first_replaced != curves_.begin() ) {
if ( !are_near( (*first_replaced)->initialPoint(), (*first)->initialPoint(), eps ) ) {
throw ContinuityError();
}
}
if ( last_replaced != (curves_.end()-1) ) {
if ( !are_near( (*(last_replaced-1))->finalPoint(), (*(last-1))->finalPoint(), eps ) ) {
throw ContinuityError();
}
}
} else if ( first_replaced != last_replaced && first_replaced != curves_.begin() && last_replaced != curves_.end()-1) {
if ( !are_near((*first_replaced)->initialPoint(), (*(last_replaced-1))->finalPoint(), eps ) ) {
throw ContinuityError();
}
}
}
Rect SVGEllipticalArc::boundsFast() const {
throw NotImplemented();
}
Rect SVGEllipticalArc::boundsExact() const {
throw NotImplemented();
}
Rect SVGEllipticalArc::boundsLocal(Interval i, unsigned deg) const {
//throw NotImplemented();
}
std::vector<Point> SVGEllipticalArc::pointAndDerivatives(Coord t, unsigned n) const {
throw NotImplemented();
}
std::vector<double> SVGEllipticalArc::roots(double v, Dim2 d) const {
//throw NotImplemented();
}
D2<SBasis> SVGEllipticalArc::toSBasis() const {
return D2<SBasis>(Linear(initial_[X], final_[X]), Linear(initial_[Y], final_[Y]));
}
}
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(substatement-open . 0))
indent-tabs-mode:nil
c-brace-offset:0
fill-column:99
End:
vim: filetype=cpp:expandtab:shiftwidth=2:tabstop=8:softtabstop=2 :
*/