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#define INKSCAPE_LPE_KNOT_CPP
/** \file
* LPE <knot> implementation
*/
/*
* Authors:
* JF Barraud
*
* Copyright (C) JF Barraud 2007 <jf.barraud@gmail.com>
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#include "live_effects/lpe-knot.h"
#include <2geom/path.h>
#include <2geom/d2.h>
#include <2geom/crossing.h>
#include <2geom/path-intersection.h>
namespace Inkscape {
namespace LivePathEffect {
LPEKnot::LPEKnot(LivePathEffectObject *lpeobject) :
Effect(lpeobject),
// initialise your parameters here:
interruption_width(_("Gap width"), _("The width of the gap in the path where it self-intersects"), "interruption_width", &wr, this, 10)
{
// register all your parameters here, so Inkscape knows which parameters this effect has:
registerParameter( dynamic_cast<Parameter *>(&interruption_width) );
}
LPEKnot::~LPEKnot()
{
}
//remove an interval from an union of intervals.
std::vector<Geom::Interval> complementOf(Geom::Interval I, std::vector<Geom::Interval> domain){
std::vector<Geom::Interval> ret;
double min = domain.front().min();
double max = domain.back().max();
Geom::Interval I1 = Geom::Interval(min,I.min());
Geom::Interval I2 = Geom::Interval(I.max(),max);
for (unsigned i = 0; i<domain.size(); i++){
boost::optional<Geom::Interval> I1i = intersect(domain.at(i),I1);
if (I1i) ret.push_back(I1i.get());
boost::optional<Geom::Interval> I2i = intersect(domain.at(i),I2);
if (I2i) ret.push_back(I2i.get());
}
return ret;
}
Geom::Interval
findShadowedTime(Geom::Path &patha,
Geom::Path &pathb,
Geom::Crossing crossing,
unsigned idx, double width){
using namespace Geom;
double curveidx, timeoncurve = modf(crossing.getOtherTime(idx),&curveidx);
if(curveidx == pathb.size() && timeoncurve == 0) { curveidx--; timeoncurve = 0.99999;}
assert(curveidx >= 0 && curveidx < pathb.size());
std::vector<Point> MV = pathb[unsigned(curveidx)].pointAndDerivatives(timeoncurve,2);
Point T = unit_vector(MV.at(1));
Point N = T.cw();
Point A = MV.at(0)-10*width*T, B = MV.at(0)+10*width*T;
std::vector<Geom::Path> cutter;
Geom::Path cutterLeft = Geom::Path();
Geom::Path cutterRight = Geom::Path();
cutterLeft.append (LineSegment (A-width*N, B-width*N));
cutterRight.append(LineSegment (A+width*N, B+width*N));
cutter.push_back(cutterLeft);
cutter.push_back(cutterRight);
std::vector<Geom::Path> patha_as_vect = std::vector<Geom::Path>(1,patha);
CrossingSet crossingTable = crossings (patha_as_vect, cutter);
double t0 = crossing.getTime(idx);
double tmin = 0,tmax = patha.size()-0.0001;
assert(crossingTable.size()>=1);
for (unsigned c=0; c<crossingTable.front().size(); c++){
double t = crossingTable.front().at(c).ta;
assert(crossingTable.front().at(c).a==0);
if (t>tmin and t<t0) tmin = t;
if (t<tmax and t>t0) tmax = t;
}
//return Interval(t0-0.1,t0+0.1);
return Interval(tmin,tmax);
}
//Just a try; this should be moved to 2geom if ever it works.
std::vector<Geom::Path>
split_loopy_bezier (std::vector<Geom::Path> const & path_in){
std::vector<Geom::Path> ret;
std::vector<Geom::Path>::const_iterator pi=path_in.begin();
for(; pi != path_in.end(); pi++) {
ret.push_back(Geom::Path());
for (Geom::Path::const_iterator curve(pi->begin()),end(pi->end()); curve != end; ++curve){
//is the current curve a cubic bezier?
if(Geom::CubicBezier const *cubic_bezier = dynamic_cast<Geom::CubicBezier const *>(&(*curve))){
Geom::CubicBezier theCurve = *cubic_bezier;
std::vector<Geom::Point> A = theCurve.points();
//is there a crossing in the polygon?
if( cross(A[2]-A[0],A[1]-A[0])*cross(A[3]-A[0],A[1]-A[0])<0 &&
cross(A[0]-A[3],A[2]-A[3])*cross(A[1]-A[3],A[2]-A[3])<0){
//split the curve where the tangent is parallel to the chord through end points.
double a = cross(A[3]-A[0],A[1]-A[2]);
double c = cross(A[3]-A[0],A[1]-A[0]);
double t; //where to split; solution of 3*at^2-(a+c)t +c = 0.
//TODO: don't we have a clean deg 2 equation solver?...
if (fabs(a)<.0001){
t = .5;
}else{
double delta = a*a-a*c+c*c;
t = ((a+c)-sqrt(delta))/2/a;
if ( t<0 || t>1 ) {t = ((a+c)+sqrt(delta))/2/a;}
}
//TODO: shouldn't Path have subdivide method?
std::pair<Geom::BezierCurve<3>, Geom::BezierCurve<3> > splitCurve;
splitCurve = theCurve.subdivide(t);
ret.back().append(splitCurve.first);
ret.back().append(splitCurve.second);
}else{//cubic bezier but no crossing.
ret.back().append(*curve);
}
}else{//not cubic bezier.
ret.back().append(*curve);
}
}
}
return ret;
}
std::vector<Geom::Path>
LPEKnot::doEffect_path (std::vector<Geom::Path> const & input_path)
{
using namespace Geom;
std::vector<Geom::Path> path_out;
double width = interruption_width;
std::vector<Geom::Path> path_in = split_loopy_bezier(input_path);
CrossingSet crossingTable = crossings_among(path_in);
for (unsigned i = 0; i < crossingTable.size(); i++){
std::vector<Interval> dom;
dom.push_back(Interval(0.,path_in.at(i).size()-0.00001));
//TODO: handle closed curves...
for (unsigned crs = 0; crs < crossingTable.at(i).size(); crs++){
Crossing crossing = crossingTable.at(i).at(crs);
unsigned j = crossing.getOther(i);
//TODO: select dir according to a parameter...
if ((crossing.dir and crossing.a==i) or (not crossing.dir and crossing.b==i) or (i==j)){
if (i==j and not crossing.dir) {
double temp = crossing.ta;
crossing.ta = crossing.tb;
crossing.tb = temp;
crossing.dir = not crossing.dir;
}
Interval hidden = findShadowedTime(path_in.at(i),path_in.at(j),crossing,i,width);
dom = complementOf(hidden,dom);
}
}
for (unsigned comp = 0; comp < dom.size(); comp++){
assert(dom.at(comp).min() >=0 and dom.at(comp).max() < path_in.at(i).size());
path_out.push_back(path_in.at(i).portion(dom.at(comp)));
}
}
return path_out;
}
/*
Geom::Piecewise<Geom::D2<Geom::SBasis> >
addLinearEnds (Geom::Piecewise<Geom::D2<Geom::SBasis> > & m){
using namespace Geom;
Piecewise<D2<SBasis> > output;
Piecewise<D2<SBasis> > start;
Piecewise<D2<SBasis> > end;
double x,y,vx,vy;
x = m.segs.front()[0].at0();
y = m.segs.front()[1].at0();
vx = m.segs.front()[0][1][0]+Tri(m.segs.front()[0][0]);
vy = m.segs.front()[1][1][0]+Tri(m.segs.front()[1][0]);
start = Piecewise<D2<SBasis> >(D2<SBasis>(Linear (x-vx,x),Linear (y-vy,y)));
start.offsetDomain(m.cuts.front()-1.);
x = m.segs.back()[0].at1();
y = m.segs.back()[1].at1();
vx = -m.segs.back()[0][1][1]+Tri(m.segs.back()[0][0]);;
vy = -m.segs.back()[1][1][1]+Tri(m.segs.back()[1][0]);;
end = Piecewise<D2<SBasis> >(D2<SBasis>(Linear (x,x+vx),Linear (y,y+vy)));
//end.offsetDomain(m.cuts.back());
output = start;
output.concat(m);
output.concat(end);
return output;
}
Geom::Piecewise<Geom::D2<Geom::SBasis> >
LPEKnot::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > & pwd2_in)
{
using namespace Geom;
Piecewise<D2<SBasis> > output;
Piecewise<D2<SBasis> > m = addLinearEnds(pwd2_in);
Piecewise<D2<SBasis> > v = derivative(pwd2_in);
Piecewise<D2<SBasis> > n = unitVector(v);
// // -------- Pleins et delies vs courbure ou direction...
// Piecewise<D2<SBasis> > a = derivative(v);
// Piecewise<SBasis> a_cross_n = cross(a,n);
// Piecewise<SBasis> v_dot_n = dot(v,n);
// //Piecewise<D2<SBasis> > rfrac = sectionize(D2<Piecewise<SBasis> >(a_cross_n,v_dot_n));
// //Piecewise<SBasis> h = atan2(rfrac)*interruption_width;
// Piecewise<SBasis> h = reciprocal(curvature(pwd2_in))*interruption_width;
//
// // Piecewise<D2<SBasis> > dir = Piecewise<D2<SBasis> >(D2<SBasis>(Linear(0),Linear(-1)));
// // Piecewise<SBasis> h = dot(n,dir)+1.;
// // h *= h*(interruption_width/4.);
//
// n = rot90(n);
// output = pwd2_in+h*n;
// output.concat(pwd2_in-h*n);
//
// //-----------
//output.concat(m);
return output;
}
*/
/* ######################## */
} //namespace LivePathEffect (setq default-directory "c:/Documents And Settings/jf/Mes Documents/InkscapeSVN")
} /* namespace Inkscape */
/*
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 :
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