lpe-sketch.cpp revision 63e3b8a7c227f111c060e81e1941679a156b1999
/** @file
* @brief LPE sketch effect implementation
*/
/* Authors:
* Jean-Francois Barraud <jf.barraud@gmail.com>
* Johan Engelen <j.b.c.engelen@utwente.nl>
*
* Copyright (C) 2007 Authors
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
#include "live_effects/lpe-sketch.h"
// You might need to include other 2geom files. You can add them here:
#include <2geom/path.h>
#include <2geom/sbasis.h>
#include <2geom/sbasis-geometric.h>
#include <2geom/sbasis-math.h>
#include <2geom/bezier-to-sbasis.h>
#include <2geom/sbasis-to-bezier.h>
#include <2geom/d2.h>
#include <2geom/sbasis-math.h>
#include <2geom/piecewise.h>
#include <2geom/crossing.h>
#include <2geom/path-intersection.h>
namespace Inkscape {
namespace LivePathEffect {
LPESketch::LPESketch(LivePathEffectObject *lpeobject) :
Effect(lpeobject),
// initialise your parameters here:
//testpointA(_("Test Point A"), _("Test A"), "ptA", &wr, this, Geom::Point(100,100)),
nbiter_approxstrokes(_("Strokes"), _("Draw that many approximating strokes"), "nbiter_approxstrokes", &wr, this, 5),
strokelength(_("Max stroke length"),
_("Maximum length of approximating strokes"), "strokelength", &wr, this, 100.),
strokelength_rdm(_("Stroke length variation"),
_("Random variation of stroke length (relative to maximum length)"), "strokelength_rdm", &wr, this, .3),
strokeoverlap(_("Max. overlap"),
_("How much successive strokes should overlap (relative to maximum length)"), "strokeoverlap", &wr, this, .3),
strokeoverlap_rdm(_("Overlap variation"),
_("Random variation of overlap (relative to maximum overlap)"), "strokeoverlap_rdm", &wr, this, .3),
ends_tolerance(_("Max. end tolerance"),
_("Maximum distance between ends of original and approximating paths (relative to maximum length)"), "ends_tolerance", &wr, this, .1),
parallel_offset(_("Average offset"),
_("Average distance each stroke is away from the original path"), "parallel_offset", &wr, this, 5.),
tremble_size(_("Max. tremble"),
_("Maximum tremble magnitude"), "tremble_size", &wr, this, 5.),
tremble_frequency(_("Tremble frequency"),
_("Average number of tremble periods in a stroke"), "tremble_frequency", &wr, this, 1.)
#ifdef LPE_SKETCH_USE_CONSTRUCTION_LINES
,nbtangents(_("Construction lines"),
_("How many construction lines (tangents) to draw"), "nbtangents", &wr, this, 5),
tgtscale(_("Scale"),
_("Scale factor relating curvature and length of construction lines (try 5*offset)"), "tgtscale", &wr, this, 10.0),
tgtlength(_("Max. length"), _("Maximum length of construction lines"), "tgtlength", &wr, this, 100.0),
tgtlength_rdm(_("Length variation"), _("Random variation of the length of construction lines"), "tgtlength_rdm", &wr, this, .3),
tgt_places_rdmness(_("Placement randomness"), _("0: evenly distributed construction lines, 1: purely random placement"), "tgt_places_rdmness", &wr, this, 1.)
#ifdef LPE_SKETCH_USE_CURVATURE
,min_curvature(_("k_min"), _("min curvature"), "k_min", &wr, this, 4.0)
,max_curvature(_("k_max"), _("max curvature"), "k_max", &wr, this, 1000.0)
#endif
#endif
{
// register all your parameters here, so Inkscape knows which parameters this effect has:
//Add some comment in the UI: *warning* the precise output of this effect might change in future releases!
//convert to path if you want to keep exact output unchanged in future releases...
//registerParameter( dynamic_cast<Parameter *>(&testpointA) );
registerParameter( dynamic_cast<Parameter *>(&nbiter_approxstrokes) );
registerParameter( dynamic_cast<Parameter *>(&strokelength) );
registerParameter( dynamic_cast<Parameter *>(&strokelength_rdm) );
registerParameter( dynamic_cast<Parameter *>(&strokeoverlap) );
registerParameter( dynamic_cast<Parameter *>(&strokeoverlap_rdm) );
registerParameter( dynamic_cast<Parameter *>(&ends_tolerance) );
registerParameter( dynamic_cast<Parameter *>(&parallel_offset) );
registerParameter( dynamic_cast<Parameter *>(&tremble_size) );
registerParameter( dynamic_cast<Parameter *>(&tremble_frequency) );
#ifdef LPE_SKETCH_USE_CONSTRUCTION_LINES
registerParameter( dynamic_cast<Parameter *>(&nbtangents) );
registerParameter( dynamic_cast<Parameter *>(&tgt_places_rdmness) );
registerParameter( dynamic_cast<Parameter *>(&tgtscale) );
registerParameter( dynamic_cast<Parameter *>(&tgtlength) );
registerParameter( dynamic_cast<Parameter *>(&tgtlength_rdm) );
#ifdef LPE_SKETCH_USE_CURVATURE
registerParameter( dynamic_cast<Parameter *>(&min_curvature) );
registerParameter( dynamic_cast<Parameter *>(&max_curvature) );
#endif
#endif
nbiter_approxstrokes.param_make_integer();
nbiter_approxstrokes.param_set_range(0, NR_HUGE);
strokelength.param_set_range(1, NR_HUGE);
strokelength.param_set_increments(1., 5.);
strokelength_rdm.param_set_range(0, 1.);
strokeoverlap.param_set_range(0, 1.);
strokeoverlap.param_set_increments(0.1, 0.30);
ends_tolerance.param_set_range(0., 1.);
parallel_offset.param_set_range(0, NR_HUGE);
tremble_frequency.param_set_range(0.01, 100.);
tremble_frequency.param_set_increments(.5, 1.5);
strokeoverlap_rdm.param_set_range(0, 1.);
#ifdef LPE_SKETCH_USE_CONSTRUCTION_LINES
nbtangents.param_make_integer();
nbtangents.param_set_range(0, NR_HUGE);
tgtscale.param_set_range(0, NR_HUGE);
tgtscale.param_set_increments(.1, .5);
tgtlength.param_set_range(0, NR_HUGE);
tgtlength.param_set_increments(1., 5.);
tgtlength_rdm.param_set_range(0, 1.);
tgt_places_rdmness.param_set_range(0, 1.);
//this is not very smart, but required to avoid having lot of tangents stacked on short components.
//Nota: we could specify a density instead of an absolute number, but this would be scale dependant.
concatenate_before_pwd2 = true;
#endif
}
LPESketch::~LPESketch()
{
}
/*
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;
}
*/
//This returns a random perturbation. Notice the domain is [s0,s0+first multiple of period>s1]...
Geom::Piecewise<Geom::D2<Geom::SBasis> >
LPESketch::computePerturbation (double s0, double s1){
using namespace Geom;
Piecewise<D2<SBasis> >res;
//global offset for this stroke.
double offsetX = 2*parallel_offset-parallel_offset.get_value();
double offsetY = 2*parallel_offset-parallel_offset.get_value();
Point A,dA,B,dB,offset = Point(offsetX,offsetY);
//start point A
for (unsigned dim=0; dim<2; dim++){
A[dim] = offset[dim] + 2*tremble_size-tremble_size.get_value();
dA[dim] = 2*tremble_size-tremble_size.get_value();
}
//compute howmany deg 3 sbasis to concat according to frequency.
unsigned count = unsigned((s1-s0)/strokelength*tremble_frequency)+1;
//unsigned count = unsigned((s1-s0)/tremble_frequency)+1;
for (unsigned i=0; i<count; i++){
D2<SBasis> perturb = D2<SBasis>(SBasis(2, Linear()), SBasis(2, Linear()));
for (unsigned dim=0; dim<2; dim++){
B[dim] = offset[dim] + 2*tremble_size-tremble_size.get_value();
perturb[dim][0] = Linear(A[dim],B[dim]);
dA[dim] = dA[dim]-B[dim]+A[dim];
//avoid dividing by 0. Very short strokes will have ends parallel to the curve...
if ( s1-s0 > 1e-2)
dB[dim] = -(2*tremble_size-tremble_size.get_value())/(s0-s1)-B[dim]+A[dim];
else
dB[dim] = -(2*tremble_size-tremble_size.get_value())-B[dim]+A[dim];
perturb[dim][1] = Linear(dA[dim],dB[dim]);
}
dA = B-A-dB;
A = B;
//dA = B-A-dB;
res.concat(Piecewise<D2<SBasis> >(perturb));
}
res.setDomain(Interval(s0,s0+count*strokelength/tremble_frequency));
//res.setDomain(Interval(s0,s0+count*tremble_frequency));
return res;
}
// Main effect body...
Geom::Piecewise<Geom::D2<Geom::SBasis> >
LPESketch::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in)
{
using namespace Geom;
//If the input path is empty, do nothing.
//Note: this happens when duplicating a 3d box... dunno why.
if (pwd2_in.size()==0) return pwd2_in;
Piecewise<D2<SBasis> > output;
// some variables for futur use (for construction lines; compute arclength only once...)
// notations will be : t = path time, s = distance from start along the path.
Piecewise<SBasis> pathlength;
double total_length = 0;
//TODO: split Construction Lines/Approximated Strokes into two separate effects?
//----- Approximated Strokes.
std::vector<Piecewise<D2<SBasis> > > pieces_in = split_at_discontinuities (pwd2_in);
//work separately on each component.
for (unsigned pieceidx = 0; pieceidx < pieces_in.size(); pieceidx++){
Piecewise<D2<SBasis> > piece = pieces_in[pieceidx];
Piecewise<SBasis> piecelength = arcLengthSb(piece,.1);
double piece_total_length = piecelength.segs.back().at1()-piecelength.segs.front().at0();
pathlength.concat(piecelength + total_length);
total_length += piece_total_length;
//TODO: better check this on the Geom::Path.
bool closed = piece.segs.front().at0() == piece.segs.back().at1();
if (closed){
piece.concat(piece);
piecelength.concat(piecelength+piece_total_length);
}
for (unsigned i = 0; i<nbiter_approxstrokes; i++){
//Basic steps:
//- Choose a rdm seg [s0,s1], find coresponding [t0,t1],
//- Pick a rdm perturbation delta(s), collect 'piece(t)+delta(s(t))' over [t0,t1] into output.
// pick a point where to start the stroke (s0 = dist from start).
double s1=0.,s0 = ends_tolerance*strokelength+0.0001;//the root finder might miss 0.
double t1, t0;
double s0_initial = s0;
bool done = false;// was the end of the component reached?
while (!done){
// if the start point is already too far... do nothing. (this should not happen!)
if (!closed && s1>piece_total_length - ends_tolerance.get_value()*strokelength) break;
if ( closed && s0>piece_total_length + s0_initial) break;
std::vector<double> times;
times = roots(piecelength-s0);
t0 = times.at(0);//there should be one and only one solution!!
// pick a new end point (s1 = s0 + strokelength).
s1 = s0 + strokelength*(1-strokelength_rdm);
// don't let it go beyond the end of the orgiginal path.
// TODO/FIXME: this might result in short strokes near the end...
if (!closed && s1>piece_total_length-ends_tolerance.get_value()*strokelength){
done = true;
//!!the root solver might miss s1==piece_total_length...
if (s1>piece_total_length){s1 = piece_total_length - ends_tolerance*strokelength-0.0001;}
}
if (closed && s1>piece_total_length + s0_initial){
done = true;
if (closed && s1>2*piece_total_length){
s1 = 2*piece_total_length - strokeoverlap*(1-strokeoverlap_rdm)*strokelength-0.0001;
}
}
times = roots(piecelength-s1);
if (times.size()==0) break;//we should not be there.
t1 = times[0];
//pick a rdm perturbation, and collect the perturbed piece into output.
Piecewise<D2<SBasis> > pwperturb = computePerturbation(s0-0.01,s1+0.01);
pwperturb = compose(pwperturb,portion(piecelength,t0,t1));
output.concat(portion(piece,t0,t1)+pwperturb);
//step points: s0 = s1 - overlap.
//TODO: make sure this has to end?
s0 = s1 - strokeoverlap*(1-strokeoverlap_rdm)*(s1-s0);
}
}
}
#ifdef LPE_SKETCH_USE_CONSTRUCTION_LINES
//----- Construction lines.
//TODO: choose places according to curvature?.
//at this point we should have:
//pathlength = arcLengthSb(pwd2_in,.1);
//total_length = pathlength.segs.back().at1()-pathlength.segs.front().at0();
Piecewise<D2<SBasis> > m = pwd2_in;
Piecewise<D2<SBasis> > v = derivative(pwd2_in);
Piecewise<D2<SBasis> > a = derivative(v);
#ifdef LPE_SKETCH_USE_CURVATURE
//---- curvature experiment...(enable
Piecewise<SBasis> k = curvature(pwd2_in);
OptInterval k_bnds = bounds_exact(abs(k));
double k_min = k_bnds->min() + k_bnds->extent() * min_curvature;
double k_max = k_bnds->min() + k_bnds->extent() * max_curvature;
Piecewise<SBasis> bump;
//SBasis bump_seg = SBasis( 2, Linear(0) );
//bump_seg[1] = Linear( 4. );
SBasis bump_seg = SBasis( 1, Linear(1) );
bump.push_cut( k_bnds->min() - 1 );
bump.push( Linear(0), k_min );
bump.push(bump_seg,k_max);
bump.push( Linear(0), k_bnds->max()+1 );
Piecewise<SBasis> repartition = compose( bump, k );
repartition = integral(repartition);
//-------------------------------
#endif
for (unsigned i=0; i<nbtangents; i++){
// pick a point where to draw a tangent (s = dist from start along path).
#ifdef LPE_SKETCH_USE_CURVATURE
double proba = repartition.firstValue()+ (rand()%100)/100.*(repartition.lastValue()-repartition.firstValue());
std::vector<double> times;
times = roots(repartition - proba);
double t = times.at(0);//there should be one and only one solution!
#else
//double s = total_length * ( i + tgtlength_rdm ) / (nbtangents+1.);
double reg_place = total_length * ( i + .5) / ( nbtangents );
double rdm_place = total_length * tgt_places_rdmness;
double s = ( 1.- tgt_places_rdmness.get_value() ) * reg_place + rdm_place ;
std::vector<double> times;
times = roots(pathlength-s);
double t = times.at(0);//there should be one and only one solution!
#endif
Point m_t = m(t), v_t = v(t), a_t = a(t);
//Compute tgt length according to curvature (not exceeding tgtlength) so that
// dist to origninal curve ~ 4 * (parallel_offset+tremble_size).
//TODO: put this 4 as a parameter in the UI...
//TODO: what if with v=0?
double l = tgtlength*(1-tgtlength_rdm)/v_t.length();
double r = pow(v_t.length(),3)/cross(a_t,v_t);
r = sqrt((2*fabs(r)-tgtscale)*tgtscale)/v_t.length();
l=(r<l)?r:l;
//collect the tgt segment into output.
D2<SBasis> tgt = D2<SBasis>();
for (unsigned dim=0; dim<2; dim++){
tgt[dim] = SBasis(Linear(m_t[dim]-v_t[dim]*l, m_t[dim]+v_t[dim]*l));
}
output.concat(Piecewise<D2<SBasis> >(tgt));
}
#endif
return output;
}
void
LPESketch::doBeforeEffect (SPLPEItem */*lpeitem*/)
{
//init random parameters.
parallel_offset.resetRandomizer();
strokelength_rdm.resetRandomizer();
strokeoverlap_rdm.resetRandomizer();
ends_tolerance.resetRandomizer();
tremble_size.resetRandomizer();
#ifdef LPE_SKETCH_USE_CONSTRUCTION_LINES
tgtlength_rdm.resetRandomizer();
tgt_places_rdmness.resetRandomizer();
#endif
}
/* ######################## */
} //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:encoding=utf-8:textwidth=99 :