live_effects/lpe-sketch.cpp

   1 /** @file
   2  * @brief LPE sketch effect implementation
   3  */
   4 /* Authors:
   5  *   Jean-Francois Barraud <jf.barraud@gmail.com>
   6  *   Johan Engelen <j.b.c.engelen@utwente.nl>
   7  *
   8  * Copyright (C) 2007 Authors
   9  *
  10  * Released under GNU GPL, read the file 'COPYING' for more information
  11  */
  12
  13 #include "live_effects/lpe-sketch.h"
  14
  15 // You might need to include other 2geom files. You can add them here:
  16 #include <2geom/path.h>
  17 #include <2geom/sbasis.h>
  18 #include <2geom/sbasis-geometric.h>
  19 #include <2geom/bezier-to-sbasis.h>
  20 #include <2geom/sbasis-to-bezier.h>
  21 #include <2geom/d2.h>
  22 #include <2geom/sbasis-math.h>
  23 #include <2geom/piecewise.h>
  24 #include <2geom/crossing.h>
  25 #include <2geom/path-intersection.h>
  26
  27 namespace Inkscape {
  28 namespace LivePathEffect {
  29
  30 LPESketch::LPESketch(LivePathEffectObject *lpeobject) :
  31     Effect(lpeobject),
  32     // initialise your parameters here:
  33     //testpointA(_("Test Point A"), _("Test A"), "ptA", &wr, this, Geom::Point(100,100)),
  34     nbiter_approxstrokes(_("Strokes"), _("Draw that many approximating strokes"), "nbiter_approxstrokes", &wr, this, 5),
  35     strokelength(_("Max stroke length"),
  36                  _("Maximum length of approximating strokes"), "strokelength", &wr, this, 100.),
  37     strokelength_rdm(_("Stroke length variation"),
  38                      _("Random variation of stroke length (relative to maximum length)"), "strokelength_rdm", &wr, this, .3),
  39     strokeoverlap(_("Max. overlap"),
  40                   _("How much successive strokes should overlap (relative to maximum length)"), "strokeoverlap", &wr, this, .3),
  41     strokeoverlap_rdm(_("Overlap variation"),
  42                       _("Random variation of overlap (relative to maximum overlap)"), "strokeoverlap_rdm", &wr, this, .3),
  43     ends_tolerance(_("Max. end tolerance"),
  44                    _("Maximum distance between ends of original and approximating paths (relative to maximum length)"), "ends_tolerance", &wr, this, .1),
  45     parallel_offset(_("Parallel offset"),
  46                     _("Average distance from approximating path to original path"), "parallel_offset", &wr, this, 5.),
  47     tremble_size(_("Max. tremble"),
  48                  _("Maximum tremble magnitude"), "tremble_size", &wr, this, 5.),
  49     tremble_frequency(_("Tremble frequency"),
  50                       _("Average number of tremble periods in an approximating stroke"), "tremble_frequency", &wr, this, 1.),
  51     nbtangents(_("Construction lines"),
  52                _("How many construction lines (tangents) to draw"), "nbtangents", &wr, this, 5),
  53     tgtscale(_("Scale"),
  54              _("Scale factor relating curvature and length of construction lines (try 5*offset)"), "tgtscale", &wr, this, 10.0),
  55     tgtlength(_("Max. length"), _("Maximum length of construction lines"), "tgtlength", &wr, this, 100.0),
  56     tgtlength_rdm(_("Length variation"), _("Random variation of the length of construction lines"), "tgtlength_rdm", &wr, this, .3)
  57 {
  58     // register all your parameters here, so Inkscape knows which parameters this effect has:
  59     //Add some comment in the UI:  *warning* the precise output of this effect might change in future releases!
  60     //convert to path if you want to keep exact output unchanged in future releases...
  61     //registerParameter( dynamic_cast<Parameter *>(&testpointA) );
  62     registerParameter( dynamic_cast<Parameter *>(&nbiter_approxstrokes) );
  63     registerParameter( dynamic_cast<Parameter *>(&strokelength) );
  64     registerParameter( dynamic_cast<Parameter *>(&strokelength_rdm) );
  65     registerParameter( dynamic_cast<Parameter *>(&strokeoverlap) );
  66     registerParameter( dynamic_cast<Parameter *>(&strokeoverlap_rdm) );
  67     registerParameter( dynamic_cast<Parameter *>(&ends_tolerance) );
  68     registerParameter( dynamic_cast<Parameter *>(&parallel_offset) );
  69     registerParameter( dynamic_cast<Parameter *>(&tremble_size) );
  70     registerParameter( dynamic_cast<Parameter *>(&tremble_frequency) );
  71     registerParameter( dynamic_cast<Parameter *>(&nbtangents) );
  72     registerParameter( dynamic_cast<Parameter *>(&tgtscale) );
  73     registerParameter( dynamic_cast<Parameter *>(&tgtlength) );
  74     registerParameter( dynamic_cast<Parameter *>(&tgtlength_rdm) );
  75
  76
  77     nbiter_approxstrokes.param_make_integer();
  78     nbiter_approxstrokes.param_set_range(0, NR_HUGE);
  79     strokelength.param_set_range(1, NR_HUGE);
  80     strokelength.param_set_increments(1., 5.);
  81     strokelength_rdm.param_set_range(0, 1.);
  82     strokeoverlap.param_set_range(0, 1.);
  83     strokeoverlap.param_set_increments(0.1, 0.30);
  84     ends_tolerance.param_set_range(0., 1.);
  85     parallel_offset.param_set_range(0, NR_HUGE);
  86     tremble_frequency.param_set_range(0.01, 100.);
  87     tremble_frequency.param_set_increments(.5, 1.5);
  88     strokeoverlap_rdm.param_set_range(0, 1.);
  89
  90     nbtangents.param_make_integer();
  91     nbtangents.param_set_range(0, NR_HUGE);
  92     tgtscale.param_set_range(0, NR_HUGE);
  93     tgtscale.param_set_increments(.1, .5);
  94     tgtlength.param_set_range(0, NR_HUGE);
  95     tgtlength.param_set_increments(1., 5.);
  96     tgtlength_rdm.param_set_range(0, 1.);
  97 }
  98
  99 LPESketch::~LPESketch()
 100 {
 101
 102 }
 103
 104 /*
 105 Geom::Piecewise<Geom::D2<Geom::SBasis> >
 106 addLinearEnds (Geom::Piecewise<Geom::D2<Geom::SBasis> > & m){
 107     using namespace Geom;
 108     Piecewise<D2<SBasis> > output;
 109     Piecewise<D2<SBasis> > start;
 110     Piecewise<D2<SBasis> > end;
 111     double x,y,vx,vy;
 112
 113     x  = m.segs.front()[0].at0();
 114     y  = m.segs.front()[1].at0();
 115     vx = m.segs.front()[0][1][0]+Tri(m.segs.front()[0][0]);
 116     vy = m.segs.front()[1][1][0]+Tri(m.segs.front()[1][0]);
 117     start = Piecewise<D2<SBasis> >(D2<SBasis>(Linear (x-vx,x),Linear (y-vy,y)));
 118     start.offsetDomain(m.cuts.front()-1.);
 119
 120     x  = m.segs.back()[0].at1();
 121     y  = m.segs.back()[1].at1();
 122     vx = -m.segs.back()[0][1][1]+Tri(m.segs.back()[0][0]);;
 123     vy = -m.segs.back()[1][1][1]+Tri(m.segs.back()[1][0]);;
 124     end = Piecewise<D2<SBasis> >(D2<SBasis>(Linear (x,x+vx),Linear (y,y+vy)));
 125     //end.offsetDomain(m.cuts.back());
 126
 127     output = start;
 128     output.concat(m);
 129     output.concat(end);
 130     return output;
 131 }
 132 */
 133
 134
 135
 136 //This returns a random perturbation. Notice the domain is [s0,s0+first multiple of period>s1]...
 137 Geom::Piecewise<Geom::D2<Geom::SBasis> >
 138 LPESketch::computePerturbation (double s0, double s1){
 139     using namespace Geom;
 140     Piecewise<D2<SBasis> >res;
 141
 142     //global offset for this stroke.
 143     double offsetX = parallel_offset-parallel_offset.get_value();
 144     double offsetY = parallel_offset-parallel_offset.get_value();
 145     Point A,dA,B,dB,offset = Point(offsetX,offsetY);
 146     //start point A
 147     for (unsigned dim=0; dim<2; dim++){
 148         A[dim]  = offset[dim] + 2*tremble_size-tremble_size.get_value();
 149         dA[dim] = 2*tremble_size-tremble_size.get_value();
 150     }
 151     //compute howmany deg 3 sbasis to concat according to frequency.
 152     unsigned count = unsigned((s1-s0)/strokelength*tremble_frequency)+1;
 153     for (unsigned i=0; i<count; i++){
 154         D2<SBasis> perturb = D2<SBasis>(SBasis(2*count, Linear()), SBasis(2*count, Linear()));
 155         for (unsigned dim=0; dim<2; dim++){
 156             B[dim] = offset[dim] + 2*tremble_size-tremble_size.get_value();
 157             perturb[dim][2*i] = Linear(A[dim],B[dim]);
 158             dA[dim] = dA[dim]-B[dim]+A[dim];
 159             dB[dim] = 2*tremble_size-tremble_size.get_value();
 160             perturb[dim][2*i+1] = Linear(dA[dim],dB[dim]);
 161         }
 162         A = B;
 163         dA = B-A-dB;
 164         res.concat(Piecewise<D2<SBasis> >(perturb));
 165     }
 166     res.setDomain(Interval(s0,s0+count*strokelength/tremble_frequency));
 167     return res;
 168 }
 169
 170
 171 // Main effect body...
 172 Geom::Piecewise<Geom::D2<Geom::SBasis> >
 173 LPESketch::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in)
 174 {
 175     using namespace Geom;
 176     //If the input path is empty, do nothing.
 177     //Note: this happens when duplicating a 3d box... dunno why.
 178     if (pwd2_in.size()==0) return pwd2_in;
 179
 180     Piecewise<D2<SBasis> > output;
 181
 182     // some variables for futur use (for construction lines; compute arclength only once...)
 183     // notations will be : t = path time, s = distance from start along the path.
 184     Piecewise<SBasis> pathlength;
 185     double total_length = 0;
 186
 187     //TODO: split Construction Lines/Approximated Strokes into two separate effects?
 188
 189     //----- Approximated Strokes.
 190     std::vector<Piecewise<D2<SBasis> > > pieces_in = split_at_discontinuities (pwd2_in);
 191
 192     //work separately on each component.
 193     for (unsigned pieceidx = 0; pieceidx < pieces_in.size(); pieceidx++){
 194
 195         Piecewise<D2<SBasis> > piece = pieces_in[pieceidx];
 196         Piecewise<SBasis> piecelength = arcLengthSb(piece,.1);
 197         double piece_total_length = piecelength.segs.back().at1()-piecelength.segs.front().at0();
 198         pathlength.concat(piecelength + total_length);
 199         total_length += piece_total_length;
 200
 201
 202         //TODO: better check this on the Geom::Path.
 203         bool closed = piece.segs.front().at0() == piece.segs.back().at1();
 204         if (closed){
 205             piece.concat(piece);
 206             piecelength.concat(piecelength+piece_total_length);
 207         }
 208
 209         for (unsigned i = 0; i<nbiter_approxstrokes; i++){
 210             //Basic steps:
 211             //- Choose a rdm seg [s0,s1], find coresponding [t0,t1],
 212             //- Pick a rdm perturbation delta(s), collect 'piece(t)+delta(s(t))' over [t0,t1] into output.
 213
 214             // pick a point where to start the stroke (s0 = dist from start).
 215             double s1=0.,s0 = ends_tolerance*strokelength+0.0001;//the root finder might miss 0.
 216             double t1, t0;
 217             double s0_initial = s0;
 218             bool done = false;// was the end of the component reached?
 219
 220             while (!done){
 221                 // if the start point is already too far... do nothing. (this should not happen!)
 222                 if (!closed && s1>piece_total_length - ends_tolerance.get_value()*strokelength) break;
 223                 if ( closed && s0>piece_total_length + s0_initial) break;
 224
 225                 std::vector<double> times;
 226                 times = roots(piecelength-s0);
 227                 t0 = times.at(0);//there should be one and only one solution!!
 228
 229                 // pick a new end point (s1 = s0 + strokelength).
 230                 s1 = s0 + strokelength*(1-strokelength_rdm);
 231                 // don't let it go beyond the end of the orgiginal path.
 232                 // TODO/FIXME: this might result in short strokes near the end...
 233                 if (!closed && s1>piece_total_length-ends_tolerance.get_value()*strokelength){
 234                     done = true;
 235                     //!!the root solver might miss s1==piece_total_length...
 236                     if (s1>piece_total_length){s1 = piece_total_length - ends_tolerance*strokelength-0.0001;}
 237                 }
 238                 if (closed && s1>piece_total_length + s0_initial){
 239                     done = true;
 240                     if (closed && s1>2*piece_total_length){
 241                         s1 = 2*piece_total_length - strokeoverlap*(1-strokeoverlap_rdm)*strokelength-0.0001;
 242                     }
 243                 }
 244                 times = roots(piecelength-s1);
 245                 if (times.size()==0) break;//we should not be there.
 246                 t1 = times[0];
 247
 248                 //pick a rdm perturbation, and collect the perturbed piece into output.
 249                 Piecewise<D2<SBasis> > pwperturb = computePerturbation(s0-0.01,s1+0.01);
 250                 pwperturb = compose(pwperturb,portion(piecelength,t0,t1));
 251
 252                 output.concat(portion(piece,t0,t1)+pwperturb);
 253
 254                 //step points: s0 = s1 - overlap.
 255                 //TODO: make sure this has to end?
 256                 s0 = s1 - strokeoverlap*(1-strokeoverlap_rdm)*(s1-s0);
 257             }
 258         }
 259     }
 260
 261     //----- Construction lines.
 262     //TODO: choose places according to curvature?.
 263
 264     //at this point we should have:
 265     //pathlength = arcLengthSb(pwd2_in,.1);
 266     //total_length = pathlength.segs.back().at1()-pathlength.segs.front().at0();
 267     Piecewise<D2<SBasis> > m = pwd2_in;
 268     Piecewise<D2<SBasis> > v = derivative(pwd2_in);
 269     Piecewise<D2<SBasis> > a = derivative(v);
 270
 271     for (unsigned i=0; i<nbtangents; i++){
 272
 273         // pick a point where to draw a tangent (s = dist from start along path).
 274         double s = total_length * ( i + tgtlength_rdm ) / (nbtangents+1.);
 275         std::vector<double> times;
 276         times = roots(pathlength-s);
 277         double t = times.at(0);//there should be one and only one solution!
 278         Point m_t = m(t), v_t = v(t), a_t = a(t);
 279         //Compute tgt length according to curvature (not exceeding tgtlength) so that
 280         //  dist to origninal curve ~ 4 * (parallel_offset+tremble_size).
 281         //TODO: put this 4 as a parameter in the UI...
 282         //TODO: what if with v=0?
 283         double l = tgtlength*(1-tgtlength_rdm)/v_t.length();
 284         double r = pow(v_t.length(),3)/cross(a_t,v_t);
 285         r = sqrt((2*fabs(r)-tgtscale)*tgtscale)/v_t.length();
 286         l=(r<l)?r:l;
 287         //collect the tgt segment into output.
 288         D2<SBasis> tgt = D2<SBasis>();
 289         for (unsigned dim=0; dim<2; dim++){
 290             tgt[dim] = SBasis(Linear(m_t[dim]-v_t[dim]*l, m_t[dim]+v_t[dim]*l));
 291         }
 292         output.concat(Piecewise<D2<SBasis> >(tgt));
 293     }
 294
 295     return output;
 296 }
 297
 298 void
 299 LPESketch::doBeforeEffect (SPLPEItem *lpeitem)
 300 {
 301     //init random parameters.
 302     parallel_offset.resetRandomizer();
 303     strokelength_rdm.resetRandomizer();
 304     strokeoverlap_rdm.resetRandomizer();
 305     ends_tolerance.resetRandomizer();
 306     tremble_size.resetRandomizer();
 307     tgtlength_rdm.resetRandomizer();
 308 }
 309
 310 /* ######################## */
 311
 312 } //namespace LivePathEffect (setq default-directory "c:/Documents And Settings/jf/Mes Documents/InkscapeSVN")
 313 } /* namespace Inkscape */
 314
 315 /*
 316   Local Variables:
 317   mode:c++
 318   c-file-style:"stroustrup"
 319   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 320   indent-tabs-mode:nil
 321   fill-column:99
 322   End:
 323 */
 324 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :