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 */
13 #include "live_effects/lpe-sketch.h"
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/sbasis-math.h>
20 #include <2geom/bezier-to-sbasis.h>
21 #include <2geom/sbasis-to-bezier.h>
22 #include <2geom/d2.h>
23 #include <2geom/sbasis-math.h>
24 #include <2geom/piecewise.h>
25 #include <2geom/crossing.h>
26 #include <2geom/path-intersection.h>
28 namespace Inkscape {
29 namespace LivePathEffect {
31 LPESketch::LPESketch(LivePathEffectObject *lpeobject) :
32 Effect(lpeobject),
33 // initialise your parameters here:
34 //testpointA(_("Test Point A"), _("Test A"), "ptA", &wr, this, Geom::Point(100,100)),
35 nbiter_approxstrokes(_("Strokes:"), _("Draw that many approximating strokes"), "nbiter_approxstrokes", &wr, this, 5),
36 strokelength(_("Max stroke length:"),
37 _("Maximum length of approximating strokes"), "strokelength", &wr, this, 100.),
38 strokelength_rdm(_("Stroke length variation:"),
39 _("Random variation of stroke length (relative to maximum length)"), "strokelength_rdm", &wr, this, .3),
40 strokeoverlap(_("Max. overlap:"),
41 _("How much successive strokes should overlap (relative to maximum length)"), "strokeoverlap", &wr, this, .3),
42 strokeoverlap_rdm(_("Overlap variation:"),
43 _("Random variation of overlap (relative to maximum overlap)"), "strokeoverlap_rdm", &wr, this, .3),
44 ends_tolerance(_("Max. end tolerance:"),
45 _("Maximum distance between ends of original and approximating paths (relative to maximum length)"), "ends_tolerance", &wr, this, .1),
46 parallel_offset(_("Average offset:"),
47 _("Average distance each stroke is away from the original path"), "parallel_offset", &wr, this, 5.),
48 tremble_size(_("Max. tremble:"),
49 _("Maximum tremble magnitude"), "tremble_size", &wr, this, 5.),
50 tremble_frequency(_("Tremble frequency:"),
51 _("Average number of tremble periods in a stroke"), "tremble_frequency", &wr, this, 1.)
52 #ifdef LPE_SKETCH_USE_CONSTRUCTION_LINES
53 ,nbtangents(_("Construction lines:"),
54 _("How many construction lines (tangents) to draw"), "nbtangents", &wr, this, 5),
55 tgtscale(_("Scale:"),
56 _("Scale factor relating curvature and length of construction lines (try 5*offset)"), "tgtscale", &wr, this, 10.0),
57 tgtlength(_("Max. length:"), _("Maximum length of construction lines"), "tgtlength", &wr, this, 100.0),
58 tgtlength_rdm(_("Length variation:"), _("Random variation of the length of construction lines"), "tgtlength_rdm", &wr, this, .3),
59 tgt_places_rdmness(_("Placement randomness:"), _("0: evenly distributed construction lines, 1: purely random placement"), "tgt_places_rdmness", &wr, this, 1.)
60 #ifdef LPE_SKETCH_USE_CURVATURE
61 ,min_curvature(_("k_min:"), _("min curvature"), "k_min", &wr, this, 4.0)
62 ,max_curvature(_("k_max:"), _("max curvature"), "k_max", &wr, this, 1000.0)
63 #endif
64 #endif
65 {
66 // register all your parameters here, so Inkscape knows which parameters this effect has:
67 //Add some comment in the UI: *warning* the precise output of this effect might change in future releases!
68 //convert to path if you want to keep exact output unchanged in future releases...
69 //registerParameter( dynamic_cast<Parameter *>(&testpointA) );
70 registerParameter( dynamic_cast<Parameter *>(&nbiter_approxstrokes) );
71 registerParameter( dynamic_cast<Parameter *>(&strokelength) );
72 registerParameter( dynamic_cast<Parameter *>(&strokelength_rdm) );
73 registerParameter( dynamic_cast<Parameter *>(&strokeoverlap) );
74 registerParameter( dynamic_cast<Parameter *>(&strokeoverlap_rdm) );
75 registerParameter( dynamic_cast<Parameter *>(&ends_tolerance) );
76 registerParameter( dynamic_cast<Parameter *>(¶llel_offset) );
77 registerParameter( dynamic_cast<Parameter *>(&tremble_size) );
78 registerParameter( dynamic_cast<Parameter *>(&tremble_frequency) );
79 #ifdef LPE_SKETCH_USE_CONSTRUCTION_LINES
80 registerParameter( dynamic_cast<Parameter *>(&nbtangents) );
81 registerParameter( dynamic_cast<Parameter *>(&tgt_places_rdmness) );
82 registerParameter( dynamic_cast<Parameter *>(&tgtscale) );
83 registerParameter( dynamic_cast<Parameter *>(&tgtlength) );
84 registerParameter( dynamic_cast<Parameter *>(&tgtlength_rdm) );
85 #ifdef LPE_SKETCH_USE_CURVATURE
86 registerParameter( dynamic_cast<Parameter *>(&min_curvature) );
87 registerParameter( dynamic_cast<Parameter *>(&max_curvature) );
88 #endif
89 #endif
91 nbiter_approxstrokes.param_make_integer();
92 nbiter_approxstrokes.param_set_range(0, NR_HUGE);
93 strokelength.param_set_range(1, NR_HUGE);
94 strokelength.param_set_increments(1., 5.);
95 strokelength_rdm.param_set_range(0, 1.);
96 strokeoverlap.param_set_range(0, 1.);
97 strokeoverlap.param_set_increments(0.1, 0.30);
98 ends_tolerance.param_set_range(0., 1.);
99 parallel_offset.param_set_range(0, NR_HUGE);
100 tremble_frequency.param_set_range(0.01, 100.);
101 tremble_frequency.param_set_increments(.5, 1.5);
102 strokeoverlap_rdm.param_set_range(0, 1.);
104 #ifdef LPE_SKETCH_USE_CONSTRUCTION_LINES
105 nbtangents.param_make_integer();
106 nbtangents.param_set_range(0, NR_HUGE);
107 tgtscale.param_set_range(0, NR_HUGE);
108 tgtscale.param_set_increments(.1, .5);
109 tgtlength.param_set_range(0, NR_HUGE);
110 tgtlength.param_set_increments(1., 5.);
111 tgtlength_rdm.param_set_range(0, 1.);
112 tgt_places_rdmness.param_set_range(0, 1.);
113 //this is not very smart, but required to avoid having lot of tangents stacked on short components.
114 //Nota: we could specify a density instead of an absolute number, but this would be scale dependant.
115 concatenate_before_pwd2 = true;
116 #endif
117 }
119 LPESketch::~LPESketch()
120 {
122 }
124 /*
125 Geom::Piecewise<Geom::D2<Geom::SBasis> >
126 addLinearEnds (Geom::Piecewise<Geom::D2<Geom::SBasis> > & m){
127 using namespace Geom;
128 Piecewise<D2<SBasis> > output;
129 Piecewise<D2<SBasis> > start;
130 Piecewise<D2<SBasis> > end;
131 double x,y,vx,vy;
133 x = m.segs.front()[0].at0();
134 y = m.segs.front()[1].at0();
135 vx = m.segs.front()[0][1][0]+Tri(m.segs.front()[0][0]);
136 vy = m.segs.front()[1][1][0]+Tri(m.segs.front()[1][0]);
137 start = Piecewise<D2<SBasis> >(D2<SBasis>(Linear (x-vx,x),Linear (y-vy,y)));
138 start.offsetDomain(m.cuts.front()-1.);
140 x = m.segs.back()[0].at1();
141 y = m.segs.back()[1].at1();
142 vx = -m.segs.back()[0][1][1]+Tri(m.segs.back()[0][0]);;
143 vy = -m.segs.back()[1][1][1]+Tri(m.segs.back()[1][0]);;
144 end = Piecewise<D2<SBasis> >(D2<SBasis>(Linear (x,x+vx),Linear (y,y+vy)));
145 //end.offsetDomain(m.cuts.back());
147 output = start;
148 output.concat(m);
149 output.concat(end);
150 return output;
151 }
152 */
156 //This returns a random perturbation. Notice the domain is [s0,s0+first multiple of period>s1]...
157 Geom::Piecewise<Geom::D2<Geom::SBasis> >
158 LPESketch::computePerturbation (double s0, double s1){
159 using namespace Geom;
160 Piecewise<D2<SBasis> >res;
162 //global offset for this stroke.
163 double offsetX = 2*parallel_offset-parallel_offset.get_value();
164 double offsetY = 2*parallel_offset-parallel_offset.get_value();
165 Point A,dA,B,dB,offset = Point(offsetX,offsetY);
166 //start point A
167 for (unsigned dim=0; dim<2; dim++){
168 A[dim] = offset[dim] + 2*tremble_size-tremble_size.get_value();
169 dA[dim] = 2*tremble_size-tremble_size.get_value();
170 }
171 //compute howmany deg 3 sbasis to concat according to frequency.
173 unsigned count = unsigned((s1-s0)/strokelength*tremble_frequency)+1;
174 //unsigned count = unsigned((s1-s0)/tremble_frequency)+1;
176 for (unsigned i=0; i<count; i++){
177 D2<SBasis> perturb = D2<SBasis>(SBasis(2, Linear()), SBasis(2, Linear()));
178 for (unsigned dim=0; dim<2; dim++){
179 B[dim] = offset[dim] + 2*tremble_size-tremble_size.get_value();
180 perturb[dim][0] = Linear(A[dim],B[dim]);
181 dA[dim] = dA[dim]-B[dim]+A[dim];
182 //avoid dividing by 0. Very short strokes will have ends parallel to the curve...
183 if ( s1-s0 > 1e-2)
184 dB[dim] = -(2*tremble_size-tremble_size.get_value())/(s0-s1)-B[dim]+A[dim];
185 else
186 dB[dim] = -(2*tremble_size-tremble_size.get_value())-B[dim]+A[dim];
187 perturb[dim][1] = Linear(dA[dim],dB[dim]);
188 }
189 dA = B-A-dB;
190 A = B;
191 //dA = B-A-dB;
192 res.concat(Piecewise<D2<SBasis> >(perturb));
193 }
194 res.setDomain(Interval(s0,s0+count*strokelength/tremble_frequency));
195 //res.setDomain(Interval(s0,s0+count*tremble_frequency));
196 return res;
197 }
200 // Main effect body...
201 Geom::Piecewise<Geom::D2<Geom::SBasis> >
202 LPESketch::doEffect_pwd2 (Geom::Piecewise<Geom::D2<Geom::SBasis> > const & pwd2_in)
203 {
204 using namespace Geom;
205 //If the input path is empty, do nothing.
206 //Note: this happens when duplicating a 3d box... dunno why.
207 if (pwd2_in.size()==0) return pwd2_in;
209 Piecewise<D2<SBasis> > output;
211 // some variables for futur use (for construction lines; compute arclength only once...)
212 // notations will be : t = path time, s = distance from start along the path.
213 Piecewise<SBasis> pathlength;
214 double total_length = 0;
216 //TODO: split Construction Lines/Approximated Strokes into two separate effects?
218 //----- Approximated Strokes.
219 std::vector<Piecewise<D2<SBasis> > > pieces_in = split_at_discontinuities (pwd2_in);
221 //work separately on each component.
222 for (unsigned pieceidx = 0; pieceidx < pieces_in.size(); pieceidx++){
224 Piecewise<D2<SBasis> > piece = pieces_in[pieceidx];
225 Piecewise<SBasis> piecelength = arcLengthSb(piece,.1);
226 double piece_total_length = piecelength.segs.back().at1()-piecelength.segs.front().at0();
227 pathlength.concat(piecelength + total_length);
228 total_length += piece_total_length;
231 //TODO: better check this on the Geom::Path.
232 bool closed = piece.segs.front().at0() == piece.segs.back().at1();
233 if (closed){
234 piece.concat(piece);
235 piecelength.concat(piecelength+piece_total_length);
236 }
238 for (unsigned i = 0; i<nbiter_approxstrokes; i++){
239 //Basic steps:
240 //- Choose a rdm seg [s0,s1], find coresponding [t0,t1],
241 //- Pick a rdm perturbation delta(s), collect 'piece(t)+delta(s(t))' over [t0,t1] into output.
243 // pick a point where to start the stroke (s0 = dist from start).
244 double s1=0.,s0 = ends_tolerance*strokelength+0.0001;//the root finder might miss 0.
245 double t1, t0;
246 double s0_initial = s0;
247 bool done = false;// was the end of the component reached?
249 while (!done){
250 // if the start point is already too far... do nothing. (this should not happen!)
251 if (!closed && s1>piece_total_length - ends_tolerance.get_value()*strokelength) break;
252 if ( closed && s0>piece_total_length + s0_initial) break;
254 std::vector<double> times;
255 times = roots(piecelength-s0);
256 t0 = times.at(0);//there should be one and only one solution!!
258 // pick a new end point (s1 = s0 + strokelength).
259 s1 = s0 + strokelength*(1-strokelength_rdm);
260 // don't let it go beyond the end of the orgiginal path.
261 // TODO/FIXME: this might result in short strokes near the end...
262 if (!closed && s1>piece_total_length-ends_tolerance.get_value()*strokelength){
263 done = true;
264 //!!the root solver might miss s1==piece_total_length...
265 if (s1>piece_total_length){s1 = piece_total_length - ends_tolerance*strokelength-0.0001;}
266 }
267 if (closed && s1>piece_total_length + s0_initial){
268 done = true;
269 if (closed && s1>2*piece_total_length){
270 s1 = 2*piece_total_length - strokeoverlap*(1-strokeoverlap_rdm)*strokelength-0.0001;
271 }
272 }
273 times = roots(piecelength-s1);
274 if (times.size()==0) break;//we should not be there.
275 t1 = times[0];
277 //pick a rdm perturbation, and collect the perturbed piece into output.
278 Piecewise<D2<SBasis> > pwperturb = computePerturbation(s0-0.01,s1+0.01);
279 pwperturb = compose(pwperturb,portion(piecelength,t0,t1));
281 output.concat(portion(piece,t0,t1)+pwperturb);
283 //step points: s0 = s1 - overlap.
284 //TODO: make sure this has to end?
285 s0 = s1 - strokeoverlap*(1-strokeoverlap_rdm)*(s1-s0);
286 }
287 }
288 }
290 #ifdef LPE_SKETCH_USE_CONSTRUCTION_LINES
292 //----- Construction lines.
293 //TODO: choose places according to curvature?.
295 //at this point we should have:
296 //pathlength = arcLengthSb(pwd2_in,.1);
297 //total_length = pathlength.segs.back().at1()-pathlength.segs.front().at0();
298 Piecewise<D2<SBasis> > m = pwd2_in;
299 Piecewise<D2<SBasis> > v = derivative(pwd2_in);
300 Piecewise<D2<SBasis> > a = derivative(v);
302 #ifdef LPE_SKETCH_USE_CURVATURE
303 //---- curvature experiment...(enable
304 Piecewise<SBasis> k = curvature(pwd2_in);
305 OptInterval k_bnds = bounds_exact(abs(k));
306 double k_min = k_bnds->min() + k_bnds->extent() * min_curvature;
307 double k_max = k_bnds->min() + k_bnds->extent() * max_curvature;
309 Piecewise<SBasis> bump;
310 //SBasis bump_seg = SBasis( 2, Linear(0) );
311 //bump_seg[1] = Linear( 4. );
312 SBasis bump_seg = SBasis( 1, Linear(1) );
313 bump.push_cut( k_bnds->min() - 1 );
314 bump.push( Linear(0), k_min );
315 bump.push(bump_seg,k_max);
316 bump.push( Linear(0), k_bnds->max()+1 );
318 Piecewise<SBasis> repartition = compose( bump, k );
319 repartition = integral(repartition);
320 //-------------------------------
321 #endif
323 for (unsigned i=0; i<nbtangents; i++){
325 // pick a point where to draw a tangent (s = dist from start along path).
326 #ifdef LPE_SKETCH_USE_CURVATURE
327 double proba = repartition.firstValue()+ (rand()%100)/100.*(repartition.lastValue()-repartition.firstValue());
328 std::vector<double> times;
329 times = roots(repartition - proba);
330 double t = times.at(0);//there should be one and only one solution!
331 #else
332 //double s = total_length * ( i + tgtlength_rdm ) / (nbtangents+1.);
333 double reg_place = total_length * ( i + .5) / ( nbtangents );
334 double rdm_place = total_length * tgt_places_rdmness;
335 double s = ( 1.- tgt_places_rdmness.get_value() ) * reg_place + rdm_place ;
336 std::vector<double> times;
337 times = roots(pathlength-s);
338 double t = times.at(0);//there should be one and only one solution!
339 #endif
340 Point m_t = m(t), v_t = v(t), a_t = a(t);
341 //Compute tgt length according to curvature (not exceeding tgtlength) so that
342 // dist to origninal curve ~ 4 * (parallel_offset+tremble_size).
343 //TODO: put this 4 as a parameter in the UI...
344 //TODO: what if with v=0?
345 double l = tgtlength*(1-tgtlength_rdm)/v_t.length();
346 double r = pow(v_t.length(),3)/cross(a_t,v_t);
347 r = sqrt((2*fabs(r)-tgtscale)*tgtscale)/v_t.length();
348 l=(r<l)?r:l;
349 //collect the tgt segment into output.
350 D2<SBasis> tgt = D2<SBasis>();
351 for (unsigned dim=0; dim<2; dim++){
352 tgt[dim] = SBasis(Linear(m_t[dim]-v_t[dim]*l, m_t[dim]+v_t[dim]*l));
353 }
354 output.concat(Piecewise<D2<SBasis> >(tgt));
355 }
356 #endif
358 return output;
359 }
361 void
362 LPESketch::doBeforeEffect (SPLPEItem */*lpeitem*/)
363 {
364 //init random parameters.
365 parallel_offset.resetRandomizer();
366 strokelength_rdm.resetRandomizer();
367 strokeoverlap_rdm.resetRandomizer();
368 ends_tolerance.resetRandomizer();
369 tremble_size.resetRandomizer();
370 #ifdef LPE_SKETCH_USE_CONSTRUCTION_LINES
371 tgtlength_rdm.resetRandomizer();
372 tgt_places_rdmness.resetRandomizer();
373 #endif
374 }
376 /* ######################## */
378 } //namespace LivePathEffect (setq default-directory "c:/Documents And Settings/jf/Mes Documents/InkscapeSVN")
379 } /* namespace Inkscape */
381 /*
382 Local Variables:
383 mode:c++
384 c-file-style:"stroustrup"
385 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
386 indent-tabs-mode:nil
387 fill-column:99
388 End:
389 */
390 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :