Fix bugs in previous commit that caused FTBFS in synfig and ETL FTBFS with older...
[synfig.git] / synfig-core / tags / synfig_0_61_06 / src / synfig / valuenode_bline.cpp
1 /* === S Y N F I G ========================================================= */
2 /*!     \file valuenode_bline.cpp
3 **      \brief Template File
4 **
5 **      $Id$
6 **
7 **      \legal
8 **      Copyright (c) 2002-2005 Robert B. Quattlebaum Jr., Adrian Bentley
9 **
10 **      This package is free software; you can redistribute it and/or
11 **      modify it under the terms of the GNU General Public License as
12 **      published by the Free Software Foundation; either version 2 of
13 **      the License, or (at your option) any later version.
14 **
15 **      This package is distributed in the hope that it will be useful,
16 **      but WITHOUT ANY WARRANTY; without even the implied warranty of
17 **      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 **      General Public License for more details.
19 **      \endlegal
20 */
21 /* ========================================================================= */
22
23 /* === H E A D E R S ======================================================= */
24
25 #ifdef USING_PCH
26 #       include "pch.h"
27 #else
28 #ifdef HAVE_CONFIG_H
29 #       include <config.h>
30 #endif
31
32 #include "valuenode_bline.h"
33 #include "valuenode_const.h"
34 #include "valuenode_composite.h"
35 #include "general.h"
36 #include "exception.h"
37 #include "blinepoint.h"
38 #include <vector>
39 #include <list>
40 #include <algorithm>
41 #include <ETL/hermite>
42 #include <ETL/calculus>
43 #include "segment.h"
44
45 #endif
46
47 /* === U S I N G =========================================================== */
48
49 using namespace std;
50 using namespace etl;
51 using namespace synfig;
52
53 /* === M A C R O S ========================================================= */
54
55 /* === G L O B A L S ======================================================= */
56
57 /* === P R O C E D U R E S ================================================= */
58
59 inline float
60 linear_interpolation(const float& a, const float& b, float c)
61 { return (b-a)*c+a; }
62
63 inline Vector
64 linear_interpolation(const Vector& a, const Vector& b, float c)
65 { return (b-a)*c+a; }
66
67 inline Vector
68 radial_interpolation(const Vector& a, const Vector& b, float c)
69 {
70         // if either extreme is zero then use linear interpolation instead
71         if (a.is_equal_to(Vector::zero()) || b.is_equal_to(Vector::zero()))
72                 return linear_interpolation(a, b, c);
73
74         affine_combo<Real,float> mag_combo;
75         affine_combo<Angle,float> ang_combo;
76
77         Real mag(mag_combo(a.mag(),b.mag(),c));
78         Angle ang(ang_combo(Angle::tan(a[1],a[0]),Angle::tan(b[1],b[0]),c));
79
80         return Point( mag*Angle::cos(ang).get(),mag*Angle::sin(ang).get() );
81 }
82
83 inline void
84 transform_coords(Vector in, Vector& out, const Point& coord_origin, const Point *coord_sys)
85 {
86         in -= coord_origin;
87         out[0] = in * coord_sys[0];
88         out[1] = in * coord_sys[1];
89 }
90
91 inline void
92 untransform_coords(const Vector& in, Vector& out, const Point& coord_origin, const Point *coord_sys)
93 {
94         out[0] = in * coord_sys[0];
95         out[1] = in * coord_sys[1];
96         out += coord_origin;
97 }
98
99 ValueBase
100 synfig::convert_bline_to_segment_list(const ValueBase& bline)
101 {
102         std::vector<Segment> ret;
103
104 //      std::vector<BLinePoint> list(bline.operator std::vector<BLinePoint>());
105         //std::vector<BLinePoint> list(bline);
106         std::vector<BLinePoint> list(bline.get_list().begin(),bline.get_list().end());
107         std::vector<BLinePoint>::const_iterator iter;
108
109         BLinePoint prev,first;
110
111         //start with prev = first and iter on the second...
112
113         if(list.empty()) return ValueBase(ret,bline.get_loop());
114         first = prev = list.front();
115
116         for(iter=++list.begin();iter!=list.end();++iter)
117         {
118                 ret.push_back(
119                         Segment(
120                                 prev.get_vertex(),
121                                 prev.get_tangent2(),
122                                 iter->get_vertex(),
123                                 iter->get_tangent1()
124                         )
125                 );
126                 prev=*iter;
127         }
128         if(bline.get_loop())
129         {
130                 ret.push_back(
131                         Segment(
132                                 prev.get_vertex(),
133                                 prev.get_tangent2(),
134                                 first.get_vertex(),
135                                 first.get_tangent1()
136                         )
137                 );
138         }
139         return ValueBase(ret,bline.get_loop());
140 }
141
142 ValueBase
143 synfig::convert_bline_to_width_list(const ValueBase& bline)
144 {
145         std::vector<Real> ret;
146 //      std::vector<BLinePoint> list(bline.operator std::vector<BLinePoint>());
147         //std::vector<BLinePoint> list(bline);
148         std::vector<BLinePoint> list(bline.get_list().begin(),bline.get_list().end());
149         std::vector<BLinePoint>::const_iterator iter;
150
151         if(bline.empty())
152                 return ValueBase(ValueBase::TYPE_LIST);
153
154         for(iter=list.begin();iter!=list.end();++iter)
155                 ret.push_back(iter->get_width());
156
157         if(bline.get_loop())
158                 ret.push_back(list.front().get_width());
159
160         return ValueBase(ret,bline.get_loop());
161 }
162
163
164 /* === M E T H O D S ======================================================= */
165
166
167 ValueNode_BLine::ValueNode_BLine():
168         ValueNode_DynamicList(ValueBase::TYPE_BLINEPOINT)
169 {
170 }
171
172 ValueNode_BLine::~ValueNode_BLine()
173 {
174 }
175
176 ValueNode_BLine*
177 ValueNode_BLine::create(const ValueBase &value)
178 {
179         if(value.get_type()!=ValueBase::TYPE_LIST)
180                 return 0;
181
182         ValueNode_BLine* value_node(new ValueNode_BLine());
183
184         if(!value.empty())
185         {
186                 switch(value.get_contained_type())
187                 {
188                 case ValueBase::TYPE_BLINEPOINT:
189                 {
190 //                      std::vector<BLinePoint> bline_points(value.operator std::vector<BLinePoint>());
191                         //std::vector<BLinePoint> bline_points(value);
192                         std::vector<BLinePoint> bline_points(value.get_list().begin(),value.get_list().end());
193                         std::vector<BLinePoint>::const_iterator iter;
194
195                         for(iter=bline_points.begin();iter!=bline_points.end();iter++)
196                         {
197                                 value_node->add(ValueNode::Handle(ValueNode_Composite::create(*iter)));
198                         }
199                         value_node->set_loop(value.get_loop());
200                 }
201                         break;
202                 case ValueBase::TYPE_SEGMENT:
203                 {
204                         // Here, we want to convert a list of segments
205                         // into a list of BLinePoints. We make an assumption
206                         // that the segment list is continuous(sp), but not necessarily
207                         // smooth.
208
209                         value_node->set_loop(false);
210 //                      std::vector<Segment> segments(value.operator std::vector<Segment>());
211 //                      std::vector<Segment> segments(value);
212                         std::vector<Segment> segments(value.get_list().begin(),value.get_list().end());
213                         std::vector<Segment>::const_iterator iter,last(segments.end());
214                         --last;
215                         ValueNode_Const::Handle prev,first;
216
217                         for(iter=segments.begin();iter!=segments.end();iter++)
218                         {
219 #define PREV_POINT      prev->get_value().get(BLinePoint())
220 #define FIRST_POINT     first->get_value().get(BLinePoint())
221 #define CURR_POINT      curr->get_value().get(BLinePoint())
222                                 if(iter==segments.begin())
223                                 {
224                                         prev=ValueNode_Const::create(ValueBase::TYPE_BLINEPOINT);
225                                         {
226                                                 BLinePoint prev_point(PREV_POINT);
227                                                 prev_point.set_vertex(iter->p1);
228                                                 prev_point.set_tangent1(iter->t1);
229                                                 prev_point.set_width(0.01);
230                                                 prev_point.set_origin(0.5);
231                                                 prev_point.set_split_tangent_flag(false);
232                                                 prev->set_value(prev_point);
233                                         }
234                                         first=prev;
235                                         value_node->add(ValueNode::Handle(prev));
236
237                                 }
238                                 if(iter==last && iter->p2.is_equal_to(FIRST_POINT.get_vertex()))
239                                 {
240                                         value_node->set_loop(true);
241                                         if(!iter->t2.is_equal_to(FIRST_POINT.get_tangent1()))
242                                         {
243                                                 BLinePoint first_point(FIRST_POINT);
244                                                 first_point.set_tangent1(iter->t2);
245                                                 first->set_value(first_point);
246                                         }
247                                         continue;
248                                 }
249
250                                 ValueNode_Const::Handle curr;
251                                 curr=ValueNode_Const::create(ValueBase::TYPE_BLINEPOINT);
252                                 {
253                                         BLinePoint curr_point(CURR_POINT);
254                                         curr_point.set_vertex(iter->p2);
255                                         curr_point.set_tangent1(iter->t2);
256                                         curr_point.set_width(0.01);
257                                         curr_point.set_origin(0.5);
258                                         curr_point.set_split_tangent_flag(false);
259                                         curr->set_value(curr_point);
260                                 }
261                                 if(!PREV_POINT.get_tangent1().is_equal_to(iter->t1))
262                                 {
263                                         BLinePoint prev_point(PREV_POINT);
264                                         prev_point.set_split_tangent_flag(true);
265                                         prev_point.set_tangent2(iter->t1);
266                                         prev->set_value(prev_point);
267                                 }
268                                 value_node->add(ValueNode::Handle(curr));
269                                 prev=curr;
270                         }
271
272                 }
273                         break;
274                 default:
275                         // We got a list of who-knows-what. We don't have any idea
276                         // what to do with it.
277                         return 0;
278                         break;
279                 }
280         }
281
282
283         return value_node;
284 }
285
286 ValueNode_BLine::ListEntry
287 ValueNode_BLine::create_list_entry(int index, Time time, Real origin)
288 {
289         ValueNode_BLine::ListEntry ret;
290
291
292         synfig::BLinePoint prev,next;
293
294         int prev_i,next_i;
295
296         index=index%link_count();
297
298         assert(index>=0);
299         ret.index=index;
300         ret.set_parent_value_node(this);
301
302         if(!list[index].status_at_time(time))
303                 next_i=find_next_valid_entry(index,time);
304         else
305                 next_i=index;
306         prev_i=find_prev_valid_entry(index,time);
307
308         synfig::info("index=%d, next_i=%d, prev_i=%d",index,next_i,prev_i);
309
310         next=(*list[next_i].value_node)(time);
311         prev=(*list[prev_i].value_node)(time);
312
313         etl::hermite<Vector> curve(prev.get_vertex(),next.get_vertex(),prev.get_tangent2(),next.get_tangent1());
314         etl::derivative< etl::hermite<Vector> > deriv(curve);
315
316         synfig::BLinePoint bline_point;
317         bline_point.set_vertex(curve(origin));
318         bline_point.set_width((next.get_width()-prev.get_width())*origin+prev.get_width());
319         bline_point.set_tangent1(deriv(origin)*min(1.0-origin,origin));
320         bline_point.set_tangent2(bline_point.get_tangent1());
321         bline_point.set_split_tangent_flag(false);
322         bline_point.set_origin(origin);
323
324         ret.value_node=ValueNode_Composite::create(bline_point);
325
326         return ret;
327 }
328
329 ValueBase
330 ValueNode_BLine::operator()(Time t)const
331 {
332         std::vector<BLinePoint> ret_list;
333
334         std::vector<ListEntry>::const_iterator iter,first_iter;
335         bool first_flag(true);
336         bool rising;
337         int index(0);
338         float next_scale(1.0f);
339
340         BLinePoint prev,first;
341         first.set_origin(100.0f);
342
343         for(iter=list.begin();iter!=list.end();++iter,index++)
344         {
345                 float amount(iter->amount_at_time(t,&rising));
346
347                 assert(amount>=0.0f);
348                 assert(amount<=1.0f);
349
350                 if(amount==1.0f)
351                 {
352                         if(first_flag)
353                         {
354                                 first_iter=iter;
355                                 first=prev=(*iter->value_node)(t).get(prev);
356                                 first_flag=false;
357                                 ret_list.push_back(first);
358                                 continue;
359                         }
360
361                         BLinePoint curr;
362                         curr=(*iter->value_node)(t).get(prev);
363
364                         if(next_scale!=1.0f)
365                         {
366                                 ret_list.back().set_split_tangent_flag(true);
367                                 ret_list.back().set_tangent2(prev.get_tangent2()*next_scale);
368
369                                 ret_list.push_back(curr);
370
371                                 ret_list.back().set_split_tangent_flag(true);
372                                 ret_list.back().set_tangent2(curr.get_tangent2());
373                                 ret_list.back().set_tangent1(curr.get_tangent1()*next_scale);
374
375                                 next_scale=1.0f;
376                         }
377                         else
378                         {
379                                 ret_list.push_back(curr);
380                         }
381
382                         prev=curr;
383                 }
384                 else
385                 if(amount>0.0f)
386                 {
387                         std::vector<ListEntry>::const_iterator begin_iter,end_iter;
388
389                         // This is where the interesting stuff happens
390                         // We need to seek forward in the list to see what the next
391                         // active point is
392
393                         BLinePoint blp_here_on;  // the current vertex, when fully on
394                         BLinePoint blp_here_off; // the current vertex, when fully off
395                         BLinePoint blp_here_now; // the current vertex, right now (between on and off)
396                         BLinePoint blp_prev_off; // the beginning of dynamic group when fully off
397                         BLinePoint blp_next_off; // the end of the dynamic group when fully off
398
399                         int dist_from_begin(0), dist_from_end(0);
400                         Time off_time, on_time;
401
402                         if(!rising)     // if not rising, then we were fully on in the past, and will be fully off in the future
403                         {
404                                 try{ on_time=iter->find_prev(t)->get_time(); }
405                                 catch(...) { on_time=Time::begin(); }
406                                 try{ off_time=iter->find_next(t)->get_time(); }
407                                 catch(...) { off_time=Time::end(); }
408                         }
409                         else // otherwise we were fully off in the past, and will be fully on in the future
410                         {
411                                 try{ off_time=iter->find_prev(t)->get_time(); }
412                                 catch(...) { off_time=Time::begin(); }
413                                 try{ on_time=iter->find_next(t)->get_time(); }
414                                 catch(...) { on_time=Time::end(); }
415                         }
416
417                         blp_here_on=(*iter->value_node)(on_time).get(blp_here_on);
418 //                      blp_here_on=(*iter->value_node)(t).get(blp_here_on);
419
420                         // Find "end" of dynamic group
421                         end_iter=iter;
422 //                      for(++end_iter;begin_iter!=list.end();++end_iter)
423                         for(++end_iter;end_iter!=list.end();++end_iter)
424                                 if(end_iter->amount_at_time(t)>amount)
425                                 {
426                                         blp_next_off=(*end_iter->value_node)(off_time).get(prev);
427                                         break;
428                                 }
429
430                         // If we did not find an end of the dynamic group...
431                         if(end_iter==list.end())
432                         {
433                                 if(get_loop())
434                                 {
435                                         end_iter=first_iter;
436                                         blp_next_off=(*end_iter->value_node)(off_time).get(prev);
437 //                                      end=first;
438                                 }
439                                 else
440                                 {
441                                         // Writeme!
442                                         end_iter=first_iter;
443                                         blp_next_off=(*end_iter->value_node)(off_time).get(prev);
444 //                                      end=first;
445                                 }
446                         }
447
448                         // Find "begin" of dynamic group
449                         begin_iter=iter;
450                         blp_prev_off.set_origin(100.0f); // set the origin to 100 (which is crazy) so that we can check to see if it was found
451                         do
452                         {
453                                 if(begin_iter==list.begin())
454                                 {
455                                         if(get_loop())
456                                                 begin_iter=list.end();
457                                         else
458                                                 break;
459                                 }
460
461                                 --begin_iter;
462                                 dist_from_begin++;
463
464                                 if(begin_iter==iter)
465                                         break;
466
467                                 if(begin_iter->amount_at_time(t)>amount)
468                                 {
469                                         blp_prev_off=(*begin_iter->value_node)(off_time).get(prev);
470                                         break;
471                                 }
472                         }while(begin_iter!=iter);
473
474                         // If we did not find a begin
475                         if(blp_prev_off.get_origin()==100.0f)
476                         {
477                                 if(get_loop())
478                                 {
479                                         begin_iter=first_iter;
480                                         blp_prev_off=(*begin_iter->value_node)(off_time).get(prev);
481 //                                      blp_prev_off=first;
482                                 }
483                                 else
484                                 {
485                                         // Writeme!
486                                         begin_iter=first_iter;
487                                         blp_prev_off=(*begin_iter->value_node)(off_time).get(prev);
488 //                                      blp_prev_off=first;
489                                 }
490                         }
491
492                         // this is how the curve looks when we have completely vanished
493                         etl::hermite<Vector> curve(blp_prev_off.get_vertex(),   blp_next_off.get_vertex(),
494                                                                            blp_prev_off.get_tangent2(), blp_next_off.get_tangent1());
495                         etl::derivative< etl::hermite<Vector> > deriv(curve);
496
497                         // where would we be on this curve, how wide will we be, and
498                         // where will our tangents point (all assuming that we hadn't vanished)
499                         blp_here_off.set_vertex(curve(blp_here_on.get_origin()));
500                         blp_here_off.set_width((blp_next_off.get_width()-blp_prev_off.get_width())*blp_here_on.get_origin()+blp_prev_off.get_width());
501                         blp_here_off.set_tangent1(deriv(blp_here_on.get_origin()));
502                         blp_here_off.set_tangent2(deriv(blp_here_on.get_origin()));
503
504                         float prev_tangent_scalar(1.0f);
505                         float next_tangent_scalar(1.0f);
506
507                         //synfig::info("index_%d:dist_from_begin=%d",index,dist_from_begin);
508                         //synfig::info("index_%d:dist_from_end=%d",index,dist_from_end);
509
510                         // If we are the next to the begin
511                         if(begin_iter==--std::vector<ListEntry>::const_iterator(iter) || dist_from_begin==1)
512                                 prev_tangent_scalar=linear_interpolation(blp_here_on.get_origin(), 1.0f, amount);
513                         else
514                                 prev_tangent_scalar=linear_interpolation(blp_here_on.get_origin()-prev.get_origin(), 1.0f, amount);
515
516                         // If we are the next to the end
517                         if(end_iter==++std::vector<ListEntry>::const_iterator(iter) || dist_from_end==1)
518                                 next_tangent_scalar=linear_interpolation(1.0-blp_here_on.get_origin(), 1.0f, amount);
519                         else if(list.end()!=++std::vector<ListEntry>::const_iterator(iter))
520                         {
521                                 BLinePoint next;
522                                 next=((*(++std::vector<ListEntry>::const_iterator(iter))->value_node)(t).get(prev));
523                                 next_tangent_scalar=linear_interpolation(next.get_origin()-blp_here_on.get_origin(), 1.0f, amount);
524                         }
525                         else
526                                 //! \todo this isn't quite right; we should handle looped blines identically no matter where the loop happens
527                                 //! and we currently don't.  this at least makes it a lot better than it was before
528                                 next_tangent_scalar=linear_interpolation(blp_next_off.get_origin()-blp_here_on.get_origin(), 1.0f, amount);
529                         next_scale=next_tangent_scalar;
530
531                         //blp_here_now.set_vertex(linear_interpolation(blp_here_off.get_vertex(), blp_here_on.get_vertex(), amount));
532                         // if(false)
533                         // {
534                         //      // My first try
535                         //      Point ref_point_begin(((*begin_iter->value_node)(off_time).get(prev).get_vertex() +
536                         //                                                 (*end_iter->value_node)(off_time).get(prev).get_vertex()) * 0.5);
537                         //      Point ref_point_end(((*begin_iter->value_node)(on_time).get(prev).get_vertex() +
538                         //                                               (*end_iter->value_node)(on_time).get(prev).get_vertex()) * 0.5);
539                         //      Point ref_point_now(((*begin_iter->value_node)(t).get(prev).get_vertex() +
540                         //                                               (*end_iter->value_node)(t).get(prev).get_vertex()) * 0.5);
541                         //      Point ref_point_linear(linear_interpolation(ref_point_begin, ref_point_end, amount));
542                         //
543                         //      blp_here_now.set_vertex(linear_interpolation(blp_here_off.get_vertex(), blp_here_on.get_vertex(), amount) +
544                         //                                                      (ref_point_now-ref_point_linear));
545                         //      blp_here_now.set_tangent1(linear_interpolation(blp_here_off.get_tangent1(), blp_here_on.get_tangent1(), amount));
546                         //      blp_here_now.set_split_tangent_flag(blp_here_on.get_split_tangent_flag());
547                         //      if(blp_here_now.get_split_tangent_flag())
548                         //              blp_here_now.set_tangent2(linear_interpolation(blp_here_off.get_tangent2(), blp_here_on.get_tangent2(), amount));
549                         // }
550                         // else
551                         {
552                                 // My second try
553
554                                 // define 3 coordinate systems:
555                                 Point off_coord_sys[2],   off_coord_origin; // when the current vertex is completely off
556                                 Point on_coord_sys[2] ,    on_coord_origin; // when the current vertex is completely on
557                                 Point curr_coord_sys[2], curr_coord_origin; // the current state - somewhere in between
558
559                                 // for each of the 3 systems, the origin is half way between the previous and next active point
560                                 // and the axes are based on a vector from the next active point to the previous
561                                 {
562                                         const Point   end_pos_at_off_time((  *end_iter->value_node)(off_time).get(prev).get_vertex());
563                                         const Point begin_pos_at_off_time((*begin_iter->value_node)(off_time).get(prev).get_vertex());
564                                         off_coord_origin=(begin_pos_at_off_time + end_pos_at_off_time)/2;
565                                         off_coord_sys[0]=(begin_pos_at_off_time - end_pos_at_off_time).norm();
566                                         off_coord_sys[1]=off_coord_sys[0].perp();
567
568                                         const Point   end_pos_at_on_time((  *end_iter->value_node)(on_time).get(prev).get_vertex());
569                                         const Point begin_pos_at_on_time((*begin_iter->value_node)(on_time).get(prev).get_vertex());
570                                         on_coord_origin=(begin_pos_at_on_time + end_pos_at_on_time)/2;
571                                         on_coord_sys[0]=(begin_pos_at_on_time - end_pos_at_on_time).norm();
572                                         on_coord_sys[1]=on_coord_sys[0].perp();
573
574                                         const Point   end_pos_at_current_time((  *end_iter->value_node)(t).get(prev).get_vertex());
575                                         const Point begin_pos_at_current_time((*begin_iter->value_node)(t).get(prev).get_vertex());
576                                         curr_coord_origin=(begin_pos_at_current_time + end_pos_at_current_time)/2;
577                                         curr_coord_sys[0]=(begin_pos_at_current_time - end_pos_at_current_time).norm();
578                                         curr_coord_sys[1]=curr_coord_sys[0].perp();
579
580                                         // Invert (transpose) the last of these matricies, since we use it for transform back
581                                         swap(curr_coord_sys[0][1],curr_coord_sys[1][0]);
582                                 }
583
584                                 /* The code that was here before used just end_iter as the origin, rather than the mid-point */
585
586                                 // We know our location and tangent(s) when fully on and fully off
587                                 // Transform each of these into their corresponding coordinate system
588                                 Point trans_on_point, trans_off_point;
589                                 Vector trans_on_t1, trans_on_t2, trans_off_t1, trans_off_t2;
590
591                                 transform_coords(blp_here_on.get_vertex(),  trans_on_point,  on_coord_origin,  on_coord_sys);
592                                 transform_coords(blp_here_off.get_vertex(), trans_off_point, off_coord_origin, off_coord_sys);
593
594 #define COORD_SYS_RADIAL_TAN_INTERP 1
595
596 #ifdef COORD_SYS_RADIAL_TAN_INTERP
597                                 transform_coords(blp_here_on.get_tangent1(),  trans_on_t1,  Point::zero(), on_coord_sys);
598                                 transform_coords(blp_here_off.get_tangent1(), trans_off_t1, Point::zero(), off_coord_sys);
599
600                                 if(blp_here_on.get_split_tangent_flag())
601                                 {
602                                         transform_coords(blp_here_on.get_tangent2(),  trans_on_t2,  Point::zero(), on_coord_sys);
603                                         transform_coords(blp_here_off.get_tangent2(), trans_off_t2, Point::zero(), off_coord_sys);
604                                 }
605 #endif
606
607                                 {
608                                         // Interpolate between the 'on' point and the 'off' point and untransform to get our point's location
609                                         Point tmp;
610                                         untransform_coords(linear_interpolation(trans_off_point, trans_on_point, amount),
611                                                                            tmp, curr_coord_origin, curr_coord_sys);
612                                         blp_here_now.set_vertex(tmp);
613                                 }
614
615 #define INTERP_FUNCTION         radial_interpolation
616 //#define INTERP_FUNCTION       linear_interpolation
617
618 #ifdef COORD_SYS_RADIAL_TAN_INTERP
619                                 {
620                                         Vector tmp;
621                                         untransform_coords(INTERP_FUNCTION(trans_off_t1,trans_on_t1,amount), tmp, Point::zero(), curr_coord_sys);
622                                         blp_here_now.set_tangent1(tmp);
623                                 }
624 #else
625                                 blp_here_now.set_tangent1(radial_interpolation(blp_here_off.get_tangent1(),blp_here_on.get_tangent1(),amount));
626 #endif
627
628                                 if (blp_here_on.get_split_tangent_flag())
629                                 {
630                                         blp_here_now.set_split_tangent_flag(true);
631 #ifdef COORD_SYS_RADIAL_TAN_INTERP
632                                         {
633                                                 Vector tmp;
634                                                 untransform_coords(INTERP_FUNCTION(trans_off_t2,trans_on_t2,amount), tmp, Point::zero(), curr_coord_sys);
635                                                 blp_here_now.set_tangent2(tmp);
636                                         }
637 #else
638                                         blp_here_now.set_tangent2(radial_interpolation(blp_here_off.get_tangent2(),blp_here_on.get_tangent2(),amount));
639 #endif
640                                 }
641                                 else
642                                         blp_here_now.set_split_tangent_flag(false);
643                         }
644
645                         blp_here_now.set_origin(blp_here_on.get_origin());
646                         blp_here_now.set_width(linear_interpolation(blp_here_off.get_width(), blp_here_on.get_width(), amount));
647
648                         // Handle the case where we are the first vertex
649                         if(first_flag)
650                         {
651                                 blp_here_now.set_tangent1(blp_here_now.get_tangent1()*prev_tangent_scalar);
652                                 first_iter=iter;
653                                 first=prev=blp_here_now;
654                                 first_flag=false;
655                                 ret_list.push_back(blp_here_now);
656                                 continue;
657                         }
658
659                         ret_list.back().set_split_tangent_flag(true);
660                         ret_list.back().set_tangent2(prev.get_tangent2()*prev_tangent_scalar);
661                         ret_list.push_back(blp_here_now);
662                         ret_list.back().set_split_tangent_flag(true);
663                         //ret_list.back().set_tangent2(blp_here_now.get_tangent1());
664                         ret_list.back().set_tangent1(blp_here_now.get_tangent1()*prev_tangent_scalar);
665
666                         prev=blp_here_now;
667                 }
668         }
669
670         if(next_scale!=1.0f)
671         {
672                 ret_list.back().set_split_tangent_flag(true);
673                 ret_list.back().set_tangent2(prev.get_tangent2()*next_scale);
674         }
675
676 /*
677         if(get_loop() && !first_flag)
678         {
679                 ret_list.push_back(
680                         Segment(
681                         prev.get_vertex(),
682                         prev.get_tangent2(),
683                         first.get_vertex(),
684                         first.get_tangent1()
685                         )
686                 );
687         }
688 */
689
690         if(list.empty())
691                 synfig::warning(string("ValueNode_BLine::operator()():")+_("No entries in list"));
692         else
693         if(ret_list.empty())
694                 synfig::warning(string("ValueNode_BLine::operator()():")+_("No entries in ret_list"));
695
696         return ValueBase(ret_list,get_loop());
697 }
698
699 String
700 ValueNode_BLine::link_local_name(int i)const
701 {
702         assert(i>=0 && (unsigned)i<list.size());
703         return etl::strprintf(_("Vertex %03d"),i+1);
704 }
705
706 ValueNode*
707 ValueNode_BLine::clone(const GUID& deriv_guid)const
708 {
709         { ValueNode* x(find_value_node(get_guid()^deriv_guid).get()); if(x)return x; }
710
711         ValueNode_BLine* ret=new ValueNode_BLine();
712         ret->set_guid(get_guid()^deriv_guid);
713
714         std::vector<ListEntry>::const_iterator iter;
715
716         for(iter=list.begin();iter!=list.end();++iter)
717         {
718                 if(iter->value_node->is_exported())
719                         ret->add(*iter);
720                 else
721                 {
722                         ListEntry list_entry(*iter);
723                         //list_entry.value_node=find_value_node(iter->value_node->get_guid()^deriv_guid).get();
724                         //if(!list_entry.value_node)
725                                 list_entry.value_node=iter->value_node->clone(deriv_guid);
726                         ret->add(list_entry);
727                         //ret->list.back().value_node=iter->value_node.clone();
728                 }
729         }
730         ret->set_loop(get_loop());
731
732         return ret;
733 }
734
735 String
736 ValueNode_BLine::get_name()const
737 {
738         return "bline";
739 }
740
741 String
742 ValueNode_BLine::get_local_name()const
743 {
744         return _("BLine");
745 }
746
747 LinkableValueNode*
748 ValueNode_BLine::create_new()const
749 {
750         assert(0);
751         return 0;
752 }
753
754 bool
755 ValueNode_BLine::check_type(ValueBase::Type type)
756 {
757         return type==ValueBase::TYPE_LIST;
758 }