aboutsummaryrefslogtreecommitdiffstats
path: root/libgnomecanvas/gnome-canvas-path-def.c
blob: 02ff22b95797e843ce43aa32b5af9b81cc8c14b6 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
#define GNOME_CANVAS_PATH_DEF_C

/*
 * GnomeCanvasPathDef
 *
 * (C) 1999-2000 Lauris Kaplinski <lauris@ximian.com>
 * Released under LGPL
 *
 * Authors: Lauris Kaplinski <lauris@ximian.com>
 *          Rusty Conover <rconover@bangtail.net>
 *
 * Copyright 1999-2001 Ximian Inc. and authors.
 */

#include <string.h>
#include <libart_lgpl/art_misc.h>
#include "gnome-canvas-path-def.h"

/* The number of points to allocate at once */
#define GNOME_CANVAS_PATH_DEF_LENSTEP 32

struct _GnomeCanvasPathDef {
    gint refcount;
    ArtBpath * bpath;
    gint end;       /* ART_END position */
    gint length;        /* Num allocated Bpaths */
    gint substart;      /* subpath start */
    gdouble x, y;       /* previous moveto position */
    guint sbpath : 1;   /* Bpath is static */
    guint hascpt : 1;   /* Currentpoint is defined */
    guint posset : 1;   /* Previous was moveto */
    guint moving : 1;   /* Bpath end is moving */
    guint allclosed : 1;    /* All subpaths are closed */
    guint allopen : 1;  /* All subpaths are open */
};

static gboolean sp_bpath_good (ArtBpath * bpath);
static ArtBpath * sp_bpath_check_subpath (ArtBpath * bpath);
static gint sp_bpath_length (const ArtBpath * bpath);
static gboolean sp_bpath_all_closed (const ArtBpath * bpath);
static gboolean sp_bpath_all_open (const ArtBpath * bpath);

/* Boxed Type Support */

static GnomeCanvasPathDef *
path_def_boxed_copy (GnomeCanvasPathDef * path_def)
{
    if (path_def)
        gnome_canvas_path_def_ref (path_def);
    return path_def;
}

GType
gnome_canvas_path_def_get_type (void)
{
    static GType t = 0;
    if (t == 0)
        t = g_boxed_type_register_static
                ("GnomeCanvasPathDef",
                 (GBoxedCopyFunc)path_def_boxed_copy,
                 (GBoxedFreeFunc)gnome_canvas_path_def_unref);
    return t;
}

/* Constructors */

/**
 * gnome_canvas_path_def_new:
 *
 * This function creates a new empty #gnome_canvas_path_def.
 *
 * Returns: the new canvas path definition.
 */
GnomeCanvasPathDef *
gnome_canvas_path_def_new (void)
{
    GnomeCanvasPathDef * path;

    path = gnome_canvas_path_def_new_sized (GNOME_CANVAS_PATH_DEF_LENSTEP);

    return path;
}

/**
 * gnome_canvas_path_def_new_sized:
 * @length: number of points to allocate for the path
 *
 * This function creates a new #gnome_canvas_path_def with @length
 * number of points allocated. It is useful, if you know the exact
 * number of points in path, so you can avoid automatic point
 * array reallocation.
 *
 * Returns: the new canvas path definition
 */
GnomeCanvasPathDef *
gnome_canvas_path_def_new_sized (gint length)
{
    GnomeCanvasPathDef * path;

    g_return_val_if_fail (length > 0, NULL);

    path = g_new (GnomeCanvasPathDef, 1);

    path->refcount = 1;
    path->bpath = art_new (ArtBpath, length);
    path->end = 0;
    path->bpath[path->end].code = ART_END;
    path->length = length;
    path->sbpath = FALSE;
    path->hascpt = FALSE;
    path->posset = FALSE;
    path->moving = FALSE;
    path->allclosed = TRUE;
    path->allopen = TRUE;

    return path;
}

/**
 * gnome_canvas_path_def_new_from_bpath:
 * @bpath: libart bezier path
 *
 * This function constructs a new #gnome_canvas_path_def and uses the
 * passed @bpath as the contents.  The passed bpath should not be
 * static as the path definition is editable when constructed with
 * this function. Also, passed bpath will be freed with art_free, if
 * path is destroyed, so use it with caution.
 * For constructing a #gnome_canvas_path_def
 * from (non-modifiable) bpath use
 * #gnome_canvas_path_def_new_from_static_bpath.
 *
 * Returns: the new canvas path definition that is populated with the
 * passed bezier path, if the @bpath is bad NULL is returned.
 */
GnomeCanvasPathDef *
gnome_canvas_path_def_new_from_bpath (ArtBpath * bpath)
{
    GnomeCanvasPathDef * path;

    g_return_val_if_fail (sp_bpath_good (bpath), NULL);

    path = g_new (GnomeCanvasPathDef, 1);

    path->refcount = 1;
    path->bpath = bpath;
    path->length = sp_bpath_length (bpath);
    path->end = path->length - 1;
    path->sbpath = FALSE;
    path->hascpt = FALSE;
    path->posset = FALSE;
    path->moving = FALSE;
    path->allclosed = sp_bpath_all_closed (bpath);
    path->allopen = sp_bpath_all_open (bpath);

    return path;
}

/**
 * gnome_canvas_path_def_new_from_static_bpath:
 * @bpath: libart bezier path
 *
 * This function constructs a new #gnome_canvas_path_def and
 * references the passed @bpath as its contents.  The
 * #gnome_canvas_path_def returned from this function is to be
 * considered static and non-editable (meaning you cannot change the
 * path from what you passed in @bpath). The bpath will not be freed,
 * if path will be destroyed, so use it with caution.
 *
 * Returns: the new canvas path definition that references the passed
 * @bpath, or if the path is bad NULL is returned.
 */
GnomeCanvasPathDef *
gnome_canvas_path_def_new_from_static_bpath (ArtBpath * bpath)
{
    GnomeCanvasPathDef * path;

    g_return_val_if_fail (sp_bpath_good (bpath), NULL);

    path = g_new (GnomeCanvasPathDef, 1);

    path->refcount = 1;
    path->bpath = bpath;
    path->length = sp_bpath_length (bpath);
    path->end = path->length - 1;
    path->sbpath = TRUE;
    path->hascpt = FALSE;
    path->posset = FALSE;
    path->moving = FALSE;
    path->allclosed = sp_bpath_all_closed (bpath);
    path->allopen = sp_bpath_all_open (bpath);

    return path;
}

/**
 * gnome_canvas_path_def_new_from_foreign_bpath:
 * @bpath: libart bezier path
 *
 * This function constructs a new #gnome_canvas_path_def and
 * duplicates the contents of the passed @bpath in the definition.
 *
 * Returns: the newly created #gnome_canvas_path_def or NULL if the
 * path is invalid.
 */
GnomeCanvasPathDef *
gnome_canvas_path_def_new_from_foreign_bpath (ArtBpath * bpath)
{
    GnomeCanvasPathDef * path;
    gint length;

    g_return_val_if_fail (sp_bpath_good (bpath), NULL);

    length = sp_bpath_length (bpath);

    path = gnome_canvas_path_def_new_sized (length);
    memcpy (path->bpath, bpath, sizeof (ArtBpath) * length);
    path->end = length - 1;
    path->allclosed = sp_bpath_all_closed (bpath);
    path->allopen = sp_bpath_all_open (bpath);

    return path;
}

/**
 * gnome_canvas_path_def_ref:
 * @path: a GnomeCanvasPathDef
 *
 * Increment the reference count of the GnomeCanvasPathDef.
 */
void
gnome_canvas_path_def_ref (GnomeCanvasPathDef * path)
{
    g_return_if_fail (path != NULL);

    path->refcount++;
}

/**
 * gnome_canvas_path_def_finish:
 * @path: a GnomeCanvasPathDef
 *
 * Trims dynamic point array to exact length of path.
 */
void
gnome_canvas_path_def_finish (GnomeCanvasPathDef * path)
{
    g_return_if_fail (path != NULL);
    g_return_if_fail (path->sbpath);

    if ((path->end + 1) < path->length) {
        path->bpath = art_renew (path->bpath, ArtBpath, path->end + 1);
        path->length = path->end + 1;
    }

    path->hascpt = FALSE;
    path->posset = FALSE;
    path->moving = FALSE;
}
/**
 * gnome_canvas_path_def_ensure_space:
 * @path: a GnomeCanvasPathDef
 * @space: number of points to guarantee are allocated at the end of
 * the path.
 *
 * This function ensures that enough space for @space points is
 * allocated at the end of the path.
 */
void
gnome_canvas_path_def_ensure_space (GnomeCanvasPathDef * path, gint space)
{
    g_return_if_fail (path != NULL);
    g_return_if_fail (space > 0);

    if (path->end + space < path->length) return;

    if (space < GNOME_CANVAS_PATH_DEF_LENSTEP) space = GNOME_CANVAS_PATH_DEF_LENSTEP;

    path->bpath = art_renew (path->bpath, ArtBpath, path->length + space);

    path->length += space;
}

/**
 * gnome_canvas_path_def_copy:
 * @dst: a GnomeCanvasPathDef where the contents of @src will be stored.
 * @src: a GnomeCanvasPathDef whose contents will be copied it @src.
 *
 * This function copies the contents @src to @dest. The old @dest path
 * array is freed and @dest is marked as non-static (editable),
 * regardless of the status of @src.
 */
void
gnome_canvas_path_def_copy (GnomeCanvasPathDef * dst, const GnomeCanvasPathDef * src)
{
    g_return_if_fail (dst != NULL);
    g_return_if_fail (src != NULL);

    if (!dst->sbpath) g_free (dst->bpath);

    memcpy (dst, src, sizeof (GnomeCanvasPathDef));

    dst->bpath = g_new (ArtBpath, src->end + 1);
    memcpy (dst->bpath, src->bpath, (src->end + 1) * sizeof (ArtBpath));

    dst->sbpath = FALSE;
}

/**
 * gnome_canvas_path_def_duplicate:
 * @path: a GnomeCanvasPathDef to duplicate
 *
 * This function duplicates the passed @path. The new path is
 * marked as non-static regardless of the state of original.
 *
 * Returns: a GnomeCanvasPathDef which is a duplicate of @path.
 */
GnomeCanvasPathDef *
gnome_canvas_path_def_duplicate (const GnomeCanvasPathDef * path)
{
    GnomeCanvasPathDef * new;

    g_return_val_if_fail (path != NULL, NULL);

    new = gnome_canvas_path_def_new_from_foreign_bpath (path->bpath);
    new->x = path->x;
    new->y = path->y;
    new->hascpt = path->hascpt;
    new->posset = path->posset;
    new->moving = path->moving;
    new->allclosed = path->allclosed;
    new->allopen = path->allopen;

    return new;
}

/**
 * gnome_canvas_path_def_concat:
 * @list: a GSList of GnomeCanvasPathDefs to concatenate into one new
 * path.
 *
 * This function concatenates a list of GnomeCanvasPathDefs into one
 * newly created GnomeCanvasPathDef.
 *
 * Returns: a new GnomeCanvasPathDef
 */
GnomeCanvasPathDef *
gnome_canvas_path_def_concat (const GSList * list)
{
    GnomeCanvasPathDef * c, * new;
    ArtBpath * bp;
    const GSList * l;
    gint length;

    g_return_val_if_fail (list != NULL, NULL);

    length = 1;

    for (l = list; l != NULL; l = l->next) {
        c = (GnomeCanvasPathDef *) l->data;
        length += c->end;
    }

    new = gnome_canvas_path_def_new_sized (length);

    bp = new->bpath;

    for (l = list; l != NULL; l = l->next) {
        c = (GnomeCanvasPathDef *) l->data;
        memcpy (bp, c->bpath, c->end * sizeof (ArtBpath));
        bp += c->end;
    }

    bp->code = ART_END;

    new->end = length - 1;

    new->allclosed = sp_bpath_all_closed (new->bpath);
    new->allopen = sp_bpath_all_open (new->bpath);

    return new;
}

/**
 * gnome_canvas_path_def_split:
 * @path: a GnomeCanvasPathDef
 *
 * This function splits the passed @path into a list of
 * GnomeCanvasPathDefs which represent each segment of the origional
 * path.  The path is split when ever an ART_MOVETO or ART_MOVETO_OPEN
 * is encountered. The closedness of resulting paths is set accordingly
 * to closedness of corresponding segment.
 *
 * Returns: a list of GnomeCanvasPathDef(s).
 */
GSList *
gnome_canvas_path_def_split (const GnomeCanvasPathDef * path)
{
    GnomeCanvasPathDef * new;
    GSList * l;
    gint p, i;

    g_return_val_if_fail (path != NULL, NULL);

    p = 0;
    l = NULL;

    while (p < path->end) {
        i = 1;
        while ((path->bpath[p + i].code == ART_LINETO) ||
               (path->bpath[p + i].code == ART_CURVETO))
            i++;
        new = gnome_canvas_path_def_new_sized (i + 1);
        memcpy (new->bpath, path->bpath + p, i * sizeof (ArtBpath));
        new->end = i;
        new->bpath[i].code = ART_END;
        new->allclosed = (new->bpath->code == ART_MOVETO);
        new->allopen = (new->bpath->code == ART_MOVETO_OPEN);
        l = g_slist_append (l, new);
        p += i;
    }

    return l;
}

/**
 * gnome_canvas_path_def_open_parts:
 * @path: a GnomeCanvasPathDef
 *
 * This function creates a new GnomeCanvasPathDef that contains all of
 * the open segments on the passed @path.
 *
 * Returns: a new GnomeCanvasPathDef that contains all of the open segemtns in @path.
 */
GnomeCanvasPathDef *
gnome_canvas_path_def_open_parts (const GnomeCanvasPathDef * path)
{
    GnomeCanvasPathDef * new;
    ArtBpath * p, * d;
    gint len;
    gboolean closed;

    g_return_val_if_fail (path != NULL, NULL);

    closed = TRUE;
    len = 0;

    for (p = path->bpath; p->code != ART_END; p++) {
        switch (p->code) {
        case ART_MOVETO_OPEN:
            closed = FALSE;
            len++;
            break;
        case ART_MOVETO:
            closed = TRUE;
            break;
        case ART_LINETO:
        case ART_CURVETO:
            if (!closed) len++;
            break;
        default:
            g_assert_not_reached ();
        }
    }

    new = gnome_canvas_path_def_new_sized (len + 1);

    closed = TRUE;
    d = new->bpath;

    for (p = path->bpath; p->code != ART_END; p++) {
        switch (p->code) {
        case ART_MOVETO_OPEN:
            closed = FALSE;
            *d++ = *p;
            break;
        case ART_MOVETO:
            closed = TRUE;
            break;
        case ART_LINETO:
        case ART_CURVETO:
            if (!closed) *d++ = *p;
            break;
        default:
            g_assert_not_reached ();
        }
    }

    d->code = ART_END;

    new->end = len;
    new->allclosed = FALSE;
    new->allopen = TRUE;

    return new;
}

/**
 * gnome_canvas_path_def_closed_parts:
 * @path: a GnomeCanvasPathDef
 *
 * This function returns a new GnomeCanvasPathDef that contains the
 * all of close parts of passed @path.
 *
 * Returns: a new GnomeCanvasPathDef that contains all of the closed
 * parts of passed @path.
 */
GnomeCanvasPathDef *
gnome_canvas_path_def_closed_parts (const GnomeCanvasPathDef * path)
{
    GnomeCanvasPathDef * new;
    ArtBpath * p, * d;
    gint len;
    gboolean closed;

    g_return_val_if_fail (path != NULL, NULL);

    closed = FALSE;
    len = 0;

    for (p = path->bpath; p->code != ART_END; p++) {
        switch (p->code) {
        case ART_MOVETO_OPEN:
            closed = FALSE;
            break;
        case ART_MOVETO:
            closed = TRUE;
            len++;
            break;
        case ART_LINETO:
        case ART_CURVETO:
            if (closed) len++;
            break;
        default:
            g_assert_not_reached ();
        }
    }

    new = gnome_canvas_path_def_new_sized (len + 1);

    closed = FALSE;
    d = new->bpath;

    for (p = path->bpath; p->code != ART_END; p++) {
        switch (p->code) {
        case ART_MOVETO_OPEN:
            closed = FALSE;
            break;
        case ART_MOVETO:
            closed = TRUE;
            *d++ = *p;
            break;
        case ART_LINETO:
        case ART_CURVETO:
            if (closed) *d++ = *p;
            break;
        default:
            g_assert_not_reached ();
        }
    }

    d->code = ART_END;

    new->end = len;
    new->allclosed = TRUE;
    new->allopen = FALSE;

    return new;
}

/**
 * gnome_canvas_path_def_close_all:
 * @path: a GnomeCanvasPathDef
 *
 * This function closes all of the open segments in the passed path
 * and returns a new GnomeCanvasPathDef.
 *
 * Returns: a GnomeCanvasPathDef that contains the contents of @path
 * but has modified the path is fully closed
 */
GnomeCanvasPathDef *
gnome_canvas_path_def_close_all (const GnomeCanvasPathDef * path)
{
    GnomeCanvasPathDef * new;
    ArtBpath * p, * d, * start;
    gint len;
    gboolean closed;

    g_return_val_if_fail (path != NULL, NULL);

    if (path->allclosed) {
        new = gnome_canvas_path_def_duplicate (path);
        return new;
    }

    len = 1;

    /* Count MOVETO_OPEN */

    for (p = path->bpath; p->code != ART_END; p++) {
        len += 1;
        if (p->code == ART_MOVETO_OPEN) len += 2;
    }

    new = gnome_canvas_path_def_new_sized (len);

    d = start = new->bpath;
    closed = TRUE;

    for (p = path->bpath; p->code != ART_END; p++) {
        switch (p->code) {
        case ART_MOVETO_OPEN:
            start = p;
            closed = FALSE;
        case ART_MOVETO:
            if ((!closed) && ((start->x3 != p->x3) || (start->y3 != p->y3))) {
                d->code = ART_LINETO;
                d->x3 = start->x3;
                d->y3 = start->y3;
                d++;
            }
            if (p->code == ART_MOVETO) closed = TRUE;
            d->code = ART_MOVETO;
            d->x3 = p->x3;
            d->y3 = p->y3;
            d++;
            break;
        case ART_LINETO:
        case ART_CURVETO:
            *d++ = *p;
            break;
        default:
            g_assert_not_reached ();
        }
    }

    if ((!closed) && ((start->x3 != p->x3) || (start->y3 != p->y3))) {
        d->code = ART_LINETO;
        d->x3 = start->x3;
        d->y3 = start->y3;
        d++;
    }

    d->code = ART_END;

    new->end = d - new->bpath;
    new->allclosed = TRUE;
    new->allopen = FALSE;

    return new;
}

/* Destructor */

/**
 * gnome_canvas_path_def_unref:
 * @path: a GnomeCanvasPathDef
 *
 * Decrease the reference count of the passed @path.  If the reference
 * count is < 1 the path is deallocated.
 */
void
gnome_canvas_path_def_unref (GnomeCanvasPathDef * path)
{
    g_return_if_fail (path != NULL);

    if (--path->refcount < 1) {
        if ((!path->sbpath) && (path->bpath)) art_free (path->bpath);
        g_free (path);
    }
}

/* Methods */
/**
 * gnome_canvas_path_def_reset:
 * @path: a GnomeCanvasPathDef
 *
 * This function clears the contents of the passed @path.
 */
void
gnome_canvas_path_def_reset (GnomeCanvasPathDef * path)
{
    g_return_if_fail (path != NULL);
    g_return_if_fail (!path->sbpath);

    path->bpath->code = ART_END;
    path->end = 0;
    path->hascpt = FALSE;
    path->posset = FALSE;
    path->moving = FALSE;
    path->allclosed = TRUE;
    path->allopen = TRUE;
}

/* Several consequtive movetos are ALLOWED */

/**
 * gnome_canvas_path_def_moveto:
 * @path: a GnomeCanvasPathDef
 * @x: x coordinate
 * @y: y coordinate
 *
 * This function adds starts new subpath on @path, and sets its
 * starting point to @x and @y. If current subpath is empty, it
 * simply changes its starting coordinates to new values.
 */
void
gnome_canvas_path_def_moveto (GnomeCanvasPathDef * path, gdouble x, gdouble y)
{
    g_return_if_fail (path != NULL);
    g_return_if_fail (!path->sbpath);
    g_return_if_fail (!path->moving);

    path->substart = path->end;
    path->hascpt = TRUE;
    path->posset = TRUE;
    path->x = x;
    path->y = y;

    path->allclosed = FALSE;
}

/**
 * gnome_canvas_path_def_lineto:
 * @path: a GnomeCanvasPathDef
 * @x: x coordinate
 * @y: y coordinate
 *
 * This function add a line segment to the passed @path with the
 * specified @x and @y coordinates.
 */
void
gnome_canvas_path_def_lineto (GnomeCanvasPathDef * path, gdouble x, gdouble y)
{
    ArtBpath * bp;

    g_return_if_fail (path != NULL);
    g_return_if_fail (!path->sbpath);
    g_return_if_fail (path->hascpt);

    if (path->moving) {
        /* simply fix endpoint */
        g_return_if_fail (!path->posset);
        g_return_if_fail (path->end > 1);
        bp = path->bpath + path->end - 1;
        g_return_if_fail (bp->code == ART_LINETO);
        bp->x3 = x;
        bp->y3 = y;
        path->moving = FALSE;
        return;
    }

    if (path->posset) {
        /* start a new segment */
        gnome_canvas_path_def_ensure_space (path, 2);
        bp = path->bpath + path->end;
        bp->code = ART_MOVETO_OPEN;
        bp->x3 = path->x;
        bp->y3 = path->y;
        bp++;
        bp->code = ART_LINETO;
        bp->x3 = x;
        bp->y3 = y;
        bp++;
        bp->code = ART_END;
        path->end += 2;
        path->posset = FALSE;
        path->allclosed = FALSE;
        return;
    }

    /* Simply add line */

    g_return_if_fail (path->end > 1);
    gnome_canvas_path_def_ensure_space (path, 1);
    bp = path->bpath + path->end;
    bp->code = ART_LINETO;
    bp->x3 = x;
    bp->y3 = y;
    bp++;
    bp->code = ART_END;
    path->end++;
}

/**
 * gnome_canvas_path_def_lineto_moving:
 * @path: a GnomeCanvasPathDef
 * @x: x coordinate
 * @y: y coordinate
 *
 * This functions adds a new line segment with loose endpoint to the path, or
 * if endpoint is already loose, changes its coordinates to @x, @y. You
 * can change the coordinates of loose endpoint as many times as you want,
 * the last ones set will be fixed, if you continue line. This is useful
 * for handling drawing with mouse.
 */
void
gnome_canvas_path_def_lineto_moving (GnomeCanvasPathDef * path, gdouble x, gdouble y)
{
    ArtBpath * bp;

    g_return_if_fail (path != NULL);
    g_return_if_fail (!path->sbpath);
    g_return_if_fail (path->hascpt);

    if (path->moving) {
        /* simply change endpoint */
        g_return_if_fail (!path->posset);
        g_return_if_fail (path->end > 1);
        bp = path->bpath + path->end - 1;
        g_return_if_fail (bp->code == ART_LINETO);
        bp->x3 = x;
        bp->y3 = y;
        return;
    }

    if (path->posset) {
        /* start a new segment */
        gnome_canvas_path_def_ensure_space (path, 2);
        bp = path->bpath + path->end;
        bp->code = ART_MOVETO_OPEN;
        bp->x3 = path->x;
        bp->y3 = path->y;
        bp++;
        bp->code = ART_LINETO;
        bp->x3 = x;
        bp->y3 = y;
        bp++;
        bp->code = ART_END;
        path->end += 2;
        path->posset = FALSE;
        path->moving = TRUE;
        path->allclosed = FALSE;
        return;
    }

    /* Simply add line */

    g_return_if_fail (path->end > 1);
    gnome_canvas_path_def_ensure_space (path, 1);
    bp = path->bpath + path->end;
    bp->code = ART_LINETO;
    bp->x3 = x;
    bp->y3 = y;
    bp++;
    bp->code = ART_END;
    path->end++;
    path->moving = TRUE;
}

/**
 * gnome_canvas_path_def_curveto:
 * @path: a GnomeCanvasPathDef
 * @x0: first control point x coordinate
 * @y0: first control point y coordinate
 * @x1: second control point x coordinate
 * @y1: second control point y coordinate
 * @x2: end of curve x coordinate
 * @y2: end of curve y coordinate
 *
 * This function adds a bezier curve segment to the path definition.
 */

void
gnome_canvas_path_def_curveto (GnomeCanvasPathDef * path,
                               gdouble x0,
                               gdouble y0,
                               gdouble x1,
                               gdouble y1,
                               gdouble x2,
                               gdouble y2)
{
    ArtBpath * bp;

    g_return_if_fail (path != NULL);
    g_return_if_fail (!path->sbpath);
    g_return_if_fail (path->hascpt);
    g_return_if_fail (!path->moving);

    if (path->posset) {
        /* start a new segment */
        gnome_canvas_path_def_ensure_space (path, 2);
        bp = path->bpath + path->end;
        bp->code = ART_MOVETO_OPEN;
        bp->x3 = path->x;
        bp->y3 = path->y;
        bp++;
        bp->code = ART_CURVETO;
        bp->x1 = x0;
        bp->y1 = y0;
        bp->x2 = x1;
        bp->y2 = y1;
        bp->x3 = x2;
        bp->y3 = y2;
        bp++;
        bp->code = ART_END;
        path->end += 2;
        path->posset = FALSE;
        path->allclosed = FALSE;
        return;
    }

    /* Simply add path */

    g_return_if_fail (path->end > 1);
    gnome_canvas_path_def_ensure_space (path, 1);
    bp = path->bpath + path->end;
    bp->code = ART_CURVETO;
    bp->x1 = x0;
    bp->y1 = y0;
    bp->x2 = x1;
    bp->y2 = y1;
    bp->x3 = x2;
    bp->y3 = y2;
    bp++;
    bp->code = ART_END;
    path->end++;
}

/**
 * gnome_canvas_path_def_closepath:
 * @path: a GnomeCanvasPathDef
 *
 * This function closes the last subpath of @path, adding a ART_LINETO to
 * subpath starting point, if needed and changing starting pathcode to
 * ART_MOVETO
 */
void
gnome_canvas_path_def_closepath (GnomeCanvasPathDef * path)
{
    ArtBpath * bs, * be;

    g_return_if_fail (path != NULL);
    g_return_if_fail (!path->sbpath);
    g_return_if_fail (path->hascpt);
    g_return_if_fail (!path->posset);
    g_return_if_fail (!path->moving);
    g_return_if_fail (!path->allclosed);
    /* We need at last M + L + L + E */
    g_return_if_fail (path->end - path->substart > 2);

    bs = path->bpath + path->substart;
    be = path->bpath + path->end - 1;

    if ((bs->x3 != be->x3) || (bs->y3 != be->y3)) {
        gnome_canvas_path_def_lineto (path, bs->x3, bs->y3);
    }

    bs = path->bpath + path->substart; /* NB. def_lineto can
                          realloc bpath */
    bs->code = ART_MOVETO;

    path->allclosed = sp_bpath_all_closed (path->bpath);
    path->allopen = sp_bpath_all_open (path->bpath);

    path->hascpt = FALSE;
}

/**
 * gnome_canvas_path_def_closepath_current:
 * @path: a GnomeCanvasPathDef
 *
 * This function closes the last subpath by setting the coordinates of
 * the endpoint of the last segment (line or curve) to starting point.
 */
void
gnome_canvas_path_def_closepath_current (GnomeCanvasPathDef * path)
{
    ArtBpath * bs, * be;

    g_return_if_fail (path != NULL);
    g_return_if_fail (!path->sbpath);
    g_return_if_fail (path->hascpt);
    g_return_if_fail (!path->posset);
    g_return_if_fail (!path->allclosed);
    /* We need at last M + L + L + E */
    g_return_if_fail (path->end - path->substart > 2);

    bs = path->bpath + path->substart;
    be = path->bpath + path->end - 1;

    be->x3 = bs->x3;
    be->y3 = bs->y3;

    bs->code = ART_MOVETO;

    path->allclosed = sp_bpath_all_closed (path->bpath);
    path->allopen = sp_bpath_all_open (path->bpath);

    path->hascpt = FALSE;
    path->moving = FALSE;
}

/**
 * gnome_canvas_path_def_bpath:
 * @path: a GnomeCanvasPathDef
 *
 * This function returns a ArtBpath that consists of the path
 * definition.
 *
 * Returns: ArtBpath
 */
ArtBpath * gnome_canvas_path_def_bpath (const GnomeCanvasPathDef * path)
{
    g_return_val_if_fail (path != NULL, NULL);

    return path->bpath;
}

/**
 * gnome_canvas_path_def_length:
 * @path: a GnomeCanvasPathDef
 *
 * This function returns the length of the path definition.  Not
 * Euclidian length of the path but rather the number of points on the
 * path.
 *
 * Returns: integer, number of points on the path.
 */
gint gnome_canvas_path_def_length (const GnomeCanvasPathDef * path)
{
    g_return_val_if_fail (path != NULL, -1);

    return path->end + 1;
}

/**
 * gnome_canvas_path_def_is_empty:
 * @path: a GnomeCanvasPathDef
 *
 * This function is a boolean test to see if the path is empty,
 * meaning containing no line segments.
 *
 * Returns: boolean, indicating if the path is empty.
 */
gboolean
gnome_canvas_path_def_is_empty (const GnomeCanvasPathDef * path)
{
    g_return_val_if_fail (path != NULL, TRUE);

    return (path->bpath->code == ART_END);
}

/**
 * gnome_canvas_path_def_has_currentpoint:
 * @path: a GnomeCanvasPathdef
 *
 * This function is a boolean test checking to see if the path has a
 * current point defined. Current point will be set by line operators,
 * and cleared by closing subpath.
 *
 * Returns: boolean, indicating if the path has a current point defined.
 */
gboolean
gnome_canvas_path_def_has_currentpoint (const GnomeCanvasPathDef * path)
{
    g_return_val_if_fail (path != NULL, FALSE);

    return (path->hascpt);
}

/**
 * gnome_canvas_path_def_currentpoint:
 * @path: a GnomeCanvasPathDef
 * @p: a ArtPoint where to store the current point
 *
 * Stores the current point of the path definition in the passed ArtPoint @p.
 */
void
gnome_canvas_path_def_currentpoint (const GnomeCanvasPathDef * path, ArtPoint * p)
{
    g_return_if_fail (path != NULL);
    g_return_if_fail (p != NULL);
    g_return_if_fail (path->hascpt);

    if (path->posset) {
        p->x = path->x;
        p->y = path->y;
    } else {
        p->x = (path->bpath + path->end - 1)->x3;
        p->y = (path->bpath + path->end - 1)->y3;
    }
}

/**
 * gnome_canvas_path_def_last_bpath:
 * @path: a GnomeCanvasPathDef
 *
 * This function returns pointer to the last ArtBpath segment in the path
 * definition.
 *
 * Returns: ArtBpath, being the last segment in the path definition or
 * null if no line segments have been defined.
 */
ArtBpath *
gnome_canvas_path_def_last_bpath (const GnomeCanvasPathDef * path)
{
    g_return_val_if_fail (path != NULL, NULL);

    if (path->end == 0) return NULL;

    return path->bpath + path->end - 1;
}

/**
 * gnome_canvas_path_def_first_bpath:
 * @path: a GnomeCanvasPathDef
 *
 * This function returns the first ArtBpath point in the definition.
 *
 * Returns: ArtBpath being the first point in the path definition or
 * null if no points are defined
*/
ArtBpath *
gnome_canvas_path_def_first_bpath (const GnomeCanvasPathDef * path)
{
    g_return_val_if_fail (path != NULL, NULL);

    if (path->end == 0) return NULL;

    return path->bpath;
}

/**
 * gnome_canvas_path_def_any_open:
 * @path: a GnomeCanvasPathDef
 *
 * This function returns a boolean value indicating if the path has
 * any open segments.
 *
 * Returns: boolean, indicating if the path has any open segments.
 */
gboolean
gnome_canvas_path_def_any_open (const GnomeCanvasPathDef * path)
{
    g_return_val_if_fail (path != NULL, FALSE);

    return (!path->allclosed);
}

/**
 * gnome_canvas_path_def_all_open:
 * @path: a GnomeCanvasPathDef
 *
 * This function returns a boolean value indicating if the path only
 * contains open segments.
 *
 * Returns: boolean, indicating if the path has all open segments.
 */
gboolean
gnome_canvas_path_def_all_open (const GnomeCanvasPathDef * path)
{
    g_return_val_if_fail (path != NULL, FALSE);

    return (path->allopen);
}

/**
 * gnome_canvas_path_def_any_closed:
 * @path: a GnomeCanvasPathDef
 *
 * This function returns a boolean valid indicating if the path has
 * any closed segements.
 *
 * Returns: boolean, indicating if the path has any closed segments.
 */
gboolean
gnome_canvas_path_def_any_closed (const GnomeCanvasPathDef * path)
{
    g_return_val_if_fail (path != NULL, FALSE);

    return (!path->allopen);
}

/**
 * gnome_canvas_path_def_all_closed:
 * @path: a GnomeCanvasPathDef
 *
 * This function returns a boolean value indicating if the path only
 * contains closed segments.
 *
 * Returns: boolean, indicating if the path has all closed segments.
 */
gboolean
gnome_canvas_path_def_all_closed (const GnomeCanvasPathDef * path)
{
    g_return_val_if_fail (path != NULL, FALSE);

    return (path->allclosed);
}

/* Private methods */

static
gboolean sp_bpath_good (ArtBpath * bpath)
{
    ArtBpath * bp;

    g_return_val_if_fail (bpath != NULL, FALSE);

    if (bpath->code == ART_END)
                return TRUE;

    bp = bpath;

    while (bp->code != ART_END) {
        bp = sp_bpath_check_subpath (bp);
        if (bp == NULL) return FALSE;
    }

    return TRUE;
}

static ArtBpath *
sp_bpath_check_subpath (ArtBpath * bpath)
{
    gint i, len;
    gboolean closed;

    g_return_val_if_fail (bpath != NULL, NULL);

    if (bpath->code == ART_MOVETO) {
        closed = TRUE;
    } else if (bpath->code == ART_MOVETO_OPEN) {
        closed = FALSE;
    } else {
        return NULL;
    }

    len = 0;

    for (i = 1; (bpath[i].code != ART_END) &&
            (bpath[i].code != ART_MOVETO) &&
            (bpath[i].code != ART_MOVETO_OPEN); i++) {
        switch (bpath[i].code) {
            case ART_LINETO:
            case ART_CURVETO:
                len++;
                break;
            default:
                return NULL;
        }
    }

    if (closed) {
        if (len < 2) return NULL;
        if ((bpath->x3 != bpath[i-1].x3) || (bpath->y3 != bpath[i-1].y3)) return NULL;
    } else {
        if (len < 1) return NULL;
    }

    return bpath + i;
}

static gint
sp_bpath_length (const ArtBpath * bpath)
{
    gint l;

    g_return_val_if_fail (bpath != NULL, FALSE);

    for (l = 0; bpath[l].code != ART_END; l++);

    l++;

    return l;
}

static gboolean
sp_bpath_all_closed (const ArtBpath * bpath)
{
    const ArtBpath * bp;

    g_return_val_if_fail (bpath != NULL, FALSE);

    for (bp = bpath; bp->code != ART_END; bp++)
        if (bp->code == ART_MOVETO_OPEN) return FALSE;

    return TRUE;
}

static gboolean
sp_bpath_all_open (const ArtBpath * bpath)
{
    const ArtBpath * bp;

    g_return_val_if_fail (bpath != NULL, FALSE);

    for (bp = bpath; bp->code != ART_END; bp++)
        if (bp->code == ART_MOVETO) return FALSE;

    return TRUE;
}