summaryrefslogtreecommitdiffstats
path: root/generic/tkCanvLine.c
blob: 97cd1f513ab823f04ee881f50606f258d6ae0f7a (plain)
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
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
/* 
 * tkCanvLine.c --
 *
 *	This file implements line items for canvas widgets.
 *
 * Copyright (c) 1991-1994 The Regents of the University of California.
 * Copyright (c) 1994-1995 Sun Microsystems, Inc.
 *
 * See the file "license.terms" for information on usage and redistribution
 * of this file, and for a DISCLAIMER OF ALL WARRANTIES.
 *
 * SCCS: @(#) tkCanvLine.c 1.46 97/04/25 16:51:02
 */

#include <stdio.h>
#include "tkInt.h"
#include "tkPort.h"

/*
 * The structure below defines the record for each line item.
 */

typedef struct LineItem  {
    Tk_Item header;		/* Generic stuff that's the same for all
				 * types.  MUST BE FIRST IN STRUCTURE. */
    Tk_Canvas canvas;		/* Canvas containing item.  Needed for
				 * parsing arrow shapes. */
    int numPoints;		/* Number of points in line (always >= 2). */
    double *coordPtr;		/* Pointer to malloc-ed array containing
				 * x- and y-coords of all points in line.
				 * X-coords are even-valued indices, y-coords
				 * are corresponding odd-valued indices. If
				 * the line has arrowheads then the first
				 * and last points have been adjusted to refer
				 * to the necks of the arrowheads rather than
				 * their tips.  The actual endpoints are
				 * stored in the *firstArrowPtr and
				 * *lastArrowPtr, if they exist. */
    int width;			/* Width of line. */
    XColor *fg;			/* Foreground color for line. */
    Pixmap fillStipple;		/* Stipple bitmap for filling line. */
    int capStyle;		/* Cap style for line. */
    int joinStyle;		/* Join style for line. */
    GC gc;			/* Graphics context for filling line. */
    GC arrowGC;			/* Graphics context for drawing arrowheads. */
    Tk_Uid arrow;		/* Indicates whether or not to draw arrowheads:
				 * "none", "first", "last", or "both". */
    float arrowShapeA;		/* Distance from tip of arrowhead to center. */
    float arrowShapeB;		/* Distance from tip of arrowhead to trailing
				 * point, measured along shaft. */
    float arrowShapeC;		/* Distance of trailing points from outside
				 * edge of shaft. */
    double *firstArrowPtr;	/* Points to array of PTS_IN_ARROW points
				 * describing polygon for arrowhead at first
				 * point in line.  First point of arrowhead
				 * is tip.  Malloc'ed.  NULL means no arrowhead
				 * at first point. */
    double *lastArrowPtr;	/* Points to polygon for arrowhead at last
				 * point in line (PTS_IN_ARROW points, first
				 * of which is tip).  Malloc'ed.  NULL means
				 * no arrowhead at last point. */
    int smooth;			/* Non-zero means draw line smoothed (i.e.
				 * with Bezier splines). */
    int splineSteps;		/* Number of steps in each spline segment. */
} LineItem;

/*
 * Number of points in an arrowHead:
 */

#define PTS_IN_ARROW 6

/*
 * Prototypes for procedures defined in this file:
 */

static int		ArrowheadPostscript _ANSI_ARGS_((Tcl_Interp *interp,
			    Tk_Canvas canvas, LineItem *linePtr,
			    double *arrowPtr));
static void		ComputeLineBbox _ANSI_ARGS_((Tk_Canvas canvas,
			    LineItem *linePtr));
static int		ConfigureLine _ANSI_ARGS_((Tcl_Interp *interp,
			    Tk_Canvas canvas, Tk_Item *itemPtr, int argc,
			    char **argv, int flags));
static int		ConfigureArrows _ANSI_ARGS_((Tk_Canvas canvas,
			    LineItem *linePtr));
static int		CreateLine _ANSI_ARGS_((Tcl_Interp *interp,
			    Tk_Canvas canvas, struct Tk_Item *itemPtr,
			    int argc, char **argv));
static void		DeleteLine _ANSI_ARGS_((Tk_Canvas canvas,
			    Tk_Item *itemPtr, Display *display));
static void		DisplayLine _ANSI_ARGS_((Tk_Canvas canvas,
			    Tk_Item *itemPtr, Display *display, Drawable dst,
			    int x, int y, int width, int height));
static int		LineCoords _ANSI_ARGS_((Tcl_Interp *interp,
			    Tk_Canvas canvas, Tk_Item *itemPtr,
			    int argc, char **argv));
static int		LineToArea _ANSI_ARGS_((Tk_Canvas canvas,
			    Tk_Item *itemPtr, double *rectPtr));
static double		LineToPoint _ANSI_ARGS_((Tk_Canvas canvas,
			    Tk_Item *itemPtr, double *coordPtr));
static int		LineToPostscript _ANSI_ARGS_((Tcl_Interp *interp,
			    Tk_Canvas canvas, Tk_Item *itemPtr, int prepass));
static int		ParseArrowShape _ANSI_ARGS_((ClientData clientData,
			    Tcl_Interp *interp, Tk_Window tkwin, char *value,
			    char *recordPtr, int offset));
static char *		PrintArrowShape _ANSI_ARGS_((ClientData clientData,
			    Tk_Window tkwin, char *recordPtr, int offset,
			    Tcl_FreeProc **freeProcPtr));
static void		ScaleLine _ANSI_ARGS_((Tk_Canvas canvas,
			    Tk_Item *itemPtr, double originX, double originY,
			    double scaleX, double scaleY));
static void		TranslateLine _ANSI_ARGS_((Tk_Canvas canvas,
			    Tk_Item *itemPtr, double deltaX, double deltaY));

/*
 * Information used for parsing configuration specs.  If you change any
 * of the default strings, be sure to change the corresponding default
 * values in CreateLine.
 */

static Tk_CustomOption arrowShapeOption = {ParseArrowShape,
	PrintArrowShape, (ClientData) NULL};
static Tk_CustomOption tagsOption = {Tk_CanvasTagsParseProc,
    Tk_CanvasTagsPrintProc, (ClientData) NULL
};

static Tk_ConfigSpec configSpecs[] = {
    {TK_CONFIG_UID, "-arrow", (char *) NULL, (char *) NULL,
	"none", Tk_Offset(LineItem, arrow), TK_CONFIG_DONT_SET_DEFAULT},
    {TK_CONFIG_CUSTOM, "-arrowshape", (char *) NULL, (char *) NULL,
	"8 10 3", Tk_Offset(LineItem, arrowShapeA),
	TK_CONFIG_DONT_SET_DEFAULT, &arrowShapeOption},
    {TK_CONFIG_CAP_STYLE, "-capstyle", (char *) NULL, (char *) NULL,
	"butt", Tk_Offset(LineItem, capStyle), TK_CONFIG_DONT_SET_DEFAULT},
    {TK_CONFIG_COLOR, "-fill", (char *) NULL, (char *) NULL,
	"black", Tk_Offset(LineItem, fg), TK_CONFIG_NULL_OK},
    {TK_CONFIG_JOIN_STYLE, "-joinstyle", (char *) NULL, (char *) NULL,
	"round", Tk_Offset(LineItem, joinStyle), TK_CONFIG_DONT_SET_DEFAULT},
    {TK_CONFIG_BOOLEAN, "-smooth", (char *) NULL, (char *) NULL,
	"0", Tk_Offset(LineItem, smooth), TK_CONFIG_DONT_SET_DEFAULT},
    {TK_CONFIG_INT, "-splinesteps", (char *) NULL, (char *) NULL,
	"12", Tk_Offset(LineItem, splineSteps), TK_CONFIG_DONT_SET_DEFAULT},
    {TK_CONFIG_BITMAP, "-stipple", (char *) NULL, (char *) NULL,
	(char *) NULL, Tk_Offset(LineItem, fillStipple), TK_CONFIG_NULL_OK},
    {TK_CONFIG_CUSTOM, "-tags", (char *) NULL, (char *) NULL,
	(char *) NULL, 0, TK_CONFIG_NULL_OK, &tagsOption},
    {TK_CONFIG_PIXELS, "-width", (char *) NULL, (char *) NULL,
	"1", Tk_Offset(LineItem, width), TK_CONFIG_DONT_SET_DEFAULT},
    {TK_CONFIG_END, (char *) NULL, (char *) NULL, (char *) NULL,
	(char *) NULL, 0, 0}
};

/*
 * The structures below defines the line item type by means
 * of procedures that can be invoked by generic item code.
 */

Tk_ItemType tkLineType = {
    "line",				/* name */
    sizeof(LineItem),			/* itemSize */
    CreateLine,				/* createProc */
    configSpecs,			/* configSpecs */
    ConfigureLine,			/* configureProc */
    LineCoords,				/* coordProc */
    DeleteLine,				/* deleteProc */
    DisplayLine,			/* displayProc */
    0,					/* alwaysRedraw */
    LineToPoint,			/* pointProc */
    LineToArea,				/* areaProc */
    LineToPostscript,			/* postscriptProc */
    ScaleLine,				/* scaleProc */
    TranslateLine,			/* translateProc */
    (Tk_ItemIndexProc *) NULL,		/* indexProc */
    (Tk_ItemCursorProc *) NULL,		/* icursorProc */
    (Tk_ItemSelectionProc *) NULL,	/* selectionProc */
    (Tk_ItemInsertProc *) NULL,		/* insertProc */
    (Tk_ItemDCharsProc *) NULL,		/* dTextProc */
    (Tk_ItemType *) NULL		/* nextPtr */
};

/*
 * The Tk_Uid's below refer to uids for the various arrow types:
 */

static Tk_Uid noneUid = NULL;
static Tk_Uid firstUid = NULL;
static Tk_Uid lastUid = NULL;
static Tk_Uid bothUid = NULL;

/*
 * The definition below determines how large are static arrays
 * used to hold spline points (splines larger than this have to
 * have their arrays malloc-ed).
 */

#define MAX_STATIC_POINTS 200

/*
 *--------------------------------------------------------------
 *
 * CreateLine --
 *
 *	This procedure is invoked to create a new line item in
 *	a canvas.
 *
 * Results:
 *	A standard Tcl return value.  If an error occurred in
 *	creating the item, then an error message is left in
 *	interp->result;  in this case itemPtr is left uninitialized,
 *	so it can be safely freed by the caller.
 *
 * Side effects:
 *	A new line item is created.
 *
 *--------------------------------------------------------------
 */

static int
CreateLine(interp, canvas, itemPtr, argc, argv)
    Tcl_Interp *interp;			/* Interpreter for error reporting. */
    Tk_Canvas canvas;			/* Canvas to hold new item. */
    Tk_Item *itemPtr;			/* Record to hold new item;  header
					 * has been initialized by caller. */
    int argc;				/* Number of arguments in argv. */
    char **argv;			/* Arguments describing line. */
{
    LineItem *linePtr = (LineItem *) itemPtr;
    int i;

    if (argc < 4) {
	Tcl_AppendResult(interp, "wrong # args: should be \"",
		Tk_PathName(Tk_CanvasTkwin(canvas)), " create ",
		itemPtr->typePtr->name, " x1 y1 x2 y2 ?x3 y3 ...? ?options?\"",
		(char *) NULL);
	return TCL_ERROR;
    }

    /*
     * Carry out initialization that is needed to set defaults and to
     * allow proper cleanup after errors during the the remainder of
     * this procedure.
     */

    linePtr->canvas = canvas;
    linePtr->numPoints = 0;
    linePtr->coordPtr = NULL;
    linePtr->width = 1;
    linePtr->fg = None;
    linePtr->fillStipple = None;
    linePtr->capStyle = CapButt;
    linePtr->joinStyle = JoinRound;
    linePtr->gc = None;
    linePtr->arrowGC = None;
    if (noneUid == NULL) {
	noneUid = Tk_GetUid("none");
	firstUid = Tk_GetUid("first");
	lastUid = Tk_GetUid("last");
	bothUid = Tk_GetUid("both");
    }
    linePtr->arrow = noneUid;
    linePtr->arrowShapeA = (float)8.0;
    linePtr->arrowShapeB = (float)10.0;
    linePtr->arrowShapeC = (float)3.0;
    linePtr->firstArrowPtr = NULL;
    linePtr->lastArrowPtr = NULL;
    linePtr->smooth = 0;
    linePtr->splineSteps = 12;

    /*
     * Count the number of points and then parse them into a point
     * array.  Leading arguments are assumed to be points if they
     * start with a digit or a minus sign followed by a digit.
     */

    for (i = 4; i < (argc-1); i+=2) {
	if ((!isdigit(UCHAR(argv[i][0]))) &&
		((argv[i][0] != '-')
		|| ((argv[i][1] != '.') && !isdigit(UCHAR(argv[i][1]))))) {
	    break;
	}
    }
    if (LineCoords(interp, canvas, itemPtr, i, argv) != TCL_OK) {
	goto error;
    }
    if (ConfigureLine(interp, canvas, itemPtr, argc-i, argv+i, 0) == TCL_OK) {
	return TCL_OK;
    }

    error:
    DeleteLine(canvas, itemPtr, Tk_Display(Tk_CanvasTkwin(canvas)));
    return TCL_ERROR;
}

/*
 *--------------------------------------------------------------
 *
 * LineCoords --
 *
 *	This procedure is invoked to process the "coords" widget
 *	command on lines.  See the user documentation for details
 *	on what it does.
 *
 * Results:
 *	Returns TCL_OK or TCL_ERROR, and sets interp->result.
 *
 * Side effects:
 *	The coordinates for the given item may be changed.
 *
 *--------------------------------------------------------------
 */

static int
LineCoords(interp, canvas, itemPtr, argc, argv)
    Tcl_Interp *interp;			/* Used for error reporting. */
    Tk_Canvas canvas;			/* Canvas containing item. */
    Tk_Item *itemPtr;			/* Item whose coordinates are to be
					 * read or modified. */
    int argc;				/* Number of coordinates supplied in
					 * argv. */
    char **argv;			/* Array of coordinates: x1, y1,
					 * x2, y2, ... */
{
    LineItem *linePtr = (LineItem *) itemPtr;
    char buffer[TCL_DOUBLE_SPACE];
    int i, numPoints;

    if (argc == 0) {
	double *coordPtr;
	int numCoords;

	numCoords = 2*linePtr->numPoints;
	if (linePtr->firstArrowPtr != NULL) {
	    coordPtr = linePtr->firstArrowPtr;
	} else {
	    coordPtr = linePtr->coordPtr;
	}
	for (i = 0; i < numCoords; i++, coordPtr++) {
	    if (i == 2) {
		coordPtr = linePtr->coordPtr+2;
	    }
	    if ((linePtr->lastArrowPtr != NULL) && (i == (numCoords-2))) {
		coordPtr = linePtr->lastArrowPtr;
	    }
	    Tcl_PrintDouble(interp, *coordPtr, buffer);
	    Tcl_AppendElement(interp, buffer);
	}
    } else if (argc < 4) {
	Tcl_AppendResult(interp,
		"too few coordinates for line: must have at least 4",
		(char *) NULL);
	return TCL_ERROR;
    } else if (argc & 1) {
	Tcl_AppendResult(interp,
		"odd number of coordinates specified for line",
		(char *) NULL);
	return TCL_ERROR;
    } else {
	numPoints = argc/2;
	if (linePtr->numPoints != numPoints) {
	    if (linePtr->coordPtr != NULL) {
		ckfree((char *) linePtr->coordPtr);
	    }
	    linePtr->coordPtr = (double *) ckalloc((unsigned)
		    (sizeof(double) * argc));
	    linePtr->numPoints = numPoints;
	}
	for (i = argc-1; i >= 0; i--) {
	    if (Tk_CanvasGetCoord(interp, canvas, argv[i],
		    &linePtr->coordPtr[i]) != TCL_OK) {
		return TCL_ERROR;
	    }
	}

	/*
	 * Update arrowheads by throwing away any existing arrow-head
	 * information and calling ConfigureArrows to recompute it.
	 */

	if (linePtr->firstArrowPtr != NULL) {
	    ckfree((char *) linePtr->firstArrowPtr);
	    linePtr->firstArrowPtr = NULL;
	}
	if (linePtr->lastArrowPtr != NULL) {
	    ckfree((char *) linePtr->lastArrowPtr);
	    linePtr->lastArrowPtr = NULL;
	}
	if (linePtr->arrow != noneUid) {
	    ConfigureArrows(canvas, linePtr);
	}
	ComputeLineBbox(canvas, linePtr);
    }
    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * ConfigureLine --
 *
 *	This procedure is invoked to configure various aspects
 *	of a line item such as its background color.
 *
 * Results:
 *	A standard Tcl result code.  If an error occurs, then
 *	an error message is left in interp->result.
 *
 * Side effects:
 *	Configuration information, such as colors and stipple
 *	patterns, may be set for itemPtr.
 *
 *--------------------------------------------------------------
 */

static int
ConfigureLine(interp, canvas, itemPtr, argc, argv, flags)
    Tcl_Interp *interp;		/* Used for error reporting. */
    Tk_Canvas canvas;		/* Canvas containing itemPtr. */
    Tk_Item *itemPtr;		/* Line item to reconfigure. */
    int argc;			/* Number of elements in argv.  */
    char **argv;		/* Arguments describing things to configure. */
    int flags;			/* Flags to pass to Tk_ConfigureWidget. */
{
    LineItem *linePtr = (LineItem *) itemPtr;
    XGCValues gcValues;
    GC newGC, arrowGC;
    unsigned long mask;
    Tk_Window tkwin;

    tkwin = Tk_CanvasTkwin(canvas);
    if (Tk_ConfigureWidget(interp, tkwin, configSpecs, argc, argv,
	    (char *) linePtr, flags) != TCL_OK) {
	return TCL_ERROR;
    }

    /*
     * A few of the options require additional processing, such as
     * graphics contexts.
     */

    if (linePtr->fg == NULL) {
	newGC = arrowGC = None;
    } else {
	gcValues.foreground = linePtr->fg->pixel;
	gcValues.join_style = linePtr->joinStyle;
	if (linePtr->width < 0) {
	    linePtr->width = 1;
	}
	gcValues.line_width = linePtr->width;
	mask = GCForeground|GCJoinStyle|GCLineWidth;
	if (linePtr->fillStipple != None) {
	    gcValues.stipple = linePtr->fillStipple;
	    gcValues.fill_style = FillStippled;
	    mask |= GCStipple|GCFillStyle;
	}
	if (linePtr->arrow == noneUid) {
	    gcValues.cap_style = linePtr->capStyle;
	    mask |= GCCapStyle;
	}
	newGC = Tk_GetGC(tkwin, mask, &gcValues);
	gcValues.line_width = 0;
	arrowGC = Tk_GetGC(tkwin, mask, &gcValues);
    }
    if (linePtr->gc != None) {
	Tk_FreeGC(Tk_Display(tkwin), linePtr->gc);
    }
    if (linePtr->arrowGC != None) {
	Tk_FreeGC(Tk_Display(tkwin), linePtr->arrowGC);
    }
    linePtr->gc = newGC;
    linePtr->arrowGC = arrowGC;

    /*
     * Keep spline parameters within reasonable limits.
     */

    if (linePtr->splineSteps < 1) {
	linePtr->splineSteps = 1;
    } else if (linePtr->splineSteps > 100) {
	linePtr->splineSteps = 100;
    }

    /*
     * Setup arrowheads, if needed.  If arrowheads are turned off,
     * restore the line's endpoints (they were shortened when the
     * arrowheads were added).
     */

    if ((linePtr->firstArrowPtr != NULL) && (linePtr->arrow != firstUid)
	    && (linePtr->arrow != bothUid)) {
	linePtr->coordPtr[0] = linePtr->firstArrowPtr[0];
	linePtr->coordPtr[1] = linePtr->firstArrowPtr[1];
	ckfree((char *) linePtr->firstArrowPtr);
	linePtr->firstArrowPtr = NULL;
    }
    if ((linePtr->lastArrowPtr != NULL) && (linePtr->arrow != lastUid)
	    && (linePtr->arrow != bothUid)) {
	int i;

	i = 2*(linePtr->numPoints-1);
	linePtr->coordPtr[i] = linePtr->lastArrowPtr[0];
	linePtr->coordPtr[i+1] = linePtr->lastArrowPtr[1];
	ckfree((char *) linePtr->lastArrowPtr);
	linePtr->lastArrowPtr = NULL;
    }
    if (linePtr->arrow != noneUid) {
	if ((linePtr->arrow != firstUid) && (linePtr->arrow != lastUid)
		&& (linePtr->arrow != bothUid)) {
	    Tcl_AppendResult(interp, "bad arrow spec \"",
		    linePtr->arrow, "\": must be none, first, last, or both",
		    (char *) NULL);
	    linePtr->arrow = noneUid;
	    return TCL_ERROR;
	}
	ConfigureArrows(canvas, linePtr);
    }

    /*
     * Recompute bounding box for line.
     */

    ComputeLineBbox(canvas, linePtr);

    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * DeleteLine --
 *
 *	This procedure is called to clean up the data structure
 *	associated with a line item.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	Resources associated with itemPtr are released.
 *
 *--------------------------------------------------------------
 */

static void
DeleteLine(canvas, itemPtr, display)
    Tk_Canvas canvas;			/* Info about overall canvas widget. */
    Tk_Item *itemPtr;			/* Item that is being deleted. */
    Display *display;			/* Display containing window for
					 * canvas. */
{
    LineItem *linePtr = (LineItem *) itemPtr;

    if (linePtr->coordPtr != NULL) {
	ckfree((char *) linePtr->coordPtr);
    }
    if (linePtr->fg != NULL) {
	Tk_FreeColor(linePtr->fg);
    }
    if (linePtr->fillStipple != None) {
	Tk_FreeBitmap(display, linePtr->fillStipple);
    }
    if (linePtr->gc != None) {
	Tk_FreeGC(display, linePtr->gc);
    }
    if (linePtr->arrowGC != None) {
	Tk_FreeGC(display, linePtr->arrowGC);
    }
    if (linePtr->firstArrowPtr != NULL) {
	ckfree((char *) linePtr->firstArrowPtr);
    }
    if (linePtr->lastArrowPtr != NULL) {
	ckfree((char *) linePtr->lastArrowPtr);
    }
}

/*
 *--------------------------------------------------------------
 *
 * ComputeLineBbox --
 *
 *	This procedure is invoked to compute the bounding box of
 *	all the pixels that may be drawn as part of a line.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The fields x1, y1, x2, and y2 are updated in the header
 *	for itemPtr.
 *
 *--------------------------------------------------------------
 */

static void
ComputeLineBbox(canvas, linePtr)
    Tk_Canvas canvas;			/* Canvas that contains item. */
    LineItem *linePtr;			/* Item whose bbos is to be
					 * recomputed. */
{
    double *coordPtr;
    int i, width;

    coordPtr = linePtr->coordPtr;
    linePtr->header.x1 = linePtr->header.x2 = (int) *coordPtr;
    linePtr->header.y1 = linePtr->header.y2 = (int) coordPtr[1];

    /*
     * Compute the bounding box of all the points in the line,
     * then expand in all directions by the line's width to take
     * care of butting or rounded corners and projecting or
     * rounded caps.  This expansion is an overestimate (worst-case
     * is square root of two over two) but it's simple.  Don't do
     * anything special for curves.  This causes an additional
     * overestimate in the bounding box, but is faster.
     */

    for (i = 1, coordPtr = linePtr->coordPtr+2; i < linePtr->numPoints;
	    i++, coordPtr += 2) {
	TkIncludePoint((Tk_Item *) linePtr, coordPtr);
    }
    width = linePtr->width;
    if (width < 1) {
	width = 1;
    }
    linePtr->header.x1 -= width;
    linePtr->header.x2 += width;
    linePtr->header.y1 -= width;
    linePtr->header.y2 += width;

    /*
     * For mitered lines, make a second pass through all the points.
     * Compute the locations of the two miter vertex points and add
     * those into the bounding box.
     */

    if (linePtr->joinStyle == JoinMiter) {
	for (i = linePtr->numPoints, coordPtr = linePtr->coordPtr; i >= 3;
		i--, coordPtr += 2) {
	    double miter[4];
	    int j;
    
	    if (TkGetMiterPoints(coordPtr, coordPtr+2, coordPtr+4,
		    (double) width, miter, miter+2)) {
		for (j = 0; j < 4; j += 2) {
		    TkIncludePoint((Tk_Item *) linePtr, miter+j);
		}
	    }
	}
    }

    /*
     * Add in the sizes of arrowheads, if any.
     */

    if (linePtr->arrow != noneUid) {
	if (linePtr->arrow != lastUid) {
	    for (i = 0, coordPtr = linePtr->firstArrowPtr; i < PTS_IN_ARROW;
		    i++, coordPtr += 2) {
		TkIncludePoint((Tk_Item *) linePtr, coordPtr);
	    }
	}
	if (linePtr->arrow != firstUid) {
	    for (i = 0, coordPtr = linePtr->lastArrowPtr; i < PTS_IN_ARROW;
		    i++, coordPtr += 2) {
		TkIncludePoint((Tk_Item *) linePtr, coordPtr);
	    }
	}
    }

    /*
     * Add one more pixel of fudge factor just to be safe (e.g.
     * X may round differently than we do).
     */

    linePtr->header.x1 -= 1;
    linePtr->header.x2 += 1;
    linePtr->header.y1 -= 1;
    linePtr->header.y2 += 1;
}

/*
 *--------------------------------------------------------------
 *
 * DisplayLine --
 *
 *	This procedure is invoked to draw a line item in a given
 *	drawable.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	ItemPtr is drawn in drawable using the transformation
 *	information in canvas.
 *
 *--------------------------------------------------------------
 */

static void
DisplayLine(canvas, itemPtr, display, drawable, x, y, width, height)
    Tk_Canvas canvas;			/* Canvas that contains item. */
    Tk_Item *itemPtr;			/* Item to be displayed. */
    Display *display;			/* Display on which to draw item. */
    Drawable drawable;			/* Pixmap or window in which to draw
					 * item. */
    int x, y, width, height;		/* Describes region of canvas that
					 * must be redisplayed (not used). */
{
    LineItem *linePtr = (LineItem *) itemPtr;
    XPoint staticPoints[MAX_STATIC_POINTS];
    XPoint *pointPtr;
    XPoint *pPtr;
    double *coordPtr;
    int i, numPoints;

    if (linePtr->gc == None) {
	return;
    }

    /*
     * Build up an array of points in screen coordinates.  Use a
     * static array unless the line has an enormous number of points;
     * in this case, dynamically allocate an array.  For smoothed lines,
     * generate the curve points on each redisplay.
     */

    if ((linePtr->smooth) && (linePtr->numPoints > 2)) {
	numPoints = 1 + linePtr->numPoints*linePtr->splineSteps;
    } else {
	numPoints = linePtr->numPoints;
    }

    if (numPoints <= MAX_STATIC_POINTS) {
	pointPtr = staticPoints;
    } else {
	pointPtr = (XPoint *) ckalloc((unsigned) (numPoints * sizeof(XPoint)));
    }

    if ((linePtr->smooth) && (linePtr->numPoints > 2)) {
	numPoints = TkMakeBezierCurve(canvas, linePtr->coordPtr,
		linePtr->numPoints, linePtr->splineSteps, pointPtr,
		(double *) NULL);
    } else {
	for (i = 0, coordPtr = linePtr->coordPtr, pPtr = pointPtr;
		i < linePtr->numPoints;  i += 1, coordPtr += 2, pPtr++) {
	    Tk_CanvasDrawableCoords(canvas, coordPtr[0], coordPtr[1],
		    &pPtr->x, &pPtr->y);
	}
    }

    /*
     * Display line, the free up line storage if it was dynamically
     * allocated.  If we're stippling, then modify the stipple offset
     * in the GC.  Be sure to reset the offset when done, since the
     * GC is supposed to be read-only.
     */

    if (linePtr->fillStipple != None) {
	Tk_CanvasSetStippleOrigin(canvas, linePtr->gc);
	Tk_CanvasSetStippleOrigin(canvas, linePtr->arrowGC);
    }
    XDrawLines(display, drawable, linePtr->gc, pointPtr, numPoints,
	    CoordModeOrigin);
    if (pointPtr != staticPoints) {
	ckfree((char *) pointPtr);
    }

    /*
     * Display arrowheads, if they are wanted.
     */

    if (linePtr->firstArrowPtr != NULL) {
	TkFillPolygon(canvas, linePtr->firstArrowPtr, PTS_IN_ARROW,
		display, drawable, linePtr->gc, NULL);
    }
    if (linePtr->lastArrowPtr != NULL) {
	TkFillPolygon(canvas, linePtr->lastArrowPtr, PTS_IN_ARROW,
		display, drawable, linePtr->gc, NULL);
    }
    if (linePtr->fillStipple != None) {
	XSetTSOrigin(display, linePtr->gc, 0, 0);
	XSetTSOrigin(display, linePtr->arrowGC, 0, 0);
    }
}

/*
 *--------------------------------------------------------------
 *
 * LineToPoint --
 *
 *	Computes the distance from a given point to a given
 *	line, in canvas units.
 *
 * Results:
 *	The return value is 0 if the point whose x and y coordinates
 *	are pointPtr[0] and pointPtr[1] is inside the line.  If the
 *	point isn't inside the line then the return value is the
 *	distance from the point to the line.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

	/* ARGSUSED */
static double
LineToPoint(canvas, itemPtr, pointPtr)
    Tk_Canvas canvas;		/* Canvas containing item. */
    Tk_Item *itemPtr;		/* Item to check against point. */
    double *pointPtr;		/* Pointer to x and y coordinates. */
{
    LineItem *linePtr = (LineItem *) itemPtr;
    double *coordPtr, *linePoints;
    double staticSpace[2*MAX_STATIC_POINTS];
    double poly[10];
    double bestDist, dist;
    int numPoints, count;
    int changedMiterToBevel;	/* Non-zero means that a mitered corner
				 * had to be treated as beveled after all
				 * because the angle was < 11 degrees. */

    bestDist = 1.0e36;

    /*
     * Handle smoothed lines by generating an expanded set of points
     * against which to do the check.
     */

    if ((linePtr->smooth) && (linePtr->numPoints > 2)) {
	numPoints = 1 + linePtr->numPoints*linePtr->splineSteps;
	if (numPoints <= MAX_STATIC_POINTS) {
	    linePoints = staticSpace;
	} else {
	    linePoints = (double *) ckalloc((unsigned)
		    (2*numPoints*sizeof(double)));
	}
	numPoints = TkMakeBezierCurve(canvas, linePtr->coordPtr,
		linePtr->numPoints, linePtr->splineSteps, (XPoint *) NULL,
		linePoints);
    } else {
	numPoints = linePtr->numPoints;
	linePoints = linePtr->coordPtr;
    }

    /*
     * The overall idea is to iterate through all of the edges of
     * the line, computing a polygon for each edge and testing the
     * point against that polygon.  In addition, there are additional
     * tests to deal with rounded joints and caps.
     */

    changedMiterToBevel = 0;
    for (count = numPoints, coordPtr = linePoints; count >= 2;
	    count--, coordPtr += 2) {

	/*
	 * If rounding is done around the first point then compute
	 * the distance between the point and the point.
	 */

	if (((linePtr->capStyle == CapRound) && (count == numPoints))
		|| ((linePtr->joinStyle == JoinRound)
			&& (count != numPoints))) {
	    dist = hypot(coordPtr[0] - pointPtr[0], coordPtr[1] - pointPtr[1])
		    - linePtr->width/2.0;
	    if (dist <= 0.0) {
		bestDist = 0.0;
		goto done;
	    } else if (dist < bestDist) {
		bestDist = dist;
	    }
	}

	/*
	 * Compute the polygonal shape corresponding to this edge,
	 * consisting of two points for the first point of the edge
	 * and two points for the last point of the edge.
	 */

	if (count == numPoints) {
	    TkGetButtPoints(coordPtr+2, coordPtr, (double) linePtr->width,
		    linePtr->capStyle == CapProjecting, poly, poly+2);
	} else if ((linePtr->joinStyle == JoinMiter) && !changedMiterToBevel) {
	    poly[0] = poly[6];
	    poly[1] = poly[7];
	    poly[2] = poly[4];
	    poly[3] = poly[5];
	} else {
	    TkGetButtPoints(coordPtr+2, coordPtr, (double) linePtr->width, 0,
		    poly, poly+2);

	    /*
	     * If this line uses beveled joints, then check the distance
	     * to a polygon comprising the last two points of the previous
	     * polygon and the first two from this polygon;  this checks
	     * the wedges that fill the mitered joint.
	     */

	    if ((linePtr->joinStyle == JoinBevel) || changedMiterToBevel) {
		poly[8] = poly[0];
		poly[9] = poly[1];
		dist = TkPolygonToPoint(poly, 5, pointPtr);
		if (dist <= 0.0) {
		    bestDist = 0.0;
		    goto done;
		} else if (dist < bestDist) {
		    bestDist = dist;
		}
		changedMiterToBevel = 0;
	    }
	}
	if (count == 2) {
	    TkGetButtPoints(coordPtr, coordPtr+2, (double) linePtr->width,
		    linePtr->capStyle == CapProjecting, poly+4, poly+6);
	} else if (linePtr->joinStyle == JoinMiter) {
	    if (TkGetMiterPoints(coordPtr, coordPtr+2, coordPtr+4,
		    (double) linePtr->width, poly+4, poly+6) == 0) {
		changedMiterToBevel = 1;
		TkGetButtPoints(coordPtr, coordPtr+2, (double) linePtr->width,
			0, poly+4, poly+6);
	    }
	} else {
	    TkGetButtPoints(coordPtr, coordPtr+2, (double) linePtr->width, 0,
		    poly+4, poly+6);
	}
	poly[8] = poly[0];
	poly[9] = poly[1];
	dist = TkPolygonToPoint(poly, 5, pointPtr);
	if (dist <= 0.0) {
	    bestDist = 0.0;
	    goto done;
	} else if (dist < bestDist) {
	    bestDist = dist;
	}
    }

    /*
     * If caps are rounded, check the distance to the cap around the
     * final end point of the line.
     */

    if (linePtr->capStyle == CapRound) {
	dist = hypot(coordPtr[0] - pointPtr[0], coordPtr[1] - pointPtr[1])
		- linePtr->width/2.0;
	if (dist <= 0.0) {
	    bestDist = 0.0;
	    goto done;
	} else if (dist < bestDist) {
	    bestDist = dist;
	}
    }

    /*
     * If there are arrowheads, check the distance to the arrowheads.
     */

    if (linePtr->arrow != noneUid) {
	if (linePtr->arrow != lastUid) {
	    dist = TkPolygonToPoint(linePtr->firstArrowPtr, PTS_IN_ARROW,
		    pointPtr);
	    if (dist <= 0.0) {
		bestDist = 0.0;
		goto done;
	    } else if (dist < bestDist) {
		bestDist = dist;
	    }
	}
	if (linePtr->arrow != firstUid) {
	    dist = TkPolygonToPoint(linePtr->lastArrowPtr, PTS_IN_ARROW,
		    pointPtr);
	    if (dist <= 0.0) {
		bestDist = 0.0;
		goto done;
	    } else if (dist < bestDist) {
		bestDist = dist;
	    }
	}
    }

    done:
    if ((linePoints != staticSpace) && (linePoints != linePtr->coordPtr)) {
	ckfree((char *) linePoints);
    }
    return bestDist;
}

/*
 *--------------------------------------------------------------
 *
 * LineToArea --
 *
 *	This procedure is called to determine whether an item
 *	lies entirely inside, entirely outside, or overlapping
 *	a given rectangular area.
 *
 * Results:
 *	-1 is returned if the item is entirely outside the
 *	area, 0 if it overlaps, and 1 if it is entirely
 *	inside the given area.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

	/* ARGSUSED */
static int
LineToArea(canvas, itemPtr, rectPtr)
    Tk_Canvas canvas;		/* Canvas containing item. */
    Tk_Item *itemPtr;		/* Item to check against line. */
    double *rectPtr;
{
    LineItem *linePtr = (LineItem *) itemPtr;
    double staticSpace[2*MAX_STATIC_POINTS];
    double *linePoints;
    int numPoints, result;

    /*
     * Handle smoothed lines by generating an expanded set of points
     * against which to do the check.
     */

    if ((linePtr->smooth) && (linePtr->numPoints > 2)) {
	numPoints = 1 + linePtr->numPoints*linePtr->splineSteps;
	if (numPoints <= MAX_STATIC_POINTS) {
	    linePoints = staticSpace;
	} else {
	    linePoints = (double *) ckalloc((unsigned)
		    (2*numPoints*sizeof(double)));
	}
	numPoints = TkMakeBezierCurve(canvas, linePtr->coordPtr,
		linePtr->numPoints, linePtr->splineSteps, (XPoint *) NULL,
		linePoints);
    } else {
	numPoints = linePtr->numPoints;
	linePoints = linePtr->coordPtr;
    }

    /*
     * Check the segments of the line.
     */

    result = TkThickPolyLineToArea(linePoints, numPoints, 
	    (double) linePtr->width, linePtr->capStyle, linePtr->joinStyle,
	    rectPtr);
    if (result == 0) {
	goto done;
    }

    /*
     * Check arrowheads, if any.
     */

    if (linePtr->arrow != noneUid) {
	if (linePtr->arrow != lastUid) {
	    if (TkPolygonToArea(linePtr->firstArrowPtr, PTS_IN_ARROW,
		    rectPtr) != result) {
		result = 0;
		goto done;
	    }
	}
	if (linePtr->arrow != firstUid) {
	    if (TkPolygonToArea(linePtr->lastArrowPtr, PTS_IN_ARROW,
		    rectPtr) != result) {
		result = 0;
		goto done;
	    }
	}
    }

    done:
    if ((linePoints != staticSpace) && (linePoints != linePtr->coordPtr)) {
	ckfree((char *) linePoints);
    }
    return result;
}

/*
 *--------------------------------------------------------------
 *
 * ScaleLine --
 *
 *	This procedure is invoked to rescale a line item.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The line referred to by itemPtr is rescaled so that the
 *	following transformation is applied to all point
 *	coordinates:
 *		x' = originX + scaleX*(x-originX)
 *		y' = originY + scaleY*(y-originY)
 *
 *--------------------------------------------------------------
 */

static void
ScaleLine(canvas, itemPtr, originX, originY, scaleX, scaleY)
    Tk_Canvas canvas;			/* Canvas containing line. */
    Tk_Item *itemPtr;			/* Line to be scaled. */
    double originX, originY;		/* Origin about which to scale rect. */
    double scaleX;			/* Amount to scale in X direction. */
    double scaleY;			/* Amount to scale in Y direction. */
{
    LineItem *linePtr = (LineItem *) itemPtr;
    double *coordPtr;
    int i;

    /*
     * Delete any arrowheads before scaling all the points (so that
     * the end-points of the line get restored).
     */

    if (linePtr->firstArrowPtr != NULL) {
	linePtr->coordPtr[0] = linePtr->firstArrowPtr[0];
	linePtr->coordPtr[1] = linePtr->firstArrowPtr[1];
	ckfree((char *) linePtr->firstArrowPtr);
	linePtr->firstArrowPtr = NULL;
    }
    if (linePtr->lastArrowPtr != NULL) {
	int i;

	i = 2*(linePtr->numPoints-1);
	linePtr->coordPtr[i] = linePtr->lastArrowPtr[0];
	linePtr->coordPtr[i+1] = linePtr->lastArrowPtr[1];
	ckfree((char *) linePtr->lastArrowPtr);
	linePtr->lastArrowPtr = NULL;
    }
    for (i = 0, coordPtr = linePtr->coordPtr; i < linePtr->numPoints;
	    i++, coordPtr += 2) {
	coordPtr[0] = originX + scaleX*(*coordPtr - originX);
	coordPtr[1] = originY + scaleY*(coordPtr[1] - originY);
    }
    if (linePtr->arrow != noneUid) {
	ConfigureArrows(canvas, linePtr);
    }
    ComputeLineBbox(canvas, linePtr);
}

/*
 *--------------------------------------------------------------
 *
 * TranslateLine --
 *
 *	This procedure is called to move a line by a given amount.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	The position of the line is offset by (xDelta, yDelta), and
 *	the bounding box is updated in the generic part of the item
 *	structure.
 *
 *--------------------------------------------------------------
 */

static void
TranslateLine(canvas, itemPtr, deltaX, deltaY)
    Tk_Canvas canvas;			/* Canvas containing item. */
    Tk_Item *itemPtr;			/* Item that is being moved. */
    double deltaX, deltaY;		/* Amount by which item is to be
					 * moved. */
{
    LineItem *linePtr = (LineItem *) itemPtr;
    double *coordPtr;
    int i;

    for (i = 0, coordPtr = linePtr->coordPtr; i < linePtr->numPoints;
	    i++, coordPtr += 2) {
	coordPtr[0] += deltaX;
	coordPtr[1] += deltaY;
    }
    if (linePtr->firstArrowPtr != NULL) {
	for (i = 0, coordPtr = linePtr->firstArrowPtr; i < PTS_IN_ARROW;
		i++, coordPtr += 2) {
	    coordPtr[0] += deltaX;
	    coordPtr[1] += deltaY;
	}
    }
    if (linePtr->lastArrowPtr != NULL) {
	for (i = 0, coordPtr = linePtr->lastArrowPtr; i < PTS_IN_ARROW;
		i++, coordPtr += 2) {
	    coordPtr[0] += deltaX;
	    coordPtr[1] += deltaY;
	}
    }
    ComputeLineBbox(canvas, linePtr);
}

/*
 *--------------------------------------------------------------
 *
 * ParseArrowShape --
 *
 *	This procedure is called back during option parsing to
 *	parse arrow shape information.
 *
 * Results:
 *	The return value is a standard Tcl result:  TCL_OK means
 *	that the arrow shape information was parsed ok, and
 *	TCL_ERROR means it couldn't be parsed.
 *
 * Side effects:
 *	Arrow information in recordPtr is updated.
 *
 *--------------------------------------------------------------
 */

	/* ARGSUSED */
static int
ParseArrowShape(clientData, interp, tkwin, value, recordPtr, offset)
    ClientData clientData;	/* Not used. */
    Tcl_Interp *interp;		/* Used for error reporting. */
    Tk_Window tkwin;		/* Not used. */
    char *value;		/* Textual specification of arrow shape. */
    char *recordPtr;		/* Pointer to item record in which to
				 * store arrow information. */
    int offset;			/* Offset of shape information in widget
				 * record. */
{
    LineItem *linePtr = (LineItem *) recordPtr;
    double a, b, c;
    int argc;
    char **argv = NULL;

    if (offset != Tk_Offset(LineItem, arrowShapeA)) {
	panic("ParseArrowShape received bogus offset");
    }

    if (Tcl_SplitList(interp, value, &argc, &argv) != TCL_OK) {
	syntaxError:
	Tcl_ResetResult(interp);
	Tcl_AppendResult(interp, "bad arrow shape \"", value,
		"\": must be list with three numbers", (char *) NULL);
	if (argv != NULL) {
	    ckfree((char *) argv);
	}
	return TCL_ERROR;
    }
    if (argc != 3) {
	goto syntaxError;
    }
    if ((Tk_CanvasGetCoord(interp, linePtr->canvas, argv[0], &a) != TCL_OK)
	    || (Tk_CanvasGetCoord(interp, linePtr->canvas, argv[1], &b)
		!= TCL_OK)
	    || (Tk_CanvasGetCoord(interp, linePtr->canvas, argv[2], &c)
		!= TCL_OK)) {
	goto syntaxError;
    }
    linePtr->arrowShapeA = (float)a;
    linePtr->arrowShapeB = (float)b;
    linePtr->arrowShapeC = (float)c;
    ckfree((char *) argv);
    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * PrintArrowShape --
 *
 *	This procedure is a callback invoked by the configuration
 *	code to return a printable value describing an arrow shape.
 *
 * Results:
 *	None.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

    /* ARGSUSED */
static char *
PrintArrowShape(clientData, tkwin, recordPtr, offset, freeProcPtr)
    ClientData clientData;	/* Not used. */
    Tk_Window tkwin;		/* Window associated with linePtr's widget. */
    char *recordPtr;		/* Pointer to item record containing current
				 * shape information. */
    int offset;			/* Offset of arrow information in record. */
    Tcl_FreeProc **freeProcPtr;	/* Store address of procedure to call to
				 * free string here. */
{
    LineItem *linePtr = (LineItem *) recordPtr;
    char *buffer;

    buffer = (char *) ckalloc(120);
    sprintf(buffer, "%.5g %.5g %.5g", linePtr->arrowShapeA,
	    linePtr->arrowShapeB, linePtr->arrowShapeC);
    *freeProcPtr = TCL_DYNAMIC;
    return buffer;
}

/*
 *--------------------------------------------------------------
 *
 * ConfigureArrows --
 *
 *	If arrowheads have been requested for a line, this
 *	procedure makes arrangements for the arrowheads.
 *
 * Results:
 *	Always returns TCL_OK.
 *
 * Side effects:
 *	Information in linePtr is set up for one or two arrowheads.
 *	the firstArrowPtr and lastArrowPtr polygons are allocated
 *	and initialized, if need be, and the end points of the line
 *	are adjusted so that a thick line doesn't stick out past
 *	the arrowheads.
 *
 *--------------------------------------------------------------
 */

	/* ARGSUSED */
static int
ConfigureArrows(canvas, linePtr)
    Tk_Canvas canvas;			/* Canvas in which arrows will be
					 * displayed (interp and tkwin
					 * fields are needed). */
    LineItem *linePtr;			/* Item to configure for arrows. */
{
    double *poly, *coordPtr;
    double dx, dy, length, sinTheta, cosTheta, temp;
    double fracHeight;			/* Line width as fraction of
					 * arrowhead width. */
    double backup;			/* Distance to backup end points
					 * so the line ends in the middle
					 * of the arrowhead. */
    double vertX, vertY;		/* Position of arrowhead vertex. */
    double shapeA, shapeB, shapeC;	/* Adjusted coordinates (see
					 * explanation below). */

    /*
     * The code below makes a tiny increase in the shape parameters
     * for the line.  This is a bit of a hack, but it seems to result
     * in displays that more closely approximate the specified parameters.
     * Without the adjustment, the arrows come out smaller than expected.
     */

    shapeA = linePtr->arrowShapeA + 0.001;
    shapeB = linePtr->arrowShapeB + 0.001;
    shapeC = linePtr->arrowShapeC + linePtr->width/2.0 + 0.001;

    /*
     * If there's an arrowhead on the first point of the line, compute
     * its polygon and adjust the first point of the line so that the
     * line doesn't stick out past the leading edge of the arrowhead.
     */

    fracHeight = (linePtr->width/2.0)/shapeC;
    backup = fracHeight*shapeB + shapeA*(1.0 - fracHeight)/2.0;
    if (linePtr->arrow != lastUid) {
	poly = linePtr->firstArrowPtr;
	if (poly == NULL) {
	    poly = (double *) ckalloc((unsigned)
		    (2*PTS_IN_ARROW*sizeof(double)));
	    poly[0] = poly[10] = linePtr->coordPtr[0];
	    poly[1] = poly[11] = linePtr->coordPtr[1];
	    linePtr->firstArrowPtr = poly;
	}
	dx = poly[0] - linePtr->coordPtr[2];
	dy = poly[1] - linePtr->coordPtr[3];
	length = hypot(dx, dy);
	if (length == 0) {
	    sinTheta = cosTheta = 0.0;
	} else {
	    sinTheta = dy/length;
	    cosTheta = dx/length;
	}
	vertX = poly[0] - shapeA*cosTheta;
	vertY = poly[1] - shapeA*sinTheta;
	temp = shapeC*sinTheta;
	poly[2] = poly[0] - shapeB*cosTheta + temp;
	poly[8] = poly[2] - 2*temp;
	temp = shapeC*cosTheta;
	poly[3] = poly[1] - shapeB*sinTheta - temp;
	poly[9] = poly[3] + 2*temp;
	poly[4] = poly[2]*fracHeight + vertX*(1.0-fracHeight);
	poly[5] = poly[3]*fracHeight + vertY*(1.0-fracHeight);
	poly[6] = poly[8]*fracHeight + vertX*(1.0-fracHeight);
	poly[7] = poly[9]*fracHeight + vertY*(1.0-fracHeight);

	/*
	 * Polygon done.  Now move the first point towards the second so
	 * that the corners at the end of the line are inside the
	 * arrowhead.
	 */

	linePtr->coordPtr[0] = poly[0] - backup*cosTheta;
	linePtr->coordPtr[1] = poly[1] - backup*sinTheta;
    }

    /*
     * Similar arrowhead calculation for the last point of the line.
     */

    if (linePtr->arrow != firstUid) {
	coordPtr = linePtr->coordPtr + 2*(linePtr->numPoints-2);
	poly = linePtr->lastArrowPtr;
	if (poly == NULL) {
	    poly = (double *) ckalloc((unsigned)
		    (2*PTS_IN_ARROW*sizeof(double)));
	    poly[0] = poly[10] = coordPtr[2];
	    poly[1] = poly[11] = coordPtr[3];
	    linePtr->lastArrowPtr = poly;
	}
	dx = poly[0] - coordPtr[0];
	dy = poly[1] - coordPtr[1];
	length = hypot(dx, dy);
	if (length == 0) {
	    sinTheta = cosTheta = 0.0;
	} else {
	    sinTheta = dy/length;
	    cosTheta = dx/length;
	}
	vertX = poly[0] - shapeA*cosTheta;
	vertY = poly[1] - shapeA*sinTheta;
	temp = shapeC*sinTheta;
	poly[2] = poly[0] - shapeB*cosTheta + temp;
	poly[8] = poly[2] - 2*temp;
	temp = shapeC*cosTheta;
	poly[3] = poly[1] - shapeB*sinTheta - temp;
	poly[9] = poly[3] + 2*temp;
	poly[4] = poly[2]*fracHeight + vertX*(1.0-fracHeight);
	poly[5] = poly[3]*fracHeight + vertY*(1.0-fracHeight);
	poly[6] = poly[8]*fracHeight + vertX*(1.0-fracHeight);
	poly[7] = poly[9]*fracHeight + vertY*(1.0-fracHeight);
	coordPtr[2] = poly[0] - backup*cosTheta;
	coordPtr[3] = poly[1] - backup*sinTheta;
    }

    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * LineToPostscript --
 *
 *	This procedure is called to generate Postscript for
 *	line items.
 *
 * Results:
 *	The return value is a standard Tcl result.  If an error
 *	occurs in generating Postscript then an error message is
 *	left in interp->result, replacing whatever used
 *	to be there.  If no error occurs, then Postscript for the
 *	item is appended to the result.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

static int
LineToPostscript(interp, canvas, itemPtr, prepass)
    Tcl_Interp *interp;			/* Leave Postscript or error message
					 * here. */
    Tk_Canvas canvas;			/* Information about overall canvas. */
    Tk_Item *itemPtr;			/* Item for which Postscript is
					 * wanted. */
    int prepass;			/* 1 means this is a prepass to
					 * collect font information;  0 means
					 * final Postscript is being created. */
{
    LineItem *linePtr = (LineItem *) itemPtr;
    char buffer[200];
    char *style;

    if (linePtr->fg == NULL) {
	return TCL_OK;
    }

    /*
     * Generate a path for the line's center-line (do this differently
     * for straight lines and smoothed lines).
     */

    if ((!linePtr->smooth) || (linePtr->numPoints <= 2)) {
	Tk_CanvasPsPath(interp, canvas, linePtr->coordPtr, linePtr->numPoints);
    } else {
	if (linePtr->fillStipple == None) {
	    TkMakeBezierPostscript(interp, canvas, linePtr->coordPtr,
		    linePtr->numPoints);
	} else {
	    /*
	     * Special hack: Postscript printers don't appear to be able
	     * to turn a path drawn with "curveto"s into a clipping path
	     * without exceeding resource limits, so TkMakeBezierPostscript
	     * won't work for stippled curves.  Instead, generate all of
	     * the intermediate points here and output them into the
	     * Postscript file with "lineto"s instead.
	     */

	    double staticPoints[2*MAX_STATIC_POINTS];
	    double *pointPtr;
	    int numPoints;

	    numPoints = 1 + linePtr->numPoints*linePtr->splineSteps;
	    pointPtr = staticPoints;
	    if (numPoints > MAX_STATIC_POINTS) {
		pointPtr = (double *) ckalloc((unsigned)
			(numPoints * 2 * sizeof(double)));
	    }
	    numPoints = TkMakeBezierCurve(canvas, linePtr->coordPtr,
		    linePtr->numPoints, linePtr->splineSteps, (XPoint *) NULL,
		    pointPtr);
	    Tk_CanvasPsPath(interp, canvas, pointPtr, numPoints);
	    if (pointPtr != staticPoints) {
		ckfree((char *) pointPtr);
	    }
	}
    }

    /*
     * Set other line-drawing parameters and stroke out the line.
     */

    sprintf(buffer, "%d setlinewidth\n", linePtr->width);
    Tcl_AppendResult(interp, buffer, (char *) NULL);
    style = "0 setlinecap\n";
    if (linePtr->capStyle == CapRound) {
	style = "1 setlinecap\n";
    } else if (linePtr->capStyle == CapProjecting) {
	style = "2 setlinecap\n";
    }
    Tcl_AppendResult(interp, style, (char *) NULL);
    style = "0 setlinejoin\n";
    if (linePtr->joinStyle == JoinRound) {
	style = "1 setlinejoin\n";
    } else if (linePtr->joinStyle == JoinBevel) {
	style = "2 setlinejoin\n";
    }
    Tcl_AppendResult(interp, style, (char *) NULL);
    if (Tk_CanvasPsColor(interp, canvas, linePtr->fg) != TCL_OK) {
	return TCL_ERROR;
    };
    if (linePtr->fillStipple != None) {
	Tcl_AppendResult(interp, "StrokeClip ", (char *) NULL);
	if (Tk_CanvasPsStipple(interp, canvas, linePtr->fillStipple)
		!= TCL_OK) {
	    return TCL_ERROR;
	}
    } else {
	Tcl_AppendResult(interp, "stroke\n", (char *) NULL);
    }

    /*
     * Output polygons for the arrowheads, if there are any.
     */

    if (linePtr->firstArrowPtr != NULL) {
	if (linePtr->fillStipple != None) {
	    Tcl_AppendResult(interp, "grestore gsave\n",
		    (char *) NULL);
	}
	if (ArrowheadPostscript(interp, canvas, linePtr,
		linePtr->firstArrowPtr) != TCL_OK) {
	    return TCL_ERROR;
	}
    }
    if (linePtr->lastArrowPtr != NULL) {
	if (linePtr->fillStipple != None) {
	    Tcl_AppendResult(interp, "grestore gsave\n", (char *) NULL);
	}
	if (ArrowheadPostscript(interp, canvas, linePtr,
		linePtr->lastArrowPtr) != TCL_OK) {
	    return TCL_ERROR;
	}
    }
    return TCL_OK;
}

/*
 *--------------------------------------------------------------
 *
 * ArrowheadPostscript --
 *
 *	This procedure is called to generate Postscript for
 *	an arrowhead for a line item.
 *
 * Results:
 *	The return value is a standard Tcl result.  If an error
 *	occurs in generating Postscript then an error message is
 *	left in interp->result, replacing whatever used
 *	to be there.  If no error occurs, then Postscript for the
 *	arrowhead is appended to the result.
 *
 * Side effects:
 *	None.
 *
 *--------------------------------------------------------------
 */

static int
ArrowheadPostscript(interp, canvas, linePtr, arrowPtr)
    Tcl_Interp *interp;			/* Leave Postscript or error message
					 * here. */
    Tk_Canvas canvas;			/* Information about overall canvas. */
    LineItem *linePtr;			/* Line item for which Postscript is
					 * being generated. */
    double *arrowPtr;			/* Pointer to first of five points
					 * describing arrowhead polygon. */
{
    Tk_CanvasPsPath(interp, canvas, arrowPtr, PTS_IN_ARROW);
    if (linePtr->fillStipple != None) {
	Tcl_AppendResult(interp, "clip ", (char *) NULL);
	if (Tk_CanvasPsStipple(interp, canvas, linePtr->fillStipple)
		!= TCL_OK) {
	    return TCL_ERROR;
	}
    } else {
	Tcl_AppendResult(interp, "fill\n", (char *) NULL);
    }
    return TCL_OK;
}