adg/adg-adim.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007,2008,2009 Nicola Fontana <ntd at entidi.it>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  * Boston, MA  02110-1301, USA.
  18  */
  19
  20
  21 /**
  22  * SECTION:adg-adim
  23  * @short_description: Angular dimensions
  24  *
  25  * The #AdgADim entity defines an angular dimension.
  26  */
  27
  28 /**
  29  * AdgADim:
  30  *
  31  * All fields are privates and should not be used directly.
  32  * Use its public methods instead.
  33  **/
  34
  35
  36 #include "adg-adim.h"
  37 #include "adg-adim-private.h"
  38 #include "adg-intl.h"
  39
  40 #define PARENT_OBJECT_CLASS  ((GObjectClass *) adg_adim_parent_class)
  41 #define PARENT_ENTITY_CLASS  ((AdgEntityClass *) adg_adim_parent_class)
  42
  43
  44 enum {
  45     PROP_0,
  46     PROP_ORG1,
  47     PROP_ORG2,
  48     PROP_HAS_EXTENSION1,
  49     PROP_HAS_EXTENSION2
  50 };
  51
  52
  53 static void             dispose                 (GObject        *object);
  54 static void             get_property            (GObject        *object,
  55                                                  guint           param_id,
  56                                                  GValue         *value,
  57                                                  GParamSpec     *pspec);
  58 static void             set_property            (GObject        *object,
  59                                                  guint           param_id,
  60                                                  const GValue   *value,
  61                                                  GParamSpec     *pspec);
  62 static void             local_changed           (AdgEntity      *entity);
  63 static void             invalidate              (AdgEntity      *entity);
  64 static void             arrange                 (AdgEntity      *entity);
  65 static void             render                  (AdgEntity      *entity,
  66                                                  cairo_t        *cr);
  67 static gchar *          default_value           (AdgDim         *dim);
  68 static void             update_geometry         (AdgADim        *adim);
  69 static void             update_entities         (AdgADim        *adim);
  70 static gboolean         set_org1                (AdgADim        *adim,
  71                                                  const AdgPair  *org1);
  72 static gboolean         set_org2                (AdgADim        *adim,
  73                                                  const AdgPair  *org2);
  74 static void             unset_trail             (AdgADim        *adim);
  75 static void             dispose_markers         (AdgADim        *adim);
  76 static gboolean         get_info                (AdgADim        *adim,
  77                                                  CpmlVector      vector[],
  78                                                  AdgPair        *center,
  79                                                  gdouble        *distance);
  80 static CpmlPath *       trail_callback          (AdgTrail       *trail,
  81                                                  gpointer        user_data);
  82
  83
  84 G_DEFINE_TYPE(AdgADim, adg_adim, ADG_TYPE_DIM);
  85
  86
  87 static void
  88 adg_adim_class_init(AdgADimClass *klass)
  89 {
  90     GObjectClass *gobject_class;
  91     AdgEntityClass *entity_class;
  92     AdgDimClass *dim_class;
  93     GParamSpec *param;
  94
  95     gobject_class = (GObjectClass *) klass;
  96     entity_class = (AdgEntityClass *) klass;
  97     dim_class = (AdgDimClass *) klass;
  98
  99     g_type_class_add_private(klass, sizeof(AdgADimPrivate));
 100
 101     gobject_class->dispose = dispose;
 102     gobject_class->get_property = get_property;
 103     gobject_class->set_property = set_property;
 104
 105     entity_class->local_changed = local_changed;
 106     entity_class->invalidate = invalidate;
 107     entity_class->arrange = arrange;
 108     entity_class->render = render;
 109
 110     dim_class->default_value = default_value;
 111
 112     param = g_param_spec_boxed("org1",
 113                                P_("First Origin"),
 114                                P_("Where the first line comes from: this point is used toghether with \"ref1\" to align the first extension line"),
 115                                ADG_TYPE_PAIR,
 116                                G_PARAM_READWRITE);
 117     g_object_class_install_property(gobject_class, PROP_ORG1, param);
 118
 119     param = g_param_spec_boxed("org2",
 120                                P_("Second Origin"),
 121                                P_("Where the second line comes from: this point is used toghether with \"ref2\" to align the second extension line"),
 122                                ADG_TYPE_PAIR,
 123                                G_PARAM_READWRITE);
 124     g_object_class_install_property(gobject_class, PROP_ORG2, param);
 125 }
 126
 127 static void
 128 adg_adim_init(AdgADim *adim)
 129 {
 130     AdgADimPrivate *data;
 131     cairo_path_data_t move_to, line_to, arc_to;
 132
 133     data = G_TYPE_INSTANCE_GET_PRIVATE(adim, ADG_TYPE_ADIM, AdgADimPrivate);
 134     move_to.header.type = CAIRO_PATH_MOVE_TO;
 135     move_to.header.length = 2;
 136     line_to.header.type = CAIRO_PATH_LINE_TO;
 137     line_to.header.length = 2;
 138     arc_to.header.type = CAIRO_PATH_ARC_TO;
 139     arc_to.header.length = 3;
 140
 141     data->org1.x = data->org1.y = 0;
 142     data->org2.x = data->org2.y = 0;
 143     data->has_extension1 = TRUE;
 144     data->has_extension2 = TRUE;
 145
 146     data->cpml.path.status = CAIRO_STATUS_INVALID_PATH_DATA;
 147     data->cpml.path.data = data->cpml.data;
 148     data->cpml.path.num_data = G_N_ELEMENTS(data->cpml.data);
 149     data->cpml.path.data[0] = move_to;
 150     data->cpml.path.data[2] = arc_to;
 151     data->cpml.path.data[5] = move_to;
 152     data->cpml.path.data[7] = line_to;
 153     data->cpml.path.data[9] = move_to;
 154     data->cpml.path.data[11] = line_to;
 155
 156     data->trail = NULL;
 157     data->marker1 = NULL;
 158     data->marker2 = NULL;
 159
 160     data->geometry_arranged = FALSE;
 161
 162     adim->data = data;
 163 }
 164
 165 static void
 166 dispose(GObject *object)
 167 {
 168     dispose_markers((AdgADim *) object);
 169
 170     if (PARENT_OBJECT_CLASS->dispose != NULL)
 171         PARENT_OBJECT_CLASS->dispose(object);
 172 }
 173
 174 static void
 175 get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
 176 {
 177     AdgADimPrivate *data = ((AdgADim *) object)->data;
 178
 179     switch (prop_id) {
 180     case PROP_ORG1:
 181         g_value_set_boxed(value, &data->org1);
 182         break;
 183     case PROP_ORG2:
 184         g_value_set_boxed(value, &data->org2);
 185         break;
 186     case PROP_HAS_EXTENSION1:
 187         g_value_set_boolean(value, data->has_extension1);
 188         break;
 189     case PROP_HAS_EXTENSION2:
 190         g_value_set_boolean(value, data->has_extension2);
 191         break;
 192     default:
 193         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 194         break;
 195     }
 196 }
 197
 198 static void
 199 set_property(GObject *object, guint prop_id,
 200              const GValue *value, GParamSpec *pspec)
 201 {
 202     AdgADim *adim;
 203     AdgADimPrivate *data;
 204
 205     adim = (AdgADim *) object;
 206     data = adim->data;
 207
 208     switch (prop_id) {
 209     case PROP_ORG1:
 210         set_org1(adim, g_value_get_boxed(value));
 211         break;
 212     case PROP_ORG2:
 213         set_org2(adim, g_value_get_boxed(value));
 214         break;
 215     case PROP_HAS_EXTENSION1:
 216         data->has_extension1 = g_value_get_boolean(value);
 217         break;
 218     case PROP_HAS_EXTENSION2:
 219         data->has_extension2 = g_value_get_boolean(value);
 220         break;
 221     default:
 222         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 223         break;
 224     }
 225 }
 226
 227
 228 /**
 229  * adg_adim_new:
 230  *
 231  * Creates a new - undefined - angular dimension. You must, at least,
 232  * define the reference points with adg_dim_set_ref(), the origins of
 233  * the lines ending with the reference points with adg_adim_set_org()
 234  * and the reference for positioning the quote with adg_dim_set_pos().
 235  *
 236  * Returns: the newly created angular dimension entity
 237  **/
 238 AdgADim *
 239 adg_adim_new(void)
 240 {
 241     return g_object_new(ADG_TYPE_ADIM, NULL);
 242 }
 243
 244 /**
 245  * adg_adim_new_full:
 246  * @ref1: first reference point
 247  * @ref2: second reference point
 248  * @org1: first origin point
 249  * @org2: second origin point
 250  *
 251  * Creates a new angular dimension, specifing all the needed
 252  * properties in one shot.
 253  *
 254  * Returns: the newly created angular dimension entity
 255  **/
 256 AdgADim *
 257 adg_adim_new_full(const AdgPair *ref1, const AdgPair *ref2,
 258                   const AdgPair *org1, const AdgPair *org2,
 259                   const AdgPair *pos)
 260 {
 261     return g_object_new(ADG_TYPE_ADIM, "ref1", ref1, "ref2", ref2,
 262                         "org1", org1, "org2", org2, "pos", pos, NULL);
 263 }
 264
 265 /**
 266  * adg_adim_new_full_explicit:
 267  * @ref1_x: the x coordinate of the first reference point
 268  * @ref1_y: the y coordinate of the first reference point
 269  * @ref2_x: the x coordinate of the second reference point
 270  * @ref2_y: the y coordinate of the second reference point
 271  * @direction: angle where to extend the dimension
 272  * @pos_x: the x coordinate of the position reference
 273  * @pos_y: the y coordinate of the position reference
 274  *
 275  * Wrappes adg_adim_new_full() with explicit values.
 276  *
 277  * Returns: the newly created linear dimension entity
 278  **/
 279 AdgADim *
 280 adg_adim_new_full_explicit(gdouble ref1_x, gdouble ref1_y,
 281                            gdouble ref2_x, gdouble ref2_y,
 282                            gdouble org1_x, gdouble org1_y,
 283                            gdouble org2_x, gdouble org2_y,
 284                            gdouble pos_x,  gdouble pos_y)
 285 {
 286     AdgPair ref1, ref2, org1, org2, pos;
 287
 288     ref1.x = ref1_x;
 289     ref1.y = ref1_y;
 290     ref2.x = ref2_x;
 291     ref2.y = ref2_y;
 292     org1.x = org1_x;
 293     org1.y = org1_y;
 294     org2.x = org2_x;
 295     org2.y = org2_y;
 296     pos.x = pos_x;
 297     pos.y = pos_y;
 298
 299     return adg_adim_new_full(&ref1, &ref2, &org1, &org2, &pos);
 300 }
 301
 302 /**
 303  * adg_adim_get_org1:
 304  * @adim: an #AdgADim
 305  *
 306  * Gets the first origin of @adim. The returned pair is owned by
 307  * @adim and should not be modified or freed.
 308  *
 309  * Returns: a pointer to the internal #AdgPair or %NULL on errors
 310  **/
 311 const AdgPair *
 312 adg_adim_get_org1(AdgADim *adim)
 313 {
 314     AdgADimPrivate *data;
 315
 316     g_return_val_if_fail(ADG_IS_ADIM(adim), NULL);
 317
 318     data = adim->data;
 319
 320     return &data->org1;
 321 }
 322
 323 /**
 324  * adg_adim_get_org2:
 325  * @adim: an #AdgADim
 326  *
 327  * Gets the second origin of @adim. The returned pair is owned by
 328  * @adim and should not be modified or freed.
 329  *
 330  * Returns: a pointer to the internal #AdgPair or %NULL on errors
 331  **/
 332 const AdgPair *
 333 adg_adim_get_org2(AdgADim *adim)
 334 {
 335     AdgADimPrivate *data;
 336
 337     g_return_val_if_fail(ADG_IS_ADIM(adim), NULL);
 338
 339     data = adim->data;
 340
 341     return &data->org2;
 342 }
 343
 344 /**
 345  * adg_adim_set_org:
 346  * @adim: an #AdgADim
 347  * @org1: the first origin
 348  * @org2: the second origin
 349  *
 350  * Sets at once the two origins on @adim.
 351  **/
 352 void
 353 adg_adim_set_org(AdgADim *adim, const AdgPair *org1, const AdgPair *org2)
 354 {
 355     GObject *object;
 356
 357     g_return_if_fail(ADG_IS_ADIM(adim));
 358
 359     object = (GObject *) adim;
 360
 361     g_object_freeze_notify(object);
 362
 363     if (set_org1(adim, org1))
 364         g_object_notify(object, "org1");
 365
 366     if (set_org2(adim, org1))
 367         g_object_notify(object, "org2");
 368
 369     g_object_thaw_notify(object);
 370 }
 371
 372
 373 static void
 374 local_changed(AdgEntity *entity)
 375 {
 376     unset_trail((AdgADim *) entity);
 377
 378     PARENT_ENTITY_CLASS->local_changed(entity);
 379 }
 380
 381 static void
 382 invalidate(AdgEntity *entity)
 383 {
 384     AdgADim *adim;
 385     AdgADimPrivate *data;
 386
 387     adim = (AdgADim *) entity;
 388     data = adim->data;
 389
 390     dispose_markers(adim);
 391     data->geometry_arranged = FALSE;
 392     unset_trail(adim);
 393
 394     if (PARENT_ENTITY_CLASS->invalidate != NULL)
 395         PARENT_ENTITY_CLASS->invalidate(entity);
 396 }
 397
 398 static void
 399 arrange(AdgEntity *entity)
 400 {
 401     AdgADim *adim;
 402     AdgDim *dim;
 403     AdgADimPrivate *data;
 404     AdgContainer *quote;
 405     const AdgMatrix *local;
 406     AdgPair ref1, ref2, base1, base12, base2;
 407     AdgPair pair;
 408
 409     PARENT_ENTITY_CLASS->arrange(entity);
 410
 411     adim = (AdgADim *) entity;
 412     dim = (AdgDim *) adim;
 413     data = adim->data;
 414     quote = adg_dim_get_quote(dim);
 415
 416     update_geometry(adim);
 417     update_entities(adim);
 418
 419     if (data->cpml.path.status == CAIRO_STATUS_SUCCESS) {
 420         AdgEntity *quote_entity = (AdgEntity *) quote;
 421         adg_entity_set_global_map(quote_entity, &data->quote.global_map);
 422         adg_entity_set_local_map(quote_entity, &data->quote.local_map);
 423         return;
 424     }
 425
 426     local = adg_entity_local_matrix(entity);
 427
 428     /* Apply the local matrix to the relevant points */
 429     cpml_pair_transform(cpml_pair_copy(&ref1, adg_dim_get_ref1(dim)), local);
 430     cpml_pair_transform(cpml_pair_copy(&ref2, adg_dim_get_ref2(dim)), local);
 431     cpml_pair_transform(cpml_pair_copy(&base1, &data->point.base1), local);
 432     cpml_pair_transform(cpml_pair_copy(&base12, &data->point.base12), local);
 433     cpml_pair_transform(cpml_pair_copy(&base2, &data->point.base2), local);
 434
 435     /* Combine points and global shifts to build the path */
 436     cpml_pair_add(cpml_pair_copy(&pair, &ref1), &data->shift.from1);
 437     cpml_pair_to_cairo(&pair, &data->cpml.data[6]);
 438
 439     cpml_pair_add(cpml_pair_copy(&pair, &base1), &data->shift.base1);
 440     cpml_pair_to_cairo(&pair, &data->cpml.data[1]);
 441
 442     cpml_pair_add(&pair, &data->shift.to1);
 443     cpml_pair_to_cairo(&pair, &data->cpml.data[8]);
 444
 445     cpml_pair_add(cpml_pair_copy(&pair, &base12), &data->shift.base12);
 446     cpml_pair_to_cairo(&pair, &data->cpml.data[3]);
 447
 448     cpml_pair_add(cpml_pair_copy(&pair, &ref2), &data->shift.from2);
 449     cpml_pair_to_cairo(&pair, &data->cpml.data[10]);
 450
 451     cpml_pair_add(cpml_pair_copy(&pair, &base2), &data->shift.base2);
 452     cpml_pair_to_cairo(&pair, &data->cpml.data[4]);
 453
 454     cpml_pair_add(&pair, &data->shift.to2);
 455     cpml_pair_to_cairo(&pair, &data->cpml.data[12]);
 456
 457     data->cpml.path.status = CAIRO_STATUS_SUCCESS;
 458
 459     if (quote != NULL) {
 460         /* Update global and local map of the quote container */
 461         AdgEntity *quote_entity;
 462         gdouble angle;
 463         AdgMatrix matrix;
 464
 465         quote_entity = (AdgEntity *) quote;
 466         angle = adg_dim_quote_angle(dim, (data->angle1 + data->angle2) / 2 + G_PI_2);
 467         adg_matrix_copy(&matrix, local);
 468         cairo_matrix_invert(&matrix);
 469
 470         cpml_pair_from_cairo(&pair, &data->cpml.data[3]);
 471         cairo_matrix_transform_point(&matrix, &pair.x, &pair.y);
 472         cairo_matrix_init_translate(&matrix, pair.x, pair.y);
 473         adg_entity_set_local_map(quote_entity, &matrix);
 474
 475         cairo_matrix_init_rotate(&matrix, angle);
 476         adg_entity_transform_global_map(quote_entity, &matrix, ADG_TRANSFORM_BEFORE);
 477
 478         adg_entity_get_global_map(quote_entity, &data->quote.global_map);
 479         adg_entity_get_local_map(quote_entity, &data->quote.local_map);
 480     }
 481
 482     /* Signal to the markers (if any) that the path has changed */
 483     if (data->marker1 != NULL) {
 484         adg_marker_set_segment(data->marker1, data->trail, 1);
 485         adg_entity_local_changed((AdgEntity *) data->marker1);
 486     }
 487
 488     if (data->marker2 != NULL) {
 489         adg_marker_set_segment(data->marker2, data->trail, 1);
 490         adg_entity_local_changed((AdgEntity *) data->marker2);
 491     }
 492
 493     /* TODO: compute the extents */
 494 }
 495
 496 static void
 497 render(AdgEntity *entity, cairo_t *cr)
 498 {
 499     AdgADim *adim;
 500     AdgDim *dim;
 501     AdgADimPrivate *data;
 502     AdgDimStyle *dim_style;
 503     AdgDress dress;
 504     const cairo_path_t *cairo_path;
 505
 506     adim = (AdgADim *) entity;
 507     dim = (AdgDim *) entity;
 508     data = adim->data;
 509     dim_style = adg_dim_get_dim_style(dim);
 510
 511     dress = adg_dim_style_get_color_dress(dim_style);
 512     adg_entity_apply_dress(entity, dress, cr);
 513
 514     if (data->marker1 != NULL)
 515         adg_entity_render((AdgEntity *) data->marker1, cr);
 516
 517     if (data->marker2 != NULL)
 518         adg_entity_render((AdgEntity *) data->marker2, cr);
 519
 520     adg_entity_render((AdgEntity *) adg_dim_get_quote(dim), cr);
 521
 522     dress = adg_dim_style_get_line_dress(dim_style);
 523     adg_entity_apply_dress(entity, dress, cr);
 524
 525     cairo_path = adg_trail_get_cairo_path(data->trail);
 526     cairo_append_path(cr, cairo_path);
 527     cairo_stroke(cr);
 528 }
 529
 530 static gchar *
 531 default_value(AdgDim *dim)
 532 {
 533     AdgADim *adim;
 534     AdgADimPrivate *data;
 535     AdgDimStyle *dim_style;
 536     gdouble angle;
 537     const gchar *format;
 538
 539     adim = (AdgADim *) dim;
 540     data = adim->data;
 541     dim_style = adg_dim_get_dim_style(dim);
 542     format = adg_dim_style_get_number_format(dim_style);
 543
 544     update_geometry(adim);
 545     angle = (data->angle2 - data->angle1) * 180 / M_PI;
 546
 547     return g_strdup_printf(format, angle);
 548 }
 549
 550 /* With "geometry" is considered any data (point, vector or angle)
 551  * that can be cached: this is strictly related on how the arrange()
 552  * method works */
 553 static void
 554 update_geometry(AdgADim *adim)
 555 {
 556     AdgADimPrivate *data;
 557     AdgDimStyle *dim_style;
 558     gdouble from_offset, to_offset;
 559     gdouble spacing, level;
 560     CpmlVector vector[3];
 561     CpmlPair center;
 562     gdouble distance;
 563
 564     data = adim->data;
 565
 566     if (data->geometry_arranged)
 567         return;
 568
 569     if (!get_info(adim, vector, &center, &distance)) {
 570         /* Parallel lines: hang with an error message */
 571         g_warning("%s: trying to set an angular dimension on parallel lines",
 572                   G_STRLOC);
 573         return;
 574     }
 575
 576     dim_style = adg_dim_get_dim_style((AdgDim *) adim);
 577     from_offset = adg_dim_style_get_from_offset(dim_style);
 578     to_offset = adg_dim_style_get_to_offset(dim_style);
 579     spacing = adg_dim_style_get_baseline_spacing(dim_style);
 580     level = adg_dim_get_level((AdgDim *) adim);
 581
 582     /* shift.from1 */
 583     cpml_vector_set_length(&vector[0], from_offset);
 584     cpml_pair_copy(&data->shift.from1, &vector[0]);
 585
 586     /* shift.base1 */
 587     cpml_vector_set_length(&vector[0], level * spacing);
 588     cpml_pair_copy(&data->shift.base1, &vector[0]);
 589
 590     /* shift.to1 */
 591     cpml_vector_set_length(&vector[0], to_offset);
 592     cpml_pair_copy(&data->shift.to1, &vector[0]);
 593
 594     /* shift.from2 */
 595     cpml_vector_set_length(&vector[2], from_offset);
 596     cpml_pair_copy(&data->shift.from2, &vector[2]);
 597
 598     /* shift.base2 */
 599     cpml_vector_set_length(&vector[2], level * spacing);
 600     cpml_pair_copy(&data->shift.base2, &vector[2]);
 601
 602     /* shift.to2 */
 603     cpml_vector_set_length(&vector[2], to_offset);
 604     cpml_pair_copy(&data->shift.to2, &vector[2]);
 605
 606     /* shift.base12 */
 607     cpml_vector_set_length(&vector[1], level * spacing);
 608     cpml_pair_copy(&data->shift.base12, &vector[1]);
 609
 610     /* Distance can be 0, so the following will leave the
 611      * vector array in undefined state */
 612
 613     /* point.base1 */
 614     cpml_vector_set_length(&vector[0], distance);
 615     cpml_pair_add(cpml_pair_copy(&data->point.base1, &vector[0]), &center);
 616
 617     /* point.base2 */
 618     cpml_vector_set_length(&vector[2], distance);
 619     cpml_pair_add(cpml_pair_copy(&data->point.base2, &vector[2]), &center);
 620
 621     /* point.base12 */
 622     cpml_vector_set_length(&vector[1], distance);
 623     cpml_pair_add(cpml_pair_copy(&data->point.base12, &vector[1]), &center);
 624
 625     data->geometry_arranged = TRUE;
 626 }
 627
 628 static void
 629 update_entities(AdgADim *adim)
 630 {
 631     AdgADimPrivate *data;
 632     AdgDimStyle *dim_style;
 633
 634     data = adim->data;
 635     dim_style = adg_dim_get_dim_style((AdgDim *) adim);
 636
 637     if (data->trail == NULL)
 638         data->trail = adg_trail_new(trail_callback, adim);
 639
 640     if (data->marker1 == NULL)
 641         data->marker1 = adg_dim_style_marker1_new(dim_style);
 642
 643     if (data->marker2 == NULL)
 644         data->marker2 = adg_dim_style_marker2_new(dim_style);
 645 }
 646
 647 static gboolean
 648 set_org1(AdgADim *adim, const AdgPair *org1)
 649 {
 650     AdgADimPrivate *data = adim->data;
 651
 652     if (adg_pair_equal(&data->org1, org1))
 653         return FALSE;
 654
 655     data->org1 = *org1;
 656
 657     return TRUE;
 658 }
 659
 660 static gboolean
 661 set_org2(AdgADim *adim, const AdgPair *org2)
 662 {
 663     AdgADimPrivate *data = adim->data;
 664
 665     if (adg_pair_equal(&data->org2, org2))
 666         return FALSE;
 667
 668     data->org2 = *org2;
 669
 670     return TRUE;
 671 }
 672
 673 static void
 674 unset_trail(AdgADim *adim)
 675 {
 676     AdgADimPrivate *data = adim->data;
 677
 678     if (data->trail != NULL)
 679         adg_model_clear((AdgModel *) data->trail);
 680
 681     data->cpml.path.status = CAIRO_STATUS_INVALID_PATH_DATA;
 682 }
 683
 684 static void
 685 dispose_markers(AdgADim *adim)
 686 {
 687     AdgADimPrivate *data = adim->data;
 688
 689     if (data->trail != NULL) {
 690         g_object_unref(data->trail);
 691         data->trail = NULL;
 692     }
 693
 694     if (data->marker1 != NULL) {
 695         g_object_unref(data->marker1);
 696         data->marker1 = NULL;
 697     }
 698
 699     if (data->marker2 != NULL) {
 700         g_object_unref(data->marker2);
 701         data->marker2 = NULL;
 702     }
 703 }
 704
 705 static gboolean
 706 get_info(AdgADim *adim, CpmlVector vector[],
 707          AdgPair *center, gdouble *distance)
 708 {
 709     AdgDim *dim;
 710     AdgADimPrivate *data;
 711     const AdgPair *ref1, *ref2;
 712     gdouble factor;
 713
 714     dim = (AdgDim *) adim;
 715     data = adim->data;
 716     ref1 = adg_dim_get_ref1(dim);
 717     ref2 = adg_dim_get_ref2(dim);
 718
 719     cpml_pair_sub(cpml_pair_copy(&vector[0], ref1), &data->org1);
 720     cpml_pair_sub(cpml_pair_copy(&vector[2], ref2), &data->org2);
 721
 722     factor = vector[0].x * vector[2].y - vector[0].y * vector[2].x;
 723     if (factor == 0)
 724         return FALSE;
 725
 726     factor = ((ref1->y - ref2->y) * vector[2].x -
 727               (ref1->x - ref2->x) * vector[2].y) / factor;
 728
 729     center->x = ref1->x + vector[0].x * factor;
 730     center->y = ref1->y + vector[0].y * factor;
 731     *distance = cpml_pair_distance(center, adg_dim_get_pos(dim));
 732     data->angle1 = cpml_vector_angle(&vector[0]);
 733     data->angle2 = cpml_vector_angle(&vector[2]);
 734     while (data->angle2 < data->angle1)
 735         data->angle2 += M_PI * 2;
 736
 737     cpml_vector_from_angle(&vector[1], (data->angle1 + data->angle2) / 2);
 738
 739     return TRUE;
 740 }
 741
 742 static CpmlPath *
 743 trail_callback(AdgTrail *trail, gpointer user_data)
 744 {
 745     AdgADim *adim;
 746     AdgADimPrivate *data;
 747
 748     adim = (AdgADim *) user_data;
 749     data = adim->data;
 750
 751     return &data->cpml.path;
 752 }