1 #define __SP_BOX3D_C__
3 /*
4 * SVG <box3d> implementation
5 *
6 * Authors:
7 * Maximilian Albert <Anhalter42@gmx.de>
8 * Lauris Kaplinski <lauris@kaplinski.com>
9 * bulia byak <buliabyak@users.sf.net>
10 *
11 * Copyright (C) 2007 Authors
12 * Copyright (C) 1999-2002 Lauris Kaplinski
13 * Copyright (C) 2000-2001 Ximian, Inc.
14 *
15 * Released under GNU GPL, read the file 'COPYING' for more information
16 */
18 #include <glibmm/i18n.h>
19 #include "attributes.h"
20 #include "xml/document.h"
21 #include "xml/repr.h"
23 #include "box3d.h"
24 #include "box3d-side.h"
25 #include "box3d-context.h"
26 #include "proj_pt.h"
27 #include "transf_mat_3x4.h"
28 #include "perspective-line.h"
29 #include "inkscape.h"
30 #include "persp3d.h"
31 #include "line-geometry.h"
32 #include "persp3d-reference.h"
33 #include "uri.h"
34 #include "2geom/geom.h"
36 #include "desktop.h"
37 #include "macros.h"
39 static void box3d_class_init(SPBox3DClass *klass);
40 static void box3d_init(SPBox3D *box3d);
42 static void box3d_build(SPObject *object, SPDocument *document, Inkscape::XML::Node *repr);
43 static void box3d_release(SPObject *object);
44 static void box3d_set(SPObject *object, unsigned int key, const gchar *value);
45 static void box3d_update(SPObject *object, SPCtx *ctx, guint flags);
46 static Inkscape::XML::Node *box3d_write(SPObject *object, Inkscape::XML::Node *repr, guint flags);
48 static gchar *box3d_description(SPItem *item);
49 static NR::Matrix box3d_set_transform(SPItem *item, NR::Matrix const &xform);
51 static void box3d_ref_changed(SPObject *old_ref, SPObject *ref, SPBox3D *box);
52 static void box3d_ref_modified(SPObject *href, guint flags, SPBox3D *box);
53 //static void box3d_ref_changed(SPObject *old_ref, SPObject *ref, Persp3D *persp);
54 //static void box3d_ref_modified(SPObject *href, guint flags, Persp3D *persp);
56 static SPGroupClass *parent_class;
58 static gint counter = 0;
60 GType
61 box3d_get_type(void)
62 {
63 static GType type = 0;
65 if (!type) {
66 GTypeInfo info = {
67 sizeof(SPBox3DClass),
68 NULL, /* base_init */
69 NULL, /* base_finalize */
70 (GClassInitFunc) box3d_class_init,
71 NULL, /* class_finalize */
72 NULL, /* class_data */
73 sizeof(SPBox3D),
74 16, /* n_preallocs */
75 (GInstanceInitFunc) box3d_init,
76 NULL, /* value_table */
77 };
78 type = g_type_register_static(SP_TYPE_GROUP, "SPBox3D", &info, (GTypeFlags) 0);
79 }
81 return type;
82 }
84 static void
85 box3d_class_init(SPBox3DClass *klass)
86 {
87 SPObjectClass *sp_object_class = (SPObjectClass *) klass;
88 SPItemClass *item_class = (SPItemClass *) klass;
90 parent_class = (SPGroupClass *) g_type_class_ref(SP_TYPE_GROUP);
92 sp_object_class->build = box3d_build;
93 sp_object_class->release = box3d_release;
94 sp_object_class->set = box3d_set;
95 sp_object_class->write = box3d_write;
96 sp_object_class->update = box3d_update;
98 item_class->description = box3d_description;
99 item_class->set_transform = box3d_set_transform;
100 }
102 static void
103 box3d_init(SPBox3D *box)
104 {
105 box->persp_href = NULL;
106 box->persp_ref = new Persp3DReference(SP_OBJECT(box));
107 new (&box->modified_connection) sigc::connection();
108 }
110 static void
111 box3d_build(SPObject *object, SPDocument *document, Inkscape::XML::Node *repr)
112 {
113 if (((SPObjectClass *) (parent_class))->build) {
114 ((SPObjectClass *) (parent_class))->build(object, document, repr);
115 }
117 SPBox3D *box = SP_BOX3D (object);
118 box->my_counter = counter++;
120 /* we initialize the z-orders to zero so that they are updated during dragging */
121 for (int i = 0; i < 6; ++i) {
122 box->z_orders[i] = 0;
123 }
125 // TODO: Create/link to the correct perspective
127 SPDocument *doc = SP_OBJECT_DOCUMENT(box);
128 if (!doc) {
129 g_print ("No document for the box!!!!\n");
130 return;
131 }
132 /**
133 if (!box->persp3d) {
134 g_print ("Box seems to be newly created since no perspective is referenced yet. We reference the current perspective.\n");
135 box->persp3d = doc->current_persp3d;
136 }
137 **/
139 box->persp_ref->changedSignal().connect(sigc::bind(sigc::ptr_fun(box3d_ref_changed), box));
141 sp_object_read_attr(object, "inkscape:perspectiveID");
142 sp_object_read_attr(object, "inkscape:corner0");
143 sp_object_read_attr(object, "inkscape:corner7");
144 }
146 /**
147 * Virtual release of SPBox3D members before destruction.
148 */
149 static void
150 box3d_release(SPObject *object)
151 {
152 SPBox3D *box = (SPBox3D *) object;
154 if (box->persp_href) {
155 g_free(box->persp_href);
156 }
157 if (box->persp_ref) {
158 box->persp_ref->detach();
159 delete box->persp_ref;
160 box->persp_ref = NULL;
161 }
163 box->modified_connection.disconnect();
164 box->modified_connection.~connection();
166 //persp3d_remove_box (box->persp_ref->getObject(), box);
168 if (((SPObjectClass *) parent_class)->release)
169 ((SPObjectClass *) parent_class)->release(object);
170 }
172 static void
173 box3d_set(SPObject *object, unsigned int key, const gchar *value)
174 {
175 SPBox3D *box = SP_BOX3D(object);
177 switch (key) {
178 case SP_ATTR_INKSCAPE_BOX3D_PERSPECTIVE_ID:
179 if ( value && box->persp_href && ( strcmp(value, box->persp_href) == 0 ) ) {
180 /* No change, do nothing. */
181 } else {
182 if (box->persp_href) {
183 g_free(box->persp_href);
184 box->persp_href = NULL;
185 }
186 if (value) {
187 box->persp_href = g_strdup(value);
189 // Now do the attaching, which emits the changed signal.
190 try {
191 box->persp_ref->attach(Inkscape::URI(value));
192 } catch (Inkscape::BadURIException &e) {
193 g_warning("%s", e.what());
194 box->persp_ref->detach();
195 }
196 } else {
197 // Detach, which emits the changed signal.
198 box->persp_ref->detach();
199 // TODO: Clean this up (also w.r.t the surrounding if construct)
200 /***
201 g_print ("No perspective given. Attaching to current perspective instead.\n");
202 g_free(box->persp_href);
203 Inkscape::XML::Node *repr = SP_OBJECT_REPR(inkscape_active_document()->current_persp3d);
204 box->persp_href = g_strdup(repr->attribute("id"));
205 box->persp_ref->attach(Inkscape::URI(box->persp_href));
206 ***/
207 }
208 }
210 // FIXME: Is the following update doubled by some call in either persp3d.cpp or vanishing_point_new.cpp?
211 box3d_position_set(box);
212 break;
213 case SP_ATTR_INKSCAPE_BOX3D_CORNER0:
214 if (value && strcmp(value, "0 : 0 : 0 : 0")) {
215 box->orig_corner0 = Proj::Pt3(value);
216 box->save_corner0 = box->orig_corner0;
217 box3d_position_set(box);
218 }
219 break;
220 case SP_ATTR_INKSCAPE_BOX3D_CORNER7:
221 if (value && strcmp(value, "0 : 0 : 0 : 0")) {
222 box->orig_corner7 = Proj::Pt3(value);
223 box->save_corner7 = box->orig_corner7;
224 box3d_position_set(box);
225 }
226 break;
227 default:
228 if (((SPObjectClass *) (parent_class))->set) {
229 ((SPObjectClass *) (parent_class))->set(object, key, value);
230 }
231 break;
232 }
233 //object->updateRepr(); // This ensures correct update of the box after undo/redo. FIXME: Why is this not present in sp-rect.cpp and similar files?
234 }
236 /**
237 * Gets called when (re)attached to another perspective.
238 */
239 static void
240 box3d_ref_changed(SPObject *old_ref, SPObject *ref, SPBox3D *box)
241 {
242 if (old_ref) {
243 sp_signal_disconnect_by_data(old_ref, box);
244 persp3d_remove_box (SP_PERSP3D(old_ref), box);
245 }
246 if ( SP_IS_PERSP3D(ref) && ref != box ) // FIXME: Comparisons sane?
247 {
248 box->modified_connection.disconnect();
249 box->modified_connection = ref->connectModified(sigc::bind(sigc::ptr_fun(&box3d_ref_modified), box));
250 box3d_ref_modified(ref, 0, box);
251 persp3d_add_box (SP_PERSP3D(ref), box);
252 }
253 }
255 static void
256 box3d_update(SPObject *object, SPCtx *ctx, guint flags)
257 {
258 if (flags & (SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_STYLE_MODIFIED_FLAG | SP_OBJECT_VIEWPORT_MODIFIED_FLAG)) {
260 /* FIXME?: Perhaps the display updates of box sides should be instantiated from here, but this
261 causes evil update loops so it's all done from box3d_position_set, which is called from
262 various other places (like the handlers in object-edit.cpp, vanishing-point.cpp, etc. */
264 }
266 // Invoke parent method
267 if (((SPObjectClass *) (parent_class))->update)
268 ((SPObjectClass *) (parent_class))->update(object, ctx, flags);
269 }
272 static Inkscape::XML::Node *box3d_write(SPObject *object, Inkscape::XML::Node *repr, guint flags)
273 {
274 SPBox3D *box = SP_BOX3D(object);
276 if ((flags & SP_OBJECT_WRITE_BUILD) && !repr) {
277 g_print ("Do we ever end up here?\n");
278 Inkscape::XML::Document *xml_doc = sp_document_repr_doc(SP_OBJECT_DOCUMENT(object));
279 repr = xml_doc->createElement("svg:g");
280 repr->setAttribute("sodipodi:type", "inkscape:box3d");
281 }
283 if (flags & SP_OBJECT_WRITE_EXT) {
285 if (box->persp_href) {
286 repr->setAttribute("inkscape:perspectiveID", box->persp_href);
287 } else {
288 /* box is not yet linked to a perspective; use the document's current perspective */
289 SPDocument *doc = inkscape_active_document();
290 if (box->persp_ref->getURI()) {
291 gchar *uri_string = box->persp_ref->getURI()->toString();
292 repr->setAttribute("inkscape:perspectiveID", uri_string);
293 g_free(uri_string);
294 } else if (doc) {
295 //persp3d_add_box (doc->current_persp3d, box);
296 Inkscape::XML::Node *persp_repr = SP_OBJECT_REPR(doc->current_persp3d);
297 const gchar *persp_id = persp_repr->attribute("id");
298 gchar *href = g_strdup_printf("#%s", persp_id);
299 repr->setAttribute("inkscape:perspectiveID", href);
300 g_free(href);
301 } else {
302 g_print ("No active document while creating perspective!!!\n");
303 }
304 }
306 gchar *coordstr0 = box->orig_corner0.coord_string();
307 gchar *coordstr7 = box->orig_corner7.coord_string();
308 repr->setAttribute("inkscape:corner0", coordstr0);
309 repr->setAttribute("inkscape:corner7", coordstr7);
310 g_free(coordstr0);
311 g_free(coordstr7);
313 box->orig_corner0.normalize();
314 box->orig_corner7.normalize();
316 box->save_corner0 = box->orig_corner0;
317 box->save_corner7 = box->orig_corner7;
318 }
320 if (((SPObjectClass *) (parent_class))->write) {
321 ((SPObjectClass *) (parent_class))->write(object, repr, flags);
322 }
324 return repr;
325 }
327 static gchar *
328 box3d_description(SPItem *item)
329 {
330 g_return_val_if_fail(SP_IS_BOX3D(item), NULL);
332 return g_strdup(_("<b>3D Box</b>"));
333 }
335 void
336 box3d_position_set (SPBox3D *box)
337 {
338 /* This draws the curve and calls requestDisplayUpdate() for each side (the latter is done in
339 box3d_side_position_set() to avoid update conflicts with the parent box) */
340 for (SPObject *child = sp_object_first_child(SP_OBJECT (box)); child != NULL; child = SP_OBJECT_NEXT(child) ) {
341 box3d_side_position_set (SP_BOX3D_SIDE (child));
342 }
343 }
345 static NR::Matrix
346 box3d_set_transform(SPItem *item, NR::Matrix const &xform)
347 {
348 SPBox3D *box = SP_BOX3D(item);
350 Persp3D *persp = box->persp_ref->getObject();
352 persp3d_apply_affine_transformation(persp, xform); // also triggers repr updates
354 /***
355 // FIXME: We somehow have to apply the transformation to strokes, patterns, and gradients. How?
356 NR::Matrix ret(NR::transform(xform));
357 gdouble const sw = hypot(ret[0], ret[1]);
358 gdouble const sh = hypot(ret[2], ret[3]);
360 SPItem *sideitem = NULL;
361 for (SPObject *side = sp_object_first_child(box); side != NULL; side = SP_OBJECT_NEXT(side)) {
362 sideitem = SP_ITEM(side);
364 // Adjust stroke width
365 sp_item_adjust_stroke(sideitem, sqrt(fabs(sw * sh)));
367 // Adjust pattern fill
368 sp_item_adjust_pattern(sideitem, xform);
370 // Adjust gradient fill
371 sp_item_adjust_gradient(sideitem, xform);
372 }
373 ***/
375 return NR::identity();
376 }
379 /**
380 * Gets called when persp(?) repr contents change: i.e. parameter change.
381 */
382 static void
383 box3d_ref_modified(SPObject *href, guint flags, SPBox3D *box)
384 {
385 /***
386 g_print ("FIXME: box3d_ref_modified was called. What should we do?\n");
387 g_print ("Here is at least the the href's id: %s\n", SP_OBJECT_REPR(href)->attribute("id"));
388 g_print (" ... and the box's, too: %s\n", SP_OBJECT_REPR(box)->attribute("id"));
389 ***/
391 }
393 Proj::Pt3
394 box3d_get_proj_corner (guint id, Proj::Pt3 const &c0, Proj::Pt3 const &c7) {
395 return Proj::Pt3 ((id & Box3D::X) ? c7[Proj::X] : c0[Proj::X],
396 (id & Box3D::Y) ? c7[Proj::Y] : c0[Proj::Y],
397 (id & Box3D::Z) ? c7[Proj::Z] : c0[Proj::Z],
398 1.0);
399 }
401 Proj::Pt3
402 box3d_get_proj_corner (SPBox3D const *box, guint id) {
403 return Proj::Pt3 ((id & Box3D::X) ? box->orig_corner7[Proj::X] : box->orig_corner0[Proj::X],
404 (id & Box3D::Y) ? box->orig_corner7[Proj::Y] : box->orig_corner0[Proj::Y],
405 (id & Box3D::Z) ? box->orig_corner7[Proj::Z] : box->orig_corner0[Proj::Z],
406 1.0);
407 }
409 NR::Point
410 box3d_get_corner_screen (SPBox3D const *box, guint id) {
411 Proj::Pt3 proj_corner (box3d_get_proj_corner (box, id));
412 if (!box->persp_ref->getObject()) {
413 //g_print ("No perspective present in box!! Should we simply use the currently active perspective?\n");
414 return NR::Point (NR_HUGE, NR_HUGE);
415 }
416 return box->persp_ref->getObject()->tmat.image(proj_corner).affine();
417 }
419 Proj::Pt3
420 box3d_get_proj_center (SPBox3D *box) {
421 box->orig_corner0.normalize();
422 box->orig_corner7.normalize();
423 return Proj::Pt3 ((box->orig_corner0[Proj::X] + box->orig_corner7[Proj::X]) / 2,
424 (box->orig_corner0[Proj::Y] + box->orig_corner7[Proj::Y]) / 2,
425 (box->orig_corner0[Proj::Z] + box->orig_corner7[Proj::Z]) / 2,
426 1.0);
427 }
429 NR::Point
430 box3d_get_center_screen (SPBox3D *box) {
431 Proj::Pt3 proj_center (box3d_get_proj_center (box));
432 if (!box->persp_ref->getObject()) {
433 //g_print ("No perspective present in box!! Should we simply use the currently active perspective?\n");
434 return NR::Point (NR_HUGE, NR_HUGE);
435 }
436 return box->persp_ref->getObject()->tmat.image(proj_center).affine();
437 }
439 /*
440 * To keep the snappoint from jumping randomly between the two lines when the mouse pointer is close to
441 * their intersection, we remember the last snapped line and keep snapping to this specific line as long
442 * as the distance from the intersection to the mouse pointer is less than remember_snap_threshold.
443 */
445 // Should we make the threshold settable in the preferences?
446 static double remember_snap_threshold = 30;
447 //static guint remember_snap_index = 0;
448 static guint remember_snap_index_center = 0;
450 static Proj::Pt3
451 box3d_snap (SPBox3D *box, int id, Proj::Pt3 const &pt_proj, Proj::Pt3 const &start_pt) {
452 double z_coord = start_pt[Proj::Z];
453 double diff_x = box->save_corner7[Proj::X] - box->save_corner0[Proj::X];
454 double diff_y = box->save_corner7[Proj::Y] - box->save_corner0[Proj::Y];
455 double x_coord = start_pt[Proj::X];
456 double y_coord = start_pt[Proj::Y];
457 Proj::Pt3 A_proj (x_coord, y_coord, z_coord, 1.0);
458 Proj::Pt3 B_proj (x_coord + diff_x, y_coord, z_coord, 1.0);
459 Proj::Pt3 C_proj (x_coord + diff_x, y_coord + diff_y, z_coord, 1.0);
460 Proj::Pt3 D_proj (x_coord, y_coord + diff_y, z_coord, 1.0);
461 Proj::Pt3 E_proj (x_coord - diff_x, y_coord + diff_y, z_coord, 1.0);
463 NR::Point A = box->persp_ref->getObject()->tmat.image(A_proj).affine();
464 NR::Point B = box->persp_ref->getObject()->tmat.image(B_proj).affine();
465 NR::Point C = box->persp_ref->getObject()->tmat.image(C_proj).affine();
466 NR::Point D = box->persp_ref->getObject()->tmat.image(D_proj).affine();
467 NR::Point E = box->persp_ref->getObject()->tmat.image(E_proj).affine();
468 NR::Point pt = box->persp_ref->getObject()->tmat.image(pt_proj).affine();
470 // TODO: Replace these lines between corners with lines from a corner to a vanishing point
471 // (this might help to prevent rounding errors if the box is small)
472 Box3D::Line pl1(A, B);
473 Box3D::Line pl2(A, D);
474 Box3D::Line diag1(A, (id == -1 || (!(id & Box3D::X) == !(id & Box3D::Y))) ? C : E);
475 Box3D::Line diag2(A, E); // diag2 is only taken into account if id equals -1, i.e., if we are snapping the center
477 int num_snap_lines = (id != -1) ? 3 : 4;
478 NR::Point snap_pts[num_snap_lines];
480 snap_pts[0] = pl1.closest_to (pt);
481 snap_pts[1] = pl2.closest_to (pt);
482 snap_pts[2] = diag1.closest_to (pt);
483 if (id == -1) {
484 snap_pts[3] = diag2.closest_to (pt);
485 }
487 gdouble const zoom = inkscape_active_desktop()->current_zoom();
489 // determine the distances to all potential snapping points
490 double snap_dists[num_snap_lines];
491 for (int i = 0; i < num_snap_lines; ++i) {
492 snap_dists[i] = NR::L2 (snap_pts[i] - pt) * zoom;
493 }
495 // while we are within a given tolerance of the starting point,
496 // keep snapping to the same point to avoid jumping
497 bool within_tolerance = true;
498 for (int i = 0; i < num_snap_lines; ++i) {
499 if (snap_dists[i] > remember_snap_threshold) {
500 within_tolerance = false;
501 break;
502 }
503 }
505 // find the closest snapping point
506 int snap_index = -1;
507 double snap_dist = NR_HUGE;
508 for (int i = 0; i < num_snap_lines; ++i) {
509 if (snap_dists[i] < snap_dist) {
510 snap_index = i;
511 snap_dist = snap_dists[i];
512 }
513 }
515 // snap to the closest point (or the previously remembered one
516 // if we are within tolerance of the starting point)
517 NR::Point result;
518 if (within_tolerance) {
519 result = snap_pts[remember_snap_index_center];
520 } else {
521 remember_snap_index_center = snap_index;
522 result = snap_pts[snap_index];
523 }
524 return box->persp_ref->getObject()->tmat.preimage (result, z_coord, Proj::Z);
525 }
527 void
528 box3d_set_corner (SPBox3D *box, const guint id, NR::Point const &new_pos, const Box3D::Axis movement, bool constrained) {
529 g_return_if_fail ((movement != Box3D::NONE) && (movement != Box3D::XYZ));
531 box->orig_corner0.normalize();
532 box->orig_corner7.normalize();
534 /* update corners 0 and 7 according to which handle was moved and to the axes of movement */
535 if (!(movement & Box3D::Z)) {
536 Proj::Pt3 pt_proj (box->persp_ref->getObject()->tmat.preimage (new_pos, (id < 4) ? box->orig_corner0[Proj::Z] :
537 box->orig_corner7[Proj::Z],
538 Proj::Z));
539 if (constrained) {
540 pt_proj = box3d_snap (box, id, pt_proj, box3d_get_proj_corner (id, box->save_corner0, box->save_corner7));
541 }
543 // normalizing pt_proj is essential because we want to mingle affine coordinates
544 pt_proj.normalize();
545 box->orig_corner0 = Proj::Pt3 ((id & Box3D::X) ? box->save_corner0[Proj::X] : pt_proj[Proj::X],
546 (id & Box3D::Y) ? box->save_corner0[Proj::Y] : pt_proj[Proj::Y],
547 box->save_corner0[Proj::Z],
548 1.0);
549 box->orig_corner7 = Proj::Pt3 ((id & Box3D::X) ? pt_proj[Proj::X] : box->save_corner7[Proj::X],
550 (id & Box3D::Y) ? pt_proj[Proj::Y] : box->save_corner7[Proj::Y],
551 box->save_corner7[Proj::Z],
552 1.0);
553 } else {
554 Box3D::PerspectiveLine pl(box->persp_ref->getObject()->tmat.image(
555 box3d_get_proj_corner (id, box->save_corner0, box->save_corner7)).affine(),
556 Proj::Z, box->persp_ref->getObject());
557 NR::Point new_pos_snapped(pl.closest_to(new_pos));
558 Proj::Pt3 pt_proj (box->persp_ref->getObject()->
559 tmat.preimage (new_pos_snapped,
560 box3d_get_proj_corner (box, id)[(movement & Box3D::Y) ? Proj::X : Proj::Y],
561 (movement & Box3D::Y) ? Proj::X : Proj::Y));
562 bool corner0_move_x = !(id & Box3D::X) && (movement & Box3D::X);
563 bool corner0_move_y = !(id & Box3D::Y) && (movement & Box3D::Y);
564 bool corner7_move_x = (id & Box3D::X) && (movement & Box3D::X);
565 bool corner7_move_y = (id & Box3D::Y) && (movement & Box3D::Y);
566 // normalizing pt_proj is essential because we want to mingle affine coordinates
567 pt_proj.normalize();
568 box->orig_corner0 = Proj::Pt3 (corner0_move_x ? pt_proj[Proj::X] : box->orig_corner0[Proj::X],
569 corner0_move_y ? pt_proj[Proj::Y] : box->orig_corner0[Proj::Y],
570 (id & Box3D::Z) ? box->orig_corner0[Proj::Z] : pt_proj[Proj::Z],
571 1.0);
572 box->orig_corner7 = Proj::Pt3 (corner7_move_x ? pt_proj[Proj::X] : box->orig_corner7[Proj::X],
573 corner7_move_y ? pt_proj[Proj::Y] : box->orig_corner7[Proj::Y],
574 (id & Box3D::Z) ? pt_proj[Proj::Z] : box->orig_corner7[Proj::Z],
575 1.0);
576 }
577 // FIXME: Should we update the box here? If so, how?
578 }
580 void box3d_set_center (SPBox3D *box, NR::Point const &new_pos, NR::Point const &old_pos, const Box3D::Axis movement, bool constrained) {
581 g_return_if_fail ((movement != Box3D::NONE) && (movement != Box3D::XYZ));
583 if (!(movement & Box3D::Z)) {
584 double coord = (box->orig_corner0[Proj::Z] + box->orig_corner7[Proj::Z]) / 2;
585 double radx = (box->orig_corner7[Proj::X] - box->orig_corner0[Proj::X]) / 2;
586 double rady = (box->orig_corner7[Proj::Y] - box->orig_corner0[Proj::Y]) / 2;
588 Proj::Pt3 pt_proj (box->persp_ref->getObject()->tmat.preimage (new_pos, coord, Proj::Z));
589 if (constrained) {
590 Proj::Pt3 old_pos_proj (box->persp_ref->getObject()->tmat.preimage (old_pos, coord, Proj::Z));
591 pt_proj = box3d_snap (box, -1, pt_proj, old_pos_proj);
592 }
593 // normalizing pt_proj is essential because we want to mingle affine coordinates
594 pt_proj.normalize();
595 box->orig_corner0 = Proj::Pt3 ((movement & Box3D::X) ? pt_proj[Proj::X] - radx : box->orig_corner0[Proj::X],
596 (movement & Box3D::Y) ? pt_proj[Proj::Y] - rady : box->orig_corner0[Proj::Y],
597 box->orig_corner0[Proj::Z],
598 1.0);
599 box->orig_corner7 = Proj::Pt3 ((movement & Box3D::X) ? pt_proj[Proj::X] + radx : box->orig_corner7[Proj::X],
600 (movement & Box3D::Y) ? pt_proj[Proj::Y] + rady : box->orig_corner7[Proj::Y],
601 box->orig_corner7[Proj::Z],
602 1.0);
603 } else {
604 double coord = (box->orig_corner0[Proj::X] + box->orig_corner7[Proj::X]) / 2;
605 double radz = (box->orig_corner7[Proj::Z] - box->orig_corner0[Proj::Z]) / 2;
607 Box3D::PerspectiveLine pl(old_pos, Proj::Z, box->persp_ref->getObject());
608 NR::Point new_pos_snapped(pl.closest_to(new_pos));
609 Proj::Pt3 pt_proj (box->persp_ref->getObject()->tmat.preimage (new_pos_snapped, coord, Proj::X));
611 /* normalizing pt_proj is essential because we want to mingle affine coordinates */
612 pt_proj.normalize();
613 box->orig_corner0 = Proj::Pt3 (box->orig_corner0[Proj::X],
614 box->orig_corner0[Proj::Y],
615 pt_proj[Proj::Z] - radz,
616 1.0);
617 box->orig_corner7 = Proj::Pt3 (box->orig_corner7[Proj::X],
618 box->orig_corner7[Proj::Y],
619 pt_proj[Proj::Z] + radz,
620 1.0);
621 }
622 }
624 /*
625 * Manipulates corner1 through corner4 to contain the indices of the corners
626 * from which the perspective lines in the direction of 'axis' emerge
627 */
628 void box3d_corners_for_PLs (const SPBox3D * box, Proj::Axis axis,
629 NR::Point &corner1, NR::Point &corner2, NR::Point &corner3, NR::Point &corner4)
630 {
631 g_return_if_fail (box->persp_ref->getObject());
632 //box->orig_corner0.normalize();
633 //box->orig_corner7.normalize();
634 double coord = (box->orig_corner0[axis] > box->orig_corner7[axis]) ?
635 box->orig_corner0[axis] :
636 box->orig_corner7[axis];
638 Proj::Pt3 c1, c2, c3, c4;
639 // FIXME: This can certainly be done more elegantly/efficiently than by a case-by-case analysis.
640 switch (axis) {
641 case Proj::X:
642 c1 = Proj::Pt3 (coord, box->orig_corner0[Proj::Y], box->orig_corner0[Proj::Z], 1.0);
643 c2 = Proj::Pt3 (coord, box->orig_corner7[Proj::Y], box->orig_corner0[Proj::Z], 1.0);
644 c3 = Proj::Pt3 (coord, box->orig_corner7[Proj::Y], box->orig_corner7[Proj::Z], 1.0);
645 c4 = Proj::Pt3 (coord, box->orig_corner0[Proj::Y], box->orig_corner7[Proj::Z], 1.0);
646 break;
647 case Proj::Y:
648 c1 = Proj::Pt3 (box->orig_corner0[Proj::X], coord, box->orig_corner0[Proj::Z], 1.0);
649 c2 = Proj::Pt3 (box->orig_corner7[Proj::X], coord, box->orig_corner0[Proj::Z], 1.0);
650 c3 = Proj::Pt3 (box->orig_corner7[Proj::X], coord, box->orig_corner7[Proj::Z], 1.0);
651 c4 = Proj::Pt3 (box->orig_corner0[Proj::X], coord, box->orig_corner7[Proj::Z], 1.0);
652 break;
653 case Proj::Z:
654 c1 = Proj::Pt3 (box->orig_corner7[Proj::X], box->orig_corner7[Proj::Y], coord, 1.0);
655 c2 = Proj::Pt3 (box->orig_corner7[Proj::X], box->orig_corner0[Proj::Y], coord, 1.0);
656 c3 = Proj::Pt3 (box->orig_corner0[Proj::X], box->orig_corner0[Proj::Y], coord, 1.0);
657 c4 = Proj::Pt3 (box->orig_corner0[Proj::X], box->orig_corner7[Proj::Y], coord, 1.0);
658 break;
659 default:
660 return;
661 }
662 corner1 = box->persp_ref->getObject()->tmat.image(c1).affine();
663 corner2 = box->persp_ref->getObject()->tmat.image(c2).affine();
664 corner3 = box->persp_ref->getObject()->tmat.image(c3).affine();
665 corner4 = box->persp_ref->getObject()->tmat.image(c4).affine();
666 }
668 /* Auxiliary function: Checks whether the half-line from A to B crosses the line segment joining C and D */
669 static bool
670 box3d_half_line_crosses_joining_line (Geom::Point const &A, Geom::Point const &B,
671 Geom::Point const &C, Geom::Point const &D) {
672 Geom::Point E; // the point of intersection
673 Geom::Point n0 = (B - A).ccw();
674 double d0 = dot(n0,A);
676 Geom::Point n1 = (D - C).ccw();
677 double d1 = dot(n1,C);
678 Geom::IntersectorKind intersects = Geom::line_intersection(n0, d0, n1, d1, E);
679 if (intersects == Geom::coincident || intersects == Geom::parallel) {
680 return false;
681 }
683 if ((dot(C,n0) < d0) == (dot(D,n0) < d0)) {
684 // C and D lie on the same side of the line AB
685 return false;
686 }
687 if ((dot(A,n1) < d1) != (dot(B,n1) < d1)) {
688 // A and B lie on different sides of the line CD
689 return true;
690 } else if (Geom::distance(E,A) < Geom::distance(E,B)) {
691 // The line CD passes on the "wrong" side of A
692 return false;
693 }
695 // The line CD passes on the "correct" side of A
696 return true;
697 }
699 static bool
700 box3d_XY_axes_are_swapped (SPBox3D *box) {
701 Persp3D *persp = box->persp_ref->getObject();
702 g_return_val_if_fail(persp, false);
703 Box3D::PerspectiveLine l1(box3d_get_corner_screen(box, 3), Proj::X, persp);
704 Box3D::PerspectiveLine l2(box3d_get_corner_screen(box, 3), Proj::Y, persp);
705 NR::Point v1(l1.direction());
706 NR::Point v2(l2.direction());
707 v1.normalize();
708 v2.normalize();
710 return (v1[NR::X]*v2[NR::Y] - v1[NR::Y]*v2[NR::X] > 0);
711 }
713 static inline void
714 box3d_aux_set_z_orders (int z_orders[6], int a, int b, int c, int d, int e, int f) {
715 z_orders[0] = a;
716 z_orders[1] = b;
717 z_orders[2] = c;
718 z_orders[3] = d;
719 z_orders[4] = e;
720 z_orders[5] = f;
721 }
723 static inline void
724 box3d_swap_z_orders (int z_orders[6]) {
725 int tmp;
726 for (int i = 0; i < 3; ++i) {
727 tmp = z_orders[i];
728 z_orders[i] = z_orders[5-i];
729 z_orders[5-i] = tmp;
730 }
731 }
733 /*
734 * In der Standard-Perspektive:
735 * 2 = vorne
736 * 1 = oben
737 * 0 = links
738 * 3 = rechts
739 * 4 = unten
740 * 5 = hinten
741 */
743 /* All VPs infinite */
744 static void
745 box3d_set_new_z_orders_case0 (SPBox3D *box, int z_orders[6], Box3D::Axis central_axis) {
746 Persp3D *persp = box->persp_ref->getObject();
747 NR::Point xdir(persp3d_get_infinite_dir(persp, Proj::X));
748 NR::Point ydir(persp3d_get_infinite_dir(persp, Proj::Y));
749 NR::Point zdir(persp3d_get_infinite_dir(persp, Proj::Z));
751 bool swapped = box3d_XY_axes_are_swapped(box);
753 //g_print ("3 infinite VPs; ");
754 switch(central_axis) {
755 case Box3D::X:
756 if (!swapped) {
757 //g_print ("central axis X (case a)");
758 box3d_aux_set_z_orders (z_orders, 2, 0, 4, 1, 3, 5);
759 } else {
760 //g_print ("central axis X (case b)");
761 box3d_aux_set_z_orders (z_orders, 3, 1, 5, 2, 4, 0);
762 }
763 break;
764 case Box3D::Y:
765 if (!swapped) {
766 //g_print ("central axis Y (case a)");
767 box3d_aux_set_z_orders (z_orders, 2, 3, 1, 4, 0, 5);
768 } else {
769 //g_print ("central axis Y (case b)");
770 box3d_aux_set_z_orders (z_orders, 5, 0, 4, 1, 3, 2);
771 }
772 break;
773 case Box3D::Z:
774 if (!swapped) {
775 //g_print ("central axis Z (case a)");
776 box3d_aux_set_z_orders (z_orders, 2, 0, 1, 4, 3, 5);
777 } else {
778 //g_print ("central axis Z (case b)");
779 box3d_aux_set_z_orders (z_orders, 5, 3, 4, 1, 0, 2);
780 }
781 break;
782 case Box3D::NONE:
783 if (!swapped) {
784 //g_print ("central axis NONE (case a)");
785 box3d_aux_set_z_orders (z_orders, 2, 3, 4, 1, 0, 5);
786 } else {
787 //g_print ("central axis NONE (case b)");
788 box3d_aux_set_z_orders (z_orders, 5, 0, 1, 4, 3, 2);
789 }
790 break;
791 default:
792 g_assert_not_reached();
793 break;
794 }
795 /**
796 if (swapped) {
797 g_print ("; swapped");
798 }
799 g_print ("\n");
800 **/
801 }
803 /* Precisely one finite VP */
804 static void
805 box3d_set_new_z_orders_case1 (SPBox3D *box, int z_orders[6], Box3D::Axis central_axis, Box3D::Axis fin_axis) {
806 Persp3D *persp = box->persp_ref->getObject();
807 NR::Point vp(persp3d_get_VP(persp, Box3D::toProj(fin_axis)).affine());
809 // note: in some of the case distinctions below we rely upon the fact that oaxis1 and oaxis2 are ordered
810 Box3D::Axis oaxis1 = Box3D::get_remaining_axes(fin_axis).first;
811 Box3D::Axis oaxis2 = Box3D::get_remaining_axes(fin_axis).second;
812 //g_print ("oaxis1 = %s, oaxis2 = %s\n", Box3D::string_from_axes(oaxis1), Box3D::string_from_axes(oaxis2));
813 int inside1 = 0;
814 int inside2 = 0;
815 inside1 = box3d_pt_lies_in_PL_sector (box, vp, 3, 3 ^ oaxis2, oaxis1);
816 inside2 = box3d_pt_lies_in_PL_sector (box, vp, 3, 3 ^ oaxis1, oaxis2);
817 //g_print ("inside1 = %d, inside2 = %d\n", inside1, inside2);
819 bool swapped = box3d_XY_axes_are_swapped(box);
821 //g_print ("2 infinite VPs; ");
822 //g_print ("finite axis: %s; ", Box3D::string_from_axes(fin_axis));
823 switch(central_axis) {
824 case Box3D::X:
825 if (!swapped) {
826 //g_print ("central axis X (case a)");
827 box3d_aux_set_z_orders (z_orders, 2, 4, 0, 1, 3, 5);
828 } else {
829 //if (inside2) {
830 //g_print ("central axis X (case b)");
831 box3d_aux_set_z_orders (z_orders, 5, 3, 1, 0, 2, 4);
832 //} else {
833 //g_print ("central axis X (case c)");
834 //box3d_aux_set_z_orders (z_orders, 5, 3, 1, 2, 0, 4);
835 //}
836 }
837 break;
838 case Box3D::Y:
839 if (inside2 > 0) {
840 //g_print ("central axis Y (case a)");
841 box3d_aux_set_z_orders (z_orders, 1, 2, 3, 0, 5, 4);
842 } else if (inside2 < 0) {
843 //g_print ("central axis Y (case b)");
844 box3d_aux_set_z_orders (z_orders, 2, 3, 1, 4, 0, 5);
845 } else {
846 if (!swapped) {
847 //g_print ("central axis Y (case c1)");
848 box3d_aux_set_z_orders (z_orders, 2, 3, 1, 5, 0, 4);
849 } else {
850 //g_print ("central axis Y (case c2)");
851 box3d_aux_set_z_orders (z_orders, 5, 0, 4, 1, 3, 2);
852 }
853 }
854 break;
855 case Box3D::Z:
856 if (inside2) {
857 if (!swapped) {
858 //g_print ("central axis Z (case a1)");
859 box3d_aux_set_z_orders (z_orders, 2, 1, 3, 0, 4, 5);
860 } else {
861 //g_print ("central axis Z (case a2)");
862 box3d_aux_set_z_orders (z_orders, 5, 3, 4, 0, 1, 2);
863 }
864 } else if (inside1) {
865 if (!swapped) {
866 //g_print ("central axis Z (case b1)");
867 box3d_aux_set_z_orders (z_orders, 2, 0, 1, 4, 3, 5);
868 } else {
869 //g_print ("central axis Z (case b2)");
870 box3d_aux_set_z_orders (z_orders, 5, 3, 4, 1, 0, 2);
871 //box3d_aux_set_z_orders (z_orders, 5, 3, 0, 1, 2, 4);
872 }
873 } else {
874 // "regular" case
875 if (!swapped) {
876 //g_print ("central axis Z (case c1)");
877 box3d_aux_set_z_orders (z_orders, 0, 1, 2, 5, 4, 3);
878 } else {
879 //g_print ("central axis Z (case c2)");
880 box3d_aux_set_z_orders (z_orders, 5, 3, 4, 0, 2, 1);
881 //box3d_aux_set_z_orders (z_orders, 5, 3, 4, 0, 2, 1);
882 }
883 }
884 break;
885 case Box3D::NONE:
886 if (!swapped) {
887 //g_print ("central axis NONE (case a)");
888 box3d_aux_set_z_orders (z_orders, 2, 3, 4, 5, 0, 1);
889 } else {
890 //g_print ("central axis NONE (case b)");
891 box3d_aux_set_z_orders (z_orders, 5, 0, 1, 3, 2, 4);
892 //box3d_aux_set_z_orders (z_orders, 2, 3, 4, 1, 0, 5);
893 }
894 break;
895 default:
896 g_assert_not_reached();
897 }
898 /**
899 if (swapped) {
900 g_print ("; swapped");
901 }
902 g_print ("\n");
903 **/
904 }
906 /* Precisely 2 finite VPs */
907 static void
908 box3d_set_new_z_orders_case2 (SPBox3D *box, int z_orders[6], Box3D::Axis central_axis, Box3D::Axis infinite_axis) {
909 Persp3D *persp = box->persp_ref->getObject();
911 NR::Point c3(box3d_get_corner_screen(box, 3));
912 NR::Point xdir(persp3d_get_PL_dir_from_pt(persp, c3, Proj::X));
913 NR::Point ydir(persp3d_get_PL_dir_from_pt(persp, c3, Proj::Y));
914 NR::Point zdir(persp3d_get_PL_dir_from_pt(persp, c3, Proj::Z));
916 bool swapped = box3d_XY_axes_are_swapped(box);
918 int insidexy = box3d_VP_lies_in_PL_sector (box, Proj::X, 3, 3 ^ Box3D::Z, Box3D::Y);
919 int insidexz = box3d_VP_lies_in_PL_sector (box, Proj::X, 3, 3 ^ Box3D::Y, Box3D::Z);
921 int insideyx = box3d_VP_lies_in_PL_sector (box, Proj::Y, 3, 3 ^ Box3D::Z, Box3D::X);
922 int insideyz = box3d_VP_lies_in_PL_sector (box, Proj::Y, 3, 3 ^ Box3D::X, Box3D::Z);
924 int insidezx = box3d_VP_lies_in_PL_sector (box, Proj::Z, 3, 3 ^ Box3D::Y, Box3D::X);
925 int insidezy = box3d_VP_lies_in_PL_sector (box, Proj::Z, 3, 3 ^ Box3D::X, Box3D::Y);
927 //g_print ("Insides: xy = %d, xz = %d, yx = %d, yz = %d, zx = %d, zy = %d\n",
928 // insidexy, insidexz, insideyx, insideyz, insidezx, insidezy);
930 //g_print ("1 infinite VP; ");
931 switch(central_axis) {
932 case Box3D::X:
933 if (!swapped) {
934 if (insidezy == -1) {
935 //g_print ("central axis X (case a1)");
936 box3d_aux_set_z_orders (z_orders, 2, 4, 0, 1, 3, 5);
937 } else if (insidexy == 1) {
938 //g_print ("central axis X (case a2)");
939 box3d_aux_set_z_orders (z_orders, 2, 4, 0, 5, 1, 3);
940 } else {
941 //g_print ("central axis X (case a3)");
942 box3d_aux_set_z_orders (z_orders, 2, 4, 0, 1, 3, 5);
943 }
944 } else {
945 if (insideyz == -1) {
946 //g_print ("central axis X (case b1)");
947 box3d_aux_set_z_orders (z_orders, 3, 1, 5, 0, 2, 4);
948 } else {
949 if (!swapped) {
950 //g_print ("central axis X (case b2)");
951 box3d_aux_set_z_orders (z_orders, 3, 1, 5, 2, 4, 0);
952 } else {
953 //g_print ("central axis X (case b3)");
954 box3d_aux_set_z_orders (z_orders, 1, 3, 5, 0, 2, 4);
955 }
956 }
957 }
958 break;
959 case Box3D::Y:
960 if (!swapped) {
961 if (insideyz == 1) {
962 //g_print ("central axis Y (case a1)");
963 box3d_aux_set_z_orders (z_orders, 2, 3, 1, 0, 5, 4);
964 } else {
965 //g_print ("central axis Y (case a2)");
966 box3d_aux_set_z_orders (z_orders, 2, 3, 1, 5, 0, 4);
967 }
968 } else {
969 //g_print ("central axis Y (case b)");
970 box3d_aux_set_z_orders (z_orders, 5, 0, 4, 1, 3, 2);
971 }
972 break;
973 case Box3D::Z:
974 if (!swapped) {
975 if (insidezy == 1) {
976 //g_print ("central axis Z (case a1)");
977 box3d_aux_set_z_orders (z_orders, 2, 1, 0, 4, 3, 5);
978 } else if (insidexy == -1) {
979 //g_print ("central axis Z (case a2)");
980 box3d_aux_set_z_orders (z_orders, 2, 1, 0, 5, 4, 3);
981 } else {
982 //g_print ("central axis Z (case a3)");
983 box3d_aux_set_z_orders (z_orders, 2, 0, 1, 5, 3, 4);
984 }
985 } else {
986 //g_print ("central axis Z (case b)");
987 box3d_aux_set_z_orders (z_orders, 5, 3, 4, 1, 0, 2);
988 }
989 break;
990 case Box3D::NONE:
991 if (!swapped) {
992 //g_print ("central axis NONE (case a)");
993 box3d_aux_set_z_orders (z_orders, 2, 3, 4, 1, 0, 5);
994 } else {
995 //g_print ("central axis NONE (case b)");
996 box3d_aux_set_z_orders (z_orders, 5, 0, 1, 4, 3, 2);
997 }
998 break;
999 default:
1000 g_assert_not_reached();
1001 break;
1002 }
1003 /**
1004 if (swapped) {
1005 g_print ("; swapped");
1006 }
1007 g_print ("\n");
1008 **/
1009 }
1011 /*
1012 * It can happen that during dragging the box is everted.
1013 * In this case the opposite sides in this direction need to be swapped
1014 */
1015 static Box3D::Axis
1016 box3d_everted_directions (SPBox3D *box) {
1017 Box3D::Axis ev = Box3D::NONE;
1019 box->orig_corner0.normalize();
1020 box->orig_corner7.normalize();
1022 if (box->orig_corner0[Proj::X] < box->orig_corner7[Proj::X])
1023 ev = (Box3D::Axis) (ev ^ Box3D::X);
1024 if (box->orig_corner0[Proj::Y] < box->orig_corner7[Proj::Y])
1025 ev = (Box3D::Axis) (ev ^ Box3D::Y);
1026 if (box->orig_corner0[Proj::Z] > box->orig_corner7[Proj::Z]) // FIXME: Remove the need to distinguish signs among the cases
1027 ev = (Box3D::Axis) (ev ^ Box3D::Z);
1029 return ev;
1030 }
1032 static void
1033 box3d_swap_sides(int z_orders[6], Box3D::Axis axis) {
1034 int pos1 = -1;
1035 int pos2 = -1;
1037 for (int i = 0; i < 6; ++i) {
1038 if (!(Box3D::int_to_face(z_orders[i]) & axis)) {
1039 if (pos1 == -1) {
1040 pos1 = i;
1041 } else {
1042 pos2 = i;
1043 break;
1044 }
1045 }
1046 }
1048 int tmp = z_orders[pos1];
1049 z_orders[pos1] = z_orders[pos2];
1050 z_orders[pos2] = tmp;
1051 }
1054 bool
1055 box3d_recompute_z_orders (SPBox3D *box) {
1056 Persp3D *persp = box->persp_ref->getObject();
1058 //g_return_val_if_fail(persp, false);
1059 if (!persp)
1060 return false;
1062 int z_orders[6];
1064 NR::Point c3(box3d_get_corner_screen(box, 3));
1066 // determine directions from corner3 to the VPs
1067 int num_finite = 0;
1068 Box3D::Axis axis_finite = Box3D::NONE;
1069 Box3D::Axis axis_infinite = Box3D::NONE;
1070 NR::Point dirs[3];
1071 for (int i = 0; i < 3; ++i) {
1072 dirs[i] = persp3d_get_PL_dir_from_pt(persp, c3, Box3D::toProj(Box3D::axes[i]));
1073 if (persp3d_VP_is_finite(persp, Proj::axes[i])) {
1074 num_finite++;
1075 axis_finite = Box3D::axes[i];
1076 } else {
1077 axis_infinite = Box3D::axes[i];
1078 }
1079 }
1081 // determine the "central" axis (if there is one)
1082 Box3D::Axis central_axis = Box3D::NONE;
1083 if(Box3D::lies_in_sector(dirs[0], dirs[1], dirs[2])) {
1084 central_axis = Box3D::Z;
1085 } else if(Box3D::lies_in_sector(dirs[1], dirs[2], dirs[0])) {
1086 central_axis = Box3D::X;
1087 } else if(Box3D::lies_in_sector(dirs[2], dirs[0], dirs[1])) {
1088 central_axis = Box3D::Y;
1089 }
1091 switch (num_finite) {
1092 case 0:
1093 // TODO: Remark: In this case (and maybe one of the others, too) the z-orders for all boxes
1094 // coincide, hence only need to be computed once in a more central location.
1095 box3d_set_new_z_orders_case0(box, z_orders, central_axis);
1096 break;
1097 case 1:
1098 box3d_set_new_z_orders_case1(box, z_orders, central_axis, axis_finite);
1099 break;
1100 case 2:
1101 case 3:
1102 box3d_set_new_z_orders_case2(box, z_orders, central_axis, axis_infinite);
1103 break;
1104 default:
1105 /*
1106 * For each VP F, check wether the half-line from the corner3 to F crosses the line segment
1107 * joining the other two VPs. If this is the case, it determines the "central" corner from
1108 * which the visible sides can be deduced. Otherwise, corner3 is the central corner.
1109 */
1110 // FIXME: We should eliminate the use of NR::Point altogether
1111 Box3D::Axis central_axis = Box3D::NONE;
1112 NR::Point vp_x = persp3d_get_VP(persp, Proj::X).affine();
1113 NR::Point vp_y = persp3d_get_VP(persp, Proj::Y).affine();
1114 NR::Point vp_z = persp3d_get_VP(persp, Proj::Z).affine();
1115 Geom::Point vpx(vp_x[NR::X], vp_x[NR::Y]);
1116 Geom::Point vpy(vp_y[NR::X], vp_y[NR::Y]);
1117 Geom::Point vpz(vp_z[NR::X], vp_z[NR::Y]);
1119 NR::Point c3 = box3d_get_corner_screen(box, 3);
1120 Geom::Point corner3(c3[NR::X], c3[NR::Y]);
1122 if (box3d_half_line_crosses_joining_line (corner3, vpx, vpy, vpz)) {
1123 central_axis = Box3D::X;
1124 } else if (box3d_half_line_crosses_joining_line (corner3, vpy, vpz, vpx)) {
1125 central_axis = Box3D::Y;
1126 } else if (box3d_half_line_crosses_joining_line (corner3, vpz, vpx, vpy)) {
1127 central_axis = Box3D::Z;
1128 }
1129 //g_print ("Crossing: %s\n", Box3D::string_from_axes(central_axis));
1131 unsigned int central_corner = 3 ^ central_axis;
1132 if (central_axis == Box3D::Z) {
1133 central_corner = central_corner ^ Box3D::XYZ;
1134 }
1135 if (box3d_XY_axes_are_swapped(box)) {
1136 //g_print ("Axes X and Y are swapped\n");
1137 central_corner = central_corner ^ Box3D::XYZ;
1138 }
1140 NR::Point c1(box3d_get_corner_screen(box, 1));
1141 NR::Point c2(box3d_get_corner_screen(box, 2));
1142 NR::Point c7(box3d_get_corner_screen(box, 7));
1144 Geom::Point corner1(c1[NR::X], c1[NR::Y]);
1145 Geom::Point corner2(c2[NR::X], c2[NR::Y]);
1146 Geom::Point corner7(c7[NR::X], c7[NR::Y]);
1147 // FIXME: At present we don't use the information about central_corner computed above.
1148 switch (central_axis) {
1149 case Box3D::Y:
1150 if (!box3d_half_line_crosses_joining_line(vpz, vpy, corner3, corner2)) {
1151 box3d_aux_set_z_orders (z_orders, 2, 3, 1, 5, 0, 4);
1152 } else {
1153 // degenerate case
1154 //g_print ("Degenerate case #1\n");
1155 box3d_aux_set_z_orders (z_orders, 2, 1, 3, 0, 5, 4);
1156 }
1157 break;
1159 case Box3D::Z:
1160 if (box3d_half_line_crosses_joining_line(vpx, vpz, corner3, corner1)) {
1161 // degenerate case
1162 //g_print ("Degenerate case #2\n");
1163 box3d_aux_set_z_orders (z_orders, 2, 0, 1, 4, 3, 5);
1164 } else if (box3d_half_line_crosses_joining_line(vpx, vpy, corner3, corner7)) {
1165 // degenerate case
1166 //g_print ("Degenerate case #3\n");
1167 box3d_aux_set_z_orders (z_orders, 2, 1, 0, 5, 3, 4);
1168 } else {
1169 box3d_aux_set_z_orders (z_orders, 2, 1, 0, 3, 4, 5);
1170 }
1171 break;
1173 case Box3D::X:
1174 if (box3d_half_line_crosses_joining_line(vpz, vpx, corner3, corner1)) {
1175 // degenerate case
1176 //g_print ("Degenerate case #4\n");
1177 box3d_aux_set_z_orders (z_orders, 2, 1, 0, 4, 5, 3);
1178 } else {
1179 box3d_aux_set_z_orders (z_orders, 2, 4, 0, 5, 1, 3);
1180 }
1181 break;
1183 case Box3D::NONE:
1184 box3d_aux_set_z_orders (z_orders, 2, 3, 4, 1, 0, 5);
1185 break;
1187 default:
1188 g_assert_not_reached();
1189 break;
1190 } // end default case
1191 }
1193 // TODO: If there are still errors in z-orders of everted boxes, we need to choose a variable corner
1194 // instead of the hard-coded corner #3 in the computations above
1195 Box3D::Axis ev = box3d_everted_directions(box);
1196 for (int i = 0; i < 3; ++i) {
1197 if (ev & Box3D::axes[i]) {
1198 box3d_swap_sides(z_orders, Box3D::axes[i]);
1199 }
1200 }
1202 // Check whether anything actually changed
1203 for (int i = 0; i < 6; ++i) {
1204 if (box->z_orders[i] != z_orders[i]) {
1205 for (int j = i; j < 6; ++j) {
1206 box->z_orders[j] = z_orders[j];
1207 }
1208 return true;
1209 }
1210 }
1211 return false;
1212 }
1214 static std::map<int, Box3DSide *>
1215 box3d_get_sides (SPBox3D *box) {
1216 std::map<int, Box3DSide *> sides;
1217 for (SPObject *side = sp_object_first_child(box); side != NULL; side = SP_OBJECT_NEXT(side)) {
1218 sides[Box3D::face_to_int(sp_repr_get_int_attribute(SP_OBJECT_REPR(side),
1219 "inkscape:box3dsidetype", -1))] = SP_BOX3D_SIDE(side);
1220 }
1221 sides.erase(-1);
1222 return sides;
1223 }
1226 // TODO: Check whether the box is everted in any direction and swap the sides opposite to this direction
1227 void
1228 box3d_set_z_orders (SPBox3D *box) {
1229 // For efficiency reasons, we only set the new z-orders if something really changed
1230 if (box3d_recompute_z_orders (box)) {
1231 std::map<int, Box3DSide *> sides = box3d_get_sides(box);
1232 std::map<int, Box3DSide *>::iterator side;
1233 for (unsigned int i = 0; i < 6; ++i) {
1234 side = sides.find(box->z_orders[i]);
1235 if (side != sides.end()) {
1236 SP_ITEM((*side).second)->lowerToBottom();
1237 }
1238 }
1239 /**
1240 g_print ("Resetting z-orders: ");
1241 for (int i = 0; i < 6; ++i) {
1242 g_print ("%d ", box->z_orders[i]);
1243 }
1244 g_print ("\n");
1245 **/
1246 }
1247 }
1249 /*
1250 * Auxiliary function for z-order recomputing:
1251 * Determines whether \a pt lies in the sector formed by the two PLs from the corners with IDs
1252 * \a i21 and \a id2 to the VP in direction \a axis. If the VP is infinite, we say that \a pt
1253 * lies in the sector if it lies between the two (parallel) PLs.
1254 * \ret * 0 if \a pt doesn't lie in the sector
1255 * * 1 if \a pt lies in the sector and either VP is finite of VP is infinite and the direction
1256 * from the edge between the two corners to \a pt points towards the VP
1257 * * -1 otherwise
1258 */
1259 // TODO: Maybe it would be useful to have a similar method for projective points pt because then we
1260 // can use it for VPs and perhaps merge the case distinctions during z-order recomputation.
1261 int
1262 box3d_pt_lies_in_PL_sector (SPBox3D const *box, NR::Point const &pt, int id1, int id2, Box3D::Axis axis) {
1263 Persp3D *persp = box->persp_ref->getObject();
1265 // the two corners
1266 NR::Point c1(box3d_get_corner_screen(box, id1));
1267 NR::Point c2(box3d_get_corner_screen(box, id2));
1269 int ret = 0;
1270 if (persp3d_VP_is_finite(persp, Box3D::toProj(axis))) {
1271 NR::Point vp(persp3d_get_VP(persp, Box3D::toProj(axis)).affine());
1272 NR::Point v1(c1 - vp);
1273 NR::Point v2(c2 - vp);
1274 NR::Point w(pt - vp);
1275 ret = static_cast<int>(Box3D::lies_in_sector(v1, v2, w));
1276 //g_print ("Case 0 - returning %d\n", ret);
1277 } else {
1278 Box3D::PerspectiveLine pl1(c1, Box3D::toProj(axis), persp);
1279 Box3D::PerspectiveLine pl2(c2, Box3D::toProj(axis), persp);
1280 if (pl1.lie_on_same_side(pt, c2) && pl2.lie_on_same_side(pt, c1)) {
1281 // test whether pt lies "towards" or "away from" the VP
1282 Box3D::Line edge(c1,c2);
1283 NR::Point c3(box3d_get_corner_screen(box, id1 ^ axis));
1284 if (edge.lie_on_same_side(pt, c3)) {
1285 ret = 1;
1286 } else {
1287 ret = -1;
1288 }
1289 }
1290 //g_print ("Case 1 - returning %d\n", ret);
1291 }
1292 return ret;
1293 }
1295 int
1296 box3d_VP_lies_in_PL_sector (SPBox3D const *box, Proj::Axis vpdir, int id1, int id2, Box3D::Axis axis) {
1297 Persp3D *persp = box->persp_ref->getObject();
1299 if (!persp3d_VP_is_finite(persp, vpdir)) {
1300 return 0;
1301 } else {
1302 return box3d_pt_lies_in_PL_sector(box, persp3d_get_VP(persp, vpdir).affine(), id1, id2, axis);
1303 }
1304 }
1306 /* swap the coordinates of corner0 and corner7 along the specified axis */
1307 static void
1308 box3d_swap_coords(SPBox3D *box, Proj::Axis axis, bool smaller = true) {
1309 box->orig_corner0.normalize();
1310 box->orig_corner7.normalize();
1311 if ((box->orig_corner0[axis] < box->orig_corner7[axis]) != smaller) {
1312 double tmp = box->orig_corner0[axis];
1313 box->orig_corner0[axis] = box->orig_corner7[axis];
1314 box->orig_corner7[axis] = tmp;
1315 }
1316 // FIXME: Should we also swap the coordinates of save_corner0 and save_corner7?
1317 }
1319 /* ensure that the coordinates of corner0 and corner7 are in the correct order (to prevent everted boxes) */
1320 void
1321 box3d_relabel_corners(SPBox3D *box) {
1322 box3d_swap_coords(box, Proj::X, false);
1323 box3d_swap_coords(box, Proj::Y, false);
1324 box3d_swap_coords(box, Proj::Z, true);
1325 }
1327 /*
1328 Local Variables:
1329 mode:c++
1330 c-file-style:"stroustrup"
1331 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1332 indent-tabs-mode:nil
1333 fill-column:99
1334 End:
1335 */
1336 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :