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/line.h>
35 #include "sp-guide.h"
36 #include "sp-namedview.h"
37 #include "preferences.h"
39 #include "desktop.h"
40 #include "desktop-handles.h"
41 #include "macros.h"
43 static void box3d_class_init(SPBox3DClass *klass);
44 static void box3d_init(SPBox3D *box3d);
46 static void box3d_build(SPObject *object, SPDocument *document, Inkscape::XML::Node *repr);
47 static void box3d_release(SPObject *object);
48 static void box3d_set(SPObject *object, unsigned int key, const gchar *value);
49 static void box3d_update(SPObject *object, SPCtx *ctx, guint flags);
50 static Inkscape::XML::Node *box3d_write(SPObject *object, Inkscape::XML::Document *doc, Inkscape::XML::Node *repr, guint flags);
52 static gchar *box3d_description(SPItem *item);
53 static Geom::Matrix box3d_set_transform(SPItem *item, Geom::Matrix const &xform);
54 static void box3d_convert_to_guides(SPItem *item);
56 static void box3d_ref_changed(SPObject *old_ref, SPObject *ref, SPBox3D *box);
58 static SPGroupClass *parent_class;
60 static gint counter = 0;
62 GType
63 box3d_get_type(void)
64 {
65 static GType type = 0;
67 if (!type) {
68 GTypeInfo info = {
69 sizeof(SPBox3DClass),
70 NULL, /* base_init */
71 NULL, /* base_finalize */
72 (GClassInitFunc) box3d_class_init,
73 NULL, /* class_finalize */
74 NULL, /* class_data */
75 sizeof(SPBox3D),
76 16, /* n_preallocs */
77 (GInstanceInitFunc) box3d_init,
78 NULL, /* value_table */
79 };
80 type = g_type_register_static(SP_TYPE_GROUP, "SPBox3D", &info, (GTypeFlags) 0);
81 }
83 return type;
84 }
86 static void
87 box3d_class_init(SPBox3DClass *klass)
88 {
89 SPObjectClass *sp_object_class = (SPObjectClass *) klass;
90 SPItemClass *item_class = (SPItemClass *) klass;
92 parent_class = (SPGroupClass *) g_type_class_ref(SP_TYPE_GROUP);
94 sp_object_class->build = box3d_build;
95 sp_object_class->release = box3d_release;
96 sp_object_class->set = box3d_set;
97 sp_object_class->write = box3d_write;
98 sp_object_class->update = box3d_update;
100 item_class->description = box3d_description;
101 item_class->set_transform = box3d_set_transform;
102 item_class->convert_to_guides = box3d_convert_to_guides;
103 }
105 static void
106 box3d_init(SPBox3D *box)
107 {
108 box->persp_href = NULL;
109 box->persp_ref = new Persp3DReference(SP_OBJECT(box));
110 }
112 static void
113 box3d_build(SPObject *object, SPDocument *document, Inkscape::XML::Node *repr)
114 {
115 if (((SPObjectClass *) (parent_class))->build) {
116 ((SPObjectClass *) (parent_class))->build(object, document, repr);
117 }
119 SPBox3D *box = SP_BOX3D (object);
120 box->my_counter = counter++;
122 /* we initialize the z-orders to zero so that they are updated during dragging */
123 for (int i = 0; i < 6; ++i) {
124 box->z_orders[i] = 0;
125 }
127 // TODO: Create/link to the correct perspective
129 SPDocument *doc = SP_OBJECT_DOCUMENT(box);
130 if (!doc)
131 return;
133 box->persp_ref->changedSignal().connect(sigc::bind(sigc::ptr_fun(box3d_ref_changed), box));
135 sp_object_read_attr(object, "inkscape:perspectiveID");
136 sp_object_read_attr(object, "inkscape:corner0");
137 sp_object_read_attr(object, "inkscape:corner7");
138 }
140 /**
141 * Virtual release of SPBox3D members before destruction.
142 */
143 static void
144 box3d_release(SPObject *object)
145 {
146 SPBox3D *box = (SPBox3D *) object;
148 if (box->persp_href) {
149 g_free(box->persp_href);
150 }
152 // We have to store this here because the Persp3DReference gets destroyed below, but we need to
153 // access it to call persp3d_remove_box(), which cannot be called earlier because the reference
154 // needs to be destroyed first.
155 Persp3D *persp = box3d_get_perspective(box);
157 if (box->persp_ref) {
158 box->persp_ref->detach();
159 delete box->persp_ref;
160 box->persp_ref = NULL;
161 }
163 if (persp) {
164 persp3d_remove_box (persp, box);
165 /*
166 // TODO: This deletes a perspective when the last box referring to it is gone. Eventually,
167 // it would be nice to have this but currently it crashes when undoing/redoing box deletion
168 // Reason: When redoing a box deletion, the associated perspective is deleted twice, first
169 // by the following code and then again by the redo mechanism! Perhaps we should perform
170 // deletion of the perspective from another location "outside" the undo/redo mechanism?
171 if (persp->perspective_impl->boxes.empty()) {
172 SPDocument *doc = SP_OBJECT_DOCUMENT(box);
173 persp->deleteObject();
174 doc->setCurrentPersp3D(persp3d_document_first_persp(doc));
175 }
176 */
177 }
179 if (((SPObjectClass *) parent_class)->release)
180 ((SPObjectClass *) parent_class)->release(object);
181 }
183 static void
184 box3d_set(SPObject *object, unsigned int key, const gchar *value)
185 {
186 SPBox3D *box = SP_BOX3D(object);
188 switch (key) {
189 case SP_ATTR_INKSCAPE_BOX3D_PERSPECTIVE_ID:
190 if ( value && box->persp_href && ( strcmp(value, box->persp_href) == 0 ) ) {
191 /* No change, do nothing. */
192 } else {
193 if (box->persp_href) {
194 g_free(box->persp_href);
195 box->persp_href = NULL;
196 }
197 if (value) {
198 box->persp_href = g_strdup(value);
200 // Now do the attaching, which emits the changed signal.
201 try {
202 box->persp_ref->attach(Inkscape::URI(value));
203 } catch (Inkscape::BadURIException &e) {
204 g_warning("%s", e.what());
205 box->persp_ref->detach();
206 }
207 } else {
208 // Detach, which emits the changed signal.
209 box->persp_ref->detach();
210 }
211 }
213 // FIXME: Is the following update doubled by some call in either persp3d.cpp or vanishing_point_new.cpp?
214 box3d_position_set(box);
215 break;
216 case SP_ATTR_INKSCAPE_BOX3D_CORNER0:
217 if (value && strcmp(value, "0 : 0 : 0 : 0")) {
218 box->orig_corner0 = Proj::Pt3(value);
219 box->save_corner0 = box->orig_corner0;
220 box3d_position_set(box);
221 }
222 break;
223 case SP_ATTR_INKSCAPE_BOX3D_CORNER7:
224 if (value && strcmp(value, "0 : 0 : 0 : 0")) {
225 box->orig_corner7 = Proj::Pt3(value);
226 box->save_corner7 = box->orig_corner7;
227 box3d_position_set(box);
228 }
229 break;
230 default:
231 if (((SPObjectClass *) (parent_class))->set) {
232 ((SPObjectClass *) (parent_class))->set(object, key, value);
233 }
234 break;
235 }
236 }
238 /**
239 * Gets called when (re)attached to another perspective.
240 */
241 static void
242 box3d_ref_changed(SPObject *old_ref, SPObject *ref, SPBox3D *box)
243 {
244 if (old_ref) {
245 sp_signal_disconnect_by_data(old_ref, box);
246 persp3d_remove_box (SP_PERSP3D(old_ref), box);
247 }
248 if ( SP_IS_PERSP3D(ref) && ref != box ) // FIXME: Comparisons sane?
249 {
250 persp3d_add_box (SP_PERSP3D(ref), box);
251 }
252 }
254 static void
255 box3d_update(SPObject *object, SPCtx *ctx, guint flags)
256 {
257 if (flags & (SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_STYLE_MODIFIED_FLAG | SP_OBJECT_VIEWPORT_MODIFIED_FLAG)) {
259 /* FIXME?: Perhaps the display updates of box sides should be instantiated from here, but this
260 causes evil update loops so it's all done from box3d_position_set, which is called from
261 various other places (like the handlers in object-edit.cpp, vanishing-point.cpp, etc. */
263 }
265 // Invoke parent method
266 if (((SPObjectClass *) (parent_class))->update)
267 ((SPObjectClass *) (parent_class))->update(object, ctx, flags);
268 }
271 static Inkscape::XML::Node *box3d_write(SPObject *object, Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, guint flags)
272 {
273 SPBox3D *box = SP_BOX3D(object);
275 if ((flags & SP_OBJECT_WRITE_BUILD) && !repr) {
276 // this is where we end up when saving as plain SVG (also in other circumstances?)
277 // thus we don' set "sodipodi:type" so that the box is only saved as an ordinary svg:g
278 repr = xml_doc->createElement("svg:g");
279 }
281 if (flags & SP_OBJECT_WRITE_EXT) {
283 if (box->persp_href) {
284 repr->setAttribute("inkscape:perspectiveID", box->persp_href);
285 } else {
286 /* box is not yet linked to a perspective; use the document's current perspective */
287 SPDocument *doc = SP_OBJECT_DOCUMENT(object);
288 if (box->persp_ref->getURI()) {
289 gchar *uri_string = box->persp_ref->getURI()->toString();
290 repr->setAttribute("inkscape:perspectiveID", uri_string);
291 g_free(uri_string);
292 } else {
293 Inkscape::XML::Node *persp_repr = SP_OBJECT_REPR(doc->getCurrentPersp3D());
294 const gchar *persp_id = persp_repr->attribute("id");
295 gchar *href = g_strdup_printf("#%s", persp_id);
296 repr->setAttribute("inkscape:perspectiveID", href);
297 g_free(href);
298 }
299 }
301 gchar *coordstr0 = box->orig_corner0.coord_string();
302 gchar *coordstr7 = box->orig_corner7.coord_string();
303 repr->setAttribute("inkscape:corner0", coordstr0);
304 repr->setAttribute("inkscape:corner7", coordstr7);
305 g_free(coordstr0);
306 g_free(coordstr7);
308 box->orig_corner0.normalize();
309 box->orig_corner7.normalize();
311 box->save_corner0 = box->orig_corner0;
312 box->save_corner7 = box->orig_corner7;
313 }
315 if (((SPObjectClass *) (parent_class))->write) {
316 ((SPObjectClass *) (parent_class))->write(object, xml_doc, repr, flags);
317 }
319 return repr;
320 }
322 static gchar *
323 box3d_description(SPItem *item)
324 {
325 g_return_val_if_fail(SP_IS_BOX3D(item), NULL);
327 return g_strdup(_("<b>3D Box</b>"));
328 }
330 void
331 box3d_position_set (SPBox3D *box)
332 {
333 /* This draws the curve and calls requestDisplayUpdate() for each side (the latter is done in
334 box3d_side_position_set() to avoid update conflicts with the parent box) */
335 for (SPObject *child = sp_object_first_child(SP_OBJECT (box)); child != NULL; child = SP_OBJECT_NEXT(child) ) {
336 if (SP_IS_BOX3D_SIDE(child))
337 box3d_side_position_set(SP_BOX3D_SIDE(child));
338 }
339 }
341 static Geom::Matrix
342 box3d_set_transform(SPItem *item, Geom::Matrix const &xform)
343 {
344 SPBox3D *box = SP_BOX3D(item);
346 // We don't apply the transform to the box directly but instead to its perspective (which is
347 // done in sp_selection_apply_affine). Here we only adjust strokes, patterns, etc.
349 Geom::Matrix ret(Geom::Matrix(xform).without_translation());
350 gdouble const sw = hypot(ret[0], ret[1]);
351 gdouble const sh = hypot(ret[2], ret[3]);
353 for (SPObject *child = sp_object_first_child(box); child != NULL; child = SP_OBJECT_NEXT(child)) {
354 if (SP_IS_ITEM(child)) {
355 SPItem *childitem = SP_ITEM(child);
357 // Adjust stroke width
358 sp_item_adjust_stroke(childitem, sqrt(fabs(sw * sh)));
360 // Adjust pattern fill
361 sp_item_adjust_pattern(childitem, xform);
363 // Adjust gradient fill
364 sp_item_adjust_gradient(childitem, xform);
366 // Adjust LPE
367 sp_item_adjust_livepatheffect(childitem, xform);
368 }
369 }
371 return Geom::identity();
372 }
374 Proj::Pt3
375 box3d_get_proj_corner (guint id, Proj::Pt3 const &c0, Proj::Pt3 const &c7) {
376 return Proj::Pt3 ((id & Box3D::X) ? c7[Proj::X] : c0[Proj::X],
377 (id & Box3D::Y) ? c7[Proj::Y] : c0[Proj::Y],
378 (id & Box3D::Z) ? c7[Proj::Z] : c0[Proj::Z],
379 1.0);
380 }
382 Proj::Pt3
383 box3d_get_proj_corner (SPBox3D const *box, guint id) {
384 return Proj::Pt3 ((id & Box3D::X) ? box->orig_corner7[Proj::X] : box->orig_corner0[Proj::X],
385 (id & Box3D::Y) ? box->orig_corner7[Proj::Y] : box->orig_corner0[Proj::Y],
386 (id & Box3D::Z) ? box->orig_corner7[Proj::Z] : box->orig_corner0[Proj::Z],
387 1.0);
388 }
390 Geom::Point
391 box3d_get_corner_screen (SPBox3D const *box, guint id, bool item_coords) {
392 Proj::Pt3 proj_corner (box3d_get_proj_corner (box, id));
393 if (!box3d_get_perspective(box)) {
394 return Geom::Point (NR_HUGE, NR_HUGE);
395 }
396 Geom::Matrix const i2d (sp_item_i2d_affine (SP_ITEM(box)));
397 if (item_coords) {
398 return box3d_get_perspective(box)->perspective_impl->tmat.image(proj_corner).affine() * i2d.inverse();
399 } else {
400 return box3d_get_perspective(box)->perspective_impl->tmat.image(proj_corner).affine();
401 }
402 }
404 Proj::Pt3
405 box3d_get_proj_center (SPBox3D *box) {
406 box->orig_corner0.normalize();
407 box->orig_corner7.normalize();
408 return Proj::Pt3 ((box->orig_corner0[Proj::X] + box->orig_corner7[Proj::X]) / 2,
409 (box->orig_corner0[Proj::Y] + box->orig_corner7[Proj::Y]) / 2,
410 (box->orig_corner0[Proj::Z] + box->orig_corner7[Proj::Z]) / 2,
411 1.0);
412 }
414 Geom::Point
415 box3d_get_center_screen (SPBox3D *box) {
416 Proj::Pt3 proj_center (box3d_get_proj_center (box));
417 if (!box3d_get_perspective(box)) {
418 return Geom::Point (NR_HUGE, NR_HUGE);
419 }
420 Geom::Matrix const i2d (sp_item_i2d_affine (SP_ITEM(box)));
421 return box3d_get_perspective(box)->perspective_impl->tmat.image(proj_center).affine() * i2d.inverse();
422 }
424 /*
425 * To keep the snappoint from jumping randomly between the two lines when the mouse pointer is close to
426 * their intersection, we remember the last snapped line and keep snapping to this specific line as long
427 * as the distance from the intersection to the mouse pointer is less than remember_snap_threshold.
428 */
430 // Should we make the threshold settable in the preferences?
431 static double remember_snap_threshold = 30;
432 static guint remember_snap_index = 0;
434 static Proj::Pt3
435 box3d_snap (SPBox3D *box, int id, Proj::Pt3 const &pt_proj, Proj::Pt3 const &start_pt) {
436 double z_coord = start_pt[Proj::Z];
437 double diff_x = box->save_corner7[Proj::X] - box->save_corner0[Proj::X];
438 double diff_y = box->save_corner7[Proj::Y] - box->save_corner0[Proj::Y];
439 double x_coord = start_pt[Proj::X];
440 double y_coord = start_pt[Proj::Y];
441 Proj::Pt3 A_proj (x_coord, y_coord, z_coord, 1.0);
442 Proj::Pt3 B_proj (x_coord + diff_x, y_coord, z_coord, 1.0);
443 Proj::Pt3 C_proj (x_coord + diff_x, y_coord + diff_y, z_coord, 1.0);
444 Proj::Pt3 D_proj (x_coord, y_coord + diff_y, z_coord, 1.0);
445 Proj::Pt3 E_proj (x_coord - diff_x, y_coord + diff_y, z_coord, 1.0);
447 Persp3DImpl *persp_impl = box3d_get_perspective(box)->perspective_impl;
448 Geom::Point A = persp_impl->tmat.image(A_proj).affine();
449 Geom::Point B = persp_impl->tmat.image(B_proj).affine();
450 Geom::Point C = persp_impl->tmat.image(C_proj).affine();
451 Geom::Point D = persp_impl->tmat.image(D_proj).affine();
452 Geom::Point E = persp_impl->tmat.image(E_proj).affine();
453 Geom::Point pt = persp_impl->tmat.image(pt_proj).affine();
455 // TODO: Replace these lines between corners with lines from a corner to a vanishing point
456 // (this might help to prevent rounding errors if the box is small)
457 Box3D::Line pl1(A, B);
458 Box3D::Line pl2(A, D);
459 Box3D::Line diag1(A, (id == -1 || (!(id & Box3D::X) == !(id & Box3D::Y))) ? C : E);
460 Box3D::Line diag2(A, E); // diag2 is only taken into account if id equals -1, i.e., if we are snapping the center
462 int num_snap_lines = (id != -1) ? 3 : 4;
463 Geom::Point snap_pts[num_snap_lines];
465 snap_pts[0] = pl1.closest_to (pt);
466 snap_pts[1] = pl2.closest_to (pt);
467 snap_pts[2] = diag1.closest_to (pt);
468 if (id == -1) {
469 snap_pts[3] = diag2.closest_to (pt);
470 }
472 gdouble const zoom = inkscape_active_desktop()->current_zoom();
474 // determine the distances to all potential snapping points
475 double snap_dists[num_snap_lines];
476 for (int i = 0; i < num_snap_lines; ++i) {
477 snap_dists[i] = Geom::L2 (snap_pts[i] - pt) * zoom;
478 }
480 // while we are within a given tolerance of the starting point,
481 // keep snapping to the same point to avoid jumping
482 bool within_tolerance = true;
483 for (int i = 0; i < num_snap_lines; ++i) {
484 if (snap_dists[i] > remember_snap_threshold) {
485 within_tolerance = false;
486 break;
487 }
488 }
490 // find the closest snapping point
491 int snap_index = -1;
492 double snap_dist = NR_HUGE;
493 for (int i = 0; i < num_snap_lines; ++i) {
494 if (snap_dists[i] < snap_dist) {
495 snap_index = i;
496 snap_dist = snap_dists[i];
497 }
498 }
500 // snap to the closest point (or the previously remembered one
501 // if we are within tolerance of the starting point)
502 Geom::Point result;
503 if (within_tolerance) {
504 result = snap_pts[remember_snap_index];
505 } else {
506 remember_snap_index = snap_index;
507 result = snap_pts[snap_index];
508 }
509 return box3d_get_perspective(box)->perspective_impl->tmat.preimage (result, z_coord, Proj::Z);
510 }
512 void
513 box3d_set_corner (SPBox3D *box, const guint id, Geom::Point const &new_pos, const Box3D::Axis movement, bool constrained) {
514 g_return_if_fail ((movement != Box3D::NONE) && (movement != Box3D::XYZ));
516 box->orig_corner0.normalize();
517 box->orig_corner7.normalize();
519 /* update corners 0 and 7 according to which handle was moved and to the axes of movement */
520 if (!(movement & Box3D::Z)) {
521 Persp3DImpl *persp_impl = box3d_get_perspective(box)->perspective_impl;
522 Proj::Pt3 pt_proj (persp_impl->tmat.preimage (new_pos, (id < 4) ? box->orig_corner0[Proj::Z] :
523 box->orig_corner7[Proj::Z], Proj::Z));
524 if (constrained) {
525 pt_proj = box3d_snap (box, id, pt_proj, box3d_get_proj_corner (id, box->save_corner0, box->save_corner7));
526 }
528 // normalizing pt_proj is essential because we want to mingle affine coordinates
529 pt_proj.normalize();
530 box->orig_corner0 = Proj::Pt3 ((id & Box3D::X) ? box->save_corner0[Proj::X] : pt_proj[Proj::X],
531 (id & Box3D::Y) ? box->save_corner0[Proj::Y] : pt_proj[Proj::Y],
532 box->save_corner0[Proj::Z],
533 1.0);
534 box->orig_corner7 = Proj::Pt3 ((id & Box3D::X) ? pt_proj[Proj::X] : box->save_corner7[Proj::X],
535 (id & Box3D::Y) ? pt_proj[Proj::Y] : box->save_corner7[Proj::Y],
536 box->save_corner7[Proj::Z],
537 1.0);
538 } else {
539 Persp3D *persp = box3d_get_perspective(box);
540 Persp3DImpl *persp_impl = box3d_get_perspective(box)->perspective_impl;
541 Box3D::PerspectiveLine pl(persp_impl->tmat.image(
542 box3d_get_proj_corner (id, box->save_corner0, box->save_corner7)).affine(),
543 Proj::Z, persp);
544 Geom::Point new_pos_snapped(pl.closest_to(new_pos));
545 Proj::Pt3 pt_proj (persp_impl->tmat.preimage (new_pos_snapped,
546 box3d_get_proj_corner (box, id)[(movement & Box3D::Y) ? Proj::X : Proj::Y],
547 (movement & Box3D::Y) ? Proj::X : Proj::Y));
548 bool corner0_move_x = !(id & Box3D::X) && (movement & Box3D::X);
549 bool corner0_move_y = !(id & Box3D::Y) && (movement & Box3D::Y);
550 bool corner7_move_x = (id & Box3D::X) && (movement & Box3D::X);
551 bool corner7_move_y = (id & Box3D::Y) && (movement & Box3D::Y);
552 // normalizing pt_proj is essential because we want to mingle affine coordinates
553 pt_proj.normalize();
554 box->orig_corner0 = Proj::Pt3 (corner0_move_x ? pt_proj[Proj::X] : box->orig_corner0[Proj::X],
555 corner0_move_y ? pt_proj[Proj::Y] : box->orig_corner0[Proj::Y],
556 (id & Box3D::Z) ? box->orig_corner0[Proj::Z] : pt_proj[Proj::Z],
557 1.0);
558 box->orig_corner7 = Proj::Pt3 (corner7_move_x ? pt_proj[Proj::X] : box->orig_corner7[Proj::X],
559 corner7_move_y ? pt_proj[Proj::Y] : box->orig_corner7[Proj::Y],
560 (id & Box3D::Z) ? pt_proj[Proj::Z] : box->orig_corner7[Proj::Z],
561 1.0);
562 }
563 // FIXME: Should we update the box here? If so, how?
564 }
566 void box3d_set_center (SPBox3D *box, Geom::Point const &new_pos, Geom::Point const &old_pos, const Box3D::Axis movement, bool constrained) {
567 g_return_if_fail ((movement != Box3D::NONE) && (movement != Box3D::XYZ));
569 box->orig_corner0.normalize();
570 box->orig_corner7.normalize();
572 Persp3D *persp = box3d_get_perspective(box);
573 if (!(movement & Box3D::Z)) {
574 double coord = (box->orig_corner0[Proj::Z] + box->orig_corner7[Proj::Z]) / 2;
575 double radx = (box->orig_corner7[Proj::X] - box->orig_corner0[Proj::X]) / 2;
576 double rady = (box->orig_corner7[Proj::Y] - box->orig_corner0[Proj::Y]) / 2;
578 Proj::Pt3 pt_proj (persp->perspective_impl->tmat.preimage (new_pos, coord, Proj::Z));
579 if (constrained) {
580 Proj::Pt3 old_pos_proj (persp->perspective_impl->tmat.preimage (old_pos, coord, Proj::Z));
581 old_pos_proj.normalize();
582 pt_proj = box3d_snap (box, -1, pt_proj, old_pos_proj);
583 }
584 // normalizing pt_proj is essential because we want to mingle affine coordinates
585 pt_proj.normalize();
586 box->orig_corner0 = Proj::Pt3 ((movement & Box3D::X) ? pt_proj[Proj::X] - radx : box->orig_corner0[Proj::X],
587 (movement & Box3D::Y) ? pt_proj[Proj::Y] - rady : box->orig_corner0[Proj::Y],
588 box->orig_corner0[Proj::Z],
589 1.0);
590 box->orig_corner7 = Proj::Pt3 ((movement & Box3D::X) ? pt_proj[Proj::X] + radx : box->orig_corner7[Proj::X],
591 (movement & Box3D::Y) ? pt_proj[Proj::Y] + rady : box->orig_corner7[Proj::Y],
592 box->orig_corner7[Proj::Z],
593 1.0);
594 } else {
595 double coord = (box->orig_corner0[Proj::X] + box->orig_corner7[Proj::X]) / 2;
596 double radz = (box->orig_corner7[Proj::Z] - box->orig_corner0[Proj::Z]) / 2;
598 Box3D::PerspectiveLine pl(old_pos, Proj::Z, persp);
599 Geom::Point new_pos_snapped(pl.closest_to(new_pos));
600 Proj::Pt3 pt_proj (persp->perspective_impl->tmat.preimage (new_pos_snapped, coord, Proj::X));
602 /* normalizing pt_proj is essential because we want to mingle affine coordinates */
603 pt_proj.normalize();
604 box->orig_corner0 = Proj::Pt3 (box->orig_corner0[Proj::X],
605 box->orig_corner0[Proj::Y],
606 pt_proj[Proj::Z] - radz,
607 1.0);
608 box->orig_corner7 = Proj::Pt3 (box->orig_corner7[Proj::X],
609 box->orig_corner7[Proj::Y],
610 pt_proj[Proj::Z] + radz,
611 1.0);
612 }
613 }
615 /*
616 * Manipulates corner1 through corner4 to contain the indices of the corners
617 * from which the perspective lines in the direction of 'axis' emerge
618 */
619 void box3d_corners_for_PLs (const SPBox3D * box, Proj::Axis axis,
620 Geom::Point &corner1, Geom::Point &corner2, Geom::Point &corner3, Geom::Point &corner4)
621 {
622 Persp3D *persp = box3d_get_perspective(box);
623 g_return_if_fail (persp);
624 Persp3DImpl *persp_impl = persp->perspective_impl;
625 //box->orig_corner0.normalize();
626 //box->orig_corner7.normalize();
627 double coord = (box->orig_corner0[axis] > box->orig_corner7[axis]) ?
628 box->orig_corner0[axis] :
629 box->orig_corner7[axis];
631 Proj::Pt3 c1, c2, c3, c4;
632 // FIXME: This can certainly be done more elegantly/efficiently than by a case-by-case analysis.
633 switch (axis) {
634 case Proj::X:
635 c1 = Proj::Pt3 (coord, box->orig_corner0[Proj::Y], box->orig_corner0[Proj::Z], 1.0);
636 c2 = Proj::Pt3 (coord, box->orig_corner7[Proj::Y], box->orig_corner0[Proj::Z], 1.0);
637 c3 = Proj::Pt3 (coord, box->orig_corner7[Proj::Y], box->orig_corner7[Proj::Z], 1.0);
638 c4 = Proj::Pt3 (coord, box->orig_corner0[Proj::Y], box->orig_corner7[Proj::Z], 1.0);
639 break;
640 case Proj::Y:
641 c1 = Proj::Pt3 (box->orig_corner0[Proj::X], coord, box->orig_corner0[Proj::Z], 1.0);
642 c2 = Proj::Pt3 (box->orig_corner7[Proj::X], coord, box->orig_corner0[Proj::Z], 1.0);
643 c3 = Proj::Pt3 (box->orig_corner7[Proj::X], coord, box->orig_corner7[Proj::Z], 1.0);
644 c4 = Proj::Pt3 (box->orig_corner0[Proj::X], coord, box->orig_corner7[Proj::Z], 1.0);
645 break;
646 case Proj::Z:
647 c1 = Proj::Pt3 (box->orig_corner7[Proj::X], box->orig_corner7[Proj::Y], coord, 1.0);
648 c2 = Proj::Pt3 (box->orig_corner7[Proj::X], box->orig_corner0[Proj::Y], coord, 1.0);
649 c3 = Proj::Pt3 (box->orig_corner0[Proj::X], box->orig_corner0[Proj::Y], coord, 1.0);
650 c4 = Proj::Pt3 (box->orig_corner0[Proj::X], box->orig_corner7[Proj::Y], coord, 1.0);
651 break;
652 default:
653 return;
654 }
655 corner1 = persp_impl->tmat.image(c1).affine();
656 corner2 = persp_impl->tmat.image(c2).affine();
657 corner3 = persp_impl->tmat.image(c3).affine();
658 corner4 = persp_impl->tmat.image(c4).affine();
659 }
661 /* Auxiliary function: Checks whether the half-line from A to B crosses the line segment joining C and D */
662 static bool
663 box3d_half_line_crosses_joining_line (Geom::Point const &A, Geom::Point const &B,
664 Geom::Point const &C, Geom::Point const &D) {
665 Geom::Point n0 = (B - A).ccw();
666 double d0 = dot(n0,A);
668 Geom::Point n1 = (D - C).ccw();
669 double d1 = dot(n1,C);
671 Geom::Line lineAB(A,B);
672 Geom::Line lineCD(C,D);
674 Geom::OptCrossing inters = Geom::OptCrossing(); // empty by default
675 try
676 {
677 inters = Geom::intersection(lineAB, lineCD);
678 }
679 catch (Geom::InfiniteSolutions e)
680 {
681 // We're probably dealing with parallel lines, so they don't really cross
682 return false;
683 }
685 if (!inters) {
686 return false;
687 }
689 Geom::Point E = lineAB.pointAt((*inters).ta); // the point of intersection
691 if ((dot(C,n0) < d0) == (dot(D,n0) < d0)) {
692 // C and D lie on the same side of the line AB
693 return false;
694 }
695 if ((dot(A,n1) < d1) != (dot(B,n1) < d1)) {
696 // A and B lie on different sides of the line CD
697 return true;
698 } else if (Geom::distance(E,A) < Geom::distance(E,B)) {
699 // The line CD passes on the "wrong" side of A
700 return false;
701 }
703 // The line CD passes on the "correct" side of A
704 return true;
705 }
707 static bool
708 box3d_XY_axes_are_swapped (SPBox3D *box) {
709 Persp3D *persp = box3d_get_perspective(box);
710 g_return_val_if_fail(persp, false);
711 Box3D::PerspectiveLine l1(box3d_get_corner_screen(box, 3, false), Proj::X, persp);
712 Box3D::PerspectiveLine l2(box3d_get_corner_screen(box, 3, false), Proj::Y, persp);
713 Geom::Point v1(l1.direction());
714 Geom::Point v2(l2.direction());
715 v1.normalize();
716 v2.normalize();
718 return (v1[Geom::X]*v2[Geom::Y] - v1[Geom::Y]*v2[Geom::X] > 0);
719 }
721 static inline void
722 box3d_aux_set_z_orders (int z_orders[6], int a, int b, int c, int d, int e, int f) {
723 z_orders[0] = a;
724 z_orders[1] = b;
725 z_orders[2] = c;
726 z_orders[3] = d;
727 z_orders[4] = e;
728 z_orders[5] = f;
729 }
731 static inline void
732 box3d_swap_z_orders (int z_orders[6]) {
733 int tmp;
734 for (int i = 0; i < 3; ++i) {
735 tmp = z_orders[i];
736 z_orders[i] = z_orders[5-i];
737 z_orders[5-i] = tmp;
738 }
739 }
741 /*
742 * In standard perspective we have:
743 * 2 = front face
744 * 1 = top face
745 * 0 = left face
746 * 3 = right face
747 * 4 = bottom face
748 * 5 = rear face
749 */
751 /* All VPs infinite */
752 static void
753 box3d_set_new_z_orders_case0 (SPBox3D *box, int z_orders[6], Box3D::Axis central_axis) {
754 Persp3D *persp = box3d_get_perspective(box);
755 Geom::Point xdir(persp3d_get_infinite_dir(persp, Proj::X));
756 Geom::Point ydir(persp3d_get_infinite_dir(persp, Proj::Y));
757 Geom::Point zdir(persp3d_get_infinite_dir(persp, Proj::Z));
759 bool swapped = box3d_XY_axes_are_swapped(box);
761 switch(central_axis) {
762 case Box3D::X:
763 if (!swapped) {
764 box3d_aux_set_z_orders (z_orders, 2, 0, 4, 1, 3, 5);
765 } else {
766 box3d_aux_set_z_orders (z_orders, 3, 1, 5, 2, 4, 0);
767 }
768 break;
769 case Box3D::Y:
770 if (!swapped) {
771 box3d_aux_set_z_orders (z_orders, 2, 3, 1, 4, 0, 5);
772 } else {
773 box3d_aux_set_z_orders (z_orders, 5, 0, 4, 1, 3, 2);
774 }
775 break;
776 case Box3D::Z:
777 if (!swapped) {
778 box3d_aux_set_z_orders (z_orders, 2, 0, 1, 4, 3, 5);
779 } else {
780 box3d_aux_set_z_orders (z_orders, 5, 3, 4, 1, 0, 2);
781 }
782 break;
783 case Box3D::NONE:
784 if (!swapped) {
785 box3d_aux_set_z_orders (z_orders, 2, 3, 4, 1, 0, 5);
786 } else {
787 box3d_aux_set_z_orders (z_orders, 5, 0, 1, 4, 3, 2);
788 }
789 break;
790 default:
791 g_assert_not_reached();
792 break;
793 }
794 }
796 /* Precisely one finite VP */
797 static void
798 box3d_set_new_z_orders_case1 (SPBox3D *box, int z_orders[6], Box3D::Axis central_axis, Box3D::Axis fin_axis) {
799 Persp3D *persp = box3d_get_perspective(box);
800 Geom::Point vp(persp3d_get_VP(persp, Box3D::toProj(fin_axis)).affine());
802 // note: in some of the case distinctions below we rely upon the fact that oaxis1 and oaxis2 are ordered
803 Box3D::Axis oaxis1 = Box3D::get_remaining_axes(fin_axis).first;
804 Box3D::Axis oaxis2 = Box3D::get_remaining_axes(fin_axis).second;
805 int inside1 = 0;
806 int inside2 = 0;
807 inside1 = box3d_pt_lies_in_PL_sector (box, vp, 3, 3 ^ oaxis2, oaxis1);
808 inside2 = box3d_pt_lies_in_PL_sector (box, vp, 3, 3 ^ oaxis1, oaxis2);
810 bool swapped = box3d_XY_axes_are_swapped(box);
812 switch(central_axis) {
813 case Box3D::X:
814 if (!swapped) {
815 box3d_aux_set_z_orders (z_orders, 2, 4, 0, 1, 3, 5);
816 } else {
817 box3d_aux_set_z_orders (z_orders, 5, 3, 1, 0, 2, 4);
818 }
819 break;
820 case Box3D::Y:
821 if (inside2 > 0) {
822 box3d_aux_set_z_orders (z_orders, 1, 2, 3, 0, 5, 4);
823 } else if (inside2 < 0) {
824 box3d_aux_set_z_orders (z_orders, 2, 3, 1, 4, 0, 5);
825 } else {
826 if (!swapped) {
827 box3d_aux_set_z_orders (z_orders, 2, 3, 1, 5, 0, 4);
828 } else {
829 box3d_aux_set_z_orders (z_orders, 5, 0, 4, 1, 3, 2);
830 }
831 }
832 break;
833 case Box3D::Z:
834 if (inside2) {
835 if (!swapped) {
836 box3d_aux_set_z_orders (z_orders, 2, 1, 3, 0, 4, 5);
837 } else {
838 box3d_aux_set_z_orders (z_orders, 5, 3, 4, 0, 1, 2);
839 }
840 } else if (inside1) {
841 if (!swapped) {
842 box3d_aux_set_z_orders (z_orders, 2, 0, 1, 4, 3, 5);
843 } else {
844 box3d_aux_set_z_orders (z_orders, 5, 3, 4, 1, 0, 2);
845 }
846 } else {
847 // "regular" case
848 if (!swapped) {
849 box3d_aux_set_z_orders (z_orders, 0, 1, 2, 5, 4, 3);
850 } else {
851 box3d_aux_set_z_orders (z_orders, 5, 3, 4, 0, 2, 1);
852 }
853 }
854 break;
855 case Box3D::NONE:
856 if (!swapped) {
857 box3d_aux_set_z_orders (z_orders, 2, 3, 4, 5, 0, 1);
858 } else {
859 box3d_aux_set_z_orders (z_orders, 5, 0, 1, 3, 2, 4);
860 }
861 break;
862 default:
863 g_assert_not_reached();
864 }
865 }
867 /* Precisely 2 finite VPs */
868 static void
869 box3d_set_new_z_orders_case2 (SPBox3D *box, int z_orders[6], Box3D::Axis central_axis, Box3D::Axis /*infinite_axis*/) {
870 Persp3D *persp = box3d_get_perspective(box);
872 Geom::Point c3(box3d_get_corner_screen(box, 3, false));
873 Geom::Point xdir(persp3d_get_PL_dir_from_pt(persp, c3, Proj::X));
874 Geom::Point ydir(persp3d_get_PL_dir_from_pt(persp, c3, Proj::Y));
875 Geom::Point zdir(persp3d_get_PL_dir_from_pt(persp, c3, Proj::Z));
877 bool swapped = box3d_XY_axes_are_swapped(box);
879 int insidexy = box3d_VP_lies_in_PL_sector (box, Proj::X, 3, 3 ^ Box3D::Z, Box3D::Y);
880 //int insidexz = box3d_VP_lies_in_PL_sector (box, Proj::X, 3, 3 ^ Box3D::Y, Box3D::Z);
882 int insideyx = box3d_VP_lies_in_PL_sector (box, Proj::Y, 3, 3 ^ Box3D::Z, Box3D::X);
883 int insideyz = box3d_VP_lies_in_PL_sector (box, Proj::Y, 3, 3 ^ Box3D::X, Box3D::Z);
885 //int insidezx = box3d_VP_lies_in_PL_sector (box, Proj::Z, 3, 3 ^ Box3D::Y, Box3D::X);
886 int insidezy = box3d_VP_lies_in_PL_sector (box, Proj::Z, 3, 3 ^ Box3D::X, Box3D::Y);
888 switch(central_axis) {
889 case Box3D::X:
890 if (!swapped) {
891 if (insidezy == -1) {
892 box3d_aux_set_z_orders (z_orders, 2, 4, 0, 1, 3, 5);
893 } else if (insidexy == 1) {
894 box3d_aux_set_z_orders (z_orders, 2, 4, 0, 5, 1, 3);
895 } else {
896 box3d_aux_set_z_orders (z_orders, 2, 4, 0, 1, 3, 5);
897 }
898 } else {
899 if (insideyz == -1) {
900 box3d_aux_set_z_orders (z_orders, 3, 1, 5, 0, 2, 4);
901 } else {
902 if (!swapped) {
903 box3d_aux_set_z_orders (z_orders, 3, 1, 5, 2, 4, 0);
904 } else {
905 if (insidexy == 0) {
906 box3d_aux_set_z_orders (z_orders, 3, 5, 1, 0, 2, 4);
907 } else {
908 box3d_aux_set_z_orders (z_orders, 3, 1, 5, 0, 2, 4);
909 }
910 }
911 }
912 }
913 break;
914 case Box3D::Y:
915 if (!swapped) {
916 if (insideyz == 1) {
917 box3d_aux_set_z_orders (z_orders, 2, 3, 1, 0, 5, 4);
918 } else {
919 box3d_aux_set_z_orders (z_orders, 2, 3, 1, 5, 0, 4);
920 }
921 } else {
922 if (insideyx == 1) {
923 box3d_aux_set_z_orders (z_orders, 4, 0, 5, 1, 3, 2);
924 } else {
925 box3d_aux_set_z_orders (z_orders, 5, 0, 4, 1, 3, 2);
926 }
927 }
928 break;
929 case Box3D::Z:
930 if (!swapped) {
931 if (insidezy == 1) {
932 box3d_aux_set_z_orders (z_orders, 2, 1, 0, 4, 3, 5);
933 } else if (insidexy == -1) {
934 box3d_aux_set_z_orders (z_orders, 2, 1, 0, 5, 4, 3);
935 } else {
936 box3d_aux_set_z_orders (z_orders, 2, 0, 1, 5, 3, 4);
937 }
938 } else {
939 box3d_aux_set_z_orders (z_orders, 3, 4, 5, 1, 0, 2);
940 }
941 break;
942 case Box3D::NONE:
943 if (!swapped) {
944 box3d_aux_set_z_orders (z_orders, 2, 3, 4, 1, 0, 5);
945 } else {
946 box3d_aux_set_z_orders (z_orders, 5, 0, 1, 4, 3, 2);
947 }
948 break;
949 default:
950 g_assert_not_reached();
951 break;
952 }
953 }
955 /*
956 * It can happen that during dragging the box is everted.
957 * In this case the opposite sides in this direction need to be swapped
958 */
959 static Box3D::Axis
960 box3d_everted_directions (SPBox3D *box) {
961 Box3D::Axis ev = Box3D::NONE;
963 box->orig_corner0.normalize();
964 box->orig_corner7.normalize();
966 if (box->orig_corner0[Proj::X] < box->orig_corner7[Proj::X])
967 ev = (Box3D::Axis) (ev ^ Box3D::X);
968 if (box->orig_corner0[Proj::Y] < box->orig_corner7[Proj::Y])
969 ev = (Box3D::Axis) (ev ^ Box3D::Y);
970 if (box->orig_corner0[Proj::Z] > box->orig_corner7[Proj::Z]) // FIXME: Remove the need to distinguish signs among the cases
971 ev = (Box3D::Axis) (ev ^ Box3D::Z);
973 return ev;
974 }
976 static void
977 box3d_swap_sides(int z_orders[6], Box3D::Axis axis) {
978 int pos1 = -1;
979 int pos2 = -1;
981 for (int i = 0; i < 6; ++i) {
982 if (!(Box3D::int_to_face(z_orders[i]) & axis)) {
983 if (pos1 == -1) {
984 pos1 = i;
985 } else {
986 pos2 = i;
987 break;
988 }
989 }
990 }
992 int tmp = z_orders[pos1];
993 z_orders[pos1] = z_orders[pos2];
994 z_orders[pos2] = tmp;
995 }
998 bool
999 box3d_recompute_z_orders (SPBox3D *box) {
1000 Persp3D *persp = box3d_get_perspective(box);
1002 if (!persp)
1003 return false;
1005 int z_orders[6];
1007 Geom::Point c3(box3d_get_corner_screen(box, 3, false));
1009 // determine directions from corner3 to the VPs
1010 int num_finite = 0;
1011 Box3D::Axis axis_finite = Box3D::NONE;
1012 Box3D::Axis axis_infinite = Box3D::NONE;
1013 Geom::Point dirs[3];
1014 for (int i = 0; i < 3; ++i) {
1015 dirs[i] = persp3d_get_PL_dir_from_pt(persp, c3, Box3D::toProj(Box3D::axes[i]));
1016 if (persp3d_VP_is_finite(persp->perspective_impl, Proj::axes[i])) {
1017 num_finite++;
1018 axis_finite = Box3D::axes[i];
1019 } else {
1020 axis_infinite = Box3D::axes[i];
1021 }
1022 }
1024 // determine the "central" axis (if there is one)
1025 Box3D::Axis central_axis = Box3D::NONE;
1026 if(Box3D::lies_in_sector(dirs[0], dirs[1], dirs[2])) {
1027 central_axis = Box3D::Z;
1028 } else if(Box3D::lies_in_sector(dirs[1], dirs[2], dirs[0])) {
1029 central_axis = Box3D::X;
1030 } else if(Box3D::lies_in_sector(dirs[2], dirs[0], dirs[1])) {
1031 central_axis = Box3D::Y;
1032 }
1034 switch (num_finite) {
1035 case 0:
1036 // TODO: Remark: In this case (and maybe one of the others, too) the z-orders for all boxes
1037 // coincide, hence only need to be computed once in a more central location.
1038 box3d_set_new_z_orders_case0(box, z_orders, central_axis);
1039 break;
1040 case 1:
1041 box3d_set_new_z_orders_case1(box, z_orders, central_axis, axis_finite);
1042 break;
1043 case 2:
1044 case 3:
1045 box3d_set_new_z_orders_case2(box, z_orders, central_axis, axis_infinite);
1046 break;
1047 default:
1048 /*
1049 * For each VP F, check wether the half-line from the corner3 to F crosses the line segment
1050 * joining the other two VPs. If this is the case, it determines the "central" corner from
1051 * which the visible sides can be deduced. Otherwise, corner3 is the central corner.
1052 */
1053 // FIXME: We should eliminate the use of Geom::Point altogether
1054 Box3D::Axis central_axis = Box3D::NONE;
1055 Geom::Point vp_x = persp3d_get_VP(persp, Proj::X).affine();
1056 Geom::Point vp_y = persp3d_get_VP(persp, Proj::Y).affine();
1057 Geom::Point vp_z = persp3d_get_VP(persp, Proj::Z).affine();
1058 Geom::Point vpx(vp_x[Geom::X], vp_x[Geom::Y]);
1059 Geom::Point vpy(vp_y[Geom::X], vp_y[Geom::Y]);
1060 Geom::Point vpz(vp_z[Geom::X], vp_z[Geom::Y]);
1062 Geom::Point c3 = box3d_get_corner_screen(box, 3, false);
1063 Geom::Point corner3(c3[Geom::X], c3[Geom::Y]);
1065 if (box3d_half_line_crosses_joining_line (corner3, vpx, vpy, vpz)) {
1066 central_axis = Box3D::X;
1067 } else if (box3d_half_line_crosses_joining_line (corner3, vpy, vpz, vpx)) {
1068 central_axis = Box3D::Y;
1069 } else if (box3d_half_line_crosses_joining_line (corner3, vpz, vpx, vpy)) {
1070 central_axis = Box3D::Z;
1071 }
1073 unsigned int central_corner = 3 ^ central_axis;
1074 if (central_axis == Box3D::Z) {
1075 central_corner = central_corner ^ Box3D::XYZ;
1076 }
1077 if (box3d_XY_axes_are_swapped(box)) {
1078 central_corner = central_corner ^ Box3D::XYZ;
1079 }
1081 Geom::Point c1(box3d_get_corner_screen(box, 1, false));
1082 Geom::Point c2(box3d_get_corner_screen(box, 2, false));
1083 Geom::Point c7(box3d_get_corner_screen(box, 7, false));
1085 Geom::Point corner1(c1[Geom::X], c1[Geom::Y]);
1086 Geom::Point corner2(c2[Geom::X], c2[Geom::Y]);
1087 Geom::Point corner7(c7[Geom::X], c7[Geom::Y]);
1088 // FIXME: At present we don't use the information about central_corner computed above.
1089 switch (central_axis) {
1090 case Box3D::Y:
1091 if (!box3d_half_line_crosses_joining_line(vpz, vpy, corner3, corner2)) {
1092 box3d_aux_set_z_orders (z_orders, 2, 3, 1, 5, 0, 4);
1093 } else {
1094 // degenerate case
1095 box3d_aux_set_z_orders (z_orders, 2, 1, 3, 0, 5, 4);
1096 }
1097 break;
1099 case Box3D::Z:
1100 if (box3d_half_line_crosses_joining_line(vpx, vpz, corner3, corner1)) {
1101 // degenerate case
1102 box3d_aux_set_z_orders (z_orders, 2, 0, 1, 4, 3, 5);
1103 } else if (box3d_half_line_crosses_joining_line(vpx, vpy, corner3, corner7)) {
1104 // degenerate case
1105 box3d_aux_set_z_orders (z_orders, 2, 1, 0, 5, 3, 4);
1106 } else {
1107 box3d_aux_set_z_orders (z_orders, 2, 1, 0, 3, 4, 5);
1108 }
1109 break;
1111 case Box3D::X:
1112 if (box3d_half_line_crosses_joining_line(vpz, vpx, corner3, corner1)) {
1113 // degenerate case
1114 box3d_aux_set_z_orders (z_orders, 2, 1, 0, 4, 5, 3);
1115 } else {
1116 box3d_aux_set_z_orders (z_orders, 2, 4, 0, 5, 1, 3);
1117 }
1118 break;
1120 case Box3D::NONE:
1121 box3d_aux_set_z_orders (z_orders, 2, 3, 4, 1, 0, 5);
1122 break;
1124 default:
1125 g_assert_not_reached();
1126 break;
1127 } // end default case
1128 }
1130 // TODO: If there are still errors in z-orders of everted boxes, we need to choose a variable corner
1131 // instead of the hard-coded corner #3 in the computations above
1132 Box3D::Axis ev = box3d_everted_directions(box);
1133 for (int i = 0; i < 3; ++i) {
1134 if (ev & Box3D::axes[i]) {
1135 box3d_swap_sides(z_orders, Box3D::axes[i]);
1136 }
1137 }
1139 // Check whether anything actually changed
1140 for (int i = 0; i < 6; ++i) {
1141 if (box->z_orders[i] != z_orders[i]) {
1142 for (int j = i; j < 6; ++j) {
1143 box->z_orders[j] = z_orders[j];
1144 }
1145 return true;
1146 }
1147 }
1148 return false;
1149 }
1151 static std::map<int, Box3DSide *>
1152 box3d_get_sides (SPBox3D *box) {
1153 std::map<int, Box3DSide *> sides;
1154 for (SPObject *side = sp_object_first_child(box); side != NULL; side = SP_OBJECT_NEXT(side)) {
1155 if (SP_IS_BOX3D_SIDE(side))
1156 sides[Box3D::face_to_int(sp_repr_get_int_attribute(SP_OBJECT_REPR(side),
1157 "inkscape:box3dsidetype", -1))] = SP_BOX3D_SIDE(side);
1158 }
1159 sides.erase(-1);
1160 return sides;
1161 }
1164 // TODO: Check whether the box is everted in any direction and swap the sides opposite to this direction
1165 void
1166 box3d_set_z_orders (SPBox3D *box) {
1167 // For efficiency reasons, we only set the new z-orders if something really changed
1168 if (box3d_recompute_z_orders (box)) {
1169 std::map<int, Box3DSide *> sides = box3d_get_sides(box);
1170 std::map<int, Box3DSide *>::iterator side;
1171 for (unsigned int i = 0; i < 6; ++i) {
1172 side = sides.find(box->z_orders[i]);
1173 if (side != sides.end()) {
1174 SP_ITEM((*side).second)->lowerToBottom();
1175 }
1176 }
1177 }
1178 }
1180 /*
1181 * Auxiliary function for z-order recomputing:
1182 * Determines whether \a pt lies in the sector formed by the two PLs from the corners with IDs
1183 * \a i21 and \a id2 to the VP in direction \a axis. If the VP is infinite, we say that \a pt
1184 * lies in the sector if it lies between the two (parallel) PLs.
1185 * \ret * 0 if \a pt doesn't lie in the sector
1186 * * 1 if \a pt lies in the sector and either VP is finite of VP is infinite and the direction
1187 * from the edge between the two corners to \a pt points towards the VP
1188 * * -1 otherwise
1189 */
1190 // TODO: Maybe it would be useful to have a similar method for projective points pt because then we
1191 // can use it for VPs and perhaps merge the case distinctions during z-order recomputation.
1192 int
1193 box3d_pt_lies_in_PL_sector (SPBox3D const *box, Geom::Point const &pt, int id1, int id2, Box3D::Axis axis) {
1194 Persp3D *persp = box3d_get_perspective(box);
1196 // the two corners
1197 Geom::Point c1(box3d_get_corner_screen(box, id1, false));
1198 Geom::Point c2(box3d_get_corner_screen(box, id2, false));
1200 int ret = 0;
1201 if (persp3d_VP_is_finite(persp->perspective_impl, Box3D::toProj(axis))) {
1202 Geom::Point vp(persp3d_get_VP(persp, Box3D::toProj(axis)).affine());
1203 Geom::Point v1(c1 - vp);
1204 Geom::Point v2(c2 - vp);
1205 Geom::Point w(pt - vp);
1206 ret = static_cast<int>(Box3D::lies_in_sector(v1, v2, w));
1207 } else {
1208 Box3D::PerspectiveLine pl1(c1, Box3D::toProj(axis), persp);
1209 Box3D::PerspectiveLine pl2(c2, Box3D::toProj(axis), persp);
1210 if (pl1.lie_on_same_side(pt, c2) && pl2.lie_on_same_side(pt, c1)) {
1211 // test whether pt lies "towards" or "away from" the VP
1212 Box3D::Line edge(c1,c2);
1213 Geom::Point c3(box3d_get_corner_screen(box, id1 ^ axis, false));
1214 if (edge.lie_on_same_side(pt, c3)) {
1215 ret = 1;
1216 } else {
1217 ret = -1;
1218 }
1219 }
1220 }
1221 return ret;
1222 }
1224 int
1225 box3d_VP_lies_in_PL_sector (SPBox3D const *box, Proj::Axis vpdir, int id1, int id2, Box3D::Axis axis) {
1226 Persp3D *persp = box3d_get_perspective(box);
1228 if (!persp3d_VP_is_finite(persp->perspective_impl, vpdir)) {
1229 return 0;
1230 } else {
1231 return box3d_pt_lies_in_PL_sector(box, persp3d_get_VP(persp, vpdir).affine(), id1, id2, axis);
1232 }
1233 }
1235 /* swap the coordinates of corner0 and corner7 along the specified axis */
1236 static void
1237 box3d_swap_coords(SPBox3D *box, Proj::Axis axis, bool smaller = true) {
1238 box->orig_corner0.normalize();
1239 box->orig_corner7.normalize();
1240 if ((box->orig_corner0[axis] < box->orig_corner7[axis]) != smaller) {
1241 double tmp = box->orig_corner0[axis];
1242 box->orig_corner0[axis] = box->orig_corner7[axis];
1243 box->orig_corner7[axis] = tmp;
1244 }
1245 // Should we also swap the coordinates of save_corner0 and save_corner7?
1246 }
1248 /* ensure that the coordinates of corner0 and corner7 are in the correct order (to prevent everted boxes) */
1249 void
1250 box3d_relabel_corners(SPBox3D *box) {
1251 box3d_swap_coords(box, Proj::X, false);
1252 box3d_swap_coords(box, Proj::Y, false);
1253 box3d_swap_coords(box, Proj::Z, true);
1254 }
1256 static void
1257 box3d_check_for_swapped_coords(SPBox3D *box, Proj::Axis axis, bool smaller) {
1258 box->orig_corner0.normalize();
1259 box->orig_corner7.normalize();
1261 if ((box->orig_corner0[axis] < box->orig_corner7[axis]) != smaller) {
1262 box->swapped = (Box3D::Axis) (box->swapped | Proj::toAffine(axis));
1263 } else {
1264 box->swapped = (Box3D::Axis) (box->swapped & ~Proj::toAffine(axis));
1265 }
1266 }
1268 static void
1269 box3d_exchange_coords(SPBox3D *box) {
1270 box->orig_corner0.normalize();
1271 box->orig_corner7.normalize();
1273 for (int i = 0; i < 3; ++i) {
1274 if (box->swapped & Box3D::axes[i]) {
1275 double tmp = box->orig_corner0[i];
1276 box->orig_corner0[i] = box->orig_corner7[i];
1277 box->orig_corner7[i] = tmp;
1278 }
1279 }
1280 }
1282 void
1283 box3d_check_for_swapped_coords(SPBox3D *box) {
1284 box3d_check_for_swapped_coords(box, Proj::X, false);
1285 box3d_check_for_swapped_coords(box, Proj::Y, false);
1286 box3d_check_for_swapped_coords(box, Proj::Z, true);
1288 box3d_exchange_coords(box);
1289 }
1291 static void
1292 box3d_extract_boxes_rec(SPObject *obj, std::list<SPBox3D *> &boxes) {
1293 if (SP_IS_BOX3D(obj)) {
1294 boxes.push_back(SP_BOX3D(obj));
1295 } else if (SP_IS_GROUP(obj)) {
1296 for (SPObject *child = sp_object_first_child(obj); child != NULL; child = SP_OBJECT_NEXT(child) ) {
1297 box3d_extract_boxes_rec(child, boxes);
1298 }
1299 }
1300 }
1302 std::list<SPBox3D *>
1303 box3d_extract_boxes(SPObject *obj) {
1304 std::list<SPBox3D *> boxes;
1305 box3d_extract_boxes_rec(obj, boxes);
1306 return boxes;
1307 }
1309 Persp3D *
1310 box3d_get_perspective(SPBox3D const *box) {
1311 return box->persp_ref->getObject();
1312 }
1314 void
1315 box3d_switch_perspectives(SPBox3D *box, Persp3D *old_persp, Persp3D *new_persp, bool recompute_corners) {
1316 if (recompute_corners) {
1317 box->orig_corner0.normalize();
1318 box->orig_corner7.normalize();
1319 double z0 = box->orig_corner0[Proj::Z];
1320 double z7 = box->orig_corner7[Proj::Z];
1321 Geom::Point corner0_screen = box3d_get_corner_screen(box, 0, false);
1322 Geom::Point corner7_screen = box3d_get_corner_screen(box, 7, false);
1324 box->orig_corner0 = new_persp->perspective_impl->tmat.preimage(corner0_screen, z0, Proj::Z);
1325 box->orig_corner7 = new_persp->perspective_impl->tmat.preimage(corner7_screen, z7, Proj::Z);
1326 }
1328 persp3d_remove_box (old_persp, box);
1329 persp3d_add_box (new_persp, box);
1331 gchar *href = g_strdup_printf("#%s", SP_OBJECT_REPR(new_persp)->attribute("id"));
1332 SP_OBJECT_REPR(box)->setAttribute("inkscape:perspectiveID", href);
1333 g_free(href);
1334 }
1336 /* Converts the 3D box to an ordinary SPGroup, adds it to the XML tree at the same position as
1337 the original box and deletes the latter */
1338 SPGroup *
1339 box3d_convert_to_group(SPBox3D *box) {
1340 SPDocument *doc = SP_OBJECT_DOCUMENT(box);
1341 Inkscape::XML::Document *xml_doc = sp_document_repr_doc(doc);
1343 // remember position of the box
1344 int pos = SP_OBJECT_REPR(box)->position();
1346 // remember important attributes
1347 Inkscape::XML::Node *repr_source = SP_OBJECT_REPR(box);
1348 gchar const *id = repr_source->attribute("id");
1349 gchar const *style = repr_source->attribute("style");
1350 gchar const *mask = repr_source->attribute("mask");
1351 gchar const *clip_path = repr_source->attribute("clip-path");
1353 // create a new group and add the sides (converted to ordinary paths) as its children
1354 Inkscape::XML::Node *grepr = xml_doc->createElement("svg:g");
1356 Inkscape::XML::Node *repr;
1357 for (SPObject *child = sp_object_first_child(SP_OBJECT(box)); child != NULL; child = SP_OBJECT_NEXT(child) ) {
1358 if (SP_IS_BOX3D_SIDE(child)) {
1359 repr = box3d_side_convert_to_path(SP_BOX3D_SIDE(child));
1360 grepr->appendChild(repr);
1361 } else {
1362 g_warning("Non-side item encountered as child of a 3D box.");
1363 }
1364 }
1366 // add the new group to the box's parent and set remembered position
1367 SPObject *parent = SP_OBJECT_PARENT(box);
1368 SP_OBJECT_REPR(parent)->appendChild(grepr);
1369 grepr->setPosition(pos);
1370 grepr->setAttribute("style", style);
1371 if (mask)
1372 grepr->setAttribute("mask", mask);
1373 if (clip_path)
1374 grepr->setAttribute("clip-path", clip_path);
1376 SP_OBJECT(box)->deleteObject(true);
1378 grepr->setAttribute("id", id);
1380 return SP_GROUP(doc->getObjectByRepr(grepr));
1381 }
1383 static inline void
1384 box3d_push_back_corner_pair(SPBox3D *box, std::list<std::pair<Geom::Point, Geom::Point> > &pts, int c1, int c2) {
1385 pts.push_back(std::make_pair(box3d_get_corner_screen(box, c1, false),
1386 box3d_get_corner_screen(box, c2, false)));
1387 }
1389 void
1390 box3d_convert_to_guides(SPItem *item) {
1391 SPBox3D *box = SP_BOX3D(item);
1392 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
1394 if (!prefs->getBool("/tools/shapes/3dbox/convertguides", true)) {
1395 sp_item_convert_to_guides(SP_ITEM(box));
1396 return;
1397 }
1399 std::list<std::pair<Geom::Point, Geom::Point> > pts;
1401 /* perspective lines in X direction */
1402 box3d_push_back_corner_pair(box, pts, 0, 1);
1403 box3d_push_back_corner_pair(box, pts, 2, 3);
1404 box3d_push_back_corner_pair(box, pts, 4, 5);
1405 box3d_push_back_corner_pair(box, pts, 6, 7);
1407 /* perspective lines in Y direction */
1408 box3d_push_back_corner_pair(box, pts, 0, 2);
1409 box3d_push_back_corner_pair(box, pts, 1, 3);
1410 box3d_push_back_corner_pair(box, pts, 4, 6);
1411 box3d_push_back_corner_pair(box, pts, 5, 7);
1413 /* perspective lines in Z direction */
1414 box3d_push_back_corner_pair(box, pts, 0, 4);
1415 box3d_push_back_corner_pair(box, pts, 1, 5);
1416 box3d_push_back_corner_pair(box, pts, 2, 6);
1417 box3d_push_back_corner_pair(box, pts, 3, 7);
1419 sp_guide_pt_pairs_to_guides(inkscape_active_desktop(), pts);
1420 }
1422 /*
1423 Local Variables:
1424 mode:c++
1425 c-file-style:"stroustrup"
1426 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1427 indent-tabs-mode:nil
1428 fill-column:99
1429 End:
1430 */
1431 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :