e5b1f62126f25983d026002cc3a8e5d3fefc3bbc
1 #define __PERSPECTIVE3D_C__
3 /*
4 * Class modelling a 3D perspective
5 *
6 * Authors:
7 * Maximilian Albert <Anhalter42@gmx.de>
8 *
9 * Copyright (C) 2007 authors
10 *
11 * Released under GNU GPL, read the file 'COPYING' for more information
12 */
14 #include "box3d.h"
15 #include "box3d-context.h"
16 #include "perspective-line.h"
17 #include <iostream>
18 #include "perspective3d.h"
20 // can probably be removed later
21 #include "inkscape.h"
22 #include "knotholder.h"
24 namespace Box3D {
26 gint Perspective3D::counter = 0;
27 GSList * Perspective3D::perspectives = NULL;
28 Perspective3D * Perspective3D::current_perspective = NULL;
30 Perspective3D *
31 get_persp_of_box (const SP3DBox *box)
32 {
33 for (GSList *p = Perspective3D::perspectives; p != NULL; p = p->next) {
34 if (((Perspective3D *) p->data)->has_box (box))
35 return (Perspective3D *) p->data;
36 }
37 g_warning ("Stray 3D box!\n");
38 g_assert_not_reached();
39 }
41 Perspective3D *
42 get_persp_of_VP (const VanishingPoint *vp)
43 {
44 Perspective3D *persp;
45 for (GSList *p = Perspective3D::perspectives; p != NULL; p = p->next) {
46 persp = (Perspective3D *) p->data;
47 // we compare the pointers, not the position/state of the VPs; is this correct?
48 if (persp->get_vanishing_point (Box3D::X) == vp ||
49 persp->get_vanishing_point (Box3D::Y) == vp ||
50 persp->get_vanishing_point (Box3D::Z) == vp)
51 return persp;
52 }
54 g_warning ("Stray vanishing point!\n");
55 g_assert_not_reached();
56 }
58 /**
59 * Computes the intersection of the two perspective lines from pt1 and pt2 to the respective
60 * vanishing points in the given directions.
61 */
62 // FIXME: This has been moved to a virtual method inside PerspectiveLine; can probably be purged
63 NR::Point
64 perspective_intersection (NR::Point pt1, Box3D::Axis dir1, NR::Point pt2, Box3D::Axis dir2, Perspective3D *persp)
65 {
66 VanishingPoint const *vp1 = persp->get_vanishing_point(dir1);
67 VanishingPoint const *vp2 = persp->get_vanishing_point(dir2);
68 NR::Maybe<NR::Point> meet = Line(pt1, *vp1).intersect(Line(pt2, *vp2));
69 // FIXME: How to handle parallel lines (also depends on the type of the VPs)?
70 if (!meet) { meet = NR::Point (0.0, 0.0); }
71 return *meet;
72 }
74 /**
75 * Find the point on the perspective line from line_pt to the
76 * vanishing point in direction dir that is closest to ext_pt.
77 */
78 NR::Point
79 perspective_line_snap (NR::Point line_pt, Box3D::Axis dir, NR::Point ext_pt, Perspective3D *persp)
80 {
81 return PerspectiveLine(line_pt, dir, persp).closest_to(ext_pt);
82 }
84 Perspective3D::Perspective3D (VanishingPoint const &pt_x, VanishingPoint const &pt_y, VanishingPoint const &pt_z)
85 : boxes (NULL)
86 {
87 vp_x = new VanishingPoint (pt_x);
88 vp_y = new VanishingPoint (pt_y);
89 vp_z = new VanishingPoint (pt_z);
91 my_counter = Perspective3D::counter++;
92 }
94 Perspective3D::Perspective3D (Perspective3D &other)
95 : boxes (NULL) // Should we add an option to copy the list of boxes?
96 {
97 vp_x = new VanishingPoint (*other.vp_x);
98 vp_y = new VanishingPoint (*other.vp_y);
99 vp_z = new VanishingPoint (*other.vp_z);
101 my_counter = Perspective3D::counter++;
102 }
104 Perspective3D::~Perspective3D ()
105 {
106 Perspective3D::remove_perspective (this);
108 // Remove the VPs from their draggers
109 SPEventContext *ec = inkscape_active_event_context();
110 if (SP_IS_3DBOX_CONTEXT (ec)) {
111 SP3DBoxContext *bc = SP_3DBOX_CONTEXT (ec);
112 // we need to check if there are any draggers because the selection
113 // is temporarily empty during duplication of boxes, e.g.
114 if (bc->_vpdrag->draggers != NULL) {
115 /***
116 g_assert (bc->_vpdrag->getDraggerFor (*vp_x) != NULL);
117 g_assert (bc->_vpdrag->getDraggerFor (*vp_y) != NULL);
118 g_assert (bc->_vpdrag->getDraggerFor (*vp_z) != NULL);
119 bc->_vpdrag->getDraggerFor (*vp_x)->removeVP (vp_x);
120 bc->_vpdrag->getDraggerFor (*vp_y)->removeVP (vp_y);
121 bc->_vpdrag->getDraggerFor (*vp_z)->removeVP (vp_z);
122 ***/
123 // TODO: the temporary perspective created when building boxes is not linked to any dragger, hence
124 // we need to do the following checks. Maybe it would be better to not create a temporary
125 // perspective at all but simply compare the VPs manually in sp_3dbox_build.
126 VPDragger * dragger;
127 dragger = bc->_vpdrag->getDraggerFor (*vp_x);
128 if (dragger)
129 dragger->removeVP (vp_x);
130 dragger = bc->_vpdrag->getDraggerFor (*vp_y);
131 if (dragger)
132 dragger->removeVP (vp_y);
133 dragger = bc->_vpdrag->getDraggerFor (*vp_z);
134 if (dragger)
135 dragger->removeVP (vp_z);
136 }
137 }
139 delete vp_x;
140 delete vp_y;
141 delete vp_z;
143 g_slist_free (boxes);
144 }
146 bool
147 Perspective3D::operator==(Perspective3D const &other)
148 {
149 // Two perspectives are equal iff their vanishing points coincide and have identical states
150 return (*vp_x == *other.vp_x && *vp_y == *other.vp_y && *vp_z == *other.vp_z);
151 }
153 VanishingPoint *
154 Perspective3D::get_vanishing_point (Box3D::Axis const dir)
155 {
156 switch (dir) {
157 case X:
158 return vp_x;
159 break;
160 case Y:
161 return vp_y;
162 break;
163 case Z:
164 return vp_z;
165 break;
166 case NONE:
167 g_warning ("Axis direction must be specified. As a workaround we return the VP in X direction.\n");
168 return vp_x;
169 break;
170 default:
171 g_warning ("Single axis direction needed to determine corresponding vanishing point.\n");
172 return get_vanishing_point (extract_first_axis_direction(dir));
173 break;
174 }
175 }
177 void
178 Perspective3D::set_vanishing_point (Box3D::Axis const dir, VanishingPoint const &pt)
179 {
180 switch (dir) {
181 case X:
182 (*vp_x) = pt;
183 break;
184 case Y:
185 (*vp_y) = pt;
186 break;
187 case Z:
188 (*vp_z) = pt;
189 break;
190 case NONE:
191 // no vanishing point to set
192 break;
193 }
194 }
196 Axis
197 Perspective3D::get_axis_of_VP (VanishingPoint *vp)
198 {
199 if (vp == vp_x) return X;
200 if (vp == vp_y) return Y;
201 if (vp == vp_z) return Z;
203 g_warning ("Vanishing point not present in the perspective.\n");
204 return NONE;
205 }
207 void
208 Perspective3D::set_vanishing_point (Box3D::Axis const dir, gdouble pt_x, gdouble pt_y, gdouble dir_x, gdouble dir_y, VPState st)
209 {
210 VanishingPoint *vp;
211 switch (dir) {
212 case X:
213 vp = vp_x;
214 break;
215 case Y:
216 vp = vp_y;
217 break;
218 case Z:
219 vp = vp_z;
220 break;
221 case NONE:
222 // no vanishing point to set
223 return;
224 }
226 vp->set_pos (pt_x, pt_y);
227 vp->v_dir = NR::Point (dir_x, dir_y);
228 vp->state = st;
229 }
231 void
232 Perspective3D::add_box (SP3DBox *box)
233 {
234 if (g_slist_find (this->boxes, box) != NULL) {
235 // Don't add the same box twice
236 g_warning ("Box already uses the current perspective. We don't add it again.\n");
237 return;
238 }
239 this->boxes = g_slist_append (this->boxes, box);
240 }
242 void
243 Perspective3D::remove_box (const SP3DBox *box)
244 {
245 if (!g_slist_find (this->boxes, box)) {
246 g_warning ("Could not find box that is to be removed in the current perspective.\n");
247 }
248 this->boxes = g_slist_remove (this->boxes, box);
249 }
251 bool
252 Perspective3D::has_box (const SP3DBox *box)
253 {
254 return (g_slist_find (this->boxes, box) != NULL);
255 }
257 /**
258 * Update the shape of a box after a handle was dragged or a VP was changed, according to the stored ratios.
259 */
260 void
261 Perspective3D::reshape_boxes (Box3D::Axis axes)
262 {
263 // TODO: Leave the "correct" corner fixed according to which face is supposed to be on front.
264 NR::Point new_pt;
265 VanishingPoint *vp;
266 for (const GSList *i = this->boxes; i != NULL; i = i->next) {
267 SP3DBox *box = SP_3DBOX (i->data);
268 if (axes & Box3D::X) {
269 vp = this->get_vanishing_point (Box3D::X);
270 new_pt = vp->get_pos() + box->ratio_x * (box->corners[3] - vp->get_pos());
271 sp_3dbox_move_corner_in_XY_plane (box, 2, new_pt);
272 }
273 if (axes & Box3D::Y) {
274 vp = this->get_vanishing_point (Box3D::Y);
275 new_pt = vp->get_pos() + box->ratio_y * (box->corners[0] - vp->get_pos());
276 sp_3dbox_move_corner_in_XY_plane (box, 2, new_pt);
277 }
278 if (axes & Box3D::Z) {
279 vp = this->get_vanishing_point (Box3D::Z);
280 new_pt = vp->get_pos() + box->ratio_z * (box->corners[0] - vp->get_pos());
281 sp_3dbox_move_corner_in_Z_direction (box, 4, new_pt);
282 }
284 sp_3dbox_set_shape (box, true);
285 // FIXME: Is there a way update the knots without accessing the
286 // statically linked function knotholder_update_knots?
287 SPEventContext *ec = inkscape_active_event_context();
288 g_assert (ec != NULL);
289 if (ec->shape_knot_holder != NULL) {
290 knotholder_update_knots(ec->shape_knot_holder, (SPItem *) box);
291 }
292 }
293 }
295 void
296 Perspective3D::update_box_reprs ()
297 {
298 for (GSList *i = this->boxes; i != NULL; i = i->next) {
299 SP_OBJECT(SP_3DBOX (i->data))->updateRepr(SP_OBJECT_WRITE_EXT);
300 }
301 }
303 // FIXME: We get compiler errors when we try to move the code from sp_3dbox_get_perspective_string to this function
304 /***
305 gchar *
306 Perspective3D::svg_string ()
307 {
308 }
309 ***/
311 void
312 Perspective3D::add_perspective (Box3D::Perspective3D * const persp)
313 {
314 // FIXME: Should we handle the case that the perspectives have equal VPs but are not identical?
315 // If so, we need to take care of relinking the boxes, etc.
316 if (persp == NULL || g_slist_find (Perspective3D::perspectives, persp)) return;
317 Perspective3D::perspectives = g_slist_prepend (Perspective3D::perspectives, persp);
318 }
320 void
321 Perspective3D::remove_perspective (Box3D::Perspective3D * const persp)
322 {
323 if (persp == NULL || !g_slist_find (Perspective3D::perspectives, persp)) return;
324 Perspective3D::perspectives = g_slist_remove (Perspective3D::perspectives, persp);
325 }
327 // find an existing perspective whose VPs are equal to those of persp
328 Box3D::Perspective3D *
329 Perspective3D::find_perspective (Box3D::Perspective3D * const persp)
330 {
331 for (GSList *p = Perspective3D::perspectives; p != NULL; p = p->next) {
332 if (*((Box3D::Perspective3D *) p->data) == *persp) {
333 return ((Box3D::Perspective3D *) p->data);
334 }
335 }
336 return NULL; // perspective was not found
337 }
339 void
340 Perspective3D::print_debugging_info ()
341 {
342 g_print ("====================================================\n");
343 for (GSList *i = Perspective3D::perspectives; i != NULL; i = i->next) {
344 Perspective3D *persp = (Perspective3D *) i->data;
345 g_print ("Perspective %d:\n", persp->my_counter);
347 VanishingPoint * vp = persp->get_vanishing_point(Box3D::X);
348 g_print (" VP X: (%f,%f) ", (*vp)[NR::X], (*vp)[NR::Y]);
349 g_print ((vp->is_finite()) ? "(finite)\n" : "(infinite)\n");
351 vp = persp->get_vanishing_point(Box3D::Y);
352 g_print (" VP Y: (%f,%f) ", (*vp)[NR::X], (*vp)[NR::Y]);
353 g_print ((vp->is_finite()) ? "(finite)\n" : "(infinite)\n");
355 vp = persp->get_vanishing_point(Box3D::Z);
356 g_print (" VP Z: (%f,%f) ", (*vp)[NR::X], (*vp)[NR::Y]);
357 g_print ((vp->is_finite()) ? "(finite)\n" : "(infinite)\n");
359 g_print ("\nBoxes: ");
360 if (persp->boxes == NULL) {
361 g_print ("none");
362 } else {
363 GSList *j;
364 for (j = persp->boxes; j != NULL; j = j->next) {
365 if (j->next == NULL) break;
366 g_print ("%d, ", SP_3DBOX (j->data)->my_counter);
367 }
368 if (j != NULL) {
369 g_print ("%d", SP_3DBOX (j->data)->my_counter);
370 }
371 }
372 }
373 g_print ("\n====================================================\n");
374 }
376 } // namespace Box3D
378 /*
379 Local Variables:
380 mode:c++
381 c-file-style:"stroustrup"
382 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
383 indent-tabs-mode:nil
384 fill-column:99
385 End:
386 */
387 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :