1 /**
2 * \file object-snapper.cpp
3 * \brief Snapping things to objects.
4 *
5 * Authors:
6 * Carl Hetherington <inkscape@carlh.net>
7 * Diederik van Lierop <mail@diedenrezi.nl>
8 *
9 * Copyright (C) 2005 - 2008 Authors
10 *
11 * Released under GNU GPL, read the file 'COPYING' for more information
12 */
14 #include "svg/svg.h"
15 #include <2geom/path-intersection.h>
16 #include <2geom/pathvector.h>
17 #include <2geom/point.h>
18 #include <2geom/rect.h>
19 #include <2geom/line.h>
20 #include <2geom/circle.h>
21 #include "document.h"
22 #include "sp-namedview.h"
23 #include "sp-image.h"
24 #include "sp-item-group.h"
25 #include "sp-item.h"
26 #include "sp-use.h"
27 #include "display/curve.h"
28 #include "inkscape.h"
29 #include "preferences.h"
30 #include "sp-text.h"
31 #include "sp-flowtext.h"
32 #include "text-editing.h"
33 #include "sp-clippath.h"
34 #include "sp-mask.h"
35 #include "helper/geom-curves.h"
36 #include "desktop.h"
38 Inkscape::ObjectSnapper::ObjectSnapper(SnapManager *sm, Geom::Coord const d)
39 : Snapper(sm, d)
40 {
41 _candidates = new std::vector<SnapCandidateItem>;
42 _points_to_snap_to = new std::vector<Inkscape::SnapCandidatePoint>;
43 _paths_to_snap_to = new std::vector<Inkscape::SnapCandidatePath >;
44 }
46 Inkscape::ObjectSnapper::~ObjectSnapper()
47 {
48 _candidates->clear();
49 delete _candidates;
51 _points_to_snap_to->clear();
52 delete _points_to_snap_to;
54 _clear_paths();
55 delete _paths_to_snap_to;
56 }
58 /**
59 * \return Snap tolerance (desktop coordinates); depends on current zoom so that it's always the same in screen pixels
60 */
61 Geom::Coord Inkscape::ObjectSnapper::getSnapperTolerance() const
62 {
63 SPDesktop const *dt = _snapmanager->getDesktop();
64 double const zoom = dt ? dt->current_zoom() : 1;
65 return _snapmanager->snapprefs.getObjectTolerance() / zoom;
66 }
68 bool Inkscape::ObjectSnapper::getSnapperAlwaysSnap() const
69 {
70 return _snapmanager->snapprefs.getObjectTolerance() == 10000; //TODO: Replace this threshold of 10000 by a constant; see also tolerance-slider.cpp
71 }
73 /**
74 * Find all items within snapping range.
75 * \param parent Pointer to the document's root, or to a clipped path or mask object
76 * \param it List of items to ignore
77 * \param bbox_to_snap Bounding box hulling the whole bunch of points, all from the same selection and having the same transformation
78 */
80 void Inkscape::ObjectSnapper::_findCandidates(SPObject* parent,
81 std::vector<SPItem const *> const *it,
82 bool const &first_point,
83 Geom::Rect const &bbox_to_snap,
84 bool const clip_or_mask,
85 Geom::Matrix const additional_affine) const // transformation of the item being clipped / masked
86 {
87 if (!ThisSnapperMightSnap()) {
88 return;
89 }
91 if (_snapmanager->getDesktop() == NULL) {
92 g_warning("desktop == NULL, so we cannot snap; please inform the developpers of this bug");
93 // Apparently the etup() method from the SnapManager class hasn't been called before trying to snap.
94 }
96 if (first_point) {
97 _candidates->clear();
98 }
100 Geom::Rect bbox_to_snap_incl = bbox_to_snap; // _incl means: will include the snapper tolerance
101 bbox_to_snap_incl.expandBy(getSnapperTolerance()); // see?
103 for (SPObject* o = sp_object_first_child(parent); o != NULL; o = SP_OBJECT_NEXT(o)) {
104 if (SP_IS_ITEM(o) && !(_snapmanager->getDesktop()->itemIsHidden(SP_ITEM(o)) && !clip_or_mask)) {
105 // Snapping to items in a locked layer is allowed
106 // Don't snap to hidden objects, unless they're a clipped path or a mask
107 /* See if this item is on the ignore list */
108 std::vector<SPItem const *>::const_iterator i;
109 if (it != NULL) {
110 i = it->begin();
111 while (i != it->end() && *i != o) {
112 i++;
113 }
114 }
116 if (it == NULL || i == it->end()) {
117 SPItem *item = SP_ITEM(o);
118 if (item) {
119 SPObject *obj = NULL;
120 if (!clip_or_mask) { // cannot clip or mask more than once
121 // The current item is not a clipping path or a mask, but might
122 // still be the subject of clipping or masking itself ; if so, then
123 // we should also consider that path or mask for snapping to
124 obj = SP_OBJECT(item->clip_ref->getObject());
125 if (obj) {
126 _findCandidates(obj, it, false, bbox_to_snap, true, sp_item_i2doc_affine(item));
127 }
128 obj = SP_OBJECT(item->mask_ref->getObject());
129 if (obj) {
130 _findCandidates(obj, it, false, bbox_to_snap, true, sp_item_i2doc_affine(item));
131 }
132 }
133 }
135 if (SP_IS_GROUP(o)) {
136 _findCandidates(o, it, false, bbox_to_snap, clip_or_mask, additional_affine);
137 } else {
138 Geom::OptRect bbox_of_item = Geom::Rect();
139 if (clip_or_mask) {
140 // Oh oh, this will get ugly. We cannot use sp_item_i2d_affine directly because we need to
141 // insert an additional transformation in document coordinates (code copied from sp_item_i2d_affine)
142 sp_item_invoke_bbox(item,
143 bbox_of_item,
144 sp_item_i2doc_affine(item) * additional_affine * _snapmanager->getDesktop()->doc2dt(),
145 true);
146 } else {
147 sp_item_invoke_bbox(item, bbox_of_item, sp_item_i2d_affine(item), true);
148 }
149 if (bbox_of_item) {
150 // See if the item is within range
151 if (bbox_to_snap_incl.intersects(*bbox_of_item)) {
152 // This item is within snapping range, so record it as a candidate
153 _candidates->push_back(SnapCandidateItem(item, clip_or_mask, additional_affine));
154 // For debugging: print the id of the candidate to the console
155 // SPObject *obj = (SPObject*)item;
156 // std::cout << "Snap candidate added: " << obj->getId() << std::endl;
157 }
158 }
159 }
160 }
161 }
162 }
163 }
166 void Inkscape::ObjectSnapper::_collectNodes(Inkscape::SnapSourceType const &t,
167 bool const &first_point) const
168 {
169 // Now, let's first collect all points to snap to. If we have a whole bunch of points to snap,
170 // e.g. when translating an item using the selector tool, then we will only do this for the
171 // first point and store the collection for later use. This significantly improves the performance
172 if (first_point) {
173 _points_to_snap_to->clear();
175 // Determine the type of bounding box we should snap to
176 SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
178 bool p_is_a_node = t & Inkscape::SNAPSOURCE_NODE_CATEGORY;
179 bool p_is_a_bbox = t & Inkscape::SNAPSOURCE_BBOX_CATEGORY;
180 bool p_is_other = t & Inkscape::SNAPSOURCE_OTHER_CATEGORY;
182 // A point considered for snapping should be either a node, a bbox corner or a guide. Pick only ONE!
183 g_assert(!((p_is_a_node && p_is_a_bbox) || (p_is_a_bbox && p_is_other) || (p_is_a_node && p_is_other)));
185 if (_snapmanager->snapprefs.getSnapToBBoxNode() || _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()) {
186 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
187 bool prefs_bbox = prefs->getBool("/tools/bounding_box");
188 bbox_type = !prefs_bbox ?
189 SPItem::APPROXIMATE_BBOX : SPItem::GEOMETRIC_BBOX;
190 }
192 // Consider the page border for snapping to
193 if (_snapmanager->snapprefs.getSnapToPageBorder()) {
194 _getBorderNodes(_points_to_snap_to);
195 }
197 for (std::vector<SnapCandidateItem>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
198 //Geom::Matrix i2doc(Geom::identity());
199 SPItem *root_item = (*i).item;
200 if (SP_IS_USE((*i).item)) {
201 root_item = sp_use_root(SP_USE((*i).item));
202 }
203 g_return_if_fail(root_item);
205 //Collect all nodes so we can snap to them
206 if (p_is_a_node || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_node) || p_is_other) {
207 // Note: there are two ways in which intersections are considered:
208 // Method 1: Intersections are calculated for each shape individually, for both the
209 // snap source and snap target (see sp_shape_snappoints)
210 // Method 2: Intersections are calculated for each curve or line that we've snapped to, i.e. only for
211 // the target (see the intersect() method in the SnappedCurve and SnappedLine classes)
212 // Some differences:
213 // - Method 1 doesn't find intersections within a set of multiple objects
214 // - Method 2 only works for targets
215 // When considering intersections as snap targets:
216 // - Method 1 only works when snapping to nodes, whereas
217 // - Method 2 only works when snapping to paths
218 // - There will be performance differences too!
219 // If both methods are being used simultaneously, then this might lead to duplicate targets!
221 // Well, here we will be looking for snap TARGETS. Both methods can therefore be used.
222 // When snapping to paths, we will get a collection of snapped lines and snapped curves. findBestSnap() will
223 // go hunting for intersections (but only when asked to in the prefs of course). In that case we can just
224 // temporarily block the intersections in sp_item_snappoints, we don't need duplicates. If we're not snapping to
225 // paths though but only to item nodes then we should still look for the intersections in sp_item_snappoints()
226 bool old_pref = _snapmanager->snapprefs.getSnapIntersectionCS();
227 if (_snapmanager->snapprefs.getSnapToItemPath()) {
228 _snapmanager->snapprefs.setSnapIntersectionCS(false);
229 }
231 sp_item_snappoints(root_item, *_points_to_snap_to, &_snapmanager->snapprefs);
233 if (_snapmanager->snapprefs.getSnapToItemPath()) {
234 _snapmanager->snapprefs.setSnapIntersectionCS(old_pref);
235 }
236 }
238 //Collect the bounding box's corners so we can snap to them
239 if (p_is_a_bbox || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_bbox) || p_is_other) {
240 // Discard the bbox of a clipped path / mask, because we don't want to snap to both the bbox
241 // of the item AND the bbox of the clipping path at the same time
242 if (!(*i).clip_or_mask) {
243 Geom::OptRect b = sp_item_bbox_desktop(root_item, bbox_type);
244 getBBoxPoints(b, _points_to_snap_to, true, _snapmanager->snapprefs.getSnapToBBoxNode(), _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints(), _snapmanager->snapprefs.getSnapBBoxMidpoints());
245 }
246 }
247 }
248 }
249 }
251 void Inkscape::ObjectSnapper::_snapNodes(SnappedConstraints &sc,
252 Inkscape::SnapCandidatePoint const &p,
253 std::vector<SnapCandidatePoint> *unselected_nodes) const
254 {
255 // Iterate through all nodes, find out which one is the closest to p, and snap to it!
257 _collectNodes(p.getSourceType(), p.getSourceNum() == 0);
259 if (unselected_nodes != NULL) {
260 _points_to_snap_to->insert(_points_to_snap_to->end(), unselected_nodes->begin(), unselected_nodes->end());
261 }
263 SnappedPoint s;
264 bool success = false;
266 for (std::vector<SnapCandidatePoint>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {
267 Geom::Coord dist = Geom::L2((*k).getPoint() - p.getPoint());
268 if (dist < getSnapperTolerance() && dist < s.getSnapDistance()) {
269 s = SnappedPoint((*k).getPoint(), p.getSourceType(), p.getSourceNum(), (*k).getTargetType(), dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, true, (*k).getTargetBBox());
270 success = true;
271 }
272 }
274 if (success) {
275 sc.points.push_back(s);
276 }
277 }
279 void Inkscape::ObjectSnapper::_snapTranslatingGuide(SnappedConstraints &sc,
280 Geom::Point const &p,
281 Geom::Point const &guide_normal) const
282 {
283 // Iterate through all nodes, find out which one is the closest to this guide, and snap to it!
284 _collectNodes(SNAPSOURCE_GUIDE, true);
286 if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
287 _collectPaths(Inkscape::SnapCandidatePoint(p, SNAPSOURCE_GUIDE), true);
288 _snapPaths(sc, Inkscape::SnapCandidatePoint(p, SNAPSOURCE_GUIDE), NULL, NULL);
289 }
291 SnappedPoint s;
293 Geom::Coord tol = getSnapperTolerance();
295 for (std::vector<SnapCandidatePoint>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {
297 // Project each node (*k) on the guide line (running through point p)
298 Geom::Point p_proj = Geom::projection((*k).getPoint(), Geom::Line(p, p + Geom::rot90(guide_normal)));
299 Geom::Coord dist = Geom::L2((*k).getPoint() - p_proj); // distance from node to the guide
300 Geom::Coord dist2 = Geom::L2(p - p_proj); // distance from projection of node on the guide, to the mouse location
301 if ((dist < tol && dist2 < tol) || getSnapperAlwaysSnap()) {
302 s = SnappedPoint((*k).getPoint(), SNAPSOURCE_GUIDE, 0, (*k).getTargetType(), dist, tol, getSnapperAlwaysSnap(), false, true, (*k).getTargetBBox());
303 sc.points.push_back(s);
304 }
305 }
306 }
309 /**
310 * Returns index of first NR_END bpath in array.
311 */
313 void Inkscape::ObjectSnapper::_collectPaths(Inkscape::SnapCandidatePoint const &p,
314 bool const &first_point) const
315 {
316 // Now, let's first collect all paths to snap to. If we have a whole bunch of points to snap,
317 // e.g. when translating an item using the selector tool, then we will only do this for the
318 // first point and store the collection for later use. This significantly improves the performance
319 if (first_point) {
320 _clear_paths();
322 // Determine the type of bounding box we should snap to
323 SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
325 bool p_is_a_node = p.getSourceType() & Inkscape::SNAPSOURCE_NODE_CATEGORY;
326 bool p_is_other = p.getSourceType() & Inkscape::SNAPSOURCE_OTHER_CATEGORY;
328 if (_snapmanager->snapprefs.getSnapToBBoxPath()) {
329 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
330 int prefs_bbox = prefs->getBool("/tools/bounding_box", 0);
331 bbox_type = !prefs_bbox ?
332 SPItem::APPROXIMATE_BBOX : SPItem::GEOMETRIC_BBOX;
333 }
335 // Consider the page border for snapping
336 if (_snapmanager->snapprefs.getSnapToPageBorder() && _snapmanager->snapprefs.getSnapModeBBoxOrNodes()) {
337 Geom::PathVector *border_path = _getBorderPathv();
338 if (border_path != NULL) {
339 _paths_to_snap_to->push_back(Inkscape::SnapCandidatePath(border_path, SNAPTARGET_PAGE_BORDER, Geom::OptRect()));
340 }
341 }
343 for (std::vector<SnapCandidateItem>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
345 /* Transform the requested snap point to this item's coordinates */
346 Geom::Matrix i2doc(Geom::identity());
347 SPItem *root_item = NULL;
348 /* We might have a clone at hand, so make sure we get the root item */
349 if (SP_IS_USE((*i).item)) {
350 i2doc = sp_use_get_root_transform(SP_USE((*i).item));
351 root_item = sp_use_root(SP_USE((*i).item));
352 g_return_if_fail(root_item);
353 } else {
354 i2doc = sp_item_i2doc_affine((*i).item);
355 root_item = (*i).item;
356 }
358 //Build a list of all paths considered for snapping to
360 //Add the item's path to snap to
361 if (_snapmanager->snapprefs.getSnapToItemPath() && _snapmanager->snapprefs.getSnapModeNode()) {
362 if (p_is_other || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_node)) {
363 // Snapping to the path of characters is very cool, but for a large
364 // chunk of text this will take ages! So limit snapping to text paths
365 // containing max. 240 characters. Snapping the bbox will not be affected
366 bool very_lenghty_prose = false;
367 if (SP_IS_TEXT(root_item) || SP_IS_FLOWTEXT(root_item)) {
368 very_lenghty_prose = sp_text_get_length(SP_TEXT(root_item)) > 240;
369 }
370 // On my AMD 3000+, the snapping lag becomes annoying at approx. 240 chars
371 // which corresponds to a lag of 500 msec. This is for snapping a rect
372 // to a single line of text.
374 // Snapping for example to a traced bitmap is also very stressing for
375 // the CPU, so we'll only snap to paths having no more than 500 nodes
376 // This also leads to a lag of approx. 500 msec (in my lousy test set-up).
377 bool very_complex_path = false;
378 if (SP_IS_PATH(root_item)) {
379 very_complex_path = sp_nodes_in_path(SP_PATH(root_item)) > 500;
380 }
382 if (!very_lenghty_prose && !very_complex_path) {
383 SPCurve *curve = curve_for_item(root_item);
384 if (curve) {
385 // We will get our own copy of the pathvector, which must be freed at some point
387 // Geom::PathVector *pv = pathvector_for_curve(root_item, curve, true, true, Geom::identity(), (*i).additional_affine);
389 Geom::PathVector *pv = new Geom::PathVector(curve->get_pathvector());
390 (*pv) *= sp_item_i2d_affine(root_item) * (*i).additional_affine * _snapmanager->getDesktop()->doc2dt(); // (_edit_transform * _i2d_transform);
392 _paths_to_snap_to->push_back(Inkscape::SnapCandidatePath(pv, SNAPTARGET_PATH, Geom::OptRect())); // Perhaps for speed, get a reference to the Geom::pathvector, and store the transformation besides it.
393 curve->unref();
394 }
395 }
396 }
397 }
399 //Add the item's bounding box to snap to
400 if (_snapmanager->snapprefs.getSnapToBBoxPath() && _snapmanager->snapprefs.getSnapModeBBox()) {
401 if (p_is_other || !(_snapmanager->snapprefs.getStrictSnapping() && p_is_a_node)) {
402 // Discard the bbox of a clipped path / mask, because we don't want to snap to both the bbox
403 // of the item AND the bbox of the clipping path at the same time
404 if (!(*i).clip_or_mask) {
405 Geom::OptRect rect;
406 sp_item_invoke_bbox(root_item, rect, i2doc, TRUE, bbox_type);
407 if (rect) {
408 Geom::PathVector *path = _getPathvFromRect(*rect);
409 rect = sp_item_bbox_desktop(root_item, bbox_type);
410 _paths_to_snap_to->push_back(Inkscape::SnapCandidatePath(path, SNAPTARGET_BBOX_EDGE, rect));
411 }
412 }
413 }
414 }
415 }
416 }
417 }
419 void Inkscape::ObjectSnapper::_snapPaths(SnappedConstraints &sc,
420 Inkscape::SnapCandidatePoint const &p,
421 std::vector<Inkscape::SnapCandidatePoint> *unselected_nodes,
422 SPPath const *selected_path) const
423 {
424 _collectPaths(p, p.getSourceNum() == 0);
425 // Now we can finally do the real snapping, using the paths collected above
427 g_assert(_snapmanager->getDesktop() != NULL);
428 Geom::Point const p_doc = _snapmanager->getDesktop()->dt2doc(p.getPoint());
430 bool const node_tool_active = _snapmanager->snapprefs.getSnapToItemPath() && selected_path != NULL;
432 if (p.getSourceNum() == 0) {
433 /* findCandidates() is used for snapping to both paths and nodes. It ignores the path that is
434 * currently being edited, because that path requires special care: when snapping to nodes
435 * only the unselected nodes of that path should be considered, and these will be passed on separately.
436 * This path must not be ignored however when snapping to the paths, so we add it here
437 * manually when applicable.
438 * */
439 if (node_tool_active) {
440 SPCurve *curve = curve_for_item(SP_ITEM(selected_path));
441 if (curve) {
442 Geom::PathVector *pathv = pathvector_for_curve(SP_ITEM(selected_path), curve, true, true, Geom::identity(), Geom::identity()); // We will get our own copy of the path, which must be freed at some point
443 _paths_to_snap_to->push_back(Inkscape::SnapCandidatePath(pathv, SNAPTARGET_PATH, Geom::OptRect(), true));
444 curve->unref();
445 }
446 }
447 }
449 int num_path = 0;
450 int num_segm = 0;
452 for (std::vector<Inkscape::SnapCandidatePath >::const_iterator it_p = _paths_to_snap_to->begin(); it_p != _paths_to_snap_to->end(); it_p++) {
453 bool const being_edited = node_tool_active && (*it_p).currently_being_edited;
454 //if true then this pathvector it_pv is currently being edited in the node tool
456 for(Geom::PathVector::iterator it_pv = (it_p->path_vector)->begin(); it_pv != (it_p->path_vector)->end(); ++it_pv) {
457 // Find a nearest point for each curve within this path
458 // n curves will return n time values with 0 <= t <= 1
459 std::vector<double> anp = (*it_pv).nearestPointPerCurve(p_doc);
461 std::vector<double>::const_iterator np = anp.begin();
462 unsigned int index = 0;
463 for (; np != anp.end(); np++, index++) {
464 Geom::Curve const *curve = &((*it_pv).at_index(index));
465 Geom::Point const sp_doc = curve->pointAt(*np);
467 bool c1 = true;
468 bool c2 = true;
469 if (being_edited) {
470 /* If the path is being edited, then we should only snap though to stationary pieces of the path
471 * and not to the pieces that are being dragged around. This way we avoid
472 * self-snapping. For this we check whether the nodes at both ends of the current
473 * piece are unselected; if they are then this piece must be stationary
474 */
475 g_assert(unselected_nodes != NULL);
476 Geom::Point start_pt = _snapmanager->getDesktop()->doc2dt(curve->pointAt(0));
477 Geom::Point end_pt = _snapmanager->getDesktop()->doc2dt(curve->pointAt(1));
478 c1 = isUnselectedNode(start_pt, unselected_nodes);
479 c2 = isUnselectedNode(end_pt, unselected_nodes);
480 /* Unfortunately, this might yield false positives for coincident nodes. Inkscape might therefore mistakenly
481 * snap to path segments that are not stationary. There are at least two possible ways to overcome this:
482 * - Linking the individual nodes of the SPPath we have here, to the nodes of the NodePath::SubPath class as being
483 * used in sp_nodepath_selected_nodes_move. This class has a member variable called "selected". For this the nodes
484 * should be in the exact same order for both classes, so we can index them
485 * - Replacing the SPPath being used here by the the NodePath::SubPath class; but how?
486 */
487 }
489 Geom::Point const sp_dt = _snapmanager->getDesktop()->doc2dt(sp_doc);
490 if (!being_edited || (c1 && c2)) {
491 Geom::Coord const dist = Geom::distance(sp_doc, p_doc);
492 if (dist < getSnapperTolerance()) {
493 sc.curves.push_back(Inkscape::SnappedCurve(sp_dt, num_path, num_segm, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, curve, p.getSourceType(), p.getSourceNum(), it_p->target_type, it_p->target_bbox));
494 }
495 }
496 }
497 num_segm++;
498 } // End of: for (Geom::PathVector::iterator ....)
499 num_path++;
500 }
501 }
503 /* Returns true if point is coincident with one of the unselected nodes */
504 bool Inkscape::ObjectSnapper::isUnselectedNode(Geom::Point const &point, std::vector<Inkscape::SnapCandidatePoint> const *unselected_nodes) const
505 {
506 if (unselected_nodes == NULL) {
507 return false;
508 }
510 if (unselected_nodes->size() == 0) {
511 return false;
512 }
514 for (std::vector<Inkscape::SnapCandidatePoint>::const_iterator i = unselected_nodes->begin(); i != unselected_nodes->end(); i++) {
515 if (Geom::L2(point - (*i).getPoint()) < 1e-4) {
516 return true;
517 }
518 }
520 return false;
521 }
523 void Inkscape::ObjectSnapper::_snapPathsConstrained(SnappedConstraints &sc,
524 Inkscape::SnapCandidatePoint const &p,
525 SnapConstraint const &c) const
526 {
528 _collectPaths(p, p.getSourceNum() == 0);
530 // Now we can finally do the real snapping, using the paths collected above
532 g_assert(_snapmanager->getDesktop() != NULL);
533 Geom::Point const p_doc = _snapmanager->getDesktop()->dt2doc(p.getPoint());
535 Geom::Point direction_vector = c.getDirection();
536 if (!is_zero(direction_vector)) {
537 direction_vector = Geom::unit_vector(direction_vector);
538 }
540 // The intersection point of the constraint line with any path, must lie within two points on the
541 // SnapConstraint: p_min_on_cl and p_max_on_cl. The distance between those points is twice the snapping tolerance
542 Geom::Point const p_proj_on_cl = p.getPoint(); // projection has already been taken care of in constrainedSnap in the snapmanager;
543 Geom::Point const p_min_on_cl = _snapmanager->getDesktop()->dt2doc(p_proj_on_cl - getSnapperTolerance() * direction_vector);
544 Geom::Point const p_max_on_cl = _snapmanager->getDesktop()->dt2doc(p_proj_on_cl + getSnapperTolerance() * direction_vector);
545 Geom::Coord tolerance = getSnapperTolerance();
547 // PS: Because the paths we're about to snap to are all expressed relative to document coordinate system, we will have
548 // to convert the snapper coordinates from the desktop coordinates to document coordinates
550 std::vector<Geom::Path> constraint_path;
551 if (c.isCircular()) {
552 Geom::Circle constraint_circle(_snapmanager->getDesktop()->dt2doc(c.getPoint()), c.getRadius());
553 constraint_circle.getPath(constraint_path);
554 } else {
555 Geom::Path constraint_line;
556 constraint_line.start(p_min_on_cl);
557 constraint_line.appendNew<Geom::LineSegment>(p_max_on_cl);
558 constraint_path.push_back(constraint_line);
559 }
561 for (std::vector<Inkscape::SnapCandidatePath >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
562 if (k->path_vector) {
563 Geom::CrossingSet cs = Geom::crossings(constraint_path, *(k->path_vector));
564 unsigned int index = 0;
565 for (Geom::CrossingSet::const_iterator i = cs.begin(); i != cs.end(); i++) {
566 if (index >= constraint_path.size()) {
567 break;
568 }
569 for (Geom::Crossings::const_iterator m = (*i).begin(); m != (*i).end(); m++) {
570 //std::cout << "ta = " << (*m).ta << " | tb = " << (*m).tb << std::endl;
571 // Reconstruct the point of intersection
572 Geom::Point p_inters = constraint_path[index].pointAt((*m).ta);
573 // .. and convert it to desktop coordinates
574 p_inters = _snapmanager->getDesktop()->doc2dt(p_inters);
575 Geom::Coord dist = Geom::L2(p_proj_on_cl - p_inters);
576 SnappedPoint s = SnappedPoint(p_inters, p.getSourceType(), p.getSourceNum(), k->target_type, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), true, k->target_bbox);;
577 if (dist <= tolerance) { // If the intersection is within snapping range, then we might snap to it
578 sc.points.push_back(s);
579 }
580 }
581 index++;
582 }
583 }
584 }
585 }
588 void Inkscape::ObjectSnapper::freeSnap(SnappedConstraints &sc,
589 Inkscape::SnapCandidatePoint const &p,
590 Geom::OptRect const &bbox_to_snap,
591 std::vector<SPItem const *> const *it,
592 std::vector<SnapCandidatePoint> *unselected_nodes) const
593 {
594 if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(p.getSourceType()) == false ) {
595 return;
596 }
598 /* Get a list of all the SPItems that we will try to snap to */
599 if (p.getSourceNum() == 0) {
600 Geom::Rect const local_bbox_to_snap = bbox_to_snap ? *bbox_to_snap : Geom::Rect(p.getPoint(), p.getPoint());
601 _findCandidates(sp_document_root(_snapmanager->getDocument()), it, p.getSourceNum() == 0, local_bbox_to_snap, false, Geom::identity());
602 }
605 bool snap_nodes = (_snapmanager->snapprefs.getSnapModeNode() && (
606 _snapmanager->snapprefs.getSnapToItemNode() ||
607 _snapmanager->snapprefs.getSnapSmoothNodes() ||
608 _snapmanager->snapprefs.getSnapLineMidpoints() ||
609 _snapmanager->snapprefs.getSnapObjectMidpoints()
610 )) || (_snapmanager->snapprefs.getSnapModeBBox() && (
611 _snapmanager->snapprefs.getSnapToBBoxNode() ||
612 _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() ||
613 _snapmanager->snapprefs.getSnapBBoxMidpoints()
614 )) || (_snapmanager->snapprefs.getSnapModeBBoxOrNodes() && (
615 _snapmanager->snapprefs.getIncludeItemCenter() ||
616 _snapmanager->snapprefs.getSnapToPageBorder()
617 ));
619 if (snap_nodes) {
620 _snapNodes(sc, p, unselected_nodes);
621 }
623 if (_snapmanager->snapprefs.getSnapModeNode() && _snapmanager->snapprefs.getSnapToItemPath() ||
624 _snapmanager->snapprefs.getSnapModeBBox() && _snapmanager->snapprefs.getSnapToBBoxPath() ||
625 _snapmanager->snapprefs.getSnapModeBBoxOrNodes() && _snapmanager->snapprefs.getSnapToPageBorder()) {
626 unsigned n = (unselected_nodes == NULL) ? 0 : unselected_nodes->size();
627 if (n > 0) {
628 /* While editing a path in the node tool, findCandidates must ignore that path because
629 * of the node snapping requirements (i.e. only unselected nodes must be snapable).
630 * That path must not be ignored however when snapping to the paths, so we add it here
631 * manually when applicable
632 */
633 SPPath *path = NULL;
634 if (it != NULL) {
635 if (it->size() == 1 && SP_IS_PATH(*it->begin())) {
636 path = SP_PATH(*it->begin());
637 } // else: *it->begin() might be a SPGroup, e.g. when editing a LPE of text that has been converted to a group of paths
638 // as reported in bug #356743. In that case we can just ignore it, i.e. not snap to this item
639 }
640 _snapPaths(sc, p, unselected_nodes, path);
641 } else {
642 _snapPaths(sc, p, NULL, NULL);
643 }
644 }
645 }
647 void Inkscape::ObjectSnapper::constrainedSnap( SnappedConstraints &sc,
648 Inkscape::SnapCandidatePoint const &p,
649 Geom::OptRect const &bbox_to_snap,
650 SnapConstraint const &c,
651 std::vector<SPItem const *> const *it) const
652 {
653 if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(p.getSourceType()) == false) {
654 return;
655 }
657 /* Get a list of all the SPItems that we will try to snap to */
658 if (p.getSourceNum() == 0) {
659 Geom::Rect const local_bbox_to_snap = bbox_to_snap ? *bbox_to_snap : Geom::Rect(p.getPoint(), p.getPoint());
660 _findCandidates(sp_document_root(_snapmanager->getDocument()), it, p.getSourceNum() == 0, local_bbox_to_snap, false, Geom::identity());
661 }
663 // A constrained snap, is a snap in only one degree of freedom (specified by the constraint line).
664 // This is useful for example when scaling an object while maintaining a fixed aspect ratio. It's
665 // nodes are only allowed to move in one direction (i.e. in one degree of freedom).
667 // When snapping to objects, we either snap to their nodes or their paths. It is however very
668 // unlikely that any node will be exactly at the constrained line, so for a constrained snap
669 // to objects we will only consider the object's paths. Beside, the nodes will be at these paths,
670 // so we will more or less snap to them anyhow.
672 if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
673 _snapPathsConstrained(sc, p, c);
674 }
675 }
678 // This method is used to snap a guide to nodes, while dragging the guide around
679 void Inkscape::ObjectSnapper::guideFreeSnap(SnappedConstraints &sc,
680 Geom::Point const &p,
681 Geom::Point const &guide_normal) const
682 {
683 /* Get a list of all the SPItems that we will try to snap to */
684 std::vector<SPItem*> cand;
685 std::vector<SPItem const *> const it; //just an empty list
687 _findCandidates(sp_document_root(_snapmanager->getDocument()), &it, true, Geom::Rect(p, p), false, Geom::identity());
688 _snapTranslatingGuide(sc, p, guide_normal);
690 }
692 // This method is used to snap the origin of a guide to nodes/paths, while dragging the origin along the guide
693 void Inkscape::ObjectSnapper::guideConstrainedSnap(SnappedConstraints &sc,
694 Geom::Point const &p,
695 Geom::Point const &guide_normal,
696 SnapConstraint const &/*c*/) const
697 {
698 /* Get a list of all the SPItems that we will try to snap to */
699 std::vector<SPItem*> cand;
700 std::vector<SPItem const *> const it; //just an empty list
702 _findCandidates(sp_document_root(_snapmanager->getDocument()), &it, true, Geom::Rect(p, p), false, Geom::identity());
703 _snapTranslatingGuide(sc, p, guide_normal);
705 }
707 /**
708 * \return true if this Snapper will snap at least one kind of point.
709 */
710 bool Inkscape::ObjectSnapper::ThisSnapperMightSnap() const
711 {
712 bool snap_to_something = (_snapmanager->snapprefs.getSnapModeNode() && (
713 _snapmanager->snapprefs.getSnapToItemPath() ||
714 _snapmanager->snapprefs.getSnapToItemNode() ||
715 _snapmanager->snapprefs.getSnapSmoothNodes() ||
716 _snapmanager->snapprefs.getSnapLineMidpoints() ||
717 _snapmanager->snapprefs.getSnapObjectMidpoints()
718 )) || (_snapmanager->snapprefs.getSnapModeBBox() && (
719 _snapmanager->snapprefs.getSnapToBBoxPath() ||
720 _snapmanager->snapprefs.getSnapToBBoxNode() ||
721 _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() ||
722 _snapmanager->snapprefs.getSnapBBoxMidpoints()
723 )) || (_snapmanager->snapprefs.getSnapModeBBoxOrNodes() && (
724 _snapmanager->snapprefs.getSnapToPageBorder() ||
725 _snapmanager->snapprefs.getIncludeItemCenter()
726 ));
728 return (_snap_enabled && snap_to_something);
729 }
731 void Inkscape::ObjectSnapper::_clear_paths() const
732 {
733 for (std::vector<Inkscape::SnapCandidatePath >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
734 delete k->path_vector;
735 }
736 _paths_to_snap_to->clear();
737 }
739 Geom::PathVector* Inkscape::ObjectSnapper::_getBorderPathv() const
740 {
741 Geom::Rect const border_rect = Geom::Rect(Geom::Point(0,0), Geom::Point(sp_document_width(_snapmanager->getDocument()),sp_document_height(_snapmanager->getDocument())));
742 return _getPathvFromRect(border_rect);
743 }
745 Geom::PathVector* Inkscape::ObjectSnapper::_getPathvFromRect(Geom::Rect const rect) const
746 {
747 SPCurve const *border_curve = SPCurve::new_from_rect(rect, true);
748 if (border_curve) {
749 Geom::PathVector *dummy = new Geom::PathVector(border_curve->get_pathvector());
750 return dummy;
751 } else {
752 return NULL;
753 }
754 }
756 void Inkscape::ObjectSnapper::_getBorderNodes(std::vector<SnapCandidatePoint> *points) const
757 {
758 Geom::Coord w = sp_document_width(_snapmanager->getDocument());
759 Geom::Coord h = sp_document_height(_snapmanager->getDocument());
760 points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(0,0), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
761 points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(0,h), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
762 points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(w,h), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
763 points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(w,0), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
764 }
766 void Inkscape::getBBoxPoints(Geom::OptRect const bbox,
767 std::vector<SnapCandidatePoint> *points,
768 bool const /*isTarget*/,
769 bool const includeCorners,
770 bool const includeLineMidpoints,
771 bool const includeObjectMidpoints)
772 {
773 if (bbox) {
774 // collect the corners of the bounding box
775 for ( unsigned k = 0 ; k < 4 ; k++ ) {
776 if (includeCorners) {
777 points->push_back(Inkscape::SnapCandidatePoint(bbox->corner(k), Inkscape::SNAPSOURCE_BBOX_CORNER, 0, Inkscape::SNAPTARGET_BBOX_CORNER, *bbox));
778 }
779 // optionally, collect the midpoints of the bounding box's edges too
780 if (includeLineMidpoints) {
781 points->push_back(Inkscape::SnapCandidatePoint((bbox->corner(k) + bbox->corner((k+1) % 4))/2, Inkscape::SNAPSOURCE_BBOX_EDGE_MIDPOINT, 0, Inkscape::SNAPTARGET_BBOX_EDGE_MIDPOINT, *bbox));
782 }
783 }
784 if (includeObjectMidpoints) {
785 points->push_back(Inkscape::SnapCandidatePoint(bbox->midpoint(), Inkscape::SNAPSOURCE_BBOX_MIDPOINT, 0, Inkscape::SNAPTARGET_BBOX_MIDPOINT, *bbox));
786 }
787 }
788 }
790 /*
791 Local Variables:
792 mode:c++
793 c-file-style:"stroustrup"
794 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
795 indent-tabs-mode:nil
796 fill-column:99
797 End:
798 */
799 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :