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 - 2010 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 || (_snapmanager->snapprefs.getIncludeItemCenter() && bbox_to_snap_incl.contains(item->getCenter()))) { // rotation center might be outside of the bounding box
153 // This item is within snapping range, so record it as a candidate
154 _candidates->push_back(SnapCandidateItem(item, clip_or_mask, additional_affine));
155 // For debugging: print the id of the candidate to the console
156 // SPObject *obj = (SPObject*)item;
157 // std::cout << "Snap candidate added: " << obj->getId() << std::endl;
158 }
159 }
160 }
161 }
162 }
163 }
164 }
167 void Inkscape::ObjectSnapper::_collectNodes(Inkscape::SnapSourceType const &t,
168 bool const &first_point) const
169 {
170 // Now, let's first collect all points to snap to. If we have a whole bunch of points to snap,
171 // e.g. when translating an item using the selector tool, then we will only do this for the
172 // first point and store the collection for later use. This significantly improves the performance
173 if (first_point) {
174 _points_to_snap_to->clear();
176 // Determine the type of bounding box we should snap to
177 SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
179 bool p_is_a_node = t & Inkscape::SNAPSOURCE_NODE_CATEGORY;
180 bool p_is_a_bbox = t & Inkscape::SNAPSOURCE_BBOX_CATEGORY;
181 bool p_is_other = t & Inkscape::SNAPSOURCE_OTHER_CATEGORY;
183 // A point considered for snapping should be either a node, a bbox corner or a guide. Pick only ONE!
184 g_assert(!((p_is_a_node && p_is_a_bbox) || (p_is_a_bbox && p_is_other) || (p_is_a_node && p_is_other)));
186 if (_snapmanager->snapprefs.getSnapToBBoxNode() || _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()) {
187 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
188 bool prefs_bbox = prefs->getBool("/tools/bounding_box");
189 bbox_type = !prefs_bbox ?
190 SPItem::APPROXIMATE_BBOX : SPItem::GEOMETRIC_BBOX;
191 }
193 // Consider the page border for snapping to
194 if (_snapmanager->snapprefs.getSnapToPageBorder()) {
195 _getBorderNodes(_points_to_snap_to);
196 }
198 for (std::vector<SnapCandidateItem>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
199 //Geom::Matrix i2doc(Geom::identity());
200 SPItem *root_item = (*i).item;
201 if (SP_IS_USE((*i).item)) {
202 root_item = sp_use_root(SP_USE((*i).item));
203 }
204 g_return_if_fail(root_item);
206 //Collect all nodes so we can snap to them
207 if (p_is_a_node || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_node) || p_is_other) {
208 // Note: there are two ways in which intersections are considered:
209 // Method 1: Intersections are calculated for each shape individually, for both the
210 // snap source and snap target (see sp_shape_snappoints)
211 // Method 2: Intersections are calculated for each curve or line that we've snapped to, i.e. only for
212 // the target (see the intersect() method in the SnappedCurve and SnappedLine classes)
213 // Some differences:
214 // - Method 1 doesn't find intersections within a set of multiple objects
215 // - Method 2 only works for targets
216 // When considering intersections as snap targets:
217 // - Method 1 only works when snapping to nodes, whereas
218 // - Method 2 only works when snapping to paths
219 // - There will be performance differences too!
220 // If both methods are being used simultaneously, then this might lead to duplicate targets!
222 // Well, here we will be looking for snap TARGETS. Both methods can therefore be used.
223 // When snapping to paths, we will get a collection of snapped lines and snapped curves. findBestSnap() will
224 // go hunting for intersections (but only when asked to in the prefs of course). In that case we can just
225 // temporarily block the intersections in sp_item_snappoints, we don't need duplicates. If we're not snapping to
226 // paths though but only to item nodes then we should still look for the intersections in sp_item_snappoints()
227 bool old_pref = _snapmanager->snapprefs.getSnapIntersectionCS();
228 if (_snapmanager->snapprefs.getSnapToItemPath()) {
229 _snapmanager->snapprefs.setSnapIntersectionCS(false);
230 }
232 bool old_pref2 = _snapmanager->snapprefs.getIncludeItemCenter();
233 if ((*i).item == _snapmanager->getRotationCenterSource()) {
234 // don't snap to this item's rotation center
235 _snapmanager->snapprefs.setIncludeItemCenter(false);
236 }
238 sp_item_snappoints(root_item, *_points_to_snap_to, &_snapmanager->snapprefs);
240 // restore the original snap preferences
241 _snapmanager->snapprefs.setSnapIntersectionCS(old_pref);
242 _snapmanager->snapprefs.setIncludeItemCenter(old_pref2);
243 }
245 //Collect the bounding box's corners so we can snap to them
246 if (p_is_a_bbox || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_bbox) || p_is_other) {
247 // Discard the bbox of a clipped path / mask, because we don't want to snap to both the bbox
248 // of the item AND the bbox of the clipping path at the same time
249 if (!(*i).clip_or_mask) {
250 Geom::OptRect b = sp_item_bbox_desktop(root_item, bbox_type);
251 getBBoxPoints(b, _points_to_snap_to, true, _snapmanager->snapprefs.getSnapToBBoxNode(), _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints(), _snapmanager->snapprefs.getSnapBBoxMidpoints());
252 }
253 }
254 }
255 }
256 }
258 void Inkscape::ObjectSnapper::_snapNodes(SnappedConstraints &sc,
259 Inkscape::SnapCandidatePoint const &p,
260 std::vector<SnapCandidatePoint> *unselected_nodes,
261 SnapConstraint const &c) const
262 {
263 // Iterate through all nodes, find out which one is the closest to p, and snap to it!
265 _collectNodes(p.getSourceType(), p.getSourceNum() == 0);
267 if (unselected_nodes != NULL && unselected_nodes->size() > 0) {
268 g_assert(_points_to_snap_to != NULL);
269 _points_to_snap_to->insert(_points_to_snap_to->end(), unselected_nodes->begin(), unselected_nodes->end());
270 }
272 SnappedPoint s;
273 bool success = false;
275 for (std::vector<SnapCandidatePoint>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {
276 Geom::Point target_pt = (*k).getPoint();
277 if (!c.isUndefined()) {
278 // We're snapping to nodes along a constraint only, so find out if this node
279 // is at the constraint, while allowing for a small margin
280 if (Geom::L2(target_pt - c.projection(target_pt)) > 1e-9) {
281 // The distance from the target point to its projection on the constraint
282 // is too large, so this point is not on the constraint. Skip it!
283 continue;
284 }
285 }
287 Geom::Coord dist = Geom::L2(target_pt - p.getPoint());
288 if (dist < getSnapperTolerance() && dist < s.getSnapDistance()) {
289 s = SnappedPoint(target_pt, p.getSourceType(), p.getSourceNum(), (*k).getTargetType(), dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, true, (*k).getTargetBBox());
290 success = true;
291 }
292 }
294 if (success) {
295 sc.points.push_back(s);
296 }
297 }
299 void Inkscape::ObjectSnapper::_snapTranslatingGuide(SnappedConstraints &sc,
300 Geom::Point const &p,
301 Geom::Point const &guide_normal) const
302 {
303 // Iterate through all nodes, find out which one is the closest to this guide, and snap to it!
304 _collectNodes(SNAPSOURCE_GUIDE, true);
306 if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
307 _collectPaths(Inkscape::SnapCandidatePoint(p, SNAPSOURCE_GUIDE), true);
308 _snapPaths(sc, Inkscape::SnapCandidatePoint(p, SNAPSOURCE_GUIDE), NULL, NULL);
309 }
311 SnappedPoint s;
313 Geom::Coord tol = getSnapperTolerance();
315 for (std::vector<SnapCandidatePoint>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {
316 Geom::Point target_pt = (*k).getPoint();
317 // Project each node (*k) on the guide line (running through point p)
318 Geom::Point p_proj = Geom::projection(target_pt, Geom::Line(p, p + Geom::rot90(guide_normal)));
319 Geom::Coord dist = Geom::L2(target_pt - p_proj); // distance from node to the guide
320 Geom::Coord dist2 = Geom::L2(p - p_proj); // distance from projection of node on the guide, to the mouse location
321 if ((dist < tol && dist2 < tol) || getSnapperAlwaysSnap()) {
322 s = SnappedPoint(target_pt, SNAPSOURCE_GUIDE, 0, (*k).getTargetType(), dist, tol, getSnapperAlwaysSnap(), false, true, (*k).getTargetBBox());
323 sc.points.push_back(s);
324 }
325 }
326 }
329 /**
330 * Returns index of first NR_END bpath in array.
331 */
333 void Inkscape::ObjectSnapper::_collectPaths(Inkscape::SnapCandidatePoint const &p,
334 bool const &first_point) const
335 {
336 // Now, let's first collect all paths to snap to. If we have a whole bunch of points to snap,
337 // e.g. when translating an item using the selector tool, then we will only do this for the
338 // first point and store the collection for later use. This significantly improves the performance
339 if (first_point) {
340 _clear_paths();
342 // Determine the type of bounding box we should snap to
343 SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
345 bool p_is_a_node = p.getSourceType() & Inkscape::SNAPSOURCE_NODE_CATEGORY;
346 bool p_is_other = p.getSourceType() & Inkscape::SNAPSOURCE_OTHER_CATEGORY;
348 if (_snapmanager->snapprefs.getSnapToBBoxPath()) {
349 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
350 int prefs_bbox = prefs->getBool("/tools/bounding_box", 0);
351 bbox_type = !prefs_bbox ?
352 SPItem::APPROXIMATE_BBOX : SPItem::GEOMETRIC_BBOX;
353 }
355 // Consider the page border for snapping
356 if (_snapmanager->snapprefs.getSnapToPageBorder() && _snapmanager->snapprefs.getSnapModeBBoxOrNodes()) {
357 Geom::PathVector *border_path = _getBorderPathv();
358 if (border_path != NULL) {
359 _paths_to_snap_to->push_back(Inkscape::SnapCandidatePath(border_path, SNAPTARGET_PAGE_BORDER, Geom::OptRect()));
360 }
361 }
363 for (std::vector<SnapCandidateItem>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
365 /* Transform the requested snap point to this item's coordinates */
366 Geom::Matrix i2doc(Geom::identity());
367 SPItem *root_item = NULL;
368 /* We might have a clone at hand, so make sure we get the root item */
369 if (SP_IS_USE((*i).item)) {
370 i2doc = sp_use_get_root_transform(SP_USE((*i).item));
371 root_item = sp_use_root(SP_USE((*i).item));
372 g_return_if_fail(root_item);
373 } else {
374 i2doc = sp_item_i2doc_affine((*i).item);
375 root_item = (*i).item;
376 }
378 //Build a list of all paths considered for snapping to
380 //Add the item's path to snap to
381 if (_snapmanager->snapprefs.getSnapToItemPath() && _snapmanager->snapprefs.getSnapModeNode()) {
382 if (p_is_other || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_node)) {
383 // Snapping to the path of characters is very cool, but for a large
384 // chunk of text this will take ages! So limit snapping to text paths
385 // containing max. 240 characters. Snapping the bbox will not be affected
386 bool very_lenghty_prose = false;
387 if (SP_IS_TEXT(root_item) || SP_IS_FLOWTEXT(root_item)) {
388 very_lenghty_prose = sp_text_get_length(SP_TEXT(root_item)) > 240;
389 }
390 // On my AMD 3000+, the snapping lag becomes annoying at approx. 240 chars
391 // which corresponds to a lag of 500 msec. This is for snapping a rect
392 // to a single line of text.
394 // Snapping for example to a traced bitmap is also very stressing for
395 // the CPU, so we'll only snap to paths having no more than 500 nodes
396 // This also leads to a lag of approx. 500 msec (in my lousy test set-up).
397 bool very_complex_path = false;
398 if (SP_IS_PATH(root_item)) {
399 very_complex_path = sp_nodes_in_path(SP_PATH(root_item)) > 500;
400 }
402 if (!very_lenghty_prose && !very_complex_path) {
403 SPCurve *curve = curve_for_item(root_item);
404 if (curve) {
405 // We will get our own copy of the pathvector, which must be freed at some point
407 // Geom::PathVector *pv = pathvector_for_curve(root_item, curve, true, true, Geom::identity(), (*i).additional_affine);
409 Geom::PathVector *pv = new Geom::PathVector(curve->get_pathvector());
410 (*pv) *= sp_item_i2d_affine(root_item) * (*i).additional_affine * _snapmanager->getDesktop()->doc2dt(); // (_edit_transform * _i2d_transform);
412 _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.
413 curve->unref();
414 }
415 }
416 }
417 }
419 //Add the item's bounding box to snap to
420 if (_snapmanager->snapprefs.getSnapToBBoxPath() && _snapmanager->snapprefs.getSnapModeBBox()) {
421 if (p_is_other || !(_snapmanager->snapprefs.getStrictSnapping() && p_is_a_node)) {
422 // Discard the bbox of a clipped path / mask, because we don't want to snap to both the bbox
423 // of the item AND the bbox of the clipping path at the same time
424 if (!(*i).clip_or_mask) {
425 Geom::OptRect rect;
426 sp_item_invoke_bbox(root_item, rect, i2doc, TRUE, bbox_type);
427 if (rect) {
428 Geom::PathVector *path = _getPathvFromRect(*rect);
429 rect = sp_item_bbox_desktop(root_item, bbox_type);
430 _paths_to_snap_to->push_back(Inkscape::SnapCandidatePath(path, SNAPTARGET_BBOX_EDGE, rect));
431 }
432 }
433 }
434 }
435 }
436 }
437 }
439 void Inkscape::ObjectSnapper::_snapPaths(SnappedConstraints &sc,
440 Inkscape::SnapCandidatePoint const &p,
441 std::vector<Inkscape::SnapCandidatePoint> *unselected_nodes,
442 SPPath const *selected_path) const
443 {
444 _collectPaths(p, p.getSourceNum() == 0);
445 // Now we can finally do the real snapping, using the paths collected above
447 g_assert(_snapmanager->getDesktop() != NULL);
448 Geom::Point const p_doc = _snapmanager->getDesktop()->dt2doc(p.getPoint());
450 bool const node_tool_active = _snapmanager->snapprefs.getSnapToItemPath() && selected_path != NULL;
452 if (p.getSourceNum() == 0) {
453 /* findCandidates() is used for snapping to both paths and nodes. It ignores the path that is
454 * currently being edited, because that path requires special care: when snapping to nodes
455 * only the unselected nodes of that path should be considered, and these will be passed on separately.
456 * This path must not be ignored however when snapping to the paths, so we add it here
457 * manually when applicable.
458 * */
459 if (node_tool_active) {
460 SPCurve *curve = curve_for_item(SP_ITEM(selected_path));
461 if (curve) {
462 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
463 _paths_to_snap_to->push_back(Inkscape::SnapCandidatePath(pathv, SNAPTARGET_PATH, Geom::OptRect(), true));
464 curve->unref();
465 }
466 }
467 }
469 int num_path = 0;
470 int num_segm = 0;
472 for (std::vector<Inkscape::SnapCandidatePath >::const_iterator it_p = _paths_to_snap_to->begin(); it_p != _paths_to_snap_to->end(); it_p++) {
473 bool const being_edited = node_tool_active && (*it_p).currently_being_edited;
474 //if true then this pathvector it_pv is currently being edited in the node tool
476 for(Geom::PathVector::iterator it_pv = (it_p->path_vector)->begin(); it_pv != (it_p->path_vector)->end(); ++it_pv) {
477 // Find a nearest point for each curve within this path
478 // n curves will return n time values with 0 <= t <= 1
479 std::vector<double> anp = (*it_pv).nearestPointPerCurve(p_doc);
481 std::vector<double>::const_iterator np = anp.begin();
482 unsigned int index = 0;
483 for (; np != anp.end(); np++, index++) {
484 Geom::Curve const *curve = &((*it_pv).at_index(index));
485 Geom::Point const sp_doc = curve->pointAt(*np);
487 bool c1 = true;
488 bool c2 = true;
489 if (being_edited) {
490 /* If the path is being edited, then we should only snap though to stationary pieces of the path
491 * and not to the pieces that are being dragged around. This way we avoid
492 * self-snapping. For this we check whether the nodes at both ends of the current
493 * piece are unselected; if they are then this piece must be stationary
494 */
495 g_assert(unselected_nodes != NULL);
496 Geom::Point start_pt = _snapmanager->getDesktop()->doc2dt(curve->pointAt(0));
497 Geom::Point end_pt = _snapmanager->getDesktop()->doc2dt(curve->pointAt(1));
498 c1 = isUnselectedNode(start_pt, unselected_nodes);
499 c2 = isUnselectedNode(end_pt, unselected_nodes);
500 /* Unfortunately, this might yield false positives for coincident nodes. Inkscape might therefore mistakenly
501 * snap to path segments that are not stationary. There are at least two possible ways to overcome this:
502 * - Linking the individual nodes of the SPPath we have here, to the nodes of the NodePath::SubPath class as being
503 * used in sp_nodepath_selected_nodes_move. This class has a member variable called "selected". For this the nodes
504 * should be in the exact same order for both classes, so we can index them
505 * - Replacing the SPPath being used here by the the NodePath::SubPath class; but how?
506 */
507 }
509 Geom::Point const sp_dt = _snapmanager->getDesktop()->doc2dt(sp_doc);
510 if (!being_edited || (c1 && c2)) {
511 Geom::Coord const dist = Geom::distance(sp_doc, p_doc);
512 if (dist < getSnapperTolerance()) {
513 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));
514 }
515 }
516 }
517 num_segm++;
518 } // End of: for (Geom::PathVector::iterator ....)
519 num_path++;
520 }
521 }
523 /* Returns true if point is coincident with one of the unselected nodes */
524 bool Inkscape::ObjectSnapper::isUnselectedNode(Geom::Point const &point, std::vector<Inkscape::SnapCandidatePoint> const *unselected_nodes) const
525 {
526 if (unselected_nodes == NULL) {
527 return false;
528 }
530 if (unselected_nodes->size() == 0) {
531 return false;
532 }
534 for (std::vector<Inkscape::SnapCandidatePoint>::const_iterator i = unselected_nodes->begin(); i != unselected_nodes->end(); i++) {
535 if (Geom::L2(point - (*i).getPoint()) < 1e-4) {
536 return true;
537 }
538 }
540 return false;
541 }
543 void Inkscape::ObjectSnapper::_snapPathsConstrained(SnappedConstraints &sc,
544 Inkscape::SnapCandidatePoint const &p,
545 SnapConstraint const &c) const
546 {
548 _collectPaths(p, p.getSourceNum() == 0);
550 // Now we can finally do the real snapping, using the paths collected above
552 g_assert(_snapmanager->getDesktop() != NULL);
553 Geom::Point const p_doc = _snapmanager->getDesktop()->dt2doc(p.getPoint());
555 Geom::Point direction_vector = c.getDirection();
556 if (!is_zero(direction_vector)) {
557 direction_vector = Geom::unit_vector(direction_vector);
558 }
560 // The intersection point of the constraint line with any path, must lie within two points on the
561 // SnapConstraint: p_min_on_cl and p_max_on_cl. The distance between those points is twice the snapping tolerance
562 Geom::Point const p_proj_on_cl = p.getPoint(); // projection has already been taken care of in constrainedSnap in the snapmanager;
563 Geom::Point const p_min_on_cl = _snapmanager->getDesktop()->dt2doc(p_proj_on_cl - getSnapperTolerance() * direction_vector);
564 Geom::Point const p_max_on_cl = _snapmanager->getDesktop()->dt2doc(p_proj_on_cl + getSnapperTolerance() * direction_vector);
565 Geom::Coord tolerance = getSnapperTolerance();
567 // PS: Because the paths we're about to snap to are all expressed relative to document coordinate system, we will have
568 // to convert the snapper coordinates from the desktop coordinates to document coordinates
570 std::vector<Geom::Path> constraint_path;
571 if (c.isCircular()) {
572 Geom::Circle constraint_circle(_snapmanager->getDesktop()->dt2doc(c.getPoint()), c.getRadius());
573 constraint_circle.getPath(constraint_path);
574 } else {
575 Geom::Path constraint_line;
576 constraint_line.start(p_min_on_cl);
577 constraint_line.appendNew<Geom::LineSegment>(p_max_on_cl);
578 constraint_path.push_back(constraint_line);
579 }
581 for (std::vector<Inkscape::SnapCandidatePath >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
582 if (k->path_vector) {
583 Geom::CrossingSet cs = Geom::crossings(constraint_path, *(k->path_vector));
584 unsigned int index = 0;
585 for (Geom::CrossingSet::const_iterator i = cs.begin(); i != cs.end(); i++) {
586 if (index >= constraint_path.size()) {
587 break;
588 }
589 for (Geom::Crossings::const_iterator m = (*i).begin(); m != (*i).end(); m++) {
590 //std::cout << "ta = " << (*m).ta << " | tb = " << (*m).tb << std::endl;
591 // Reconstruct the point of intersection
592 Geom::Point p_inters = constraint_path[index].pointAt((*m).ta);
593 // .. and convert it to desktop coordinates
594 p_inters = _snapmanager->getDesktop()->doc2dt(p_inters);
595 Geom::Coord dist = Geom::L2(p_proj_on_cl - p_inters);
596 SnappedPoint s = SnappedPoint(p_inters, p.getSourceType(), p.getSourceNum(), k->target_type, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), true, k->target_bbox);;
597 if (dist <= tolerance) { // If the intersection is within snapping range, then we might snap to it
598 sc.points.push_back(s);
599 }
600 }
601 index++;
602 }
603 }
604 }
605 }
608 void Inkscape::ObjectSnapper::freeSnap(SnappedConstraints &sc,
609 Inkscape::SnapCandidatePoint const &p,
610 Geom::OptRect const &bbox_to_snap,
611 std::vector<SPItem const *> const *it,
612 std::vector<SnapCandidatePoint> *unselected_nodes) const
613 {
614 if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(p.getSourceType()) == false ) {
615 return;
616 }
618 /* Get a list of all the SPItems that we will try to snap to */
619 if (p.getSourceNum() == 0) {
620 Geom::Rect const local_bbox_to_snap = bbox_to_snap ? *bbox_to_snap : Geom::Rect(p.getPoint(), p.getPoint());
621 _findCandidates(sp_document_root(_snapmanager->getDocument()), it, p.getSourceNum() == 0, local_bbox_to_snap, false, Geom::identity());
622 }
624 // TODO: Argh, UGLY! Get rid of this here, move this logic to the snap manager
625 bool snap_nodes = (_snapmanager->snapprefs.getSnapModeNode() && (
626 _snapmanager->snapprefs.getSnapToItemNode() ||
627 _snapmanager->snapprefs.getSnapSmoothNodes() ||
628 _snapmanager->snapprefs.getSnapLineMidpoints() ||
629 _snapmanager->snapprefs.getSnapObjectMidpoints()
630 )) || (_snapmanager->snapprefs.getSnapModeBBox() && (
631 _snapmanager->snapprefs.getSnapToBBoxNode() ||
632 _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() ||
633 _snapmanager->snapprefs.getSnapBBoxMidpoints()
634 )) || (_snapmanager->snapprefs.getSnapModeBBoxOrNodes() && (
635 _snapmanager->snapprefs.getIncludeItemCenter() ||
636 _snapmanager->snapprefs.getSnapToPageBorder()
637 ));
639 if (snap_nodes) {
640 _snapNodes(sc, p, unselected_nodes);
641 }
643 if ((_snapmanager->snapprefs.getSnapModeNode() && _snapmanager->snapprefs.getSnapToItemPath()) ||
644 (_snapmanager->snapprefs.getSnapModeBBox() && _snapmanager->snapprefs.getSnapToBBoxPath()) ||
645 (_snapmanager->snapprefs.getSnapModeBBoxOrNodes() && _snapmanager->snapprefs.getSnapToPageBorder())) {
646 unsigned n = (unselected_nodes == NULL) ? 0 : unselected_nodes->size();
647 if (n > 0) {
648 /* While editing a path in the node tool, findCandidates must ignore that path because
649 * of the node snapping requirements (i.e. only unselected nodes must be snapable).
650 * That path must not be ignored however when snapping to the paths, so we add it here
651 * manually when applicable
652 */
653 SPPath *path = NULL;
654 if (it != NULL) {
655 if (it->size() == 1 && SP_IS_PATH(*it->begin())) {
656 path = SP_PATH(*it->begin());
657 } // else: *it->begin() might be a SPGroup, e.g. when editing a LPE of text that has been converted to a group of paths
658 // as reported in bug #356743. In that case we can just ignore it, i.e. not snap to this item
659 }
660 _snapPaths(sc, p, unselected_nodes, path);
661 } else {
662 _snapPaths(sc, p, NULL, NULL);
663 }
664 }
665 }
667 void Inkscape::ObjectSnapper::constrainedSnap( SnappedConstraints &sc,
668 Inkscape::SnapCandidatePoint const &p,
669 Geom::OptRect const &bbox_to_snap,
670 SnapConstraint const &c,
671 std::vector<SPItem const *> const *it,
672 std::vector<SnapCandidatePoint> *unselected_nodes) const
673 {
674 if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(p.getSourceType()) == false) {
675 return;
676 }
678 /* Get a list of all the SPItems that we will try to snap to */
679 if (p.getSourceNum() == 0) {
680 Geom::Rect const local_bbox_to_snap = bbox_to_snap ? *bbox_to_snap : Geom::Rect(p.getPoint(), p.getPoint());
681 _findCandidates(sp_document_root(_snapmanager->getDocument()), it, p.getSourceNum() == 0, local_bbox_to_snap, false, Geom::identity());
682 }
684 // A constrained snap, is a snap in only one degree of freedom (specified by the constraint line).
685 // This is useful for example when scaling an object while maintaining a fixed aspect ratio. It's
686 // nodes are only allowed to move in one direction (i.e. in one degree of freedom).
688 // TODO: Argh, UGLY! Get rid of this here, move this logic to the snap manager
689 bool snap_nodes = (_snapmanager->snapprefs.getSnapModeNode() && (
690 _snapmanager->snapprefs.getSnapToItemNode() ||
691 _snapmanager->snapprefs.getSnapSmoothNodes() ||
692 _snapmanager->snapprefs.getSnapLineMidpoints() ||
693 _snapmanager->snapprefs.getSnapObjectMidpoints()
694 )) || (_snapmanager->snapprefs.getSnapModeBBox() && (
695 _snapmanager->snapprefs.getSnapToBBoxNode() ||
696 _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() ||
697 _snapmanager->snapprefs.getSnapBBoxMidpoints()
698 )) || (_snapmanager->snapprefs.getSnapModeBBoxOrNodes() && (
699 _snapmanager->snapprefs.getIncludeItemCenter() ||
700 _snapmanager->snapprefs.getSnapToPageBorder()
701 ));
703 if (snap_nodes) {
704 _snapNodes(sc, p, unselected_nodes, c);
705 }
707 if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
708 _snapPathsConstrained(sc, p, c);
709 }
710 }
713 // This method is used to snap a guide to nodes, while dragging the guide around
714 void Inkscape::ObjectSnapper::guideFreeSnap(SnappedConstraints &sc,
715 Geom::Point const &p,
716 Geom::Point const &guide_normal) const
717 {
718 /* Get a list of all the SPItems that we will try to snap to */
719 std::vector<SPItem*> cand;
720 std::vector<SPItem const *> const it; //just an empty list
722 _findCandidates(sp_document_root(_snapmanager->getDocument()), &it, true, Geom::Rect(p, p), false, Geom::identity());
723 _snapTranslatingGuide(sc, p, guide_normal);
725 }
727 // This method is used to snap the origin of a guide to nodes/paths, while dragging the origin along the guide
728 void Inkscape::ObjectSnapper::guideConstrainedSnap(SnappedConstraints &sc,
729 Geom::Point const &p,
730 Geom::Point const &guide_normal,
731 SnapConstraint const &/*c*/) const
732 {
733 /* Get a list of all the SPItems that we will try to snap to */
734 std::vector<SPItem*> cand;
735 std::vector<SPItem const *> const it; //just an empty list
737 _findCandidates(sp_document_root(_snapmanager->getDocument()), &it, true, Geom::Rect(p, p), false, Geom::identity());
738 _snapTranslatingGuide(sc, p, guide_normal);
740 }
742 /**
743 * \return true if this Snapper will snap at least one kind of point.
744 */
745 bool Inkscape::ObjectSnapper::ThisSnapperMightSnap() const
746 {
747 bool snap_to_something = (_snapmanager->snapprefs.getSnapModeNode() && (
748 _snapmanager->snapprefs.getSnapToItemPath() ||
749 _snapmanager->snapprefs.getSnapToItemNode() ||
750 _snapmanager->snapprefs.getSnapSmoothNodes() ||
751 _snapmanager->snapprefs.getSnapLineMidpoints() ||
752 _snapmanager->snapprefs.getSnapObjectMidpoints()
753 )) || (_snapmanager->snapprefs.getSnapModeBBox() && (
754 _snapmanager->snapprefs.getSnapToBBoxPath() ||
755 _snapmanager->snapprefs.getSnapToBBoxNode() ||
756 _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() ||
757 _snapmanager->snapprefs.getSnapBBoxMidpoints()
758 )) || (_snapmanager->snapprefs.getSnapModeBBoxOrNodes() && (
759 _snapmanager->snapprefs.getSnapToPageBorder() ||
760 _snapmanager->snapprefs.getIncludeItemCenter()
761 ));
763 return (_snap_enabled && snap_to_something);
764 }
766 void Inkscape::ObjectSnapper::_clear_paths() const
767 {
768 for (std::vector<Inkscape::SnapCandidatePath >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
769 delete k->path_vector;
770 }
771 _paths_to_snap_to->clear();
772 }
774 Geom::PathVector* Inkscape::ObjectSnapper::_getBorderPathv() const
775 {
776 Geom::Rect const border_rect = Geom::Rect(Geom::Point(0,0), Geom::Point(sp_document_width(_snapmanager->getDocument()),sp_document_height(_snapmanager->getDocument())));
777 return _getPathvFromRect(border_rect);
778 }
780 Geom::PathVector* Inkscape::ObjectSnapper::_getPathvFromRect(Geom::Rect const rect) const
781 {
782 SPCurve const *border_curve = SPCurve::new_from_rect(rect, true);
783 if (border_curve) {
784 Geom::PathVector *dummy = new Geom::PathVector(border_curve->get_pathvector());
785 return dummy;
786 } else {
787 return NULL;
788 }
789 }
791 void Inkscape::ObjectSnapper::_getBorderNodes(std::vector<SnapCandidatePoint> *points) const
792 {
793 Geom::Coord w = sp_document_width(_snapmanager->getDocument());
794 Geom::Coord h = sp_document_height(_snapmanager->getDocument());
795 points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(0,0), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
796 points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(0,h), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
797 points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(w,h), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
798 points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(w,0), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
799 }
801 void Inkscape::getBBoxPoints(Geom::OptRect const bbox,
802 std::vector<SnapCandidatePoint> *points,
803 bool const /*isTarget*/,
804 bool const includeCorners,
805 bool const includeLineMidpoints,
806 bool const includeObjectMidpoints)
807 {
808 if (bbox) {
809 // collect the corners of the bounding box
810 for ( unsigned k = 0 ; k < 4 ; k++ ) {
811 if (includeCorners) {
812 points->push_back(Inkscape::SnapCandidatePoint(bbox->corner(k), Inkscape::SNAPSOURCE_BBOX_CORNER, 0, Inkscape::SNAPTARGET_BBOX_CORNER, *bbox));
813 }
814 // optionally, collect the midpoints of the bounding box's edges too
815 if (includeLineMidpoints) {
816 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));
817 }
818 }
819 if (includeObjectMidpoints) {
820 points->push_back(Inkscape::SnapCandidatePoint(bbox->midpoint(), Inkscape::SNAPSOURCE_BBOX_MIDPOINT, 0, Inkscape::SNAPTARGET_BBOX_MIDPOINT, *bbox));
821 }
822 }
823 }
825 /*
826 Local Variables:
827 mode:c++
828 c-file-style:"stroustrup"
829 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
830 indent-tabs-mode:nil
831 fill-column:99
832 End:
833 */
834 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :