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/point.h>
17 #include <2geom/rect.h>
18 #include <2geom/line.h>
19 #include "document.h"
20 #include "sp-namedview.h"
21 #include "sp-image.h"
22 #include "sp-item-group.h"
23 #include "sp-item.h"
24 #include "sp-use.h"
25 #include "display/curve.h"
26 #include "inkscape.h"
27 #include "preferences.h"
28 #include "sp-text.h"
29 #include "sp-flowtext.h"
30 #include "text-editing.h"
31 #include "sp-clippath.h"
32 #include "sp-mask.h"
33 #include "helper/geom-curves.h"
34 #include "desktop.h"
36 Inkscape::ObjectSnapper::ObjectSnapper(SnapManager *sm, Geom::Coord const d)
37 : Snapper(sm, d)
38 {
39 _candidates = new std::vector<SnapCandidateItem>;
40 _points_to_snap_to = new std::vector<Inkscape::SnapCandidatePoint>;
41 _paths_to_snap_to = new std::vector<Inkscape::SnapCandidatePath >;
42 }
44 Inkscape::ObjectSnapper::~ObjectSnapper()
45 {
46 _candidates->clear();
47 delete _candidates;
49 _points_to_snap_to->clear();
50 delete _points_to_snap_to;
52 _clear_paths();
53 delete _paths_to_snap_to;
54 }
56 /**
57 * \return Snap tolerance (desktop coordinates); depends on current zoom so that it's always the same in screen pixels
58 */
59 Geom::Coord Inkscape::ObjectSnapper::getSnapperTolerance() const
60 {
61 SPDesktop const *dt = _snapmanager->getDesktop();
62 double const zoom = dt ? dt->current_zoom() : 1;
63 return _snapmanager->snapprefs.getObjectTolerance() / zoom;
64 }
66 bool Inkscape::ObjectSnapper::getSnapperAlwaysSnap() const
67 {
68 return _snapmanager->snapprefs.getObjectTolerance() == 10000; //TODO: Replace this threshold of 10000 by a constant; see also tolerance-slider.cpp
69 }
71 /**
72 * Find all items within snapping range.
73 * \param parent Pointer to the document's root, or to a clipped path or mask object
74 * \param it List of items to ignore
75 * \param bbox_to_snap Bounding box hulling the whole bunch of points, all from the same selection and having the same transformation
76 * \param DimensionToSnap Snap in X, Y, or both directions.
77 */
79 void Inkscape::ObjectSnapper::_findCandidates(SPObject* parent,
80 std::vector<SPItem const *> const *it,
81 bool const &first_point,
82 Geom::Rect const &bbox_to_snap,
83 DimensionToSnap const snap_dim,
84 bool const clip_or_mask,
85 Geom::Matrix const additional_affine) const // transformation of the item being clipped / masked
86 {
87 bool const c1 = (snap_dim == TRANSL_SNAP_XY) && ThisSnapperMightSnap();
88 bool const c2 = (snap_dim != TRANSL_SNAP_XY) && GuidesMightSnap();
90 if (!(c1 || c2)) {
91 return;
92 }
94 if (_snapmanager->getDesktop() == NULL) {
95 g_warning("desktop == NULL, so we cannot snap; please inform the developpers of this bug");
96 // Apparently the etup() method from the SnapManager class hasn't been called before trying to snap.
97 }
100 if (first_point) {
101 _candidates->clear();
102 }
104 Geom::Rect bbox_to_snap_incl = bbox_to_snap; // _incl means: will include the snapper tolerance
105 bbox_to_snap_incl.expandBy(getSnapperTolerance()); // see?
107 for (SPObject* o = sp_object_first_child(parent); o != NULL; o = SP_OBJECT_NEXT(o)) {
108 if (SP_IS_ITEM(o) && !(_snapmanager->getDesktop()->itemIsHidden(SP_ITEM(o)) && !clip_or_mask)) {
109 // Snapping to items in a locked layer is allowed
110 // Don't snap to hidden objects, unless they're a clipped path or a mask
111 /* See if this item is on the ignore list */
112 std::vector<SPItem const *>::const_iterator i;
113 if (it != NULL) {
114 i = it->begin();
115 while (i != it->end() && *i != o) {
116 i++;
117 }
118 }
120 if (it == NULL || i == it->end()) {
121 SPItem *item = SP_ITEM(o);
122 if (item) {
123 SPObject *obj = NULL;
124 if (!clip_or_mask) { // cannot clip or mask more than once
125 // The current item is not a clipping path or a mask, but might
126 // still be the subject of clipping or masking itself ; if so, then
127 // we should also consider that path or mask for snapping to
128 obj = SP_OBJECT(item->clip_ref->getObject());
129 if (obj) {
130 _findCandidates(obj, it, false, bbox_to_snap, snap_dim, true, sp_item_i2doc_affine(item));
131 }
132 obj = SP_OBJECT(item->mask_ref->getObject());
133 if (obj) {
134 _findCandidates(obj, it, false, bbox_to_snap, snap_dim, true, sp_item_i2doc_affine(item));
135 }
136 }
137 }
139 if (SP_IS_GROUP(o)) {
140 _findCandidates(o, it, false, bbox_to_snap, snap_dim, clip_or_mask, additional_affine);
141 } else {
142 Geom::OptRect bbox_of_item = Geom::Rect();
143 if (clip_or_mask) {
144 // Oh oh, this will get ugly. We cannot use sp_item_i2d_affine directly because we need to
145 // insert an additional transformation in document coordinates (code copied from sp_item_i2d_affine)
146 sp_item_invoke_bbox(item,
147 bbox_of_item,
148 sp_item_i2doc_affine(item) * additional_affine * _snapmanager->getDesktop()->doc2dt(),
149 true);
150 } else {
151 sp_item_invoke_bbox(item, bbox_of_item, sp_item_i2d_affine(item), true);
152 }
153 if (bbox_of_item) {
154 // See if the item is within range
155 if (bbox_to_snap_incl.intersects(*bbox_of_item)) {
156 // This item is within snapping range, so record it as a candidate
157 _candidates->push_back(SnapCandidateItem(item, clip_or_mask, additional_affine));
158 // For debugging: print the id of the candidate to the console
159 // SPObject *obj = (SPObject*)item;
160 // std::cout << "Snap candidate added: " << obj->getId() << std::endl;
161 }
162 }
163 }
164 }
165 }
166 }
167 }
170 void Inkscape::ObjectSnapper::_collectNodes(Inkscape::SnapSourceType const &t,
171 bool const &first_point) const
172 {
173 // Now, let's first collect all points to snap to. If we have a whole bunch of points to snap,
174 // e.g. when translating an item using the selector tool, then we will only do this for the
175 // first point and store the collection for later use. This significantly improves the performance
176 if (first_point) {
177 _points_to_snap_to->clear();
179 // Determine the type of bounding box we should snap to
180 SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
182 bool p_is_a_node = t & Inkscape::SNAPSOURCE_NODE_CATEGORY;
183 bool p_is_a_bbox = t & Inkscape::SNAPSOURCE_BBOX_CATEGORY;
184 bool p_is_other = t & Inkscape::SNAPSOURCE_OTHER_CATEGORY;
186 // A point considered for snapping should be either a node, a bbox corner or a guide. Pick only ONE!
187 g_assert(!((p_is_a_node && p_is_a_bbox) || (p_is_a_bbox && p_is_other) || (p_is_a_node && p_is_other)));
189 if (_snapmanager->snapprefs.getSnapToBBoxNode() || _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()) {
190 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
191 bool prefs_bbox = prefs->getBool("/tools/bounding_box");
192 bbox_type = !prefs_bbox ?
193 SPItem::APPROXIMATE_BBOX : SPItem::GEOMETRIC_BBOX;
194 }
196 // Consider the page border for snapping to
197 if (_snapmanager->snapprefs.getSnapToPageBorder()) {
198 _getBorderNodes(_points_to_snap_to);
199 }
201 for (std::vector<SnapCandidateItem>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
202 //Geom::Matrix i2doc(Geom::identity());
203 SPItem *root_item = (*i).item;
204 if (SP_IS_USE((*i).item)) {
205 root_item = sp_use_root(SP_USE((*i).item));
206 }
207 g_return_if_fail(root_item);
209 //Collect all nodes so we can snap to them
210 if (p_is_a_node || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_node) || p_is_other) {
211 // Note: there are two ways in which intersections are considered:
212 // Method 1: Intersections are calculated for each shape individually, for both the
213 // snap source and snap target (see sp_shape_snappoints)
214 // Method 2: Intersections are calculated for each curve or line that we've snapped to, i.e. only for
215 // the target (see the intersect() method in the SnappedCurve and SnappedLine classes)
216 // Some differences:
217 // - Method 1 doesn't find intersections within a set of multiple objects
218 // - Method 2 only works for targets
219 // When considering intersections as snap targets:
220 // - Method 1 only works when snapping to nodes, whereas
221 // - Method 2 only works when snapping to paths
222 // - There will be performance differences too!
223 // If both methods are being used simultaneously, then this might lead to duplicate targets!
225 // Well, here we will be looking for snap TARGETS. Both methods can therefore be used.
226 // When snapping to paths, we will get a collection of snapped lines and snapped curves. findBestSnap() will
227 // go hunting for intersections (but only when asked to in the prefs of course). In that case we can just
228 // temporarily block the intersections in sp_item_snappoints, we don't need duplicates. If we're not snapping to
229 // paths though but only to item nodes then we should still look for the intersections in sp_item_snappoints()
230 bool old_pref = _snapmanager->snapprefs.getSnapIntersectionCS();
231 if (_snapmanager->snapprefs.getSnapToItemPath()) {
232 _snapmanager->snapprefs.setSnapIntersectionCS(false);
233 }
235 sp_item_snappoints(root_item, *_points_to_snap_to, &_snapmanager->snapprefs);
237 if (_snapmanager->snapprefs.getSnapToItemPath()) {
238 _snapmanager->snapprefs.setSnapIntersectionCS(old_pref);
239 }
240 }
242 //Collect the bounding box's corners so we can snap to them
243 if (p_is_a_bbox || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_bbox) || p_is_other) {
244 // Discard the bbox of a clipped path / mask, because we don't want to snap to both the bbox
245 // of the item AND the bbox of the clipping path at the same time
246 if (!(*i).clip_or_mask) {
247 Geom::OptRect b = sp_item_bbox_desktop(root_item, bbox_type);
248 getBBoxPoints(b, _points_to_snap_to, true, _snapmanager->snapprefs.getSnapToBBoxNode(), _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints(), _snapmanager->snapprefs.getSnapBBoxMidpoints());
249 }
250 }
251 }
252 }
253 }
255 void Inkscape::ObjectSnapper::_snapNodes(SnappedConstraints &sc,
256 Inkscape::SnapCandidatePoint const &p,
257 std::vector<SnapCandidatePoint> *unselected_nodes) const
258 {
259 // Iterate through all nodes, find out which one is the closest to p, and snap to it!
261 _collectNodes(p.getSourceType(), p.getSourceNum() == 0);
263 if (unselected_nodes != NULL) {
264 _points_to_snap_to->insert(_points_to_snap_to->end(), unselected_nodes->begin(), unselected_nodes->end());
265 }
267 SnappedPoint s;
268 bool success = false;
270 for (std::vector<SnapCandidatePoint>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {
271 Geom::Coord dist = Geom::L2((*k).getPoint() - p.getPoint());
272 if (dist < getSnapperTolerance() && dist < s.getSnapDistance()) {
273 s = SnappedPoint((*k).getPoint(), p.getSourceType(), p.getSourceNum(), (*k).getTargetType(), dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, true, (*k).getTargetBBox());
274 success = true;
275 }
276 }
278 if (success) {
279 sc.points.push_back(s);
280 }
281 }
283 void Inkscape::ObjectSnapper::_snapTranslatingGuideToNodes(SnappedConstraints &sc,
284 Geom::Point const &p,
285 Geom::Point const &guide_normal) const
286 {
287 // Iterate through all nodes, find out which one is the closest to this guide, and snap to it!
288 _collectNodes(SNAPSOURCE_GUIDE, true);
290 // Although we won't snap to paths here (which would give us under constrained snaps) we can still snap to intersections of paths.
291 if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
292 _collectPaths(Inkscape::SnapCandidatePoint(p, SNAPSOURCE_GUIDE), true);
293 _snapPaths(sc, Inkscape::SnapCandidatePoint(p, SNAPSOURCE_GUIDE), NULL, NULL);
294 // The paths themselves should be discarded in findBestSnap(), as we should only snap to their intersections
295 }
297 SnappedPoint s;
299 Geom::Coord tol = getSnapperTolerance();
301 for (std::vector<SnapCandidatePoint>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {
302 // Project each node (*k) on the guide line (running through point p)
303 Geom::Point p_proj = Geom::projection((*k).getPoint(), Geom::Line(p, p + Geom::rot90(guide_normal)));
304 Geom::Coord dist = Geom::L2((*k).getPoint() - p_proj); // distance from node to the guide
305 Geom::Coord dist2 = Geom::L2(p - p_proj); // distance from projection of node on the guide, to the mouse location
306 if ((dist < tol && dist2 < tol) || getSnapperAlwaysSnap()) {
307 s = SnappedPoint((*k).getPoint(), SNAPSOURCE_GUIDE, 0, (*k).getTargetType(), dist, tol, getSnapperAlwaysSnap(), false, true, (*k).getTargetBBox());
308 sc.points.push_back(s);
309 }
310 }
311 }
314 /**
315 * Returns index of first NR_END bpath in array.
316 */
318 void Inkscape::ObjectSnapper::_collectPaths(Inkscape::SnapCandidatePoint const &p,
319 bool const &first_point) const
320 {
321 // Now, let's first collect all paths to snap to. If we have a whole bunch of points to snap,
322 // e.g. when translating an item using the selector tool, then we will only do this for the
323 // first point and store the collection for later use. This significantly improves the performance
324 if (first_point) {
325 _clear_paths();
327 // Determine the type of bounding box we should snap to
328 SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
330 bool p_is_a_node = p.getSourceType() & Inkscape::SNAPSOURCE_NODE_CATEGORY;
331 bool p_is_other = p.getSourceType() & Inkscape::SNAPSOURCE_OTHER_CATEGORY;
333 if (_snapmanager->snapprefs.getSnapToBBoxPath()) {
334 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
335 int prefs_bbox = prefs->getBool("/tools/bounding_box", 0);
336 bbox_type = !prefs_bbox ?
337 SPItem::APPROXIMATE_BBOX : SPItem::GEOMETRIC_BBOX;
338 }
340 // Consider the page border for snapping
341 if (_snapmanager->snapprefs.getSnapToPageBorder()) {
342 Geom::PathVector *border_path = _getBorderPathv();
343 if (border_path != NULL) {
344 _paths_to_snap_to->push_back(Inkscape::SnapCandidatePath(border_path, SNAPTARGET_PAGE_BORDER, Geom::OptRect()));
345 }
346 }
348 for (std::vector<SnapCandidateItem>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
350 /* Transform the requested snap point to this item's coordinates */
351 Geom::Matrix i2doc(Geom::identity());
352 SPItem *root_item = NULL;
353 /* We might have a clone at hand, so make sure we get the root item */
354 if (SP_IS_USE((*i).item)) {
355 i2doc = sp_use_get_root_transform(SP_USE((*i).item));
356 root_item = sp_use_root(SP_USE((*i).item));
357 g_return_if_fail(root_item);
358 } else {
359 i2doc = sp_item_i2doc_affine((*i).item);
360 root_item = (*i).item;
361 }
363 //Build a list of all paths considered for snapping to
365 //Add the item's path to snap to
366 if (_snapmanager->snapprefs.getSnapToItemPath()) {
367 if (p_is_other || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_node)) {
368 // Snapping to the path of characters is very cool, but for a large
369 // chunk of text this will take ages! So limit snapping to text paths
370 // containing max. 240 characters. Snapping the bbox will not be affected
371 bool very_lenghty_prose = false;
372 if (SP_IS_TEXT(root_item) || SP_IS_FLOWTEXT(root_item)) {
373 very_lenghty_prose = sp_text_get_length(SP_TEXT(root_item)) > 240;
374 }
375 // On my AMD 3000+, the snapping lag becomes annoying at approx. 240 chars
376 // which corresponds to a lag of 500 msec. This is for snapping a rect
377 // to a single line of text.
379 // Snapping for example to a traced bitmap is also very stressing for
380 // the CPU, so we'll only snap to paths having no more than 500 nodes
381 // This also leads to a lag of approx. 500 msec (in my lousy test set-up).
382 bool very_complex_path = false;
383 if (SP_IS_PATH(root_item)) {
384 very_complex_path = sp_nodes_in_path(SP_PATH(root_item)) > 500;
385 }
387 if (!very_lenghty_prose && !very_complex_path) {
388 SPCurve *curve = curve_for_item(root_item);
389 if (curve) {
390 // We will get our own copy of the path, which must be freed at some point
391 Geom::PathVector *borderpathv = pathvector_for_curve(root_item, curve, true, true, Geom::identity(), (*i).additional_affine);
392 _paths_to_snap_to->push_back(Inkscape::SnapCandidatePath(borderpathv, 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()) {
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 ConstraintLine 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,
541 // must lie within two points on the constraintline: p_min_on_cl and p_max_on_cl
542 // The distance between those points is twice the snapping tolerance
543 Geom::Point const p_proj_on_cl = p.getPoint(); // projection has already been taken care of in constrainedSnap in the snapmanager;
544 Geom::Point const p_min_on_cl = _snapmanager->getDesktop()->dt2doc(p_proj_on_cl - getSnapperTolerance() * direction_vector);
545 Geom::Point const p_max_on_cl = _snapmanager->getDesktop()->dt2doc(p_proj_on_cl + getSnapperTolerance() * direction_vector);
547 Geom::Path cl;
548 std::vector<Geom::Path> clv;
549 cl.start(p_min_on_cl);
550 cl.appendNew<Geom::LineSegment>(p_max_on_cl);
551 clv.push_back(cl);
553 for (std::vector<Inkscape::SnapCandidatePath >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
554 if (k->path_vector) {
555 Geom::CrossingSet cs = Geom::crossings(clv, *(k->path_vector));
556 if (cs.size() > 0) {
557 // We need only the first element of cs, because cl is only a single straight linesegment
558 // This first element contains a vector filled with crossings of cl with k->first
559 for (std::vector<Geom::Crossing>::const_iterator m = cs[0].begin(); m != cs[0].end(); m++) {
560 if ((*m).ta >= 0 && (*m).ta <= 1 ) {
561 // Reconstruct the point of intersection
562 Geom::Point p_inters = p_min_on_cl + ((*m).ta) * (p_max_on_cl - p_min_on_cl);
563 // When it's within snapping range, then return it
564 // (within snapping range == between p_min_on_cl and p_max_on_cl == 0 < ta < 1)
565 Geom::Coord dist = Geom::L2(_snapmanager->getDesktop()->dt2doc(p_proj_on_cl) - p_inters);
566 SnappedPoint s(_snapmanager->getDesktop()->doc2dt(p_inters), p.getSourceType(), p.getSourceNum(), k->target_type, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), true, k->target_bbox);
567 sc.points.push_back(s);
568 }
569 }
570 }
571 }
572 }
573 }
576 void Inkscape::ObjectSnapper::freeSnap(SnappedConstraints &sc,
577 Inkscape::SnapCandidatePoint const &p,
578 Geom::OptRect const &bbox_to_snap,
579 std::vector<SPItem const *> const *it,
580 std::vector<SnapCandidatePoint> *unselected_nodes) const
581 {
582 if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(p.getSourceType()) == false ) {
583 return;
584 }
586 /* Get a list of all the SPItems that we will try to snap to */
587 if (p.getSourceNum() == 0) {
588 Geom::Rect const local_bbox_to_snap = bbox_to_snap ? *bbox_to_snap : Geom::Rect(p.getPoint(), p.getPoint());
589 _findCandidates(sp_document_root(_snapmanager->getDocument()), it, p.getSourceNum() == 0, local_bbox_to_snap, TRANSL_SNAP_XY, false, Geom::identity());
590 }
592 if (_snapmanager->snapprefs.getSnapToItemNode() || _snapmanager->snapprefs.getSnapSmoothNodes()
593 || _snapmanager->snapprefs.getSnapToBBoxNode() || _snapmanager->snapprefs.getSnapToPageBorder()
594 || _snapmanager->snapprefs.getSnapLineMidpoints() || _snapmanager->snapprefs.getSnapObjectMidpoints()
595 || _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()
596 || _snapmanager->snapprefs.getIncludeItemCenter()) {
597 _snapNodes(sc, p, unselected_nodes);
598 }
600 if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
601 unsigned n = (unselected_nodes == NULL) ? 0 : unselected_nodes->size();
602 if (n > 0) {
603 /* While editing a path in the node tool, findCandidates must ignore that path because
604 * of the node snapping requirements (i.e. only unselected nodes must be snapable).
605 * That path must not be ignored however when snapping to the paths, so we add it here
606 * manually when applicable
607 */
608 SPPath *path = NULL;
609 if (it != NULL) {
610 if (it->size() == 1 && SP_IS_PATH(*it->begin())) {
611 path = SP_PATH(*it->begin());
612 } // else: *it->begin() might be a SPGroup, e.g. when editing a LPE of text that has been converted to a group of paths
613 // as reported in bug #356743. In that case we can just ignore it, i.e. not snap to this item
614 }
615 _snapPaths(sc, p, unselected_nodes, path);
616 } else {
617 _snapPaths(sc, p, NULL, NULL);
618 }
619 }
620 }
622 void Inkscape::ObjectSnapper::constrainedSnap( SnappedConstraints &sc,
623 Inkscape::SnapCandidatePoint const &p,
624 Geom::OptRect const &bbox_to_snap,
625 ConstraintLine const &c,
626 std::vector<SPItem const *> const *it) const
627 {
628 if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(p.getSourceType()) == false) {
629 return;
630 }
632 /* Get a list of all the SPItems that we will try to snap to */
633 if (p.getSourceNum() == 0) {
634 Geom::Rect const local_bbox_to_snap = bbox_to_snap ? *bbox_to_snap : Geom::Rect(p.getPoint(), p.getPoint());
635 _findCandidates(sp_document_root(_snapmanager->getDocument()), it, p.getSourceNum() == 0, local_bbox_to_snap, TRANSL_SNAP_XY, false, Geom::identity());
636 }
638 // A constrained snap, is a snap in only one degree of freedom (specified by the constraint line).
639 // This is useful for example when scaling an object while maintaining a fixed aspect ratio. It's
640 // nodes are only allowed to move in one direction (i.e. in one degree of freedom).
642 // When snapping to objects, we either snap to their nodes or their paths. It is however very
643 // unlikely that any node will be exactly at the constrained line, so for a constrained snap
644 // to objects we will only consider the object's paths. Beside, the nodes will be at these paths,
645 // so we will more or less snap to them anyhow.
647 if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
648 _snapPathsConstrained(sc, p, c);
649 }
650 }
653 // This method is used to snap a guide to nodes, while dragging the guide around
654 void Inkscape::ObjectSnapper::guideFreeSnap(SnappedConstraints &sc,
655 Geom::Point const &p,
656 Geom::Point const &guide_normal) const
657 {
658 /* Get a list of all the SPItems that we will try to snap to */
659 std::vector<SPItem*> cand;
660 std::vector<SPItem const *> const it; //just an empty list
662 DimensionToSnap snap_dim;
663 if (guide_normal == to_2geom(component_vectors[Geom::Y])) {
664 snap_dim = GUIDE_TRANSL_SNAP_Y;
665 } else if (guide_normal == to_2geom(component_vectors[Geom::X])) {
666 snap_dim = GUIDE_TRANSL_SNAP_X;
667 } else {
668 snap_dim = ANGLED_GUIDE_TRANSL_SNAP;
669 }
671 _findCandidates(sp_document_root(_snapmanager->getDocument()), &it, true, Geom::Rect(p, p), snap_dim, false, Geom::identity());
672 _snapTranslatingGuideToNodes(sc, p, guide_normal);
674 }
676 // This method is used to snap the origin of a guide to nodes/paths, while dragging the origin along the guide
677 void Inkscape::ObjectSnapper::guideConstrainedSnap(SnappedConstraints &sc,
678 Geom::Point const &p,
679 Geom::Point const &guide_normal,
680 ConstraintLine const &/*c*/) const
681 {
682 /* Get a list of all the SPItems that we will try to snap to */
683 std::vector<SPItem*> cand;
684 std::vector<SPItem const *> const it; //just an empty list
686 DimensionToSnap snap_dim;
687 if (guide_normal == to_2geom(component_vectors[Geom::Y])) {
688 snap_dim = GUIDE_TRANSL_SNAP_Y;
689 } else if (guide_normal == to_2geom(component_vectors[Geom::X])) {
690 snap_dim = GUIDE_TRANSL_SNAP_X;
691 } else {
692 snap_dim = ANGLED_GUIDE_TRANSL_SNAP;
693 }
695 _findCandidates(sp_document_root(_snapmanager->getDocument()), &it, true, Geom::Rect(p, p), snap_dim, false, Geom::identity());
696 _snapTranslatingGuideToNodes(sc, p, guide_normal);
698 }
700 /**
701 * \return true if this Snapper will snap at least one kind of point.
702 */
703 bool Inkscape::ObjectSnapper::ThisSnapperMightSnap() const
704 {
705 bool snap_to_something = _snapmanager->snapprefs.getSnapToItemPath()
706 || _snapmanager->snapprefs.getSnapToItemNode() || _snapmanager->snapprefs.getSnapSmoothNodes()
707 || _snapmanager->snapprefs.getSnapToBBoxPath()
708 || _snapmanager->snapprefs.getSnapToBBoxNode()
709 || _snapmanager->snapprefs.getSnapToPageBorder()
710 || _snapmanager->snapprefs.getSnapLineMidpoints() || _snapmanager->snapprefs.getSnapObjectMidpoints()
711 || _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()
712 || _snapmanager->snapprefs.getIncludeItemCenter();
714 return (_snap_enabled && _snapmanager->snapprefs.getSnapModeBBoxOrNodes() && snap_to_something);
715 }
717 bool Inkscape::ObjectSnapper::GuidesMightSnap() const // almost the same as ThisSnapperMightSnap above, but only looking at points (and not paths)
718 {
719 bool snap_to_something = _snapmanager->snapprefs.getSnapToItemNode() || _snapmanager->snapprefs.getSnapSmoothNodes()
720 || _snapmanager->snapprefs.getSnapToPageBorder()
721 || (_snapmanager->snapprefs.getSnapModeBBox() && _snapmanager->snapprefs.getSnapToBBoxNode())
722 || (_snapmanager->snapprefs.getSnapModeBBox() && (_snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()))
723 || (_snapmanager->snapprefs.getSnapModeNode() && (_snapmanager->snapprefs.getSnapLineMidpoints() || _snapmanager->snapprefs.getSnapObjectMidpoints()))
724 || (_snapmanager->snapprefs.getSnapModeNode() && _snapmanager->snapprefs.getIncludeItemCenter())
725 || (_snapmanager->snapprefs.getSnapModeNode() && (_snapmanager->snapprefs.getSnapToItemPath() && _snapmanager->snapprefs.getSnapIntersectionCS()));
727 return (_snap_enabled && _snapmanager->snapprefs.getSnapModeGuide() && snap_to_something);
728 }
730 void Inkscape::ObjectSnapper::_clear_paths() const
731 {
732 for (std::vector<Inkscape::SnapCandidatePath >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
733 delete k->path_vector;
734 }
735 _paths_to_snap_to->clear();
736 }
738 Geom::PathVector* Inkscape::ObjectSnapper::_getBorderPathv() const
739 {
740 Geom::Rect const border_rect = Geom::Rect(Geom::Point(0,0), Geom::Point(sp_document_width(_snapmanager->getDocument()),sp_document_height(_snapmanager->getDocument())));
741 return _getPathvFromRect(border_rect);
742 }
744 Geom::PathVector* Inkscape::ObjectSnapper::_getPathvFromRect(Geom::Rect const rect) const
745 {
746 SPCurve const *border_curve = SPCurve::new_from_rect(rect, true);
747 if (border_curve) {
748 Geom::PathVector *dummy = new Geom::PathVector(border_curve->get_pathvector());
749 return dummy;
750 } else {
751 return NULL;
752 }
753 }
755 void Inkscape::ObjectSnapper::_getBorderNodes(std::vector<SnapCandidatePoint> *points) const
756 {
757 Geom::Coord w = sp_document_width(_snapmanager->getDocument());
758 Geom::Coord h = sp_document_height(_snapmanager->getDocument());
759 points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(0,0), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
760 points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(0,h), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
761 points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(w,h), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
762 points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(w,0), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
763 }
765 void Inkscape::getBBoxPoints(Geom::OptRect const bbox,
766 std::vector<SnapCandidatePoint> *points,
767 bool const /*isTarget*/,
768 bool const includeCorners,
769 bool const includeLineMidpoints,
770 bool const includeObjectMidpoints)
771 {
772 if (bbox) {
773 // collect the corners of the bounding box
774 for ( unsigned k = 0 ; k < 4 ; k++ ) {
775 if (includeCorners) {
776 points->push_back(Inkscape::SnapCandidatePoint(bbox->corner(k), Inkscape::SNAPSOURCE_BBOX_CORNER, 0, Inkscape::SNAPTARGET_BBOX_CORNER, *bbox));
777 }
778 // optionally, collect the midpoints of the bounding box's edges too
779 if (includeLineMidpoints) {
780 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));
781 }
782 }
783 if (includeObjectMidpoints) {
784 points->push_back(Inkscape::SnapCandidatePoint(bbox->midpoint(), Inkscape::SNAPSOURCE_BBOX_MIDPOINT, 0, Inkscape::SNAPTARGET_BBOX_MIDPOINT, *bbox));
785 }
786 }
787 }
789 /*
790 Local Variables:
791 mode:c++
792 c-file-style:"stroustrup"
793 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
794 indent-tabs-mode:nil
795 fill-column:99
796 End:
797 */
798 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :