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::SnapCandidate::SnapCandidate(SPItem* item, bool clip_or_mask, Geom::Matrix additional_affine)
37 : item(item), clip_or_mask(clip_or_mask), additional_affine(additional_affine)
38 {
39 }
41 Inkscape::SnapCandidate::~SnapCandidate()
42 {
43 }
45 Inkscape::ObjectSnapper::ObjectSnapper(SnapManager *sm, Geom::Coord const d)
46 : Snapper(sm, d)
47 {
48 _candidates = new std::vector<SnapCandidate>;
49 _points_to_snap_to = new std::vector<std::pair<Geom::Point, int> >;
50 _paths_to_snap_to = new std::vector<std::pair<Geom::PathVector*, SnapTargetType> >;
51 }
53 Inkscape::ObjectSnapper::~ObjectSnapper()
54 {
55 _candidates->clear();
56 delete _candidates;
58 _points_to_snap_to->clear();
59 delete _points_to_snap_to;
61 _clear_paths();
62 delete _paths_to_snap_to;
63 }
65 /**
66 * \return Snap tolerance (desktop coordinates); depends on current zoom so that it's always the same in screen pixels
67 */
68 Geom::Coord Inkscape::ObjectSnapper::getSnapperTolerance() const
69 {
70 SPDesktop const *dt = _snapmanager->getDesktop();
71 double const zoom = dt ? dt->current_zoom() : 1;
72 return _snapmanager->snapprefs.getObjectTolerance() / zoom;
73 }
75 bool Inkscape::ObjectSnapper::getSnapperAlwaysSnap() const
76 {
77 return _snapmanager->snapprefs.getObjectTolerance() == 10000; //TODO: Replace this threshold of 10000 by a constant; see also tolerance-slider.cpp
78 }
80 /**
81 * Find all items within snapping range.
82 * \param parent Pointer to the document's root, or to a clipped path or mask object
83 * \param it List of items to ignore
84 * \param first_point If true then this point is the first one from a whole bunch of points
85 * \param bbox_to_snap Bounding box hulling the whole bunch of points, all from the same selection and having the same transformation
86 * \param DimensionToSnap Snap in X, Y, or both directions.
87 */
89 void Inkscape::ObjectSnapper::_findCandidates(SPObject* parent,
90 std::vector<SPItem const *> const *it,
91 bool const &first_point,
92 Geom::Rect const &bbox_to_snap,
93 DimensionToSnap const snap_dim,
94 bool const clip_or_mask,
95 Geom::Matrix const additional_affine) const // transformation of the item being clipped / masked
96 {
97 bool const c1 = (snap_dim == TRANSL_SNAP_XY) && ThisSnapperMightSnap();
98 bool const c2 = (snap_dim != TRANSL_SNAP_XY) && GuidesMightSnap();
100 if (!(c1 || c2)) {
101 return;
102 }
104 if (first_point) {
105 _candidates->clear();
106 }
108 Geom::Rect bbox_to_snap_incl = bbox_to_snap; // _incl means: will include the snapper tolerance
109 bbox_to_snap_incl.expandBy(getSnapperTolerance()); // see?
111 for (SPObject* o = sp_object_first_child(parent); o != NULL; o = SP_OBJECT_NEXT(o)) {
112 g_assert(_snapmanager->getDesktop() != NULL);
113 if (SP_IS_ITEM(o) && !(_snapmanager->getDesktop()->itemIsHidden(SP_ITEM(o)) && !clip_or_mask)) {
114 // Snapping to items in a locked layer is allowed
115 // Don't snap to hidden objects, unless they're a clipped path or a mask
116 /* See if this item is on the ignore list */
117 std::vector<SPItem const *>::const_iterator i;
118 if (it != NULL) {
119 i = it->begin();
120 while (i != it->end() && *i != o) {
121 i++;
122 }
123 }
125 if (it == NULL || i == it->end()) {
126 SPItem *item = SP_ITEM(o);
127 if (item) {
128 SPObject *obj = NULL;
129 if (!clip_or_mask) { // cannot clip or mask more than once
130 // The current item is not a clipping path or a mask, but might
131 // still be the subject of clipping or masking itself ; if so, then
132 // we should also consider that path or mask for snapping to
133 obj = SP_OBJECT(item->clip_ref->getObject());
134 if (obj) {
135 _findCandidates(obj, it, false, bbox_to_snap, snap_dim, true, sp_item_i2doc_affine(item));
136 }
137 obj = SP_OBJECT(item->mask_ref->getObject());
138 if (obj) {
139 _findCandidates(obj, it, false, bbox_to_snap, snap_dim, true, sp_item_i2doc_affine(item));
140 }
141 }
142 }
144 if (SP_IS_GROUP(o)) {
145 _findCandidates(o, it, false, bbox_to_snap, snap_dim, clip_or_mask, additional_affine);
146 } else {
147 Geom::OptRect bbox_of_item = Geom::Rect();
148 if (clip_or_mask) {
149 // Oh oh, this will get ugly. We cannot use sp_item_i2d_affine directly because we need to
150 // insert an additional transformation in document coordinates (code copied from sp_item_i2d_affine)
151 sp_item_invoke_bbox(item,
152 bbox_of_item,
153 sp_item_i2doc_affine(item) * additional_affine * _snapmanager->getDesktop()->doc2dt(),
154 true);
155 } else {
156 sp_item_invoke_bbox(item, bbox_of_item, sp_item_i2d_affine(item), true);
157 }
158 if (bbox_of_item) {
159 // See if the item is within range
160 if (bbox_to_snap_incl.intersects(*bbox_of_item)) {
161 // This item is within snapping range, so record it as a candidate
162 _candidates->push_back(SnapCandidate(item, clip_or_mask, additional_affine));
163 // For debugging: print the id of the candidate to the console
164 //SPObject *obj = (SPObject*)item;
165 //std::cout << "Snap candidate added: " << obj->id << std::endl;
166 }
167 }
168 }
169 }
170 }
171 }
172 }
175 void Inkscape::ObjectSnapper::_collectNodes(Inkscape::SnapPreferences::PointType const &t,
176 bool const &first_point) const
177 {
178 // Now, let's first collect all points to snap to. If we have a whole bunch of points to snap,
179 // e.g. when translating an item using the selector tool, then we will only do this for the
180 // first point and store the collection for later use. This significantly improves the performance
181 if (first_point) {
182 _points_to_snap_to->clear();
184 // Determine the type of bounding box we should snap to
185 SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
187 bool p_is_a_node = t & Inkscape::SnapPreferences::SNAPPOINT_NODE;
188 bool p_is_a_bbox = t & Inkscape::SnapPreferences::SNAPPOINT_BBOX;
189 bool p_is_a_guide = t & Inkscape::SnapPreferences::SNAPPOINT_GUIDE;
191 // A point considered for snapping should be either a node, a bbox corner or a guide. Pick only ONE!
192 g_assert(!((p_is_a_node && p_is_a_bbox) || (p_is_a_bbox && p_is_a_guide) || (p_is_a_node && p_is_a_guide)));
194 if (_snapmanager->snapprefs.getSnapToBBoxNode() || _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()) {
195 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
196 bool prefs_bbox = prefs->getBool("/tools/bounding_box");
197 bbox_type = !prefs_bbox ?
198 SPItem::APPROXIMATE_BBOX : SPItem::GEOMETRIC_BBOX;
199 }
201 // Consider the page border for snapping to
202 if (_snapmanager->snapprefs.getSnapToPageBorder()) {
203 _getBorderNodes(_points_to_snap_to);
204 }
206 for (std::vector<SnapCandidate>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
207 //Geom::Matrix i2doc(Geom::identity());
208 SPItem *root_item = (*i).item;
209 if (SP_IS_USE((*i).item)) {
210 root_item = sp_use_root(SP_USE((*i).item));
211 }
212 g_return_if_fail(root_item);
214 //Collect all nodes so we can snap to them
215 if (p_is_a_node || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_node) || p_is_a_guide) {
216 // Note: there are two ways in which intersections are considered:
217 // Method 1: Intersections are calculated for each shape individually, for both the
218 // snap source and snap target (see sp_shape_snappoints)
219 // Method 2: Intersections are calculated for each curve or line that we've snapped to, i.e. only for
220 // the target (see the intersect() method in the SnappedCurve and SnappedLine classes)
221 // Some differences:
222 // - Method 1 doesn't find intersections within a set of multiple objects
223 // - Method 2 only works for targets
224 // When considering intersections as snap targets:
225 // - Method 1 only works when snapping to nodes, whereas
226 // - Method 2 only works when snapping to paths
227 // - There will be performance differences too!
228 // If both methods are being used simultaneously, then this might lead to duplicate targets!
230 // Well, here we will be looking for snap TARGETS. Both methods can therefore be used.
231 // When snapping to paths, we will get a collection of snapped lines and snapped curves. findBestSnap() will
232 // go hunting for intersections (but only when asked to in the prefs of course). In that case we can just
233 // temporarily block the intersections in sp_item_snappoints, we don't need duplicates. If we're not snapping to
234 // paths though but only to item nodes then we should still look for the intersections in sp_item_snappoints()
235 bool old_pref = _snapmanager->snapprefs.getSnapIntersectionCS();
236 if (_snapmanager->snapprefs.getSnapToItemPath()) {
237 _snapmanager->snapprefs.setSnapIntersectionCS(false);
238 }
240 sp_item_snappoints(root_item, true, *_points_to_snap_to, &_snapmanager->snapprefs);
242 if (_snapmanager->snapprefs.getSnapToItemPath()) {
243 _snapmanager->snapprefs.setSnapIntersectionCS(old_pref);
244 }
245 }
247 //Collect the bounding box's corners so we can snap to them
248 if (p_is_a_bbox || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_bbox) || p_is_a_guide) {
249 // Discard the bbox of a clipped path / mask, because we don't want to snap to both the bbox
250 // of the item AND the bbox of the clipping path at the same time
251 if (!(*i).clip_or_mask) {
252 Geom::OptRect b = sp_item_bbox_desktop(root_item, bbox_type);
253 getBBoxPoints(b, _points_to_snap_to, true, _snapmanager->snapprefs.getSnapToBBoxNode(), _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints(), _snapmanager->snapprefs.getSnapBBoxMidpoints());
254 }
255 }
256 }
257 }
258 }
260 void Inkscape::ObjectSnapper::_snapNodes(SnappedConstraints &sc,
261 Inkscape::SnapPreferences::PointType const &t,
262 Geom::Point const &p,
263 SnapSourceType const &source_type,
264 bool const &first_point,
265 std::vector<std::pair<Geom::Point, int> > *unselected_nodes) const
266 {
267 // Iterate through all nodes, find out which one is the closest to p, and snap to it!
269 _collectNodes(t, first_point);
271 if (unselected_nodes != NULL) {
272 _points_to_snap_to->insert(_points_to_snap_to->end(), unselected_nodes->begin(), unselected_nodes->end());
273 }
275 SnappedPoint s;
276 bool success = false;
278 for (std::vector<std::pair<Geom::Point, int> >::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {
279 Geom::Coord dist = Geom::L2((*k).first - p);
280 if (dist < getSnapperTolerance() && dist < s.getSnapDistance()) {
281 s = SnappedPoint((*k).first, source_type, static_cast<Inkscape::SnapTargetType>((*k).second), dist, getSnapperTolerance(), getSnapperAlwaysSnap(), true);
282 success = true;
283 }
284 }
286 if (success) {
287 sc.points.push_back(s);
288 }
289 }
291 void Inkscape::ObjectSnapper::_snapTranslatingGuideToNodes(SnappedConstraints &sc,
292 Inkscape::SnapPreferences::PointType const &t,
293 Geom::Point const &p,
294 Geom::Point const &guide_normal) const
295 {
296 // Iterate through all nodes, find out which one is the closest to this guide, and snap to it!
297 _collectNodes(t, true);
299 // Although we won't snap to paths here (which would give us under constrained snaps) we can still snap to intersections of paths.
300 if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
301 _collectPaths(t, true);
302 _snapPaths(sc, t, p, SNAPSOURCE_GUIDE, true, NULL, NULL);
303 // The paths themselves should be discarded in findBestSnap(), as we should only snap to their intersections
304 }
306 SnappedPoint s;
308 Geom::Coord tol = getSnapperTolerance();
310 for (std::vector<std::pair<Geom::Point, int> >::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {
311 // Project each node (*k) on the guide line (running through point p)
312 Geom::Point p_proj = Geom::projection((*k).first, Geom::Line(p, p + Geom::rot90(guide_normal)));
313 Geom::Coord dist = Geom::L2((*k).first - p_proj); // distance from node to the guide
314 Geom::Coord dist2 = Geom::L2(p - p_proj); // distance from projection of node on the guide, to the mouse location
315 if ((dist < tol && dist2 < tol) || getSnapperAlwaysSnap()) {
316 s = SnappedPoint((*k).first, SNAPSOURCE_GUIDE, static_cast<Inkscape::SnapTargetType>((*k).second), dist, tol, getSnapperAlwaysSnap(), true);
317 sc.points.push_back(s);
318 }
319 }
320 }
323 /**
324 * Returns index of first NR_END bpath in array.
325 */
327 void Inkscape::ObjectSnapper::_collectPaths(Inkscape::SnapPreferences::PointType const &t,
328 bool const &first_point) const
329 {
330 // Now, let's first collect all paths to snap to. If we have a whole bunch of points to snap,
331 // e.g. when translating an item using the selector tool, then we will only do this for the
332 // first point and store the collection for later use. This significantly improves the performance
333 if (first_point) {
334 _clear_paths();
336 // Determine the type of bounding box we should snap to
337 SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
339 bool p_is_a_node = t & Inkscape::SnapPreferences::SNAPPOINT_NODE;
340 bool p_is_a_guide = t & Inkscape::SnapPreferences::SNAPPOINT_GUIDE;
342 if (_snapmanager->snapprefs.getSnapToBBoxPath()) {
343 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
344 int prefs_bbox = prefs->getBool("/tools/bounding_box", 0);
345 bbox_type = !prefs_bbox ?
346 SPItem::APPROXIMATE_BBOX : SPItem::GEOMETRIC_BBOX;
347 }
349 // Consider the page border for snapping
350 if (_snapmanager->snapprefs.getSnapToPageBorder()) {
351 Geom::PathVector *border_path = _getBorderPathv();
352 if (border_path != NULL) {
353 _paths_to_snap_to->push_back(std::make_pair(border_path, SNAPTARGET_PAGE_BORDER));
354 }
355 }
357 for (std::vector<SnapCandidate>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
359 /* Transform the requested snap point to this item's coordinates */
360 Geom::Matrix i2doc(Geom::identity());
361 SPItem *root_item = NULL;
362 /* We might have a clone at hand, so make sure we get the root item */
363 if (SP_IS_USE((*i).item)) {
364 i2doc = sp_use_get_root_transform(SP_USE((*i).item));
365 root_item = sp_use_root(SP_USE((*i).item));
366 g_return_if_fail(root_item);
367 } else {
368 i2doc = sp_item_i2doc_affine((*i).item);
369 root_item = (*i).item;
370 }
372 //Build a list of all paths considered for snapping to
374 //Add the item's path to snap to
375 if (_snapmanager->snapprefs.getSnapToItemPath()) {
376 if (p_is_a_guide || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_node)) {
377 // Snapping to the path of characters is very cool, but for a large
378 // chunk of text this will take ages! So limit snapping to text paths
379 // containing max. 240 characters. Snapping the bbox will not be affected
380 bool very_lenghty_prose = false;
381 if (SP_IS_TEXT(root_item) || SP_IS_FLOWTEXT(root_item)) {
382 very_lenghty_prose = sp_text_get_length(SP_TEXT(root_item)) > 240;
383 }
384 // On my AMD 3000+, the snapping lag becomes annoying at approx. 240 chars
385 // which corresponds to a lag of 500 msec. This is for snapping a rect
386 // to a single line of text.
388 // Snapping for example to a traced bitmap is also very stressing for
389 // the CPU, so we'll only snap to paths having no more than 500 nodes
390 // This also leads to a lag of approx. 500 msec (in my lousy test set-up).
391 bool very_complex_path = false;
392 if (SP_IS_PATH(root_item)) {
393 very_complex_path = sp_nodes_in_path(SP_PATH(root_item)) > 500;
394 }
396 if (!very_lenghty_prose && !very_complex_path) {
397 SPCurve *curve = curve_for_item(root_item);
398 if (curve) {
399 // We will get our own copy of the path, which must be freed at some point
400 Geom::PathVector *borderpathv = pathvector_for_curve(root_item, curve, true, true, Geom::identity(), (*i).additional_affine);
401 _paths_to_snap_to->push_back(std::make_pair(borderpathv, SNAPTARGET_PATH)); // Perhaps for speed, get a reference to the Geom::pathvector, and store the transformation besides it.
402 curve->unref();
403 }
404 }
405 }
406 }
408 //Add the item's bounding box to snap to
409 if (_snapmanager->snapprefs.getSnapToBBoxPath()) {
410 if (p_is_a_guide || !(_snapmanager->snapprefs.getStrictSnapping() && p_is_a_node)) {
411 // Discard the bbox of a clipped path / mask, because we don't want to snap to both the bbox
412 // of the item AND the bbox of the clipping path at the same time
413 if (!(*i).clip_or_mask) {
414 Geom::OptRect rect;
415 sp_item_invoke_bbox(root_item, rect, i2doc, TRUE, bbox_type);
416 if (rect) {
417 Geom::PathVector *path = _getPathvFromRect(*rect);
418 _paths_to_snap_to->push_back(std::make_pair(path, SNAPTARGET_BBOX_EDGE));
419 }
420 }
421 }
422 }
423 }
424 }
425 }
427 void Inkscape::ObjectSnapper::_snapPaths(SnappedConstraints &sc,
428 Inkscape::SnapPreferences::PointType const &t,
429 Geom::Point const &p,
430 SnapSourceType const &source_type,
431 bool const &first_point,
432 std::vector<std::pair<Geom::Point, int> > *unselected_nodes,
433 SPPath const *selected_path) const
434 {
435 _collectPaths(t, first_point);
436 // Now we can finally do the real snapping, using the paths collected above
438 g_assert(_snapmanager->getDesktop() != NULL);
439 Geom::Point const p_doc = _snapmanager->getDesktop()->dt2doc(p);
441 bool const node_tool_active = _snapmanager->snapprefs.getSnapToItemPath() && selected_path != NULL;
443 if (first_point) {
444 /* findCandidates() is used for snapping to both paths and nodes. It ignores the path that is
445 * currently being edited, because that path requires special care: when snapping to nodes
446 * only the unselected nodes of that path should be considered, and these will be passed on separately.
447 * This path must not be ignored however when snapping to the paths, so we add it here
448 * manually when applicable.
449 *
450 * Note that this path must be the last in line!
451 * */
452 if (node_tool_active) {
453 SPCurve *curve = curve_for_item(SP_ITEM(selected_path));
454 if (curve) {
455 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
456 _paths_to_snap_to->push_back(std::make_pair(pathv, SNAPTARGET_PATH));
457 curve->unref();
458 }
459 }
460 }
462 for (std::vector<std::pair<Geom::PathVector*, SnapTargetType> >::const_iterator it_p = _paths_to_snap_to->begin(); it_p != _paths_to_snap_to->end(); it_p++) {
463 bool const being_edited = (node_tool_active && (*it_p) == _paths_to_snap_to->back());
464 //if true then this pathvector it_pv is currently being edited in the node tool
466 // char * svgd = sp_svg_write_path(**it_p->first);
467 // std::cout << "Dumping the pathvector: " << svgd << std::endl;
469 for(Geom::PathVector::iterator it_pv = (it_p->first)->begin(); it_pv != (it_p->first)->end(); ++it_pv) {
470 // Find a nearest point for each curve within this path
471 // n curves will return n time values with 0 <= t <= 1
472 std::vector<double> anp = (*it_pv).nearestPointPerCurve(p_doc);
474 std::vector<double>::const_iterator np = anp.begin();
475 unsigned int index = 0;
476 for (; np != anp.end(); np++, index++) {
477 Geom::Curve const *curve = &((*it_pv).at_index(index));
478 Geom::Point const sp_doc = curve->pointAt(*np);
480 bool c1 = true;
481 bool c2 = true;
482 if (being_edited) {
483 /* If the path is being edited, then we should only snap though to stationary pieces of the path
484 * and not to the pieces that are being dragged around. This way we avoid
485 * self-snapping. For this we check whether the nodes at both ends of the current
486 * piece are unselected; if they are then this piece must be stationary
487 */
488 g_assert(unselected_nodes != NULL);
489 Geom::Point start_pt = _snapmanager->getDesktop()->doc2dt(curve->pointAt(0));
490 Geom::Point end_pt = _snapmanager->getDesktop()->doc2dt(curve->pointAt(1));
491 c1 = isUnselectedNode(start_pt, unselected_nodes);
492 c2 = isUnselectedNode(end_pt, unselected_nodes);
493 /* Unfortunately, this might yield false positives for coincident nodes. Inkscape might therefore mistakenly
494 * snap to path segments that are not stationary. There are at least two possible ways to overcome this:
495 * - Linking the individual nodes of the SPPath we have here, to the nodes of the NodePath::SubPath class as being
496 * used in sp_nodepath_selected_nodes_move. This class has a member variable called "selected". For this the nodes
497 * should be in the exact same order for both classes, so we can index them
498 * - Replacing the SPPath being used here by the the NodePath::SubPath class; but how?
499 */
500 }
502 Geom::Point const sp_dt = _snapmanager->getDesktop()->doc2dt(sp_doc);
503 if (!being_edited || (c1 && c2)) {
504 Geom::Coord const dist = Geom::distance(sp_doc, p_doc);
505 if (dist < getSnapperTolerance()) {
506 sc.curves.push_back(Inkscape::SnappedCurve(sp_dt, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, curve, source_type, it_p->second));
507 }
508 }
509 }
510 } // End of: for (Geom::PathVector::iterator ....)
511 }
512 }
514 /* Returns true if point is coincident with one of the unselected nodes */
515 bool Inkscape::ObjectSnapper::isUnselectedNode(Geom::Point const &point, std::vector<std::pair<Geom::Point, int> > const *unselected_nodes) const
516 {
517 if (unselected_nodes == NULL) {
518 return false;
519 }
521 if (unselected_nodes->size() == 0) {
522 return false;
523 }
525 for (std::vector<std::pair<Geom::Point, int> >::const_iterator i = unselected_nodes->begin(); i != unselected_nodes->end(); i++) {
526 if (Geom::L2(point - (*i).first) < 1e-4) {
527 return true;
528 }
529 }
531 return false;
532 }
534 void Inkscape::ObjectSnapper::_snapPathsConstrained(SnappedConstraints &sc,
535 Inkscape::SnapPreferences::PointType const &t,
536 Geom::Point const &p,
537 SnapSourceType const source_type,
538 bool const &first_point,
539 ConstraintLine const &c) const
540 {
542 _collectPaths(t, first_point);
544 // Now we can finally do the real snapping, using the paths collected above
546 g_assert(_snapmanager->getDesktop() != NULL);
547 Geom::Point const p_doc = _snapmanager->getDesktop()->dt2doc(p);
549 Geom::Point direction_vector = c.getDirection();
550 if (!is_zero(direction_vector)) {
551 direction_vector = Geom::unit_vector(direction_vector);
552 }
554 // The intersection point of the constraint line with any path,
555 // must lie within two points on the constraintline: p_min_on_cl and p_max_on_cl
556 // The distance between those points is twice the snapping tolerance
557 Geom::Point const p_proj_on_cl = p; // projection has already been taken care of in constrainedSnap in the snapmanager;
558 Geom::Point const p_min_on_cl = _snapmanager->getDesktop()->dt2doc(p_proj_on_cl - getSnapperTolerance() * direction_vector);
559 Geom::Point const p_max_on_cl = _snapmanager->getDesktop()->dt2doc(p_proj_on_cl + getSnapperTolerance() * direction_vector);
561 Geom::Path cl;
562 std::vector<Geom::Path> clv;
563 cl.start(p_min_on_cl);
564 cl.appendNew<Geom::LineSegment>(p_max_on_cl);
565 clv.push_back(cl);
567 for (std::vector<std::pair<Geom::PathVector*, SnapTargetType> >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
568 if (k->first) {
569 Geom::CrossingSet cs = Geom::crossings(clv, *(k->first));
570 if (cs.size() > 0) {
571 // We need only the first element of cs, because cl is only a single straight linesegment
572 // This first element contains a vector filled with crossings of cl with k->first
573 for (std::vector<Geom::Crossing>::const_iterator m = cs[0].begin(); m != cs[0].end(); m++) {
574 if ((*m).ta >= 0 && (*m).ta <= 1 ) {
575 // Reconstruct the point of intersection
576 Geom::Point p_inters = p_min_on_cl + ((*m).ta) * (p_max_on_cl - p_min_on_cl);
577 // When it's within snapping range, then return it
578 // (within snapping range == between p_min_on_cl and p_max_on_cl == 0 < ta < 1)
579 Geom::Coord dist = Geom::L2(_snapmanager->getDesktop()->dt2doc(p_proj_on_cl) - p_inters);
580 SnappedPoint s(_snapmanager->getDesktop()->doc2dt(p_inters), source_type, k->second, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), true);
581 sc.points.push_back(s);
582 }
583 }
584 }
585 }
586 }
587 }
590 void Inkscape::ObjectSnapper::freeSnap(SnappedConstraints &sc,
591 Inkscape::SnapPreferences::PointType const &t,
592 Geom::Point const &p,
593 SnapSourceType const &source_type,
594 bool const &first_point,
595 Geom::OptRect const &bbox_to_snap,
596 std::vector<SPItem const *> const *it,
597 std::vector<std::pair<Geom::Point, int> > *unselected_nodes) const
598 {
599 if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(t) == false ) {
600 return;
601 }
603 /* Get a list of all the SPItems that we will try to snap to */
604 if (first_point) {
605 Geom::Rect const local_bbox_to_snap = bbox_to_snap ? *bbox_to_snap : Geom::Rect(p, p);
606 _findCandidates(sp_document_root(_snapmanager->getDocument()), it, first_point, local_bbox_to_snap, TRANSL_SNAP_XY, false, Geom::identity());
607 }
609 if (_snapmanager->snapprefs.getSnapToItemNode() || _snapmanager->snapprefs.getSnapSmoothNodes()
610 || _snapmanager->snapprefs.getSnapToBBoxNode() || _snapmanager->snapprefs.getSnapToPageBorder()
611 || _snapmanager->snapprefs.getSnapLineMidpoints() || _snapmanager->snapprefs.getSnapObjectMidpoints()
612 || _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()
613 || _snapmanager->snapprefs.getIncludeItemCenter()) {
614 _snapNodes(sc, t, p, source_type, first_point, unselected_nodes);
615 }
617 if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
618 unsigned n = (unselected_nodes == NULL) ? 0 : unselected_nodes->size();
619 if (n > 0) {
620 /* While editing a path in the node tool, findCandidates must ignore that path because
621 * of the node snapping requirements (i.e. only unselected nodes must be snapable).
622 * That path must not be ignored however when snapping to the paths, so we add it here
623 * manually when applicable
624 */
625 SPPath *path = NULL;
626 if (it != NULL) {
627 if (it->size() == 1 && SP_IS_PATH(*it->begin())) {
628 path = SP_PATH(*it->begin());
629 } // else: *it->begin() might be a SPGroup, e.g. when editing a LPE of text that has been converted to a group of paths
630 // as reported in bug #356743. In that case we can just ignore it, i.e. not snap to this item
631 }
632 _snapPaths(sc, t, p, source_type, first_point, unselected_nodes, path);
633 } else {
634 _snapPaths(sc, t, p, source_type, first_point, NULL, NULL);
635 }
636 }
637 }
639 void Inkscape::ObjectSnapper::constrainedSnap( SnappedConstraints &sc,
640 Inkscape::SnapPreferences::PointType const &t,
641 Geom::Point const &p,
642 SnapSourceType const &source_type,
643 bool const &first_point,
644 Geom::OptRect const &bbox_to_snap,
645 ConstraintLine const &c,
646 std::vector<SPItem const *> const *it) const
647 {
648 if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(t) == false) {
649 return;
650 }
652 /* Get a list of all the SPItems that we will try to snap to */
653 if (first_point) {
654 Geom::Rect const local_bbox_to_snap = bbox_to_snap ? *bbox_to_snap : Geom::Rect(p, p);
655 _findCandidates(sp_document_root(_snapmanager->getDocument()), it, first_point, local_bbox_to_snap, TRANSL_SNAP_XY, false, Geom::identity());
656 }
658 // A constrained snap, is a snap in only one degree of freedom (specified by the constraint line).
659 // This is useful for example when scaling an object while maintaining a fixed aspect ratio. It's
660 // nodes are only allowed to move in one direction (i.e. in one degree of freedom).
662 // When snapping to objects, we either snap to their nodes or their paths. It is however very
663 // unlikely that any node will be exactly at the constrained line, so for a constrained snap
664 // to objects we will only consider the object's paths. Beside, the nodes will be at these paths,
665 // so we will more or less snap to them anyhow.
667 if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
668 _snapPathsConstrained(sc, t, p, source_type, first_point, c);
669 }
670 }
673 // This method is used to snap a guide to nodes, while dragging the guide around
674 void Inkscape::ObjectSnapper::guideFreeSnap(SnappedConstraints &sc,
675 Geom::Point const &p,
676 Geom::Point const &guide_normal) const
677 {
678 /* Get a list of all the SPItems that we will try to snap to */
679 std::vector<SPItem*> cand;
680 std::vector<SPItem const *> const it; //just an empty list
682 DimensionToSnap snap_dim;
683 if (guide_normal == to_2geom(component_vectors[Geom::Y])) {
684 snap_dim = GUIDE_TRANSL_SNAP_Y;
685 } else if (guide_normal == to_2geom(component_vectors[Geom::X])) {
686 snap_dim = GUIDE_TRANSL_SNAP_X;
687 } else {
688 snap_dim = ANGLED_GUIDE_TRANSL_SNAP;
689 }
691 _findCandidates(sp_document_root(_snapmanager->getDocument()), &it, true, Geom::Rect(p, p), snap_dim, false, Geom::identity());
692 _snapTranslatingGuideToNodes(sc, Inkscape::SnapPreferences::SNAPPOINT_GUIDE, p, guide_normal);
694 }
696 // This method is used to snap the origin of a guide to nodes/paths, while dragging the origin along the guide
697 void Inkscape::ObjectSnapper::guideConstrainedSnap(SnappedConstraints &sc,
698 Geom::Point const &p,
699 Geom::Point const &guide_normal,
700 ConstraintLine const &c) const
701 {
702 /* Get a list of all the SPItems that we will try to snap to */
703 std::vector<SPItem*> cand;
704 std::vector<SPItem const *> const it; //just an empty list
706 DimensionToSnap snap_dim;
707 if (guide_normal == to_2geom(component_vectors[Geom::Y])) {
708 snap_dim = GUIDE_TRANSL_SNAP_Y;
709 } else if (guide_normal == to_2geom(component_vectors[Geom::X])) {
710 snap_dim = GUIDE_TRANSL_SNAP_X;
711 } else {
712 snap_dim = ANGLED_GUIDE_TRANSL_SNAP;
713 }
715 _findCandidates(sp_document_root(_snapmanager->getDocument()), &it, true, Geom::Rect(p, p), snap_dim, false, Geom::identity());
716 _snapTranslatingGuideToNodes(sc, Inkscape::SnapPreferences::SNAPPOINT_GUIDE, p, guide_normal);
718 }
720 /**
721 * \return true if this Snapper will snap at least one kind of point.
722 */
723 bool Inkscape::ObjectSnapper::ThisSnapperMightSnap() const
724 {
725 bool snap_to_something = _snapmanager->snapprefs.getSnapToItemPath()
726 || _snapmanager->snapprefs.getSnapToItemNode()
727 || _snapmanager->snapprefs.getSnapToBBoxPath()
728 || _snapmanager->snapprefs.getSnapToBBoxNode()
729 || _snapmanager->snapprefs.getSnapToPageBorder()
730 || _snapmanager->snapprefs.getSnapLineMidpoints() || _snapmanager->snapprefs.getSnapObjectMidpoints()
731 || _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()
732 || _snapmanager->snapprefs.getIncludeItemCenter();
734 return (_snap_enabled && _snapmanager->snapprefs.getSnapModeBBoxOrNodes() && snap_to_something);
735 }
737 bool Inkscape::ObjectSnapper::GuidesMightSnap() const // almost the same as ThisSnapperMightSnap above, but only looking at points (and not paths)
738 {
739 bool snap_to_something = _snapmanager->snapprefs.getSnapToItemNode()
740 || _snapmanager->snapprefs.getSnapToPageBorder()
741 || (_snapmanager->snapprefs.getSnapModeBBox() && _snapmanager->snapprefs.getSnapToBBoxNode())
742 || (_snapmanager->snapprefs.getSnapModeBBox() && (_snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()))
743 || (_snapmanager->snapprefs.getSnapModeNode() && (_snapmanager->snapprefs.getSnapLineMidpoints() || _snapmanager->snapprefs.getSnapObjectMidpoints()))
744 || (_snapmanager->snapprefs.getSnapModeNode() && _snapmanager->snapprefs.getIncludeItemCenter())
745 || (_snapmanager->snapprefs.getSnapModeNode() && (_snapmanager->snapprefs.getSnapToItemPath() && _snapmanager->snapprefs.getSnapIntersectionCS()));
747 return (_snap_enabled && _snapmanager->snapprefs.getSnapModeGuide() && snap_to_something);
748 }
750 void Inkscape::ObjectSnapper::_clear_paths() const
751 {
752 for (std::vector<std::pair<Geom::PathVector*, SnapTargetType> >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
753 g_free(k->first);
754 }
755 _paths_to_snap_to->clear();
756 }
758 Geom::PathVector* Inkscape::ObjectSnapper::_getBorderPathv() const
759 {
760 Geom::Rect const border_rect = Geom::Rect(Geom::Point(0,0), Geom::Point(sp_document_width(_snapmanager->getDocument()),sp_document_height(_snapmanager->getDocument())));
761 return _getPathvFromRect(border_rect);
762 }
764 Geom::PathVector* Inkscape::ObjectSnapper::_getPathvFromRect(Geom::Rect const rect) const
765 {
766 SPCurve const *border_curve = SPCurve::new_from_rect(rect);
767 if (border_curve) {
768 Geom::PathVector *dummy = new Geom::PathVector(border_curve->get_pathvector());
769 return dummy;
770 } else {
771 return NULL;
772 }
773 }
775 void Inkscape::ObjectSnapper::_getBorderNodes(std::vector<std::pair<Geom::Point, int> > *points) const
776 {
777 Geom::Coord w = sp_document_width(_snapmanager->getDocument());
778 Geom::Coord h = sp_document_height(_snapmanager->getDocument());
779 points->push_back(std::make_pair(Geom::Point(0,0), SNAPTARGET_PAGE_CORNER));
780 points->push_back(std::make_pair(Geom::Point(0,h), SNAPTARGET_PAGE_CORNER));
781 points->push_back(std::make_pair(Geom::Point(w,h), SNAPTARGET_PAGE_CORNER));
782 points->push_back(std::make_pair(Geom::Point(w,0), SNAPTARGET_PAGE_CORNER));
783 }
785 void Inkscape::getBBoxPoints(Geom::OptRect const bbox, std::vector<std::pair<Geom::Point, int> > *points, bool const isTarget, bool const includeCorners, bool const includeLineMidpoints, bool const includeObjectMidpoints)
786 {
787 if (bbox) {
788 // collect the corners of the bounding box
789 for ( unsigned k = 0 ; k < 4 ; k++ ) {
790 if (includeCorners) {
791 points->push_back(std::make_pair((bbox->corner(k)), isTarget ? int(Inkscape::SNAPTARGET_BBOX_CORNER) : int(Inkscape::SNAPSOURCE_BBOX_CORNER)));
792 }
793 // optionally, collect the midpoints of the bounding box's edges too
794 if (includeLineMidpoints) {
795 points->push_back(std::make_pair((bbox->corner(k) + bbox->corner((k+1) % 4))/2, isTarget ? int(Inkscape::SNAPTARGET_BBOX_EDGE_MIDPOINT) : int(Inkscape::SNAPSOURCE_BBOX_EDGE_MIDPOINT)));
796 }
797 }
798 if (includeObjectMidpoints) {
799 points->push_back(std::make_pair(bbox->midpoint(), isTarget ? int(Inkscape::SNAPTARGET_BBOX_MIDPOINT) : int(Inkscape::SNAPSOURCE_BBOX_MIDPOINT)));
800 }
801 }
802 }
804 /*
805 Local Variables:
806 mode:c++
807 c-file-style:"stroustrup"
808 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
809 indent-tabs-mode:nil
810 fill-column:99
811 End:
812 */
813 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :