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 bbox_to_snap Bounding box hulling the whole bunch of points, all from the same selection and having the same transformation
85 * \param DimensionToSnap Snap in X, Y, or both directions.
86 */
88 void Inkscape::ObjectSnapper::_findCandidates(SPObject* parent,
89 std::vector<SPItem const *> const *it,
90 bool const &first_point,
91 Geom::Rect const &bbox_to_snap,
92 DimensionToSnap const snap_dim,
93 bool const clip_or_mask,
94 Geom::Matrix const additional_affine) const // transformation of the item being clipped / masked
95 {
96 bool const c1 = (snap_dim == TRANSL_SNAP_XY) && ThisSnapperMightSnap();
97 bool const c2 = (snap_dim != TRANSL_SNAP_XY) && GuidesMightSnap();
99 if (!(c1 || c2)) {
100 return;
101 }
103 if (first_point) {
104 _candidates->clear();
105 }
107 Geom::Rect bbox_to_snap_incl = bbox_to_snap; // _incl means: will include the snapper tolerance
108 bbox_to_snap_incl.expandBy(getSnapperTolerance()); // see?
110 for (SPObject* o = sp_object_first_child(parent); o != NULL; o = SP_OBJECT_NEXT(o)) {
111 g_assert(_snapmanager->getDesktop() != NULL);
112 if (SP_IS_ITEM(o) && !(_snapmanager->getDesktop()->itemIsHidden(SP_ITEM(o)) && !clip_or_mask)) {
113 // Snapping to items in a locked layer is allowed
114 // Don't snap to hidden objects, unless they're a clipped path or a mask
115 /* See if this item is on the ignore list */
116 std::vector<SPItem const *>::const_iterator i;
117 if (it != NULL) {
118 i = it->begin();
119 while (i != it->end() && *i != o) {
120 i++;
121 }
122 }
124 if (it == NULL || i == it->end()) {
125 SPItem *item = SP_ITEM(o);
126 if (item) {
127 SPObject *obj = NULL;
128 if (!clip_or_mask) { // cannot clip or mask more than once
129 // The current item is not a clipping path or a mask, but might
130 // still be the subject of clipping or masking itself ; if so, then
131 // we should also consider that path or mask for snapping to
132 obj = SP_OBJECT(item->clip_ref->getObject());
133 if (obj) {
134 _findCandidates(obj, it, false, bbox_to_snap, snap_dim, true, sp_item_i2doc_affine(item));
135 }
136 obj = SP_OBJECT(item->mask_ref->getObject());
137 if (obj) {
138 _findCandidates(obj, it, false, bbox_to_snap, snap_dim, true, sp_item_i2doc_affine(item));
139 }
140 }
141 }
143 if (SP_IS_GROUP(o)) {
144 _findCandidates(o, it, false, bbox_to_snap, snap_dim, clip_or_mask, additional_affine);
145 } else {
146 Geom::OptRect bbox_of_item = Geom::Rect();
147 if (clip_or_mask) {
148 // Oh oh, this will get ugly. We cannot use sp_item_i2d_affine directly because we need to
149 // insert an additional transformation in document coordinates (code copied from sp_item_i2d_affine)
150 sp_item_invoke_bbox(item,
151 bbox_of_item,
152 sp_item_i2doc_affine(item) * additional_affine * _snapmanager->getDesktop()->doc2dt(),
153 true);
154 } else {
155 sp_item_invoke_bbox(item, bbox_of_item, sp_item_i2d_affine(item), true);
156 }
157 if (bbox_of_item) {
158 // See if the item is within range
159 if (bbox_to_snap_incl.intersects(*bbox_of_item)) {
160 // This item is within snapping range, so record it as a candidate
161 _candidates->push_back(SnapCandidate(item, clip_or_mask, additional_affine));
162 // For debugging: print the id of the candidate to the console
163 //SPObject *obj = (SPObject*)item;
164 //std::cout << "Snap candidate added: " << obj->id << std::endl;
165 }
166 }
167 }
168 }
169 }
170 }
171 }
174 void Inkscape::ObjectSnapper::_collectNodes(Inkscape::SnapPreferences::PointType const &t,
175 bool const &first_point) const
176 {
177 // Now, let's first collect all points to snap to. If we have a whole bunch of points to snap,
178 // e.g. when translating an item using the selector tool, then we will only do this for the
179 // first point and store the collection for later use. This significantly improves the performance
180 if (first_point) {
181 _points_to_snap_to->clear();
183 // Determine the type of bounding box we should snap to
184 SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
186 bool p_is_a_node = t & Inkscape::SnapPreferences::SNAPPOINT_NODE;
187 bool p_is_a_bbox = t & Inkscape::SnapPreferences::SNAPPOINT_BBOX;
188 bool p_is_a_guide = t & Inkscape::SnapPreferences::SNAPPOINT_GUIDE;
190 // A point considered for snapping should be either a node, a bbox corner or a guide. Pick only ONE!
191 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)));
193 if (_snapmanager->snapprefs.getSnapToBBoxNode() || _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()) {
194 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
195 bool prefs_bbox = prefs->getBool("/tools/bounding_box");
196 bbox_type = !prefs_bbox ?
197 SPItem::APPROXIMATE_BBOX : SPItem::GEOMETRIC_BBOX;
198 }
200 // Consider the page border for snapping to
201 if (_snapmanager->snapprefs.getSnapToPageBorder()) {
202 _getBorderNodes(_points_to_snap_to);
203 }
205 for (std::vector<SnapCandidate>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
206 //Geom::Matrix i2doc(Geom::identity());
207 SPItem *root_item = (*i).item;
208 if (SP_IS_USE((*i).item)) {
209 root_item = sp_use_root(SP_USE((*i).item));
210 }
211 g_return_if_fail(root_item);
213 //Collect all nodes so we can snap to them
214 if (p_is_a_node || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_node) || p_is_a_guide) {
215 // Note: there are two ways in which intersections are considered:
216 // Method 1: Intersections are calculated for each shape individually, for both the
217 // snap source and snap target (see sp_shape_snappoints)
218 // Method 2: Intersections are calculated for each curve or line that we've snapped to, i.e. only for
219 // the target (see the intersect() method in the SnappedCurve and SnappedLine classes)
220 // Some differences:
221 // - Method 1 doesn't find intersections within a set of multiple objects
222 // - Method 2 only works for targets
223 // When considering intersections as snap targets:
224 // - Method 1 only works when snapping to nodes, whereas
225 // - Method 2 only works when snapping to paths
226 // - There will be performance differences too!
227 // If both methods are being used simultaneously, then this might lead to duplicate targets!
229 // Well, here we will be looking for snap TARGETS. Both methods can therefore be used.
230 // When snapping to paths, we will get a collection of snapped lines and snapped curves. findBestSnap() will
231 // go hunting for intersections (but only when asked to in the prefs of course). In that case we can just
232 // temporarily block the intersections in sp_item_snappoints, we don't need duplicates. If we're not snapping to
233 // paths though but only to item nodes then we should still look for the intersections in sp_item_snappoints()
234 bool old_pref = _snapmanager->snapprefs.getSnapIntersectionCS();
235 if (_snapmanager->snapprefs.getSnapToItemPath()) {
236 _snapmanager->snapprefs.setSnapIntersectionCS(false);
237 }
239 sp_item_snappoints(root_item, true, *_points_to_snap_to, &_snapmanager->snapprefs);
241 if (_snapmanager->snapprefs.getSnapToItemPath()) {
242 _snapmanager->snapprefs.setSnapIntersectionCS(old_pref);
243 }
244 }
246 //Collect the bounding box's corners so we can snap to them
247 if (p_is_a_bbox || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_bbox) || p_is_a_guide) {
248 // Discard the bbox of a clipped path / mask, because we don't want to snap to both the bbox
249 // of the item AND the bbox of the clipping path at the same time
250 if (!(*i).clip_or_mask) {
251 Geom::OptRect b = sp_item_bbox_desktop(root_item, bbox_type);
252 getBBoxPoints(b, _points_to_snap_to, true, _snapmanager->snapprefs.getSnapToBBoxNode(), _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints(), _snapmanager->snapprefs.getSnapBBoxMidpoints());
253 }
254 }
255 }
256 }
257 }
259 void Inkscape::ObjectSnapper::_snapNodes(SnappedConstraints &sc,
260 Inkscape::SnapPreferences::PointType const &t,
261 Geom::Point const &p,
262 SnapSourceType const &source_type,
263 long source_num,
264 std::vector<std::pair<Geom::Point, int> > *unselected_nodes) const
265 {
266 // Iterate through all nodes, find out which one is the closest to p, and snap to it!
268 _collectNodes(t, source_num == 0);
270 if (unselected_nodes != NULL) {
271 _points_to_snap_to->insert(_points_to_snap_to->end(), unselected_nodes->begin(), unselected_nodes->end());
272 }
274 SnappedPoint s;
275 bool success = false;
277 for (std::vector<std::pair<Geom::Point, int> >::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {
278 Geom::Coord dist = Geom::L2((*k).first - p);
279 if (dist < getSnapperTolerance() && dist < s.getSnapDistance()) {
280 s = SnappedPoint((*k).first, source_type, source_num, static_cast<Inkscape::SnapTargetType>((*k).second), dist, getSnapperTolerance(), getSnapperAlwaysSnap(), true);
281 success = true;
282 }
283 }
285 if (success) {
286 sc.points.push_back(s);
287 }
288 }
290 void Inkscape::ObjectSnapper::_snapTranslatingGuideToNodes(SnappedConstraints &sc,
291 Inkscape::SnapPreferences::PointType const &t,
292 Geom::Point const &p,
293 Geom::Point const &guide_normal) const
294 {
295 // Iterate through all nodes, find out which one is the closest to this guide, and snap to it!
296 _collectNodes(t, true);
298 // Although we won't snap to paths here (which would give us under constrained snaps) we can still snap to intersections of paths.
299 if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
300 _collectPaths(t, true);
301 _snapPaths(sc, t, p, SNAPSOURCE_GUIDE, 0, NULL, NULL);
302 // The paths themselves should be discarded in findBestSnap(), as we should only snap to their intersections
303 }
305 SnappedPoint s;
307 Geom::Coord tol = getSnapperTolerance();
309 for (std::vector<std::pair<Geom::Point, int> >::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {
310 // Project each node (*k) on the guide line (running through point p)
311 Geom::Point p_proj = Geom::projection((*k).first, Geom::Line(p, p + Geom::rot90(guide_normal)));
312 Geom::Coord dist = Geom::L2((*k).first - p_proj); // distance from node to the guide
313 Geom::Coord dist2 = Geom::L2(p - p_proj); // distance from projection of node on the guide, to the mouse location
314 if ((dist < tol && dist2 < tol) || getSnapperAlwaysSnap()) {
315 s = SnappedPoint((*k).first, SNAPSOURCE_GUIDE, 0, static_cast<Inkscape::SnapTargetType>((*k).second), dist, tol, getSnapperAlwaysSnap(), true);
316 sc.points.push_back(s);
317 }
318 }
319 }
322 /**
323 * Returns index of first NR_END bpath in array.
324 */
326 void Inkscape::ObjectSnapper::_collectPaths(Inkscape::SnapPreferences::PointType const &t,
327 bool const &first_point) const
328 {
329 // Now, let's first collect all paths to snap to. If we have a whole bunch of points to snap,
330 // e.g. when translating an item using the selector tool, then we will only do this for the
331 // first point and store the collection for later use. This significantly improves the performance
332 if (first_point) {
333 _clear_paths();
335 // Determine the type of bounding box we should snap to
336 SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
338 bool p_is_a_node = t & Inkscape::SnapPreferences::SNAPPOINT_NODE;
339 bool p_is_a_guide = t & Inkscape::SnapPreferences::SNAPPOINT_GUIDE;
341 if (_snapmanager->snapprefs.getSnapToBBoxPath()) {
342 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
343 int prefs_bbox = prefs->getBool("/tools/bounding_box", 0);
344 bbox_type = !prefs_bbox ?
345 SPItem::APPROXIMATE_BBOX : SPItem::GEOMETRIC_BBOX;
346 }
348 // Consider the page border for snapping
349 if (_snapmanager->snapprefs.getSnapToPageBorder()) {
350 Geom::PathVector *border_path = _getBorderPathv();
351 if (border_path != NULL) {
352 _paths_to_snap_to->push_back(std::make_pair(border_path, SNAPTARGET_PAGE_BORDER));
353 }
354 }
356 for (std::vector<SnapCandidate>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
358 /* Transform the requested snap point to this item's coordinates */
359 Geom::Matrix i2doc(Geom::identity());
360 SPItem *root_item = NULL;
361 /* We might have a clone at hand, so make sure we get the root item */
362 if (SP_IS_USE((*i).item)) {
363 i2doc = sp_use_get_root_transform(SP_USE((*i).item));
364 root_item = sp_use_root(SP_USE((*i).item));
365 g_return_if_fail(root_item);
366 } else {
367 i2doc = sp_item_i2doc_affine((*i).item);
368 root_item = (*i).item;
369 }
371 //Build a list of all paths considered for snapping to
373 //Add the item's path to snap to
374 if (_snapmanager->snapprefs.getSnapToItemPath()) {
375 if (p_is_a_guide || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_node)) {
376 // Snapping to the path of characters is very cool, but for a large
377 // chunk of text this will take ages! So limit snapping to text paths
378 // containing max. 240 characters. Snapping the bbox will not be affected
379 bool very_lenghty_prose = false;
380 if (SP_IS_TEXT(root_item) || SP_IS_FLOWTEXT(root_item)) {
381 very_lenghty_prose = sp_text_get_length(SP_TEXT(root_item)) > 240;
382 }
383 // On my AMD 3000+, the snapping lag becomes annoying at approx. 240 chars
384 // which corresponds to a lag of 500 msec. This is for snapping a rect
385 // to a single line of text.
387 // Snapping for example to a traced bitmap is also very stressing for
388 // the CPU, so we'll only snap to paths having no more than 500 nodes
389 // This also leads to a lag of approx. 500 msec (in my lousy test set-up).
390 bool very_complex_path = false;
391 if (SP_IS_PATH(root_item)) {
392 very_complex_path = sp_nodes_in_path(SP_PATH(root_item)) > 500;
393 }
395 if (!very_lenghty_prose && !very_complex_path) {
396 SPCurve *curve = curve_for_item(root_item);
397 if (curve) {
398 // We will get our own copy of the path, which must be freed at some point
399 Geom::PathVector *borderpathv = pathvector_for_curve(root_item, curve, true, true, Geom::identity(), (*i).additional_affine);
400 _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.
401 curve->unref();
402 }
403 }
404 }
405 }
407 //Add the item's bounding box to snap to
408 if (_snapmanager->snapprefs.getSnapToBBoxPath()) {
409 if (p_is_a_guide || !(_snapmanager->snapprefs.getStrictSnapping() && p_is_a_node)) {
410 // Discard the bbox of a clipped path / mask, because we don't want to snap to both the bbox
411 // of the item AND the bbox of the clipping path at the same time
412 if (!(*i).clip_or_mask) {
413 Geom::OptRect rect;
414 sp_item_invoke_bbox(root_item, rect, i2doc, TRUE, bbox_type);
415 if (rect) {
416 Geom::PathVector *path = _getPathvFromRect(*rect);
417 _paths_to_snap_to->push_back(std::make_pair(path, SNAPTARGET_BBOX_EDGE));
418 }
419 }
420 }
421 }
422 }
423 }
424 }
426 void Inkscape::ObjectSnapper::_snapPaths(SnappedConstraints &sc,
427 Inkscape::SnapPreferences::PointType const &t,
428 Geom::Point const &p,
429 SnapSourceType const &source_type,
430 long source_num,
431 std::vector<std::pair<Geom::Point, int> > *unselected_nodes,
432 SPPath const *selected_path) const
433 {
434 _collectPaths(t, source_num == 0);
435 // Now we can finally do the real snapping, using the paths collected above
437 g_assert(_snapmanager->getDesktop() != NULL);
438 Geom::Point const p_doc = _snapmanager->getDesktop()->dt2doc(p);
440 bool const node_tool_active = _snapmanager->snapprefs.getSnapToItemPath() && selected_path != NULL;
442 if (source_num == 0) {
443 /* findCandidates() is used for snapping to both paths and nodes. It ignores the path that is
444 * currently being edited, because that path requires special care: when snapping to nodes
445 * only the unselected nodes of that path should be considered, and these will be passed on separately.
446 * This path must not be ignored however when snapping to the paths, so we add it here
447 * manually when applicable.
448 *
449 * Note that this path must be the last in line!
450 * */
451 if (node_tool_active) {
452 SPCurve *curve = curve_for_item(SP_ITEM(selected_path));
453 if (curve) {
454 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
455 _paths_to_snap_to->push_back(std::make_pair(pathv, SNAPTARGET_PATH));
456 curve->unref();
457 }
458 }
459 }
461 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++) {
462 bool const being_edited = (node_tool_active && (*it_p) == _paths_to_snap_to->back());
463 //if true then this pathvector it_pv is currently being edited in the node tool
465 // char * svgd = sp_svg_write_path(**it_p->first);
466 // std::cout << "Dumping the pathvector: " << svgd << std::endl;
468 for(Geom::PathVector::iterator it_pv = (it_p->first)->begin(); it_pv != (it_p->first)->end(); ++it_pv) {
469 // Find a nearest point for each curve within this path
470 // n curves will return n time values with 0 <= t <= 1
471 std::vector<double> anp = (*it_pv).nearestPointPerCurve(p_doc);
473 std::vector<double>::const_iterator np = anp.begin();
474 unsigned int index = 0;
475 for (; np != anp.end(); np++, index++) {
476 Geom::Curve const *curve = &((*it_pv).at_index(index));
477 Geom::Point const sp_doc = curve->pointAt(*np);
479 bool c1 = true;
480 bool c2 = true;
481 if (being_edited) {
482 /* If the path is being edited, then we should only snap though to stationary pieces of the path
483 * and not to the pieces that are being dragged around. This way we avoid
484 * self-snapping. For this we check whether the nodes at both ends of the current
485 * piece are unselected; if they are then this piece must be stationary
486 */
487 g_assert(unselected_nodes != NULL);
488 Geom::Point start_pt = _snapmanager->getDesktop()->doc2dt(curve->pointAt(0));
489 Geom::Point end_pt = _snapmanager->getDesktop()->doc2dt(curve->pointAt(1));
490 c1 = isUnselectedNode(start_pt, unselected_nodes);
491 c2 = isUnselectedNode(end_pt, unselected_nodes);
492 /* Unfortunately, this might yield false positives for coincident nodes. Inkscape might therefore mistakenly
493 * snap to path segments that are not stationary. There are at least two possible ways to overcome this:
494 * - Linking the individual nodes of the SPPath we have here, to the nodes of the NodePath::SubPath class as being
495 * used in sp_nodepath_selected_nodes_move. This class has a member variable called "selected". For this the nodes
496 * should be in the exact same order for both classes, so we can index them
497 * - Replacing the SPPath being used here by the the NodePath::SubPath class; but how?
498 */
499 }
501 Geom::Point const sp_dt = _snapmanager->getDesktop()->doc2dt(sp_doc);
502 if (!being_edited || (c1 && c2)) {
503 Geom::Coord const dist = Geom::distance(sp_doc, p_doc);
504 if (dist < getSnapperTolerance()) {
505 sc.curves.push_back(Inkscape::SnappedCurve(sp_dt, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, curve, source_type, source_num, it_p->second));
506 }
507 }
508 }
509 } // End of: for (Geom::PathVector::iterator ....)
510 }
511 }
513 /* Returns true if point is coincident with one of the unselected nodes */
514 bool Inkscape::ObjectSnapper::isUnselectedNode(Geom::Point const &point, std::vector<std::pair<Geom::Point, int> > const *unselected_nodes) const
515 {
516 if (unselected_nodes == NULL) {
517 return false;
518 }
520 if (unselected_nodes->size() == 0) {
521 return false;
522 }
524 for (std::vector<std::pair<Geom::Point, int> >::const_iterator i = unselected_nodes->begin(); i != unselected_nodes->end(); i++) {
525 if (Geom::L2(point - (*i).first) < 1e-4) {
526 return true;
527 }
528 }
530 return false;
531 }
533 void Inkscape::ObjectSnapper::_snapPathsConstrained(SnappedConstraints &sc,
534 Inkscape::SnapPreferences::PointType const &t,
535 Geom::Point const &p,
536 SnapSourceType const source_type,
537 long source_num,
538 ConstraintLine const &c) const
539 {
541 _collectPaths(t, source_num == 0);
543 // Now we can finally do the real snapping, using the paths collected above
545 g_assert(_snapmanager->getDesktop() != NULL);
546 Geom::Point const p_doc = _snapmanager->getDesktop()->dt2doc(p);
548 Geom::Point direction_vector = c.getDirection();
549 if (!is_zero(direction_vector)) {
550 direction_vector = Geom::unit_vector(direction_vector);
551 }
553 // The intersection point of the constraint line with any path,
554 // must lie within two points on the constraintline: p_min_on_cl and p_max_on_cl
555 // The distance between those points is twice the snapping tolerance
556 Geom::Point const p_proj_on_cl = p; // projection has already been taken care of in constrainedSnap in the snapmanager;
557 Geom::Point const p_min_on_cl = _snapmanager->getDesktop()->dt2doc(p_proj_on_cl - getSnapperTolerance() * direction_vector);
558 Geom::Point const p_max_on_cl = _snapmanager->getDesktop()->dt2doc(p_proj_on_cl + getSnapperTolerance() * direction_vector);
560 Geom::Path cl;
561 std::vector<Geom::Path> clv;
562 cl.start(p_min_on_cl);
563 cl.appendNew<Geom::LineSegment>(p_max_on_cl);
564 clv.push_back(cl);
566 for (std::vector<std::pair<Geom::PathVector*, SnapTargetType> >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
567 if (k->first) {
568 Geom::CrossingSet cs = Geom::crossings(clv, *(k->first));
569 if (cs.size() > 0) {
570 // We need only the first element of cs, because cl is only a single straight linesegment
571 // This first element contains a vector filled with crossings of cl with k->first
572 for (std::vector<Geom::Crossing>::const_iterator m = cs[0].begin(); m != cs[0].end(); m++) {
573 if ((*m).ta >= 0 && (*m).ta <= 1 ) {
574 // Reconstruct the point of intersection
575 Geom::Point p_inters = p_min_on_cl + ((*m).ta) * (p_max_on_cl - p_min_on_cl);
576 // When it's within snapping range, then return it
577 // (within snapping range == between p_min_on_cl and p_max_on_cl == 0 < ta < 1)
578 Geom::Coord dist = Geom::L2(_snapmanager->getDesktop()->dt2doc(p_proj_on_cl) - p_inters);
579 SnappedPoint s(_snapmanager->getDesktop()->doc2dt(p_inters), source_type, source_num, k->second, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), true);
580 sc.points.push_back(s);
581 }
582 }
583 }
584 }
585 }
586 }
589 void Inkscape::ObjectSnapper::freeSnap(SnappedConstraints &sc,
590 Inkscape::SnapPreferences::PointType const &t,
591 Geom::Point const &p,
592 SnapSourceType const &source_type,
593 long source_num,
594 Geom::OptRect const &bbox_to_snap,
595 std::vector<SPItem const *> const *it,
596 std::vector<std::pair<Geom::Point, int> > *unselected_nodes) const
597 {
598 if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(t) == false ) {
599 return;
600 }
602 /* Get a list of all the SPItems that we will try to snap to */
603 if (source_num == 0) {
604 Geom::Rect const local_bbox_to_snap = bbox_to_snap ? *bbox_to_snap : Geom::Rect(p, p);
605 _findCandidates(sp_document_root(_snapmanager->getDocument()), it, source_num == 0, local_bbox_to_snap, TRANSL_SNAP_XY, false, Geom::identity());
606 }
608 if (_snapmanager->snapprefs.getSnapToItemNode() || _snapmanager->snapprefs.getSnapSmoothNodes()
609 || _snapmanager->snapprefs.getSnapToBBoxNode() || _snapmanager->snapprefs.getSnapToPageBorder()
610 || _snapmanager->snapprefs.getSnapLineMidpoints() || _snapmanager->snapprefs.getSnapObjectMidpoints()
611 || _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()
612 || _snapmanager->snapprefs.getIncludeItemCenter()) {
613 _snapNodes(sc, t, p, source_type, source_num, unselected_nodes);
614 }
616 if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
617 unsigned n = (unselected_nodes == NULL) ? 0 : unselected_nodes->size();
618 if (n > 0) {
619 /* While editing a path in the node tool, findCandidates must ignore that path because
620 * of the node snapping requirements (i.e. only unselected nodes must be snapable).
621 * That path must not be ignored however when snapping to the paths, so we add it here
622 * manually when applicable
623 */
624 SPPath *path = NULL;
625 if (it != NULL) {
626 if (it->size() == 1 && SP_IS_PATH(*it->begin())) {
627 path = SP_PATH(*it->begin());
628 } // else: *it->begin() might be a SPGroup, e.g. when editing a LPE of text that has been converted to a group of paths
629 // as reported in bug #356743. In that case we can just ignore it, i.e. not snap to this item
630 }
631 _snapPaths(sc, t, p, source_type, source_num, unselected_nodes, path);
632 } else {
633 _snapPaths(sc, t, p, source_type, source_num, NULL, NULL);
634 }
635 }
636 }
638 void Inkscape::ObjectSnapper::constrainedSnap( SnappedConstraints &sc,
639 Inkscape::SnapPreferences::PointType const &t,
640 Geom::Point const &p,
641 SnapSourceType const &source_type,
642 long source_num,
643 Geom::OptRect const &bbox_to_snap,
644 ConstraintLine const &c,
645 std::vector<SPItem const *> const *it) const
646 {
647 if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(t) == false) {
648 return;
649 }
651 /* Get a list of all the SPItems that we will try to snap to */
652 if (source_num == 0) {
653 Geom::Rect const local_bbox_to_snap = bbox_to_snap ? *bbox_to_snap : Geom::Rect(p, p);
654 _findCandidates(sp_document_root(_snapmanager->getDocument()), it, source_num == 0, local_bbox_to_snap, TRANSL_SNAP_XY, false, Geom::identity());
655 }
657 // A constrained snap, is a snap in only one degree of freedom (specified by the constraint line).
658 // This is useful for example when scaling an object while maintaining a fixed aspect ratio. It's
659 // nodes are only allowed to move in one direction (i.e. in one degree of freedom).
661 // When snapping to objects, we either snap to their nodes or their paths. It is however very
662 // unlikely that any node will be exactly at the constrained line, so for a constrained snap
663 // to objects we will only consider the object's paths. Beside, the nodes will be at these paths,
664 // so we will more or less snap to them anyhow.
666 if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
667 _snapPathsConstrained(sc, t, p, source_type, 0, c);
668 }
669 }
672 // This method is used to snap a guide to nodes, while dragging the guide around
673 void Inkscape::ObjectSnapper::guideFreeSnap(SnappedConstraints &sc,
674 Geom::Point const &p,
675 Geom::Point const &guide_normal) const
676 {
677 /* Get a list of all the SPItems that we will try to snap to */
678 std::vector<SPItem*> cand;
679 std::vector<SPItem const *> const it; //just an empty list
681 DimensionToSnap snap_dim;
682 if (guide_normal == to_2geom(component_vectors[Geom::Y])) {
683 snap_dim = GUIDE_TRANSL_SNAP_Y;
684 } else if (guide_normal == to_2geom(component_vectors[Geom::X])) {
685 snap_dim = GUIDE_TRANSL_SNAP_X;
686 } else {
687 snap_dim = ANGLED_GUIDE_TRANSL_SNAP;
688 }
690 _findCandidates(sp_document_root(_snapmanager->getDocument()), &it, true, Geom::Rect(p, p), snap_dim, false, Geom::identity());
691 _snapTranslatingGuideToNodes(sc, Inkscape::SnapPreferences::SNAPPOINT_GUIDE, p, guide_normal);
693 }
695 // This method is used to snap the origin of a guide to nodes/paths, while dragging the origin along the guide
696 void Inkscape::ObjectSnapper::guideConstrainedSnap(SnappedConstraints &sc,
697 Geom::Point const &p,
698 Geom::Point const &guide_normal,
699 ConstraintLine const &/*c*/) const
700 {
701 /* Get a list of all the SPItems that we will try to snap to */
702 std::vector<SPItem*> cand;
703 std::vector<SPItem const *> const it; //just an empty list
705 DimensionToSnap snap_dim;
706 if (guide_normal == to_2geom(component_vectors[Geom::Y])) {
707 snap_dim = GUIDE_TRANSL_SNAP_Y;
708 } else if (guide_normal == to_2geom(component_vectors[Geom::X])) {
709 snap_dim = GUIDE_TRANSL_SNAP_X;
710 } else {
711 snap_dim = ANGLED_GUIDE_TRANSL_SNAP;
712 }
714 _findCandidates(sp_document_root(_snapmanager->getDocument()), &it, true, Geom::Rect(p, p), snap_dim, false, Geom::identity());
715 _snapTranslatingGuideToNodes(sc, Inkscape::SnapPreferences::SNAPPOINT_GUIDE, p, guide_normal);
717 }
719 /**
720 * \return true if this Snapper will snap at least one kind of point.
721 */
722 bool Inkscape::ObjectSnapper::ThisSnapperMightSnap() const
723 {
724 bool snap_to_something = _snapmanager->snapprefs.getSnapToItemPath()
725 || _snapmanager->snapprefs.getSnapToItemNode()
726 || _snapmanager->snapprefs.getSnapToBBoxPath()
727 || _snapmanager->snapprefs.getSnapToBBoxNode()
728 || _snapmanager->snapprefs.getSnapToPageBorder()
729 || _snapmanager->snapprefs.getSnapLineMidpoints() || _snapmanager->snapprefs.getSnapObjectMidpoints()
730 || _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()
731 || _snapmanager->snapprefs.getIncludeItemCenter();
733 return (_snap_enabled && _snapmanager->snapprefs.getSnapModeBBoxOrNodes() && snap_to_something);
734 }
736 bool Inkscape::ObjectSnapper::GuidesMightSnap() const // almost the same as ThisSnapperMightSnap above, but only looking at points (and not paths)
737 {
738 bool snap_to_something = _snapmanager->snapprefs.getSnapToItemNode()
739 || _snapmanager->snapprefs.getSnapToPageBorder()
740 || (_snapmanager->snapprefs.getSnapModeBBox() && _snapmanager->snapprefs.getSnapToBBoxNode())
741 || (_snapmanager->snapprefs.getSnapModeBBox() && (_snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()))
742 || (_snapmanager->snapprefs.getSnapModeNode() && (_snapmanager->snapprefs.getSnapLineMidpoints() || _snapmanager->snapprefs.getSnapObjectMidpoints()))
743 || (_snapmanager->snapprefs.getSnapModeNode() && _snapmanager->snapprefs.getIncludeItemCenter())
744 || (_snapmanager->snapprefs.getSnapModeNode() && (_snapmanager->snapprefs.getSnapToItemPath() && _snapmanager->snapprefs.getSnapIntersectionCS()));
746 return (_snap_enabled && _snapmanager->snapprefs.getSnapModeGuide() && snap_to_something);
747 }
749 void Inkscape::ObjectSnapper::_clear_paths() const
750 {
751 for (std::vector<std::pair<Geom::PathVector*, SnapTargetType> >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
752 g_free(k->first);
753 }
754 _paths_to_snap_to->clear();
755 }
757 Geom::PathVector* Inkscape::ObjectSnapper::_getBorderPathv() const
758 {
759 Geom::Rect const border_rect = Geom::Rect(Geom::Point(0,0), Geom::Point(sp_document_width(_snapmanager->getDocument()),sp_document_height(_snapmanager->getDocument())));
760 return _getPathvFromRect(border_rect);
761 }
763 Geom::PathVector* Inkscape::ObjectSnapper::_getPathvFromRect(Geom::Rect const rect) const
764 {
765 SPCurve const *border_curve = SPCurve::new_from_rect(rect);
766 if (border_curve) {
767 Geom::PathVector *dummy = new Geom::PathVector(border_curve->get_pathvector());
768 return dummy;
769 } else {
770 return NULL;
771 }
772 }
774 void Inkscape::ObjectSnapper::_getBorderNodes(std::vector<std::pair<Geom::Point, int> > *points) const
775 {
776 Geom::Coord w = sp_document_width(_snapmanager->getDocument());
777 Geom::Coord h = sp_document_height(_snapmanager->getDocument());
778 points->push_back(std::make_pair(Geom::Point(0,0), SNAPTARGET_PAGE_CORNER));
779 points->push_back(std::make_pair(Geom::Point(0,h), SNAPTARGET_PAGE_CORNER));
780 points->push_back(std::make_pair(Geom::Point(w,h), SNAPTARGET_PAGE_CORNER));
781 points->push_back(std::make_pair(Geom::Point(w,0), SNAPTARGET_PAGE_CORNER));
782 }
784 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)
785 {
786 if (bbox) {
787 // collect the corners of the bounding box
788 for ( unsigned k = 0 ; k < 4 ; k++ ) {
789 if (includeCorners) {
790 points->push_back(std::make_pair((bbox->corner(k)), isTarget ? int(Inkscape::SNAPTARGET_BBOX_CORNER) : int(Inkscape::SNAPSOURCE_BBOX_CORNER)));
791 }
792 // optionally, collect the midpoints of the bounding box's edges too
793 if (includeLineMidpoints) {
794 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)));
795 }
796 }
797 if (includeObjectMidpoints) {
798 points->push_back(std::make_pair(bbox->midpoint(), isTarget ? int(Inkscape::SNAPTARGET_BBOX_MIDPOINT) : int(Inkscape::SNAPSOURCE_BBOX_MIDPOINT)));
799 }
800 }
801 }
803 /*
804 Local Variables:
805 mode:c++
806 c-file-style:"stroustrup"
807 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
808 indent-tabs-mode:nil
809 fill-column:99
810 End:
811 */
812 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :