9ee575e22e789731df282b06058af3884179e8ad
1 #define __SP_DESKTOP_SNAP_C__
3 /**
4 * \file snap.cpp
5 * \brief SnapManager class.
6 *
7 * Authors:
8 * Lauris Kaplinski <lauris@kaplinski.com>
9 * Frank Felfe <innerspace@iname.com>
10 * Nathan Hurst <njh@njhurst.com>
11 * Carl Hetherington <inkscape@carlh.net>
12 * Diederik van Lierop <mail@diedenrezi.nl>
13 *
14 * Copyright (C) 2006-2007 Johan Engelen <johan@shouraizou.nl>
15 * Copyrigth (C) 2004 Nathan Hurst
16 * Copyright (C) 1999-2010 Authors
17 *
18 * Released under GNU GPL, read the file 'COPYING' for more information
19 */
21 #include <utility>
23 #include "sp-namedview.h"
24 #include "snap.h"
25 #include "snapped-line.h"
26 #include "snapped-curve.h"
28 #include "display/canvas-grid.h"
29 #include "display/snap-indicator.h"
31 #include "inkscape.h"
32 #include "desktop.h"
33 #include "selection.h"
34 #include "sp-guide.h"
35 #include "preferences.h"
36 #include "event-context.h"
37 using std::vector;
39 /**
40 * Construct a SnapManager for a SPNamedView.
41 *
42 * \param v `Owning' SPNamedView.
43 */
45 SnapManager::SnapManager(SPNamedView const *v) :
46 guide(this, 0),
47 object(this, 0),
48 snapprefs(),
49 _named_view(v)
50 {
51 }
53 /**
54 * \brief Return a list of snappers
55 *
56 * Inkscape snaps to objects, grids, and guides. For each of these snap targets a
57 * separate class is used, which has been derived from the base Snapper class. The
58 * getSnappers() method returns a list of pointers to instances of this class. This
59 * list contains exactly one instance of the guide snapper and of the object snapper
60 * class, but any number of grid snappers (because each grid has its own snapper
61 * instance)
62 *
63 * \return List of snappers that we use.
64 */
65 SnapManager::SnapperList
66 SnapManager::getSnappers() const
67 {
68 SnapManager::SnapperList s;
69 s.push_back(&guide);
70 s.push_back(&object);
72 SnapManager::SnapperList gs = getGridSnappers();
73 s.splice(s.begin(), gs);
75 return s;
76 }
78 /**
79 * \brief Return a list of gridsnappers
80 *
81 * Each grid has its own instance of the snapper class. This way snapping can
82 * be enabled per grid individually. A list will be returned containing the
83 * pointers to these instances, but only for grids that are being displayed
84 * and for which snapping is enabled.
85 *
86 * \return List of gridsnappers that we use.
87 */
88 SnapManager::SnapperList
89 SnapManager::getGridSnappers() const
90 {
91 SnapperList s;
93 if (_desktop && _desktop->gridsEnabled() && snapprefs.getSnapToGrids()) {
94 for ( GSList const *l = _named_view->grids; l != NULL; l = l->next) {
95 Inkscape::CanvasGrid *grid = (Inkscape::CanvasGrid*) l->data;
96 s.push_back(grid->snapper);
97 }
98 }
100 return s;
101 }
103 /**
104 * \brief Return true if any snapping might occur, whether its to grids, guides or objects
105 *
106 * Each snapper instance handles its own snapping target, e.g. grids, guides or
107 * objects. This method iterates through all these snapper instances and returns
108 * true if any of the snappers might possible snap, considering only the relevant
109 * snapping preferences.
110 *
111 * \return true if one of the snappers will try to snap to something.
112 */
114 bool SnapManager::someSnapperMightSnap() const
115 {
116 if ( !snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally() ) {
117 return false;
118 }
120 SnapperList const s = getSnappers();
121 SnapperList::const_iterator i = s.begin();
122 while (i != s.end() && (*i)->ThisSnapperMightSnap() == false) {
123 i++;
124 }
126 return (i != s.end());
127 }
129 /**
130 * \return true if one of the grids might be snapped to.
131 */
133 bool SnapManager::gridSnapperMightSnap() const
134 {
135 if ( !snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally() ) {
136 return false;
137 }
139 SnapperList const s = getGridSnappers();
140 SnapperList::const_iterator i = s.begin();
141 while (i != s.end() && (*i)->ThisSnapperMightSnap() == false) {
142 i++;
143 }
145 return (i != s.end());
146 }
148 /**
149 * \brief Try to snap a point to grids, guides or objects.
150 *
151 * Try to snap a point to grids, guides or objects, in two degrees-of-freedom,
152 * i.e. snap in any direction on the two dimensional canvas to the nearest
153 * snap target. freeSnapReturnByRef() is equal in snapping behavior to
154 * freeSnap(), but the former returns the snapped point trough the referenced
155 * parameter p. This parameter p initially contains the position of the snap
156 * source and will we overwritten by the target position if snapping has occurred.
157 * This makes snapping transparent to the calling code. If this is not desired
158 * because either the calling code must know whether snapping has occurred, or
159 * because the original position should not be touched, then freeSnap() should be
160 * called instead.
161 *
162 * PS:
163 * 1) SnapManager::setup() must have been called before calling this method,
164 * but only once for a set of points
165 * 2) Only to be used when a single source point is to be snapped; it assumes
166 * that source_num = 0, which is inefficient when snapping sets our source points
167 *
168 * \param p Current position of the snap source; will be overwritten by the position of the snap target if snapping has occurred
169 * \param source_type Detailed description of the source type, will be used by the snap indicator
170 * \param bbox_to_snap Bounding box hulling the set of points, all from the same selection and having the same transformation
171 */
173 void SnapManager::freeSnapReturnByRef(Geom::Point &p,
174 Inkscape::SnapSourceType const source_type,
175 Geom::OptRect const &bbox_to_snap) const
176 {
177 //TODO: SnapCandidatePoint and point_type are somewhat redundant; can't we get rid of the point_type parameter?
178 Inkscape::SnappedPoint const s = freeSnap(Inkscape::SnapCandidatePoint(p, source_type), bbox_to_snap);
179 s.getPoint(p);
180 }
183 /**
184 * \brief Try to snap a point to grids, guides or objects.
185 *
186 * Try to snap a point to grids, guides or objects, in two degrees-of-freedom,
187 * i.e. snap in any direction on the two dimensional canvas to the nearest
188 * snap target. freeSnap() is equal in snapping behavior to
189 * freeSnapReturnByRef(). Please read the comments of the latter for more details
190 *
191 * PS: SnapManager::setup() must have been called before calling this method,
192 * but only once for a set of points
193 *
194 * \param p Source point to be snapped
195 * \param bbox_to_snap Bounding box hulling the set of points, all from the same selection and having the same transformation
196 * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics
197 */
200 Inkscape::SnappedPoint SnapManager::freeSnap(Inkscape::SnapCandidatePoint const &p,
201 Geom::OptRect const &bbox_to_snap) const
202 {
203 if (!someSnapperMightSnap()) {
204 return Inkscape::SnappedPoint(p, Inkscape::SNAPTARGET_UNDEFINED, NR_HUGE, 0, false, false);
205 }
207 SnappedConstraints sc;
208 SnapperList const snappers = getSnappers();
210 for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) {
211 (*i)->freeSnap(sc, p, bbox_to_snap, &_items_to_ignore, _unselected_nodes);
212 }
214 return findBestSnap(p, sc, false);
215 }
217 void SnapManager::preSnap(Inkscape::SnapCandidatePoint const &p)
218 {
219 // setup() must have been called before calling this method!
221 if (_snapindicator) {
222 _snapindicator = false; // prevent other methods from drawing a snap indicator; we want to control this here
223 Inkscape::SnappedPoint s = freeSnap(p);
224 if (s.getSnapped()) {
225 _desktop->snapindicator->set_new_snaptarget(s, true);
226 } else {
227 _desktop->snapindicator->remove_snaptarget();
228 }
229 _snapindicator = true; // restore the original value
230 }
231 }
233 /**
234 * \brief Snap to the closest multiple of a grid pitch
235 *
236 * When pasting, we would like to snap to the grid. Problem is that we don't know which
237 * nodes were aligned to the grid at the time of copying, so we don't know which nodes
238 * to snap. If we'd snap an unaligned node to the grid, previously aligned nodes would
239 * become unaligned. That's undesirable. Instead we will make sure that the offset
240 * between the source and its pasted copy is a multiple of the grid pitch. If the source
241 * was aligned, then the copy will therefore also be aligned.
242 *
243 * PS: Whether we really find a multiple also depends on the snapping range! Most users
244 * will have "always snap" enabled though, in which case a multiple will always be found.
245 * PS2: When multiple grids are present then the result will become ambiguous. There is no
246 * way to control to which grid this method will snap.
247 *
248 * \param t Vector that represents the offset of the pasted copy with respect to the original
249 * \return Offset vector after snapping to the closest multiple of a grid pitch
250 */
252 Geom::Point SnapManager::multipleOfGridPitch(Geom::Point const &t) const
253 {
254 if (!snapprefs.getSnapEnabledGlobally()) // No need to check for snapprefs.getSnapPostponedGlobally() here
255 return t;
257 if (_desktop && _desktop->gridsEnabled()) {
258 bool success = false;
259 Geom::Point nearest_multiple;
260 Geom::Coord nearest_distance = NR_HUGE;
262 // It will snap to the grid for which we find the closest snap. This might be a different
263 // grid than to which the objects were initially aligned. I don't see an easy way to fix
264 // this, so when using multiple grids one can get unexpected results
266 // Cannot use getGridSnappers() because we need both the grids AND their snappers
267 // Therefore we iterate through all grids manually
268 for (GSList const *l = _named_view->grids; l != NULL; l = l->next) {
269 Inkscape::CanvasGrid *grid = (Inkscape::CanvasGrid*) l->data;
270 const Inkscape::Snapper* snapper = grid->snapper;
271 if (snapper && snapper->ThisSnapperMightSnap()) {
272 // To find the nearest multiple of the grid pitch for a given translation t, we
273 // will use the grid snapper. Simply snapping the value t to the grid will do, but
274 // only if the origin of the grid is at (0,0). If it's not then compensate for this
275 // in the translation t
276 Geom::Point const t_offset = t + grid->origin;
277 SnappedConstraints sc;
278 // Only the first three parameters are being used for grid snappers
279 snapper->freeSnap(sc, Inkscape::SnapCandidatePoint(t_offset, Inkscape::SNAPSOURCE_UNDEFINED),Geom::OptRect(), NULL, NULL);
280 // Find the best snap for this grid, including intersections of the grid-lines
281 Inkscape::SnappedPoint s = findBestSnap(Inkscape::SnapCandidatePoint(t_offset, Inkscape::SNAPSOURCE_UNDEFINED), sc, false);
282 if (s.getSnapped() && (s.getSnapDistance() < nearest_distance)) {
283 // use getSnapDistance() instead of getWeightedDistance() here because the pointer's position
284 // doesn't tell us anything about which node to snap
285 success = true;
286 nearest_multiple = s.getPoint() - to_2geom(grid->origin);
287 nearest_distance = s.getSnapDistance();
288 }
289 }
290 }
292 if (success)
293 return nearest_multiple;
294 }
296 return t;
297 }
299 /**
300 * \brief Try to snap a point along a constraint line to grids, guides or objects.
301 *
302 * Try to snap a point to grids, guides or objects, in only one degree-of-freedom,
303 * i.e. snap in a specific direction on the two dimensional canvas to the nearest
304 * snap target.
305 *
306 * constrainedSnapReturnByRef() is equal in snapping behavior to
307 * constrainedSnap(), but the former returns the snapped point trough the referenced
308 * parameter p. This parameter p initially contains the position of the snap
309 * source and will we overwritten by the target position if snapping has occurred.
310 * This makes snapping transparent to the calling code. If this is not desired
311 * because either the calling code must know whether snapping has occurred, or
312 * because the original position should not be touched, then constrainedSnap() should
313 * be called instead.
314 *
315 * PS:
316 * 1) SnapManager::setup() must have been called before calling this method,
317 * but only once for a set of points
318 * 2) Only to be used when a single source point is to be snapped; it assumes
319 * that source_num = 0, which is inefficient when snapping sets our source points
321 *
322 * \param p Current position of the snap source; will be overwritten by the position of the snap target if snapping has occurred
323 * \param source_type Detailed description of the source type, will be used by the snap indicator
324 * \param constraint The direction or line along which snapping must occur
325 * \param bbox_to_snap Bounding box hulling the set of points, all from the same selection and having the same transformation
326 */
328 void SnapManager::constrainedSnapReturnByRef(Geom::Point &p,
329 Inkscape::SnapSourceType const source_type,
330 Inkscape::Snapper::ConstraintLine const &constraint,
331 Geom::OptRect const &bbox_to_snap) const
332 {
333 Inkscape::SnappedPoint const s = constrainedSnap(Inkscape::SnapCandidatePoint(p, source_type, 0), constraint, bbox_to_snap);
334 s.getPoint(p);
335 }
337 /**
338 * \brief Try to snap a point along a constraint line to grids, guides or objects.
339 *
340 * Try to snap a point to grids, guides or objects, in only one degree-of-freedom,
341 * i.e. snap in a specific direction on the two dimensional canvas to the nearest
342 * snap target. constrainedSnap is equal in snapping behavior to
343 * constrainedSnapReturnByRef(). Please read the comments of the latter for more details.
344 *
345 * PS: SnapManager::setup() must have been called before calling this method,
346 * but only once for a set of points
347 *
348 * \param p Source point to be snapped
349 * \param constraint The direction or line along which snapping must occur
350 * \param bbox_to_snap Bounding box hulling the set of points, all from the same selection and having the same transformation
351 */
353 Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::SnapCandidatePoint const &p,
354 Inkscape::Snapper::ConstraintLine const &constraint,
355 Geom::OptRect const &bbox_to_snap) const
356 {
357 if (!someSnapperMightSnap()) {
358 return Inkscape::SnappedPoint(p, Inkscape::SNAPTARGET_UNDEFINED, NR_HUGE, 0, false, false);
359 }
361 // First project the mouse pointer onto the constraint
362 Geom::Point pp = constraint.projection(p.getPoint());
363 // Then try to snap the projected point
364 Inkscape::SnapCandidatePoint candidate(pp, p.getSourceType(), p.getSourceNum(), Inkscape::SNAPTARGET_UNDEFINED, Geom::Rect());
366 SnappedConstraints sc;
367 SnapperList const snappers = getSnappers();
368 for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) {
369 (*i)->constrainedSnap(sc, candidate, bbox_to_snap, constraint, &_items_to_ignore);
370 }
372 return findBestSnap(candidate, sc, true);
373 }
375 /**
376 * \brief Try to snap a point of a guide to another guide or to a node
377 *
378 * Try to snap a point of a guide to another guide or to a node in two degrees-
379 * of-freedom, i.e. snap in any direction on the two dimensional canvas to the
380 * nearest snap target. This method is used when dragging or rotating a guide
381 *
382 * PS: SnapManager::setup() must have been called before calling this method,
383 *
384 * \param p Current position of the point on the guide that is to be snapped; will be overwritten by the position of the snap target if snapping has occurred
385 * \param guide_normal Vector normal to the guide line
386 */
387 void SnapManager::guideFreeSnap(Geom::Point &p, Geom::Point const &guide_normal, SPGuideDragType drag_type) const
388 {
389 if (!snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally()) {
390 return;
391 }
393 if (!(object.GuidesMightSnap() || snapprefs.getSnapToGuides())) {
394 return;
395 }
397 Inkscape::SnapCandidatePoint candidate(p, Inkscape::SNAPSOURCE_GUIDE_ORIGIN);
398 if (drag_type == SP_DRAG_ROTATE) {
399 candidate = Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_GUIDE);
400 }
402 // Snap to nodes
403 SnappedConstraints sc;
404 if (object.GuidesMightSnap()) {
405 object.guideFreeSnap(sc, p, guide_normal);
406 }
408 // Snap to guides & grid lines
409 SnapperList snappers = getGridSnappers();
410 snappers.push_back(&guide);
411 for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) {
412 (*i)->freeSnap(sc, candidate, Geom::OptRect(), NULL, NULL);
413 }
415 // Snap to intersections of curves, but not to the curves themselves! (see _snapTranslatingGuideToNodes in object-snapper.cpp)
416 Inkscape::SnappedPoint const s = findBestSnap(candidate, sc, false, true);
418 s.getPoint(p);
419 }
421 /**
422 * \brief Try to snap a point on a guide to the intersection with another guide or a path
423 *
424 * Try to snap a point on a guide to the intersection of that guide with another
425 * guide or with a path. The snapped point will lie somewhere on the guide-line,
426 * making this is a constrained snap, i.e. in only one degree-of-freedom.
427 * This method is used when dragging the origin of the guide along the guide itself.
428 *
429 * PS: SnapManager::setup() must have been called before calling this method,
430 *
431 * \param p Current position of the point on the guide that is to be snapped; will be overwritten by the position of the snap target if snapping has occurred
432 * \param guide_normal Vector normal to the guide line
433 */
435 void SnapManager::guideConstrainedSnap(Geom::Point &p, SPGuide const &guideline) const
436 {
437 if (!snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally()) {
438 return;
439 }
441 if (!(object.ThisSnapperMightSnap() || snapprefs.getSnapToGuides())) {
442 return;
443 }
445 Inkscape::SnapCandidatePoint candidate(p, Inkscape::SNAPSOURCE_GUIDE_ORIGIN, Inkscape::SNAPTARGET_UNDEFINED);
447 // Snap to nodes or paths
448 SnappedConstraints sc;
449 Inkscape::Snapper::ConstraintLine cl(guideline.point_on_line, Geom::rot90(guideline.normal_to_line));
450 if (object.ThisSnapperMightSnap()) {
451 object.constrainedSnap(sc, candidate, Geom::OptRect(), cl, NULL);
452 }
454 // Snap to guides & grid lines
455 SnapperList snappers = getGridSnappers();
456 snappers.push_back(&guide);
457 for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) {
458 (*i)->constrainedSnap(sc, candidate, Geom::OptRect(), cl, NULL);
459 }
461 Inkscape::SnappedPoint const s = findBestSnap(candidate, sc, false);
462 s.getPoint(p);
463 }
465 /**
466 * \brief Method for snapping sets of points while they are being transformed
467 *
468 * Method for snapping sets of points while they are being transformed, when using
469 * for example the selector tool. This method is for internal use only, and should
470 * not have to be called directly. Use freeSnapTransalation(), constrainedSnapScale(),
471 * etc. instead.
472 *
473 * This is what is being done in this method: transform each point, find out whether
474 * a free snap or constrained snap is more appropriate, do the snapping, calculate
475 * some metrics to quantify the snap "distance", and see if it's better than the
476 * previous snap. Finally, the best ("nearest") snap from all these points is returned.
477 *
478 * \param points Collection of points to snap (snap sources), at their untransformed position, all points undergoing the same transformation. Paired with an identifier of the type of the snap source.
479 * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed).
480 * \param constrained true if the snap is constrained, e.g. for stretching or for purely horizontal translation.
481 * \param constraint The direction or line along which snapping must occur, if 'constrained' is true; otherwise undefined.
482 * \param transformation_type Type of transformation to apply to points before trying to snap them.
483 * \param transformation Description of the transformation; details depend on the type.
484 * \param origin Origin of the transformation, if applicable.
485 * \param dim Dimension to which the transformation applies, if applicable.
486 * \param uniform true if the transformation should be uniform; only applicable for stretching and scaling.
487 * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics.
488 */
490 Inkscape::SnappedPoint SnapManager::_snapTransformed(
491 std::vector<Inkscape::SnapCandidatePoint> const &points,
492 Geom::Point const &pointer,
493 bool constrained,
494 Inkscape::Snapper::ConstraintLine const &constraint,
495 Transformation transformation_type,
496 Geom::Point const &transformation,
497 Geom::Point const &origin,
498 Geom::Dim2 dim,
499 bool uniform) const
500 {
501 /* We have a list of points, which we are proposing to transform in some way. We need to see
502 ** if any of these points, when transformed, snap to anything. If they do, we return the
503 ** appropriate transformation with `true'; otherwise we return the original scale with `false'.
504 */
506 /* Quick check to see if we have any snappers that are enabled
507 ** Also used to globally disable all snapping
508 */
509 if (someSnapperMightSnap() == false) {
510 return Inkscape::SnappedPoint(pointer);
511 }
513 std::vector<Inkscape::SnapCandidatePoint> transformed_points;
514 Geom::Rect bbox;
516 long source_num = 0;
517 for (std::vector<Inkscape::SnapCandidatePoint>::const_iterator i = points.begin(); i != points.end(); i++) {
519 /* Work out the transformed version of this point */
520 Geom::Point transformed = _transformPoint(*i, transformation_type, transformation, origin, dim, uniform);
522 // add the current transformed point to the box hulling all transformed points
523 if (i == points.begin()) {
524 bbox = Geom::Rect(transformed, transformed);
525 } else {
526 bbox.expandTo(transformed);
527 }
529 transformed_points.push_back(Inkscape::SnapCandidatePoint(transformed, (*i).getSourceType(), source_num));
530 source_num++;
531 }
533 /* The current best transformation */
534 Geom::Point best_transformation = transformation;
536 /* The current best metric for the best transformation; lower is better, NR_HUGE
537 ** means that we haven't snapped anything.
538 */
539 Geom::Point best_scale_metric(NR_HUGE, NR_HUGE);
540 Inkscape::SnappedPoint best_snapped_point;
541 g_assert(best_snapped_point.getAlwaysSnap() == false); // Check initialization of snapped point
542 g_assert(best_snapped_point.getAtIntersection() == false);
544 std::vector<Inkscape::SnapCandidatePoint>::const_iterator j = transformed_points.begin();
547 // std::cout << std::endl;
548 for (std::vector<Inkscape::SnapCandidatePoint>::const_iterator i = points.begin(); i != points.end(); i++) {
550 /* Snap it */
551 Inkscape::SnappedPoint snapped_point;
552 Inkscape::Snapper::ConstraintLine dedicated_constraint = constraint;
553 Geom::Point const b = ((*i).getPoint() - origin); // vector to original point
555 if (constrained) {
556 if ((transformation_type == SCALE || transformation_type == STRETCH) && uniform) {
557 // When uniformly scaling, each point will have its own unique constraint line,
558 // running from the scaling origin to the original untransformed point. We will
559 // calculate that line here
560 dedicated_constraint = Inkscape::Snapper::ConstraintLine(origin, b);
561 } else if (transformation_type == STRETCH) { // when non-uniform stretching {
562 dedicated_constraint = Inkscape::Snapper::ConstraintLine((*i).getPoint(), component_vectors[dim]);
563 } else if (transformation_type == TRANSLATION) {
564 // When doing a constrained translation, all points will move in the same direction, i.e.
565 // either horizontally or vertically. The lines along which they move are therefore all
566 // parallel, but might not be colinear. Therefore we will have to set the point through
567 // which the constraint-line runs here, for each point individually.
568 dedicated_constraint.setPoint((*i).getPoint());
569 } // else: leave the original constraint, e.g. for skewing
570 if (transformation_type == SCALE && !uniform) {
571 g_warning("Non-uniform constrained scaling is not supported!");
572 }
573 snapped_point = constrainedSnap(*j, dedicated_constraint, bbox);
574 } else {
575 bool const c1 = fabs(b[Geom::X]) < 1e-6;
576 bool const c2 = fabs(b[Geom::Y]) < 1e-6;
577 if (transformation_type == SCALE && (c1 || c2) && !(c1 && c2)) {
578 // When scaling, a point aligned either horizontally or vertically with the origin can only
579 // move in that specific direction; therefore it should only snap in that direction, otherwise
580 // we will get snapped points with an invalid transformation
581 dedicated_constraint = Inkscape::Snapper::ConstraintLine(origin, component_vectors[c1]);
582 snapped_point = constrainedSnap(*j, dedicated_constraint, bbox);
583 } else {
584 snapped_point = freeSnap(*j, bbox);
585 }
586 }
587 // std::cout << "dist = " << snapped_point.getSnapDistance() << std::endl;
588 snapped_point.setPointerDistance(Geom::L2(pointer - (*i).getPoint()));
590 Geom::Point result;
592 if (snapped_point.getSnapped()) {
593 /* We snapped. Find the transformation that describes where the snapped point has
594 ** ended up, and also the metric for this transformation.
595 */
596 Geom::Point const a = (snapped_point.getPoint() - origin); // vector to snapped point
597 //Geom::Point const b = (*i - origin); // vector to original point
599 switch (transformation_type) {
600 case TRANSLATION:
601 result = snapped_point.getPoint() - (*i).getPoint();
602 /* Consider the case in which a box is almost aligned with a grid in both
603 * horizontal and vertical directions. The distance to the intersection of
604 * the grid lines will always be larger then the distance to a single grid
605 * line. If we prefer snapping to an intersection instead of to a single
606 * grid line, then we cannot use "metric = Geom::L2(result)". Therefore the
607 * snapped distance will be used as a metric. Please note that the snapped
608 * distance is defined as the distance to the nearest line of the intersection,
609 * and not to the intersection itself!
610 */
611 // Only for translations, the relevant metric will be the real snapped distance,
612 // so we don't have to do anything special here
613 break;
614 case SCALE:
615 {
616 result = Geom::Point(NR_HUGE, NR_HUGE);
617 // If this point *i is horizontally or vertically aligned with
618 // the origin of the scaling, then it will scale purely in X or Y
619 // We can therefore only calculate the scaling in this direction
620 // and the scaling factor for the other direction should remain
621 // untouched (unless scaling is uniform ofcourse)
622 for (int index = 0; index < 2; index++) {
623 if (fabs(b[index]) > 1e-6) { // if SCALING CAN occur in this direction
624 if (fabs(fabs(a[index]/b[index]) - fabs(transformation[index])) > 1e-12) { // if SNAPPING DID occur in this direction
625 result[index] = a[index] / b[index]; // then calculate it!
626 }
627 // we might leave result[1-index] = NR_HUGE
628 // if scaling didn't occur in the other direction
629 }
630 }
631 if (uniform) {
632 if (fabs(result[0]) < fabs(result[1])) {
633 result[1] = result[0];
634 } else {
635 result[0] = result[1];
636 }
637 }
638 // Compare the resulting scaling with the desired scaling
639 Geom::Point scale_metric = Geom::abs(result - transformation); // One or both of its components might be NR_HUGE
640 snapped_point.setSnapDistance(std::min(scale_metric[0], scale_metric[1]));
641 snapped_point.setSecondSnapDistance(std::max(scale_metric[0], scale_metric[1]));
642 break;
643 }
644 case STRETCH:
645 result = Geom::Point(NR_HUGE, NR_HUGE);
646 if (fabs(b[dim]) > 1e-6) { // if STRETCHING will occur for this point
647 result[dim] = a[dim] / b[dim];
648 result[1-dim] = uniform ? result[dim] : 1;
649 } else { // STRETCHING might occur for this point, but only when the stretching is uniform
650 if (uniform && fabs(b[1-dim]) > 1e-6) {
651 result[1-dim] = a[1-dim] / b[1-dim];
652 result[dim] = result[1-dim];
653 }
654 }
655 // Store the metric for this transformation as a virtual distance
656 snapped_point.setSnapDistance(std::abs(result[dim] - transformation[dim]));
657 snapped_point.setSecondSnapDistance(NR_HUGE);
658 break;
659 case SKEW:
660 result[0] = (snapped_point.getPoint()[dim] - ((*i).getPoint())[dim]) / (((*i).getPoint())[1 - dim] - origin[1 - dim]); // skew factor
661 result[1] = transformation[1]; // scale factor
662 // Store the metric for this transformation as a virtual distance
663 snapped_point.setSnapDistance(std::abs(result[0] - transformation[0]));
664 snapped_point.setSecondSnapDistance(NR_HUGE);
665 break;
666 default:
667 g_assert_not_reached();
668 }
670 // When scaling, we're considering the best transformation in each direction separately. We will have a metric in each
671 // direction, whereas for all other transformation we only a single one-dimensional metric. That's why we need to handle
672 // the scaling metric differently
673 if (best_snapped_point.isOtherSnapBetter(snapped_point, true)) {
674 best_transformation = result;
675 best_snapped_point = snapped_point;
676 }
677 }
679 j++;
680 }
682 Geom::Coord best_metric;
683 if (transformation_type == SCALE) {
684 // When scaling, don't ever exit with one of scaling components set to NR_HUGE
685 for (int index = 0; index < 2; index++) {
686 if (best_transformation[index] == NR_HUGE) {
687 if (uniform && best_transformation[1-index] < NR_HUGE) {
688 best_transformation[index] = best_transformation[1-index];
689 } else {
690 best_transformation[index] = transformation[index];
691 }
692 }
693 }
694 }
696 best_metric = best_snapped_point.getSnapDistance();
697 best_snapped_point.setTransformation(best_transformation);
698 // Using " < 1e6" instead of " < NR_HUGE" for catching some rounding errors
699 // These rounding errors might be caused by NRRects, see bug #1584301
700 best_snapped_point.setSnapDistance(best_metric < 1e6 ? best_metric : NR_HUGE);
701 return best_snapped_point;
702 }
705 /**
706 * \brief Apply a translation to a set of points and try to snap freely in 2 degrees-of-freedom
707 *
708 * \param p Collection of points to snap (snap sources), at their untransformed position, all points undergoing the same transformation. Paired with an identifier of the type of the snap source.
709 * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed).
710 * \param tr Proposed translation; the final translation can only be calculated after snapping has occurred
711 * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics.
712 */
714 Inkscape::SnappedPoint SnapManager::freeSnapTranslation(std::vector<Inkscape::SnapCandidatePoint> const &p,
715 Geom::Point const &pointer,
716 Geom::Point const &tr) const
717 {
718 if (p.size() == 1) {
719 Geom::Point pt = _transformPoint(p.at(0), TRANSLATION, tr, Geom::Point(0,0), Geom::X, false);
720 _displaySnapsource(Inkscape::SnapCandidatePoint(pt, p.at(0).getSourceType()));
721 }
723 return _snapTransformed(p, pointer, false, Geom::Point(0,0), TRANSLATION, tr, Geom::Point(0,0), Geom::X, false);
724 }
726 /**
727 * \brief Apply a translation to a set of points and try to snap along a constraint
728 *
729 * \param point_type Category of points to which the source point belongs: node or bounding box.
730 * \param p Collection of points to snap (snap sources), at their untransformed position, all points undergoing the same transformation. Paired with an identifier of the type of the snap source.
731 * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed).
732 * \param constraint The direction or line along which snapping must occur.
733 * \param tr Proposed translation; the final translation can only be calculated after snapping has occurred.
734 * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics.
735 */
737 Inkscape::SnappedPoint SnapManager::constrainedSnapTranslation(std::vector<Inkscape::SnapCandidatePoint> const &p,
738 Geom::Point const &pointer,
739 Inkscape::Snapper::ConstraintLine const &constraint,
740 Geom::Point const &tr) const
741 {
742 if (p.size() == 1) {
743 Geom::Point pt = _transformPoint(p.at(0), TRANSLATION, tr, Geom::Point(0,0), Geom::X, false);
744 _displaySnapsource(Inkscape::SnapCandidatePoint(pt, p.at(0).getSourceType()));
745 }
747 return _snapTransformed(p, pointer, true, constraint, TRANSLATION, tr, Geom::Point(0,0), Geom::X, false);
748 }
751 /**
752 * \brief Apply a scaling to a set of points and try to snap freely in 2 degrees-of-freedom
753 *
754 * \param point_type Category of points to which the source point belongs: node or bounding box.
755 * \param p Collection of points to snap (snap sources), at their untransformed position, all points undergoing the same transformation. Paired with an identifier of the type of the snap source.
756 * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed).
757 * \param s Proposed scaling; the final scaling can only be calculated after snapping has occurred
758 * \param o Origin of the scaling
759 * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics.
760 */
762 Inkscape::SnappedPoint SnapManager::freeSnapScale(std::vector<Inkscape::SnapCandidatePoint> const &p,
763 Geom::Point const &pointer,
764 Geom::Scale const &s,
765 Geom::Point const &o) const
766 {
767 if (p.size() == 1) {
768 Geom::Point pt = _transformPoint(p.at(0), SCALE, Geom::Point(s[Geom::X], s[Geom::Y]), o, Geom::X, false);
769 _displaySnapsource(Inkscape::SnapCandidatePoint(pt, p.at(0).getSourceType()));
770 }
772 return _snapTransformed(p, pointer, false, Geom::Point(0,0), SCALE, Geom::Point(s[Geom::X], s[Geom::Y]), o, Geom::X, false);
773 }
776 /**
777 * \brief Apply a scaling to a set of points and snap such that the aspect ratio of the selection is preserved
778 *
779 * \param point_type Category of points to which the source point belongs: node or bounding box.
780 * \param p Collection of points to snap (snap sources), at their untransformed position, all points undergoing the same transformation. Paired with an identifier of the type of the snap source.
781 * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed).
782 * \param s Proposed scaling; the final scaling can only be calculated after snapping has occurred
783 * \param o Origin of the scaling
784 * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics.
785 */
787 Inkscape::SnappedPoint SnapManager::constrainedSnapScale(std::vector<Inkscape::SnapCandidatePoint> const &p,
788 Geom::Point const &pointer,
789 Geom::Scale const &s,
790 Geom::Point const &o) const
791 {
792 // When constrained scaling, only uniform scaling is supported.
793 if (p.size() == 1) {
794 Geom::Point pt = _transformPoint(p.at(0), SCALE, Geom::Point(s[Geom::X], s[Geom::Y]), o, Geom::X, true);
795 _displaySnapsource(Inkscape::SnapCandidatePoint(pt, p.at(0).getSourceType()));
796 }
798 return _snapTransformed(p, pointer, true, Geom::Point(0,0), SCALE, Geom::Point(s[Geom::X], s[Geom::Y]), o, Geom::X, true);
799 }
801 /**
802 * \brief Apply a stretch to a set of points and snap such that the direction of the stretch is preserved
803 *
804 * \param point_type Category of points to which the source point belongs: node or bounding box.
805 * \param p Collection of points to snap (snap sources), at their untransformed position, all points undergoing the same transformation. Paired with an identifier of the type of the snap source.
806 * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed).
807 * \param s Proposed stretch; the final stretch can only be calculated after snapping has occurred
808 * \param o Origin of the stretching
809 * \param d Dimension in which to apply proposed stretch.
810 * \param u true if the stretch should be uniform (i.e. to be applied equally in both dimensions)
811 * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics.
812 */
814 Inkscape::SnappedPoint SnapManager::constrainedSnapStretch(std::vector<Inkscape::SnapCandidatePoint> const &p,
815 Geom::Point const &pointer,
816 Geom::Coord const &s,
817 Geom::Point const &o,
818 Geom::Dim2 d,
819 bool u) const
820 {
821 if (p.size() == 1) {
822 Geom::Point pt = _transformPoint(p.at(0), STRETCH, Geom::Point(s, s), o, d, u);
823 _displaySnapsource(Inkscape::SnapCandidatePoint(pt, p.at(0).getSourceType()));
824 }
826 return _snapTransformed(p, pointer, true, Geom::Point(0,0), STRETCH, Geom::Point(s, s), o, d, u);
827 }
829 /**
830 * \brief Apply a skew to a set of points and snap such that the direction of the skew is preserved
831 *
832 * \param point_type Category of points to which the source point belongs: node or bounding box.
833 * \param p Collection of points to snap (snap sources), at their untransformed position, all points undergoing the same transformation. Paired with an identifier of the type of the snap source.
834 * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed).
835 * \param constraint The direction or line along which snapping must occur.
836 * \param s Proposed skew; the final skew can only be calculated after snapping has occurred
837 * \param o Origin of the proposed skew
838 * \param d Dimension in which to apply proposed skew.
839 * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics.
840 */
842 Inkscape::SnappedPoint SnapManager::constrainedSnapSkew(std::vector<Inkscape::SnapCandidatePoint> const &p,
843 Geom::Point const &pointer,
844 Inkscape::Snapper::ConstraintLine const &constraint,
845 Geom::Point const &s,
846 Geom::Point const &o,
847 Geom::Dim2 d) const
848 {
849 // "s" contains skew factor in s[0], and scale factor in s[1]
851 // Snapping the nodes of the bounding box of a selection that is being transformed, will only work if
852 // the transformation of the bounding box is equal to the transformation of the individual nodes. This is
853 // NOT the case for example when rotating or skewing. The bounding box itself cannot possibly rotate or skew,
854 // so it's corners have a different transformation. The snappers cannot handle this, therefore snapping
855 // of bounding boxes is not allowed here.
856 if (p.size() > 0) {
857 g_assert(!(p.at(0).getSourceType() & Inkscape::SNAPSOURCE_BBOX_CATEGORY));
858 }
860 if (p.size() == 1) {
861 Geom::Point pt = _transformPoint(p.at(0), SKEW, s, o, d, false);
862 _displaySnapsource(Inkscape::SnapCandidatePoint(pt, p.at(0).getSourceType()));
863 }
865 return _snapTransformed(p, pointer, true, constraint, SKEW, s, o, d, false);
866 }
868 /**
869 * \brief Given a set of possible snap targets, find the best target (which is not necessarily
870 * also the nearest target), and show the snap indicator if requested
871 *
872 * \param p Source point to be snapped
873 * \param sc A structure holding all snap targets that have been found so far
874 * \param constrained True if the snap is constrained, e.g. for stretching or for purely horizontal translation.
875 * \param noCurves If true, then do consider snapping to intersections of curves, but not to the curves themselves
876 * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics
877 */
879 Inkscape::SnappedPoint SnapManager::findBestSnap(Inkscape::SnapCandidatePoint const &p,
880 SnappedConstraints const &sc,
881 bool constrained,
882 bool noCurves) const
883 {
885 /*
886 std::cout << "Type and number of snapped constraints: " << std::endl;
887 std::cout << " Points : " << sc.points.size() << std::endl;
888 std::cout << " Lines : " << sc.lines.size() << std::endl;
889 std::cout << " Grid lines : " << sc.grid_lines.size()<< std::endl;
890 std::cout << " Guide lines : " << sc.guide_lines.size()<< std::endl;
891 std::cout << " Curves : " << sc.curves.size()<< std::endl;
892 */
894 // Store all snappoints
895 std::list<Inkscape::SnappedPoint> sp_list;
897 // search for the closest snapped point
898 Inkscape::SnappedPoint closestPoint;
899 if (getClosestSP(sc.points, closestPoint)) {
900 sp_list.push_back(closestPoint);
901 }
903 // search for the closest snapped curve
904 if (!noCurves) {
905 Inkscape::SnappedCurve closestCurve;
906 if (getClosestCurve(sc.curves, closestCurve)) {
907 sp_list.push_back(Inkscape::SnappedPoint(closestCurve));
908 }
909 }
911 if (snapprefs.getSnapIntersectionCS()) {
912 // search for the closest snapped intersection of curves
913 Inkscape::SnappedPoint closestCurvesIntersection;
914 if (getClosestIntersectionCS(sc.curves, p.getPoint(), closestCurvesIntersection, _desktop->dt2doc())) {
915 closestCurvesIntersection.setSource(p.getSourceType());
916 sp_list.push_back(closestCurvesIntersection);
917 }
918 }
920 // search for the closest snapped grid line
921 Inkscape::SnappedLine closestGridLine;
922 if (getClosestSL(sc.grid_lines, closestGridLine)) {
923 sp_list.push_back(Inkscape::SnappedPoint(closestGridLine));
924 }
926 // search for the closest snapped guide line
927 Inkscape::SnappedLine closestGuideLine;
928 if (getClosestSL(sc.guide_lines, closestGuideLine)) {
929 sp_list.push_back(Inkscape::SnappedPoint(closestGuideLine));
930 }
932 // When freely snapping to a grid/guide/path, only one degree of freedom is eliminated
933 // Therefore we will try get fully constrained by finding an intersection with another grid/guide/path
935 // When doing a constrained snap however, we're already at an intersection of the constrained line and
936 // the grid/guide/path we're snapping to. This snappoint is therefore fully constrained, so there's
937 // no need to look for additional intersections
938 if (!constrained) {
939 // search for the closest snapped intersection of grid lines
940 Inkscape::SnappedPoint closestGridPoint;
941 if (getClosestIntersectionSL(sc.grid_lines, closestGridPoint)) {
942 closestGridPoint.setSource(p.getSourceType());
943 closestGridPoint.setTarget(Inkscape::SNAPTARGET_GRID_INTERSECTION);
944 sp_list.push_back(closestGridPoint);
945 }
947 // search for the closest snapped intersection of guide lines
948 Inkscape::SnappedPoint closestGuidePoint;
949 if (getClosestIntersectionSL(sc.guide_lines, closestGuidePoint)) {
950 closestGuidePoint.setSource(p.getSourceType());
951 closestGuidePoint.setTarget(Inkscape::SNAPTARGET_GUIDE_INTERSECTION);
952 sp_list.push_back(closestGuidePoint);
953 }
955 // search for the closest snapped intersection of grid with guide lines
956 if (snapprefs.getSnapIntersectionGG()) {
957 Inkscape::SnappedPoint closestGridGuidePoint;
958 if (getClosestIntersectionSL(sc.grid_lines, sc.guide_lines, closestGridGuidePoint)) {
959 closestGridGuidePoint.setSource(p.getSourceType());
960 closestGridGuidePoint.setTarget(Inkscape::SNAPTARGET_GRID_GUIDE_INTERSECTION);
961 sp_list.push_back(closestGridGuidePoint);
962 }
963 }
964 }
966 // now let's see which snapped point gets a thumbs up
967 Inkscape::SnappedPoint bestSnappedPoint(p.getPoint());
968 // std::cout << "Finding the best snap..." << std::endl;
969 for (std::list<Inkscape::SnappedPoint>::const_iterator i = sp_list.begin(); i != sp_list.end(); i++) {
970 // first find out if this snapped point is within snapping range
971 // std::cout << "sp = " << (*i).getPoint() << " | source = " << (*i).getSource() << " | target = " << (*i).getTarget();
972 if ((*i).getSnapDistance() <= (*i).getTolerance()) {
973 // if it's the first point, or if it is closer than the best snapped point so far
974 if (i == sp_list.begin() || bestSnappedPoint.isOtherSnapBetter(*i, false)) {
975 // then prefer this point over the previous one
976 bestSnappedPoint = *i;
977 }
978 }
979 // std::cout << std::endl;
980 }
982 // Update the snap indicator, if requested
983 if (_snapindicator) {
984 if (bestSnappedPoint.getSnapped()) {
985 _desktop->snapindicator->set_new_snaptarget(bestSnappedPoint);
986 } else {
987 _desktop->snapindicator->remove_snaptarget();
988 }
989 }
991 // std::cout << "findBestSnap = " << bestSnappedPoint.getPoint() << " | dist = " << bestSnappedPoint.getSnapDistance() << std::endl;
992 return bestSnappedPoint;
993 }
995 /// Convenience shortcut when there is only one item to ignore
996 void SnapManager::setup(SPDesktop const *desktop,
997 bool snapindicator,
998 SPItem const *item_to_ignore,
999 std::vector<Inkscape::SnapCandidatePoint> *unselected_nodes,
1000 SPGuide *guide_to_ignore)
1001 {
1002 g_assert(desktop != NULL);
1003 _items_to_ignore.clear();
1004 _items_to_ignore.push_back(item_to_ignore);
1005 _desktop = desktop;
1006 _snapindicator = snapindicator;
1007 _unselected_nodes = unselected_nodes;
1008 _guide_to_ignore = guide_to_ignore;
1009 }
1011 /**
1012 * \brief Prepare the snap manager for the actual snapping, which includes building a list of snap targets
1013 * to ignore and toggling the snap indicator
1014 *
1015 * There are two overloaded setup() methods, of which the other one only allows for a single item to be ignored
1016 * whereas this one will take a list of items to ignore
1017 *
1018 * \param desktop Reference to the desktop to which this snap manager is attached
1019 * \param snapindicator If true then a snap indicator will be displayed automatically (when enabled in the preferences)
1020 * \param items_to_ignore These items will not be snapped to, e.g. the items that are currently being dragged. This avoids "self-snapping"
1021 * \param unselected_nodes Stationary nodes of the path that is currently being edited in the node tool and
1022 * that can be snapped too. Nodes not in this list will not be snapped to, to avoid "self-snapping". Of each
1023 * unselected node both the position (Geom::Point) and the type (Inkscape::SnapTargetType) will be stored
1024 * \param guide_to_ignore Guide that is currently being dragged and should not be snapped to
1025 */
1027 void SnapManager::setup(SPDesktop const *desktop,
1028 bool snapindicator,
1029 std::vector<SPItem const *> &items_to_ignore,
1030 std::vector<Inkscape::SnapCandidatePoint> *unselected_nodes,
1031 SPGuide *guide_to_ignore)
1032 {
1033 g_assert(desktop != NULL);
1034 _items_to_ignore = items_to_ignore;
1035 _desktop = desktop;
1036 _snapindicator = snapindicator;
1037 _unselected_nodes = unselected_nodes;
1038 _guide_to_ignore = guide_to_ignore;
1039 }
1041 /// Setup, taking the list of items to ignore from the desktop's selection.
1042 void SnapManager::setupIgnoreSelection(SPDesktop const *desktop,
1043 bool snapindicator,
1044 std::vector<Inkscape::SnapCandidatePoint> *unselected_nodes,
1045 SPGuide *guide_to_ignore)
1046 {
1047 _desktop = desktop;
1048 _snapindicator = snapindicator;
1049 _unselected_nodes = unselected_nodes;
1050 _guide_to_ignore = guide_to_ignore;
1051 _items_to_ignore.clear();
1053 Inkscape::Selection *sel = _desktop->selection;
1054 GSList const *items = sel->itemList();
1055 for (GSList *i = const_cast<GSList*>(items); i; i = i->next) {
1056 _items_to_ignore.push_back(static_cast<SPItem const *>(i->data));
1057 }
1058 }
1060 SPDocument *SnapManager::getDocument() const
1061 {
1062 return _named_view->document;
1063 }
1065 /**
1066 * \brief Takes an untransformed point, applies the given transformation, and returns the transformed point. Eliminates lots of duplicated code
1067 *
1068 * \param p The untransformed position of the point, paired with an identifier of the type of the snap source.
1069 * \param transformation_type Type of transformation to apply.
1070 * \param transformation Mathematical description of the transformation; details depend on the type.
1071 * \param origin Origin of the transformation, if applicable.
1072 * \param dim Dimension to which the transformation applies, if applicable.
1073 * \param uniform true if the transformation should be uniform; only applicable for stretching and scaling.
1074 * \return The position of the point after transformation
1075 */
1077 Geom::Point SnapManager::_transformPoint(Inkscape::SnapCandidatePoint const &p,
1078 Transformation const transformation_type,
1079 Geom::Point const &transformation,
1080 Geom::Point const &origin,
1081 Geom::Dim2 const dim,
1082 bool const uniform) const
1083 {
1084 /* Work out the transformed version of this point */
1085 Geom::Point transformed;
1086 switch (transformation_type) {
1087 case TRANSLATION:
1088 transformed = p.getPoint() + transformation;
1089 break;
1090 case SCALE:
1091 transformed = (p.getPoint() - origin) * Geom::Scale(transformation[Geom::X], transformation[Geom::Y]) + origin;
1092 break;
1093 case STRETCH:
1094 {
1095 Geom::Scale s(1, 1);
1096 if (uniform)
1097 s[Geom::X] = s[Geom::Y] = transformation[dim];
1098 else {
1099 s[dim] = transformation[dim];
1100 s[1 - dim] = 1;
1101 }
1102 transformed = ((p.getPoint() - origin) * s) + origin;
1103 break;
1104 }
1105 case SKEW:
1106 // Apply the skew factor
1107 transformed[dim] = (p.getPoint())[dim] + transformation[0] * ((p.getPoint())[1 - dim] - origin[1 - dim]);
1108 // While skewing, mirroring and scaling (by integer multiples) in the opposite direction is also allowed.
1109 // Apply that scale factor here
1110 transformed[1-dim] = (p.getPoint() - origin)[1 - dim] * transformation[1] + origin[1 - dim];
1111 break;
1112 default:
1113 g_assert_not_reached();
1114 }
1116 return transformed;
1117 }
1119 /**
1120 * \brief Mark the location of the snap source (not the snap target!) on the canvas by drawing a symbol
1121 *
1122 * \param point_type Category of points to which the source point belongs: node, guide or bounding box
1123 * \param p The transformed position of the source point, paired with an identifier of the type of the snap source.
1124 */
1126 void SnapManager::_displaySnapsource(Inkscape::SnapCandidatePoint const &p) const {
1128 Inkscape::Preferences *prefs = Inkscape::Preferences::get();
1129 if (prefs->getBool("/options/snapclosestonly/value")) {
1130 bool p_is_a_node = p.getSourceType() & Inkscape::SNAPSOURCE_NODE_CATEGORY;
1131 bool p_is_a_bbox = p.getSourceType() & Inkscape::SNAPSOURCE_BBOX_CATEGORY;
1133 if (snapprefs.getSnapEnabledGlobally() && ((p_is_a_node && snapprefs.getSnapModeNode()) || (p_is_a_bbox && snapprefs.getSnapModeBBox()))) {
1134 _desktop->snapindicator->set_new_snapsource(p);
1135 } else {
1136 _desktop->snapindicator->remove_snapsource();
1137 }
1138 }
1139 }
1141 /*
1142 Local Variables:
1143 mode:c++
1144 c-file-style:"stroustrup"
1145 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
1146 indent-tabs-mode:nil
1147 fill-column:99
1148 End:
1149 */
1150 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :