a6b91e07447a70ae60b306574516f22729e933b9
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 *
13 * Copyright (C) 2006-2007 Johan Engelen <johan@shouraizou.nl>
14 * Copyrigth (C) 2004 Nathan Hurst
15 * Copyright (C) 1999-2002 Authors
16 *
17 * Released under GNU GPL, read the file 'COPYING' for more information
18 */
20 #include <utility>
22 #include "sp-namedview.h"
23 #include "snap.h"
24 #include "snapped-line.h"
26 #include <libnr/nr-point-fns.h>
27 #include <libnr/nr-scale-ops.h>
28 #include <libnr/nr-values.h>
30 #include "display/canvas-grid.h"
32 #include "inkscape.h"
33 #include "desktop.h"
34 #include "sp-guide.h"
35 using std::vector;
37 /**
38 * Construct a SnapManager for a SPNamedView.
39 *
40 * \param v `Owning' SPNamedView.
41 */
43 SnapManager::SnapManager(SPNamedView const *v) :
44 guide(v, 0),
45 object(v, 0),
46 _named_view(v),
47 _include_item_center(false)
48 {
50 }
53 /**
54 * \return List of snappers that we use.
55 */
56 SnapManager::SnapperList
57 SnapManager::getSnappers() const
58 {
59 SnapManager::SnapperList s;
60 s.push_back(&guide);
61 s.push_back(&object);
63 SnapManager::SnapperList gs = getGridSnappers();
64 s.splice(s.begin(), gs);
66 return s;
67 }
69 /**
70 * \return List of gridsnappers that we use.
71 */
72 SnapManager::SnapperList
73 SnapManager::getGridSnappers() const
74 {
75 SnapperList s;
77 //FIXME: this code should actually do this: add new grid snappers that are active for this desktop. now it just adds all gridsnappers
78 SPDesktop* desktop = SP_ACTIVE_DESKTOP;
79 if (desktop && desktop->gridsEnabled()) {
80 for ( GSList const *l = _named_view->grids; l != NULL; l = l->next) {
81 Inkscape::CanvasGrid *grid = (Inkscape::CanvasGrid*) l->data;
82 s.push_back(grid->snapper);
83 }
84 }
86 return s;
87 }
89 /**
90 * \return true if one of the snappers will try to snap something.
91 */
93 bool SnapManager::SomeSnapperMightSnap() const
94 {
95 SnapperList const s = getSnappers();
96 SnapperList::const_iterator i = s.begin();
97 while (i != s.end() && (*i)->ThisSnapperMightSnap() == false) {
98 i++;
99 }
101 return (i != s.end());
102 }
104 /*
105 * The snappers have too many parameters to adjust individually. Therefore only
106 * two snapping modes are presented to the user: snapping bounding box corners (to
107 * other bounding boxes, grids or guides), and/or snapping nodes (to other nodes,
108 * paths, grids or guides). To select either of these modes (or both), use the
109 * methods defined below: setSnapModeBBox() and setSnapModeNode().
110 *
111 * */
114 void SnapManager::setSnapModeBBox(bool enabled)
115 {
116 //The default values are being set in sp_namedview_set() (in sp-namedview.cpp)
117 guide.setSnapFrom(Inkscape::Snapper::SNAPPOINT_BBOX, enabled);
119 for ( GSList const *l = _named_view->grids; l != NULL; l = l->next) {
120 Inkscape::CanvasGrid *grid = (Inkscape::CanvasGrid*) l->data;
121 grid->snapper->setSnapFrom(Inkscape::Snapper::SNAPPOINT_BBOX, enabled);
122 }
124 object.setSnapFrom(Inkscape::Snapper::SNAPPOINT_BBOX, enabled);
125 //object.setSnapToBBoxNode(enabled); // On second thought, these should be controlled
126 //object.setSnapToBBoxPath(enabled); // separately by the snapping prefs dialog
127 object.setStrictSnapping(true); //don't snap bboxes to nodes/paths and vice versa
128 }
130 bool SnapManager::getSnapModeBBox() const
131 {
132 return guide.getSnapFrom(Inkscape::Snapper::SNAPPOINT_BBOX);
133 }
135 void SnapManager::setSnapModeNode(bool enabled)
136 {
137 guide.setSnapFrom(Inkscape::Snapper::SNAPPOINT_NODE, enabled);
139 for ( GSList const *l = _named_view->grids; l != NULL; l = l->next) {
140 Inkscape::CanvasGrid *grid = (Inkscape::CanvasGrid*) l->data;
141 grid->snapper->setSnapFrom(Inkscape::Snapper::SNAPPOINT_NODE, enabled);
142 }
144 object.setSnapFrom(Inkscape::Snapper::SNAPPOINT_NODE, enabled);
145 //object.setSnapToItemNode(enabled); // On second thought, these should be controlled
146 //object.setSnapToItemPath(enabled); // separately by the snapping prefs dialog
147 object.setStrictSnapping(true);
148 }
150 bool SnapManager::getSnapModeNode() const
151 {
152 return guide.getSnapFrom(Inkscape::Snapper::SNAPPOINT_NODE);
153 }
155 void SnapManager::setSnapModeGuide(bool enabled)
156 {
157 object.setSnapFrom(Inkscape::Snapper::SNAPPOINT_GUIDE, enabled);
158 }
160 bool SnapManager::getSnapModeGuide() const
161 {
162 return object.getSnapFrom(Inkscape::Snapper::SNAPPOINT_GUIDE);
163 }
165 /**
166 * Try to snap a point to any interested snappers.
167 *
168 * \param t Type of point.
169 * \param p Point.
170 * \param it Item to ignore when snapping.
171 * \return Snapped point.
172 */
174 Inkscape::SnappedPoint SnapManager::freeSnap(Inkscape::Snapper::PointType t,
175 NR::Point const &p,
176 SPItem const *it) const
178 {
179 std::list<SPItem const *> lit;
180 lit.push_back(it);
182 std::vector<NR::Point> points_to_snap;
183 points_to_snap.push_back(p);
185 return freeSnap(t, p, true, points_to_snap, lit);
186 }
188 /**
189 * Try to snap a point to any of the specified snappers.
190 *
191 * \param t Type of point.
192 * \param p Point.
193 * \param first_point If true then this point is the first one from a whole bunch of points
194 * \param points_to_snap The whole bunch of points, all from the same selection and having the same transformation
195 * \param it List of items to ignore when snapping.
196 * \param snappers List of snappers to try to snap to
197 * \return Snapped point.
198 */
200 Inkscape::SnappedPoint SnapManager::freeSnap(Inkscape::Snapper::PointType t,
201 NR::Point const &p,
202 bool const &first_point,
203 std::vector<NR::Point> &points_to_snap,
204 std::list<SPItem const *> const &it) const
205 {
207 SnappedConstraints sc;
209 SnapperList const snappers = getSnappers();
211 for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) {
212 (*i)->freeSnap(sc, t, p, first_point, points_to_snap, it);
213 }
215 return findBestSnap(p, sc);
216 }
218 /**
219 * Try to snap a point to any interested snappers. A snap will only occur along
220 * a line described by a Inkscape::Snapper::ConstraintLine.
221 *
222 * \param t Type of point.
223 * \param p Point.
224 * \param c Constraint line.
225 * \param it Item to ignore when snapping.
226 * \return Snapped point.
227 */
229 Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::Snapper::PointType t,
230 NR::Point const &p,
231 Inkscape::Snapper::ConstraintLine const &c,
232 SPItem const *it) const
233 {
234 std::list<SPItem const *> lit;
235 lit.push_back(it);
237 std::vector<NR::Point> points_to_snap;
238 points_to_snap.push_back(p);
240 return constrainedSnap(t, p, true, points_to_snap, c, lit);
241 }
245 /**
246 * Try to snap a point to any interested snappers. A snap will only occur along
247 * a line described by a Inkscape::Snapper::ConstraintLine.
248 *
249 * \param t Type of point.
250 * \param p Point.
251 * \param first_point If true then this point is the first one from a whole bunch of points
252 * \param points_to_snap The whole bunch of points, all from the same selection and having the same transformation
253 * \param c Constraint line.
254 * \param it List of items to ignore when snapping.
255 * \return Snapped point.
256 */
258 Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::Snapper::PointType t,
259 NR::Point const &p,
260 bool const &first_point,
261 std::vector<NR::Point> &points_to_snap,
262 Inkscape::Snapper::ConstraintLine const &c,
263 std::list<SPItem const *> const &it) const
264 {
266 SnappedConstraints sc;
268 SnapperList const snappers = getSnappers();
269 for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) {
270 (*i)->constrainedSnap(sc, t, p, first_point, points_to_snap, c, it);
271 }
273 return findBestSnap(p, sc);
274 }
276 Inkscape::SnappedPoint SnapManager::guideSnap(NR::Point const &p,
277 NR::Point const &guide_normal) const
278 {
279 Inkscape::ObjectSnapper::DimensionToSnap snap_dim;
280 if (guide_normal == component_vectors[NR::Y]) {
281 snap_dim = Inkscape::ObjectSnapper::SNAP_Y;
282 } else if (guide_normal == component_vectors[NR::X]) {
283 snap_dim = Inkscape::ObjectSnapper::SNAP_X;
284 } else {
285 g_warning("WARNING: snapping of angled guides is not supported yet!");
286 snap_dim = Inkscape::ObjectSnapper::SNAP_XY;
287 }
289 SnappedConstraints sc;
290 object.guideSnap(sc, p, snap_dim);
292 return findBestSnap(p, sc);
293 }
296 /**
297 * Main internal snapping method, which is called by the other, friendlier, public
298 * methods. It's a bit hairy as it has lots of parameters, but it saves on a lot
299 * of duplicated code.
300 *
301 * \param type Type of points being snapped.
302 * \param points List of points to snap.
303 * \param ignore List of items to ignore while snapping.
304 * \param constrained true if the snap is constrained.
305 * \param constraint Constraint line to use, if `constrained' is true, otherwise undefined.
306 * \param transformation_type Type of transformation to apply to points before trying to snap them.
307 * \param transformation Description of the transformation; details depend on the type.
308 * \param origin Origin of the transformation, if applicable.
309 * \param dim Dimension of the transformation, if applicable.
310 * \param uniform true if the transformation should be uniform, if applicable.
311 */
313 std::pair<NR::Point, bool> SnapManager::_snapTransformed(
314 Inkscape::Snapper::PointType type,
315 std::vector<NR::Point> const &points,
316 std::list<SPItem const *> const &ignore,
317 bool constrained,
318 Inkscape::Snapper::ConstraintLine const &constraint,
319 Transformation transformation_type,
320 NR::Point const &transformation,
321 NR::Point const &origin,
322 NR::Dim2 dim,
323 bool uniform) const
324 {
325 /* We have a list of points, which we are proposing to transform in some way. We need to see
326 ** if any of these points, when transformed, snap to anything. If they do, we return the
327 ** appropriate transformation with `true'; otherwise we return the original scale with `false'.
328 */
330 /* Quick check to see if we have any snappers that are enabled */
331 if (SomeSnapperMightSnap() == false) {
332 return std::make_pair(transformation, false);
333 }
335 std::vector<NR::Point> transformed_points;
337 for (std::vector<NR::Point>::const_iterator i = points.begin(); i != points.end(); i++) {
339 /* Work out the transformed version of this point */
340 NR::Point transformed;
341 switch (transformation_type) {
342 case TRANSLATION:
343 transformed = *i + transformation;
344 break;
345 case SCALE:
346 transformed = ((*i - origin) * NR::scale(transformation[NR::X], transformation[NR::Y])) + origin;
347 break;
348 case STRETCH:
349 {
350 NR::scale s(1, 1);
351 if (uniform)
352 s[NR::X] = s[NR::Y] = transformation[dim];
353 else {
354 s[dim] = transformation[dim];
355 s[1 - dim] = 1;
356 }
357 transformed = ((*i - origin) * s) + origin;
358 break;
359 }
360 case SKEW:
361 transformed = *i;
362 transformed[dim] += transformation[dim] * ((*i)[1 - dim] - origin[1 - dim]);
363 break;
364 default:
365 g_assert_not_reached();
366 }
368 // add the current transformed point to the box hulling all transformed points
369 transformed_points.push_back(transformed);
370 }
372 /* The current best transformation */
373 NR::Point best_transformation = transformation;
375 /* The current best metric for the best transformation; lower is better, NR_HUGE
376 ** means that we haven't snapped anything.
377 */
378 double best_metric = NR_HUGE;
380 std::vector<NR::Point>::const_iterator j = transformed_points.begin();
382 // std::cout << std::endl;
384 for (std::vector<NR::Point>::const_iterator i = points.begin(); i != points.end(); i++) {
386 /* Snap it */
387 Inkscape::SnappedPoint const snapped = constrained ?
388 constrainedSnap(type, *j, i == points.begin(), transformed_points, constraint, ignore) : freeSnap(type, *j, i == points.begin(), transformed_points, ignore);
390 NR::Point result;
391 NR::Coord metric;
393 if (snapped.getDistance() < NR_HUGE) {
394 /* We snapped. Find the transformation that describes where the snapped point has
395 ** ended up, and also the metric for this transformation.
396 */
397 switch (transformation_type) {
398 case TRANSLATION:
399 result = snapped.getPoint() - *i;
400 /* Consider the case in which a box is almost aligned with a grid in both
401 * horizontal and vertical directions. The distance to the intersection of
402 * the grid lines will always be larger then the distance to a single grid
403 * line. If we prefer snapping to an intersection instead of to a single
404 * grid line, then we cannot use "metric = NR::L2(result)". Therefore the
405 * snapped distance will be used as a metric. Please note that the snapped
406 * distance is defined as the distance to the nearest line of the intersection,
407 * and not to the intersection itself!
408 */
409 metric = snapped.getDistance(); //used to be: metric = NR::L2(result);
410 break;
411 case SCALE:
412 {
413 NR::Point const a = (snapped.getPoint() - origin);
414 NR::Point const b = (*i - origin);
415 result = NR::Point(a[NR::X] / b[NR::X], a[NR::Y] / b[NR::Y]);
416 metric = std::abs(NR::L2(result) - NR::L2(transformation));
417 break;
418 }
419 case STRETCH:
420 {
421 for (int a = 0; a < 2; a++) {
422 if (uniform || a == dim) {
423 result[a] = (snapped.getPoint()[dim] - origin[dim]) / ((*i)[dim] - origin[dim]);
424 } else {
425 result[a] = 1;
426 }
427 }
428 metric = std::abs(result[dim] - transformation[dim]);
429 break;
430 }
431 case SKEW:
432 result[dim] = (snapped.getPoint()[dim] - (*i)[dim]) / ((*i)[1 - dim] - origin[1 - dim]);
433 metric = std::abs(result[dim] - transformation[dim]);
434 break;
435 default:
436 g_assert_not_reached();
437 }
439 /* Note it if it's the best so far */
440 if ((metric < best_metric) || ((metric == best_metric) && snapped.getAtIntersection() == true)) {
441 best_transformation = result;
442 best_metric = metric;
443 // std::cout << "SEL ";;
444 } //else { std::cout << " ";}
445 }
447 // std::cout << "P_orig = " << (*i) << " | metric = " << metric << " | distance = " << snapped.getDistance() << " | P_snap = " << snapped.getPoint() << std::endl;
448 j++;
449 }
451 // Using " < 1e6" instead of " < NR::HUGE" for catching some rounding errors
452 // These rounding errors might be caused by NRRects, see bug #1584301
453 return std::make_pair(best_transformation, best_metric < 1e6);
454 }
457 /**
458 * Try to snap a list of points to any interested snappers after they have undergone
459 * a translation.
460 *
461 * \param t Type of points.
462 * \param p Points.
463 * \param it List of items to ignore when snapping.
464 * \param tr Proposed translation.
465 * \return Snapped translation, if a snap occurred, and a flag indicating whether a snap occurred.
466 */
468 std::pair<NR::Point, bool> SnapManager::freeSnapTranslation(Inkscape::Snapper::PointType t,
469 std::vector<NR::Point> const &p,
470 std::list<SPItem const *> const &it,
471 NR::Point const &tr) const
472 {
473 return _snapTransformed(
474 t, p, it, false, NR::Point(), TRANSLATION, tr, NR::Point(), NR::X, false
475 );
476 }
479 /**
480 * Try to snap a list of points to any interested snappers after they have undergone a
481 * translation. A snap will only occur along a line described by a
482 * Inkscape::Snapper::ConstraintLine.
483 *
484 * \param t Type of points.
485 * \param p Points.
486 * \param it List of items to ignore when snapping.
487 * \param c Constraint line.
488 * \param tr Proposed translation.
489 * \return Snapped translation, if a snap occurred, and a flag indicating whether a snap occurred.
490 */
492 std::pair<NR::Point, bool> SnapManager::constrainedSnapTranslation(Inkscape::Snapper::PointType t,
493 std::vector<NR::Point> const &p,
494 std::list<SPItem const *> const &it,
495 Inkscape::Snapper::ConstraintLine const &c,
496 NR::Point const &tr) const
497 {
498 return _snapTransformed(
499 t, p, it, true, c, TRANSLATION, tr, NR::Point(), NR::X, false
500 );
501 }
504 /**
505 * Try to snap a list of points to any interested snappers after they have undergone
506 * a scale.
507 *
508 * \param t Type of points.
509 * \param p Points.
510 * \param it List of items to ignore when snapping.
511 * \param s Proposed scale.
512 * \param o Origin of proposed scale.
513 * \return Snapped scale, if a snap occurred, and a flag indicating whether a snap occurred.
514 */
516 std::pair<NR::scale, bool> SnapManager::freeSnapScale(Inkscape::Snapper::PointType t,
517 std::vector<NR::Point> const &p,
518 std::list<SPItem const *> const &it,
519 NR::scale const &s,
520 NR::Point const &o) const
521 {
522 return _snapTransformed(
523 t, p, it, false, NR::Point(), SCALE, NR::Point(s[NR::X], s[NR::Y]), o, NR::X, false
524 );
525 }
528 /**
529 * Try to snap a list of points to any interested snappers after they have undergone
530 * a scale. A snap will only occur along a line described by a
531 * Inkscape::Snapper::ConstraintLine.
532 *
533 * \param t Type of points.
534 * \param p Points.
535 * \param it List of items to ignore when snapping.
536 * \param s Proposed scale.
537 * \param o Origin of proposed scale.
538 * \return Snapped scale, if a snap occurred, and a flag indicating whether a snap occurred.
539 */
541 std::pair<NR::scale, bool> SnapManager::constrainedSnapScale(Inkscape::Snapper::PointType t,
542 std::vector<NR::Point> const &p,
543 std::list<SPItem const *> const &it,
544 Inkscape::Snapper::ConstraintLine const &c,
545 NR::scale const &s,
546 NR::Point const &o) const
547 {
548 return _snapTransformed(
549 t, p, it, true, c, SCALE, NR::Point(s[NR::X], s[NR::Y]), o, NR::X, false
550 );
551 }
554 /**
555 * Try to snap a list of points to any interested snappers after they have undergone
556 * a stretch.
557 *
558 * \param t Type of points.
559 * \param p Points.
560 * \param it List of items to ignore when snapping.
561 * \param s Proposed stretch.
562 * \param o Origin of proposed stretch.
563 * \param d Dimension in which to apply proposed stretch.
564 * \param u true if the stretch should be uniform (ie to be applied equally in both dimensions)
565 * \return Snapped stretch, if a snap occurred, and a flag indicating whether a snap occurred.
566 */
568 std::pair<NR::Coord, bool> SnapManager::freeSnapStretch(Inkscape::Snapper::PointType t,
569 std::vector<NR::Point> const &p,
570 std::list<SPItem const *> const &it,
571 NR::Coord const &s,
572 NR::Point const &o,
573 NR::Dim2 d,
574 bool u) const
575 {
576 std::pair<NR::Point, bool> const r = _snapTransformed(
577 t, p, it, false, NR::Point(), STRETCH, NR::Point(s, s), o, d, u
578 );
580 return std::make_pair(r.first[d], r.second);
581 }
584 /**
585 * Try to snap a list of points to any interested snappers after they have undergone
586 * a skew.
587 *
588 * \param t Type of points.
589 * \param p Points.
590 * \param it List of items to ignore when snapping.
591 * \param s Proposed skew.
592 * \param o Origin of proposed skew.
593 * \param d Dimension in which to apply proposed skew.
594 * \return Snapped skew, if a snap occurred, and a flag indicating whether a snap occurred.
595 */
597 std::pair<NR::Coord, bool> SnapManager::freeSnapSkew(Inkscape::Snapper::PointType t,
598 std::vector<NR::Point> const &p,
599 std::list<SPItem const *> const &it,
600 NR::Coord const &s,
601 NR::Point const &o,
602 NR::Dim2 d) const
603 {
604 std::pair<NR::Point, bool> const r = _snapTransformed(
605 t, p, it, false, NR::Point(), SKEW, NR::Point(s, s), o, d, false
606 );
608 return std::make_pair(r.first[d], r.second);
609 }
611 Inkscape::SnappedPoint SnapManager::findBestSnap(NR::Point const &p, SnappedConstraints &sc) const
612 {
613 NR::Coord const guide_sens = guide.getDistance();
614 NR::Coord grid_sens = 0;
616 SnapManager::SnapperList const gs = getGridSnappers();
617 SnapperList::const_iterator i = gs.begin();
618 if (i != gs.end()) {
619 grid_sens = (*i)->getDistance();
620 }
622 // Store all snappoints, optionally together with their specific snapping range
623 std::list<std::pair<Inkscape::SnappedPoint, NR::Coord> > sp_list;
624 // Most of these snapped points are already within the snapping range, because
625 // they have already been filtered by their respective snappers. In that case
626 // we can set the snapping range to NR_HUGE here. If however we're looking at
627 // intersections of e.g. a grid and guide line, then we'll have to determine
628 // once again whether we're within snapping range. In this case we will set
629 // the snapping range to e.g. min(guide_sens, grid_sens)
631 // search for the closest snapped point
632 Inkscape::SnappedPoint closestPoint;
633 if (getClosestSP(sc.points, closestPoint)) {
634 sp_list.push_back(std::make_pair(closestPoint, NR_HUGE));
635 }
637 // search for the closest snapped line segment
638 Inkscape::SnappedLineSegment closestLineSegment;
639 if (getClosestSLS(sc.lines, closestLineSegment)) {
640 sp_list.push_back(std::make_pair(Inkscape::SnappedPoint(closestLineSegment), NR_HUGE));
641 }
643 if (_intersectionLS) {
644 // search for the closest snapped intersection of line segments
645 Inkscape::SnappedPoint closestLineSegmentIntersection;
646 if (getClosestIntersectionSLS(sc.lines, closestLineSegmentIntersection)) {
647 sp_list.push_back(std::make_pair(closestLineSegmentIntersection, NR_HUGE));
648 }
649 }
651 // search for the closest snapped grid line
652 Inkscape::SnappedLine closestGridLine;
653 if (getClosestSL(sc.grid_lines, closestGridLine)) {
654 sp_list.push_back(std::make_pair(Inkscape::SnappedPoint(closestGridLine), NR_HUGE));
655 }
657 // search for the closest snapped guide line
658 Inkscape::SnappedLine closestGuideLine;
659 if (getClosestSL(sc.guide_lines, closestGuideLine)) {
660 sp_list.push_back(std::make_pair(Inkscape::SnappedPoint(closestGuideLine), NR_HUGE));
661 }
663 // search for the closest snapped intersection of grid lines
664 Inkscape::SnappedPoint closestGridPoint;
665 if (getClosestIntersectionSL(sc.grid_lines, closestGridPoint)) {
666 sp_list.push_back(std::make_pair(closestGridPoint, NR_HUGE));
667 }
669 // search for the closest snapped intersection of guide lines
670 Inkscape::SnappedPoint closestGuidePoint;
671 if (getClosestIntersectionSL(sc.guide_lines, closestGuidePoint)) {
672 sp_list.push_back(std::make_pair(closestGuidePoint, NR_HUGE));
673 }
675 // search for the closest snapped intersection of grid with guide lines
676 if (_intersectionGG) {
677 Inkscape::SnappedPoint closestGridGuidePoint;
678 if (getClosestIntersectionSL(sc.grid_lines, sc.guide_lines, closestGridGuidePoint)) {
679 sp_list.push_back(std::make_pair(closestGridGuidePoint, std::min(guide_sens, grid_sens)));
680 }
681 }
683 // now let's see which snapped point gets a thumbs up
684 Inkscape::SnappedPoint bestPoint(p, NR_HUGE);
685 for (std::list<std::pair<Inkscape::SnappedPoint, NR::Coord> >::const_iterator i = sp_list.begin(); i != sp_list.end(); i++) {
686 // first find out if this snapped point is within snapping range
687 if ((*i).first.getDistance() <= (*i).second) {
688 // if it's the first point
689 bool c1 = (i == sp_list.begin());
690 // or, if it's closer
691 bool c2 = (*i).first.getDistance() < bestPoint.getDistance();
692 // or, if it's just as close but at an intersection
693 bool c3 = ((*i).first.getDistance() == bestPoint.getDistance()) && (*i).first.getAtIntersection();
694 // then prefer this point over the previous one
695 if (c1 || c2 || c3) {
696 bestPoint = (*i).first;
697 }
698 }
699 }
700 return bestPoint;
701 }
703 /*
704 Local Variables:
705 mode:c++
706 c-file-style:"stroustrup"
707 c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
708 indent-tabs-mode:nil
709 fill-column:99
710 End:
711 */
712 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:encoding=utf-8:textwidth=99 :