Code

Mnemonics in "Fill and stroke", "Align and distribute", and "Transform" dialogs ...
[inkscape.git] / src / object-snapper.cpp
index 67b465d034f60787cfe2cc08665bfb6530bbdce3..43651f002405e12ced35ea1743a6862668ec5bfb 100644 (file)
@@ -4,14 +4,22 @@
  *
  * Authors:
  *   Carl Hetherington <inkscape@carlh.net>
+ *   Diederik van Lierop <mail@diedenrezi.nl>
+ *   Jon A. Cruz <jon@joncruz.org>
+ *   Abhishek Sharma
  *
- * Copyright (C) 2005 Authors
+ * Copyright (C) 2005 - 2010 Authors
  *
  * Released under GNU GPL, read the file 'COPYING' for more information
  */
 
-#include "libnr/n-art-bpath.h"
-#include "libnr/nr-rect-ops.h"
+#include "svg/svg.h"
+#include <2geom/path-intersection.h>
+#include <2geom/pathvector.h>
+#include <2geom/point.h>
+#include <2geom/rect.h>
+#include <2geom/line.h>
+#include <2geom/circle.h>
 #include "document.h"
 #include "sp-namedview.h"
 #include "sp-image.h"
 #include "sp-item.h"
 #include "sp-use.h"
 #include "display/curve.h"
-#include "desktop.h"
 #include "inkscape.h"
-#include "prefs-utils.h"
+#include "preferences.h"
 #include "sp-text.h"
 #include "sp-flowtext.h"
 #include "text-editing.h"
+#include "sp-clippath.h"
+#include "sp-mask.h"
+#include "helper/geom-curves.h"
+#include "desktop.h"
 
-Inkscape::ObjectSnapper::ObjectSnapper(SPNamedView const *nv, NR::Coord const d)
-    : Snapper(nv, d), _snap_to_itemnode(true), _snap_to_itempath(true),
-    _snap_to_bboxnode(true), _snap_to_bboxpath(true), _strict_snapping(true),
-    _include_item_center(false)
+Inkscape::ObjectSnapper::ObjectSnapper(SnapManager *sm, Geom::Coord const d)
+    : Snapper(sm, d)
 {
-    _candidates = new std::vector<SPItem*>;
-    _points_to_snap_to = new std::vector<NR::Point>;
-    _paths_to_snap_to = new std::vector<Path*>;
+    _candidates = new std::vector<SnapCandidateItem>;
+    _points_to_snap_to = new std::vector<Inkscape::SnapCandidatePoint>;
+    _paths_to_snap_to = new std::vector<Inkscape::SnapCandidatePath >;
 }
 
 Inkscape::ObjectSnapper::~ObjectSnapper()
 {
-    _candidates->clear(); //Don't delete the candidates themselves, as these are not ours!
+    _candidates->clear();
     delete _candidates;
 
     _points_to_snap_to->clear();
     delete _points_to_snap_to;
 
-    for (std::vector<Path*>::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
-        delete *k;
-    }
-    _paths_to_snap_to->clear();
+    _clear_paths();
     delete _paths_to_snap_to;
 }
 
 /**
- *    Find all items within snapping range.
- *     \param r Pointer to the current document
+ *  \return Snap tolerance (desktop coordinates); depends on current zoom so that it's always the same in screen pixels
+ */
+Geom::Coord Inkscape::ObjectSnapper::getSnapperTolerance() const
+{
+    SPDesktop const *dt = _snapmanager->getDesktop();
+    double const zoom =  dt ? dt->current_zoom() : 1;
+    return _snapmanager->snapprefs.getObjectTolerance() / zoom;
+}
+
+bool Inkscape::ObjectSnapper::getSnapperAlwaysSnap() const
+{
+    return _snapmanager->snapprefs.getObjectTolerance() == 10000; //TODO: Replace this threshold of 10000 by a constant; see also tolerance-slider.cpp
+}
+
+/**
+ *  Find all items within snapping range.
+ *  \param parent Pointer to the document's root, or to a clipped path or mask object
  *  \param it List of items to ignore
- *  \param first_point If true then this point is the first one from a whole bunch of points
- *  \param points_to_snap The whole bunch of points, all from the same selection and having the same transformation
- *  \param DimensionToSnap Snap in X, Y, or both directions.
+ *  \param bbox_to_snap Bounding box hulling the whole bunch of points, all from the same selection and having the same transformation
  */
 
-void Inkscape::ObjectSnapper::_findCandidates(SPObject* r,
-                                              std::list<SPItem const *> const &it,
+void Inkscape::ObjectSnapper::_findCandidates(SPObject* parent,
+                                              std::vector<SPItem const *> const *it,
                                               bool const &first_point,
-                                              std::vector<NR::Point> &points_to_snap,
-                                              DimensionToSnap const snap_dim) const
+                                              Geom::Rect const &bbox_to_snap,
+                                              bool const clip_or_mask,
+                                              Geom::Matrix const additional_affine) const // transformation of the item being clipped / masked
 {
-    if (ThisSnapperMightSnap()) {
-        SPDesktop const *desktop = SP_ACTIVE_DESKTOP;
+    if (!ThisSnapperMightSnap()) {
+        return;
+    }
 
-        if (first_point) {
-            _candidates->clear();
-        }
+    if (_snapmanager->getDesktop() == NULL) {
+        g_warning("desktop == NULL, so we cannot snap; please inform the developpers of this bug");
+        // Apparently the etup() method from the SnapManager class hasn't been called before trying to snap.
+    }
 
-        for (SPObject* o = sp_object_first_child(r); o != NULL; o = SP_OBJECT_NEXT(o)) {
-            if (SP_IS_ITEM(o) && !SP_ITEM(o)->isLocked() && !desktop->itemIsHidden(SP_ITEM(o))) {
+    if (first_point) {
+        _candidates->clear();
+    }
 
-                /* See if this item is on the ignore list */
-                std::list<SPItem const *>::const_iterator i = it.begin();
-                while (i != it.end() && *i != o) {
+    Geom::Rect bbox_to_snap_incl = bbox_to_snap; // _incl means: will include the snapper tolerance
+    bbox_to_snap_incl.expandBy(getSnapperTolerance()); // see?
+
+    for ( SPObject *o = parent->firstChild(); o; o = o->getNext() ) {
+        g_assert(_snapmanager->getDesktop() != NULL);
+        if (SP_IS_ITEM(o) && !(_snapmanager->getDesktop()->itemIsHidden(SP_ITEM(o)) && !clip_or_mask)) {
+            // Snapping to items in a locked layer is allowed
+            // Don't snap to hidden objects, unless they're a clipped path or a mask
+            /* See if this item is on the ignore list */
+            std::vector<SPItem const *>::const_iterator i;
+            if (it != NULL) {
+                i = it->begin();
+                while (i != it->end() && *i != o) {
                     i++;
                 }
+            }
+
+            if (it == NULL || i == it->end()) {
+                SPItem *item = SP_ITEM(o);
+                if (item) {
+                    SPObject *obj = NULL;
+                    if (!clip_or_mask) { // cannot clip or mask more than once
+                        // The current item is not a clipping path or a mask, but might
+                        // still be the subject of clipping or masking itself ; if so, then
+                        // we should also consider that path or mask for snapping to
+                        obj = SP_OBJECT(item->clip_ref->getObject());
+                        if (obj) {
+                            _findCandidates(obj, it, false, bbox_to_snap, true, item->i2doc_affine());
+                        }
+                        obj = SP_OBJECT(item->mask_ref->getObject());
+                        if (obj) {
+                            _findCandidates(obj, it, false, bbox_to_snap, true, item->i2doc_affine());
+                        }
+                    }
+                }
 
-                if (i == it.end()) {
-                    /* See if the item is within range */
-                    if (SP_IS_GROUP(o)) {
-                        _findCandidates(o, it, false, points_to_snap, snap_dim);
+                if (SP_IS_GROUP(o)) {
+                    _findCandidates(o, it, false, bbox_to_snap, clip_or_mask, additional_affine);
+                } else {
+                    Geom::OptRect bbox_of_item = Geom::Rect();
+                    if (clip_or_mask) {
+                        // Oh oh, this will get ugly. We cannot use sp_item_i2d_affine directly because we need to
+                        // insert an additional transformation in document coordinates (code copied from sp_item_i2d_affine)
+                        item->invoke_bbox(bbox_of_item,
+                            item->i2doc_affine() * additional_affine * _snapmanager->getDesktop()->doc2dt(),
+                            true);
                     } else {
-                        // Now let's see if any of the snapping points is within
-                        // snapping range of this object
-                        NR::Maybe<NR::Rect> b = sp_item_bbox_desktop(SP_ITEM(o));
-                        if (b) {
-                            for (std::vector<NR::Point>::const_iterator i = points_to_snap.begin(); i != points_to_snap.end(); i++) {
-                                NR::Point b_min = b->min();
-                                NR::Point b_max = b->max();
-                                double d = getDistance();
-                                bool withinX = ((*i)[NR::X] >= b_min[NR::X] - d) && ((*i)[NR::X] <= b_max[NR::X] + d);
-                                bool withinY = ((*i)[NR::Y] >= b_min[NR::Y] - d) && ((*i)[NR::Y] <= b_max[NR::Y] + d);
-                                if (snap_dim == SNAP_X && withinX || snap_dim == SNAP_Y && withinY || snap_dim == SNAP_XY && withinX && withinY) {
-                                    //We've found a point that is within snapping range
-                                    //of this object, so record it as a candidate
-                                    _candidates->push_back(SP_ITEM(o));
-                                    break;
-                                }
-                            }
+                        item->invoke_bbox( bbox_of_item, item->i2d_affine(), true);
+                    }
+                    if (bbox_of_item) {
+                        // See if the item is within range
+                        if (bbox_to_snap_incl.intersects(*bbox_of_item)
+                                || (_snapmanager->snapprefs.getIncludeItemCenter() && bbox_to_snap_incl.contains(item->getCenter()))) { // rotation center might be outside of the bounding box
+                            // This item is within snapping range, so record it as a candidate
+                            _candidates->push_back(SnapCandidateItem(item, clip_or_mask, additional_affine));
+                            // For debugging: print the id of the candidate to the console
+                            // SPObject *obj = (SPObject*)item;
+                            // std::cout << "Snap candidate added: " << obj->getId() << std::endl;
                         }
                     }
                 }
@@ -113,140 +166,235 @@ void Inkscape::ObjectSnapper::_findCandidates(SPObject* r,
 }
 
 
-bool Inkscape::ObjectSnapper::_snapNodes(Inkscape::Snapper::PointType const &t,
-                                         Inkscape::SnappedPoint &s,
-                                         NR::Point const &p,
-                                         bool const &first_point,
-                                         DimensionToSnap const snap_dim) const
+void Inkscape::ObjectSnapper::_collectNodes(Inkscape::SnapSourceType const &t,
+                                            bool const &first_point) const
 {
-    bool success = false;
-
-    // Determine the type of bounding box we should snap to
-    SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
-    if (_snap_to_bboxnode) {
-        gchar const *prefs_bbox = prefs_get_string_attribute("tools.select", "bounding_box");
-        bbox_type = (prefs_bbox != NULL && strcmp(prefs_bbox, "geometric")==0)? SPItem::GEOMETRIC_BBOX : SPItem::APPROXIMATE_BBOX;
-    }
-
-    bool p_is_a_node = t & Inkscape::Snapper::SNAPPOINT_NODE;
-    bool p_is_a_bbox = t & Inkscape::Snapper::SNAPPOINT_BBOX;
-    bool p_is_a_guide = t & Inkscape::Snapper::SNAPPOINT_GUIDE;
-
-    // A point considered for snapping should be either a node, a bbox corner or a guide. Pick only ONE!
-    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));
-
     // Now, let's first collect all points to snap to. If we have a whole bunch of points to snap,
     // e.g. when translating an item using the selector tool, then we will only do this for the
-    // first point and store the collection for later use. This dramatically improves the performance
+    // first point and store the collection for later use. This significantly improves the performance
     if (first_point) {
         _points_to_snap_to->clear();
-        for (std::vector<SPItem*>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
-            //NR::Matrix i2doc(NR::identity());
-            SPItem *root_item = *i;
-            if (SP_IS_USE(*i)) {
-                root_item = sp_use_root(SP_USE(*i));
+
+         // Determine the type of bounding box we should snap to
+        SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
+
+        bool p_is_a_node = t & Inkscape::SNAPSOURCE_NODE_CATEGORY;
+        bool p_is_a_bbox = t & Inkscape::SNAPSOURCE_BBOX_CATEGORY;
+        bool p_is_other = t & Inkscape::SNAPSOURCE_OTHER_CATEGORY;
+
+        // A point considered for snapping should be either a node, a bbox corner or a guide. Pick only ONE!
+        g_assert(!((p_is_a_node && p_is_a_bbox) || (p_is_a_bbox && p_is_other) || (p_is_a_node && p_is_other)));
+
+        if (_snapmanager->snapprefs.getSnapToBBoxNode() || _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() || _snapmanager->snapprefs.getSnapBBoxMidpoints()) {
+            Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+            bool prefs_bbox = prefs->getBool("/tools/bounding_box");
+            bbox_type = !prefs_bbox ?
+                SPItem::APPROXIMATE_BBOX : SPItem::GEOMETRIC_BBOX;
+        }
+
+        // Consider the page border for snapping to
+        if (_snapmanager->snapprefs.getSnapToPageBorder()) {
+            _getBorderNodes(_points_to_snap_to);
+        }
+
+        for (std::vector<SnapCandidateItem>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
+            //Geom::Matrix i2doc(Geom::identity());
+            SPItem *root_item = (*i).item;
+            if (SP_IS_USE((*i).item)) {
+                root_item = sp_use_root(SP_USE((*i).item));
             }
+            g_return_if_fail(root_item);
 
             //Collect all nodes so we can snap to them
-            if (_snap_to_itemnode) {
-                if (!(_strict_snapping && !p_is_a_node) || p_is_a_guide) {
-                    sp_item_snappoints(root_item, _include_item_center, SnapPointsIter(*_points_to_snap_to));
+            if (p_is_a_node || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_node) || p_is_other) {
+                // Note: there are two ways in which intersections are considered:
+                // Method 1: Intersections are calculated for each shape individually, for both the
+                //           snap source and snap target (see sp_shape_snappoints)
+                // Method 2: Intersections are calculated for each curve or line that we've snapped to, i.e. only for
+                //           the target (see the intersect() method in the SnappedCurve and SnappedLine classes)
+                // Some differences:
+                // - Method 1 doesn't find intersections within a set of multiple objects
+                // - Method 2 only works for targets
+                // When considering intersections as snap targets:
+                // - Method 1 only works when snapping to nodes, whereas
+                // - Method 2 only works when snapping to paths
+                // - There will be performance differences too!
+                // If both methods are being used simultaneously, then this might lead to duplicate targets!
+
+                // Well, here we will be looking for snap TARGETS. Both methods can therefore be used.
+                // When snapping to paths, we will get a collection of snapped lines and snapped curves. findBestSnap() will
+                // go hunting for intersections (but only when asked to in the prefs of course). In that case we can just
+                // temporarily block the intersections in sp_item_snappoints, we don't need duplicates. If we're not snapping to
+                // paths though but only to item nodes then we should still look for the intersections in sp_item_snappoints()
+                bool old_pref = _snapmanager->snapprefs.getSnapIntersectionCS();
+                if (_snapmanager->snapprefs.getSnapToItemPath()) {
+                    _snapmanager->snapprefs.setSnapIntersectionCS(false);
                 }
-            }
 
-            //Collect the bounding box's corners so we can snap to them
-            if (_snap_to_bboxnode) {
-                if (!(_strict_snapping && !p_is_a_bbox) || p_is_a_guide) {
-                    NR::Maybe<NR::Rect> b = sp_item_bbox_desktop(root_item, bbox_type);
-                    if (b) {
-                        for ( unsigned k = 0 ; k < 4 ; k++ ) {
-                            _points_to_snap_to->push_back(b->corner(k));
+                // We should not snap a transformation center to any of the centers of the items in the
+                // current selection (see the comment in SelTrans::centerRequest())
+                bool old_pref2 = _snapmanager->snapprefs.getIncludeItemCenter();
+                if (old_pref2) {
+                    for ( GSList const *itemlist = _snapmanager->getRotationCenterSource(); itemlist != NULL; itemlist = g_slist_next(itemlist) ) {
+                        if ((*i).item == reinterpret_cast<SPItem*>(itemlist->data)) {
+                            // don't snap to this item's rotation center
+                            _snapmanager->snapprefs.setIncludeItemCenter(false);
+                            break;
                         }
                     }
                 }
+
+                root_item->getSnappoints(*_points_to_snap_to, &_snapmanager->snapprefs);
+
+                // restore the original snap preferences
+                _snapmanager->snapprefs.setSnapIntersectionCS(old_pref);
+                _snapmanager->snapprefs.setIncludeItemCenter(old_pref2);
+            }
+
+            //Collect the bounding box's corners so we can snap to them
+            if (p_is_a_bbox || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_bbox) || p_is_other) {
+                // Discard the bbox of a clipped path / mask, because we don't want to snap to both the bbox
+                // of the item AND the bbox of the clipping path at the same time
+                if (!(*i).clip_or_mask) {
+                    Geom::OptRect b = root_item->getBboxDesktop(bbox_type);
+                    getBBoxPoints(b, _points_to_snap_to, true, _snapmanager->snapprefs.getSnapToBBoxNode(), _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints(), _snapmanager->snapprefs.getSnapBBoxMidpoints());
+                }
             }
         }
     }
+}
+
+void Inkscape::ObjectSnapper::_snapNodes(SnappedConstraints &sc,
+                                         Inkscape::SnapCandidatePoint const &p,
+                                         std::vector<SnapCandidatePoint> *unselected_nodes,
+                                         SnapConstraint const &c,
+                                         Geom::Point const &p_proj_on_constraint) const
+{
+    // Iterate through all nodes, find out which one is the closest to p, and snap to it!
+
+    _collectNodes(p.getSourceType(), p.getSourceNum() <= 0);
+
+    if (unselected_nodes != NULL && unselected_nodes->size() > 0) {
+        g_assert(_points_to_snap_to != NULL);
+        _points_to_snap_to->insert(_points_to_snap_to->end(), unselected_nodes->begin(), unselected_nodes->end());
+    }
 
-    //Do the snapping, using all the nodes and corners collected above
-    for (std::vector<NR::Point>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {
-        /* Try to snap to this node of the path */
-        NR::Coord dist = NR_HUGE;
-        NR::Point snapped_point;
-        switch (snap_dim) {
-            case SNAP_X:
-                dist = fabs((*k)[NR::X] - p[NR::X]);
-                snapped_point = NR::Point((*k)[NR::X], p[NR::Y]);
-                break;
-            case SNAP_Y:
-                dist = fabs((*k)[NR::Y] - p[NR::Y]);
-                snapped_point = NR::Point(p[NR::X], (*k)[NR::Y]);
-                break;
-            case SNAP_XY:
-                dist = NR::L2(*k - p);
-                snapped_point = *k;
-                break;
+    SnappedPoint s;
+    bool success = false;
+
+    for (std::vector<SnapCandidatePoint>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {
+        Geom::Point target_pt = (*k).getPoint();
+        Geom::Coord dist = NR_HUGE;
+        if (!c.isUndefined()) {
+            // We're snapping to nodes along a constraint only, so find out if this node
+            // is at the constraint, while allowing for a small margin
+            if (Geom::L2(target_pt - c.projection(target_pt)) > 1e-9) {
+                // The distance from the target point to its projection on the constraint
+                // is too large, so this point is not on the constraint. Skip it!
+                continue;
+            }
+            dist = Geom::L2(target_pt - p_proj_on_constraint);
+        } else {
+            // Free (unconstrained) snapping
+            dist = Geom::L2(target_pt - p.getPoint());
         }
 
-        if (dist < getDistance() && dist < s.getDistance()) {
-            s = SnappedPoint(snapped_point, dist);
+        if (dist < getSnapperTolerance() && dist < s.getSnapDistance()) {
+            s = SnappedPoint(target_pt, p.getSourceType(), p.getSourceNum(), (*k).getTargetType(), dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, true, (*k).getTargetBBox());
             success = true;
         }
     }
 
-    return success;
+    if (success) {
+        sc.points.push_back(s);
+    }
 }
 
-
-bool Inkscape::ObjectSnapper::_snapPaths(Inkscape::Snapper::PointType const &t,
-                                         Inkscape::SnappedPoint &s,
-                                         NR::Point const &p,
-                                         bool const &first_point) const
+void Inkscape::ObjectSnapper::_snapTranslatingGuide(SnappedConstraints &sc,
+                                         Geom::Point const &p,
+                                         Geom::Point const &guide_normal) const
 {
-    bool success = false;
-    /* FIXME: this seems like a hack.  Perhaps Snappers should be
-    ** in SPDesktop rather than SPNamedView?
-    */
-    SPDesktop const *desktop = SP_ACTIVE_DESKTOP;
-
-    NR::Point const p_doc = desktop->dt2doc(p);
-
-    // Determine the type of bounding box we should snap to
-    SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
-    if (_snap_to_bboxpath) {
-        gchar const *prefs_bbox = prefs_get_string_attribute("tools.select", "bounding_box");
-        bbox_type = (prefs_bbox != NULL && strcmp(prefs_bbox, "geometric")==0)? SPItem::GEOMETRIC_BBOX : SPItem::APPROXIMATE_BBOX;
+    // Iterate through all nodes, find out which one is the closest to this guide, and snap to it!
+    _collectNodes(SNAPSOURCE_GUIDE, true);
+
+    if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
+        _collectPaths(p, SNAPSOURCE_GUIDE, true);
+        _snapPaths(sc, Inkscape::SnapCandidatePoint(p, SNAPSOURCE_GUIDE), NULL, NULL);
+    }
+
+    SnappedPoint s;
+
+    Geom::Coord tol = getSnapperTolerance();
+
+    for (std::vector<SnapCandidatePoint>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); k++) {
+        Geom::Point target_pt = (*k).getPoint();
+        // Project each node (*k) on the guide line (running through point p)
+        Geom::Point p_proj = Geom::projection(target_pt, Geom::Line(p, p + Geom::rot90(guide_normal)));
+        Geom::Coord dist = Geom::L2(target_pt - p_proj); // distance from node to the guide
+        Geom::Coord dist2 = Geom::L2(p - p_proj); // distance from projection of node on the guide, to the mouse location
+        if ((dist < tol && dist2 < tol) || getSnapperAlwaysSnap()) {
+            s = SnappedPoint(target_pt, SNAPSOURCE_GUIDE, 0, (*k).getTargetType(), dist, tol, getSnapperAlwaysSnap(), false, true, (*k).getTargetBBox());
+            sc.points.push_back(s);
+        }
     }
+}
 
-    bool p_is_a_node = t & Inkscape::Snapper::SNAPPOINT_NODE;
 
+/**
+ * Returns index of first NR_END bpath in array.
+ */
+
+void Inkscape::ObjectSnapper::_collectPaths(Geom::Point /*p*/,
+                                         Inkscape::SnapSourceType const source_type,
+                                         bool const &first_point) const
+{
     // Now, let's first collect all paths to snap to. If we have a whole bunch of points to snap,
     // e.g. when translating an item using the selector tool, then we will only do this for the
-    // first point and store the collection for later use. This dramatically improves the performance
+    // first point and store the collection for later use. This significantly improves the performance
     if (first_point) {
-        for (std::vector<Path*>::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
-            delete *k;
+        _clear_paths();
+
+        // Determine the type of bounding box we should snap to
+        SPItem::BBoxType bbox_type = SPItem::GEOMETRIC_BBOX;
+
+        bool p_is_a_node = source_type & Inkscape::SNAPSOURCE_NODE_CATEGORY;
+        bool p_is_other = source_type & Inkscape::SNAPSOURCE_OTHER_CATEGORY;
+
+        if (_snapmanager->snapprefs.getSnapToBBoxPath()) {
+            Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+            int prefs_bbox = prefs->getBool("/tools/bounding_box", 0);
+            bbox_type = !prefs_bbox ?
+                SPItem::APPROXIMATE_BBOX : SPItem::GEOMETRIC_BBOX;
+        }
+
+        // Consider the page border for snapping
+        if (_snapmanager->snapprefs.getSnapToPageBorder() && _snapmanager->snapprefs.getSnapModeBBoxOrNodes()) {
+            Geom::PathVector *border_path = _getBorderPathv();
+            if (border_path != NULL) {
+                _paths_to_snap_to->push_back(Inkscape::SnapCandidatePath(border_path, SNAPTARGET_PAGE_BORDER, Geom::OptRect()));
+            }
         }
-        _paths_to_snap_to->clear();
-        for (std::vector<SPItem*>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
+
+        for (std::vector<SnapCandidateItem>::const_iterator i = _candidates->begin(); i != _candidates->end(); i++) {
 
             /* Transform the requested snap point to this item's coordinates */
-            NR::Matrix i2doc(NR::identity());
+            Geom::Matrix i2doc(Geom::identity());
             SPItem *root_item = NULL;
             /* We might have a clone at hand, so make sure we get the root item */
-            if (SP_IS_USE(*i)) {
-                i2doc = sp_use_get_root_transform(SP_USE(*i));
-                root_item = sp_use_root(SP_USE(*i));
+            if (SP_IS_USE((*i).item)) {
+                i2doc = sp_use_get_root_transform(SP_USE((*i).item));
+                root_item = sp_use_root(SP_USE((*i).item));
+                g_return_if_fail(root_item);
             } else {
-                i2doc = sp_item_i2doc_affine(*i);
-                root_item = *i;
+                i2doc = (*i).item->i2doc_affine();
+                root_item = (*i).item;
             }
 
             //Build a list of all paths considered for snapping to
 
             //Add the item's path to snap to
-            if (_snap_to_itempath) {
-                if (!(_strict_snapping && !p_is_a_node)) {
+            if (_snapmanager->snapprefs.getSnapToItemPath() && _snapmanager->snapprefs.getSnapModeNode()) {
+                if (p_is_other || !(_snapmanager->snapprefs.getStrictSnapping() && !p_is_a_node)) {
                     // Snapping to the path of characters is very cool, but for a large
                     // chunk of text this will take ages! So limit snapping to text paths
                     // containing max. 240 characters. Snapping the bbox will not be affected
@@ -266,134 +414,375 @@ bool Inkscape::ObjectSnapper::_snapPaths(Inkscape::Snapper::PointType const &t,
                         very_complex_path = sp_nodes_in_path(SP_PATH(root_item)) > 500;
                     }
 
-                     if (!very_lenghty_prose && !very_complex_path) {
-                        _paths_to_snap_to->push_back(Path_for_item(root_item, true, true));
-                     }
+                    if (!very_lenghty_prose && !very_complex_path) {
+                        SPCurve *curve = curve_for_item(root_item);
+                        if (curve) {
+                            // We will get our own copy of the pathvector, which must be freed at some point
+
+                            // Geom::PathVector *pv = pathvector_for_curve(root_item, curve, true, true, Geom::identity(), (*i).additional_affine);
+
+                            Geom::PathVector *pv = new Geom::PathVector(curve->get_pathvector());
+                            (*pv) *= root_item->i2d_affine() * (*i).additional_affine * _snapmanager->getDesktop()->doc2dt(); // (_edit_transform * _i2d_transform);
+
+                            _paths_to_snap_to->push_back(Inkscape::SnapCandidatePath(pv, SNAPTARGET_PATH, Geom::OptRect())); // Perhaps for speed, get a reference to the Geom::pathvector, and store the transformation besides it.
+                            curve->unref();
+                        }
+                    }
                 }
             }
 
             //Add the item's bounding box to snap to
-            if (_snap_to_bboxpath) {
-                if (!(_strict_snapping && p_is_a_node)) {
-                    //This will get ugly... rect -> curve -> bpath
-                    NRRect rect;
-                    sp_item_invoke_bbox(root_item, &rect, i2doc, TRUE, bbox_type);
-                    NR::Maybe<NR::Rect> bbox = rect.upgrade();
-                    SPCurve *curve = sp_curve_new_from_rect(bbox);
-                    if (curve) {
-                        NArtBpath *bpath = SP_CURVE_BPATH(curve);
-                        if (bpath) {
-                            Path *path = bpath_to_Path(bpath);
-                            if (path) {
-                                _paths_to_snap_to->push_back(path);
-                            }
-                            delete bpath;
+            if (_snapmanager->snapprefs.getSnapToBBoxPath() && _snapmanager->snapprefs.getSnapModeBBox()) {
+                if (p_is_other || !(_snapmanager->snapprefs.getStrictSnapping() && p_is_a_node)) {
+                    // Discard the bbox of a clipped path / mask, because we don't want to snap to both the bbox
+                    // of the item AND the bbox of the clipping path at the same time
+                    if (!(*i).clip_or_mask) {
+                        Geom::OptRect rect;
+                        root_item->invoke_bbox( rect, i2doc, TRUE, bbox_type);
+                        if (rect) {
+                            Geom::PathVector *path = _getPathvFromRect(*rect);
+                            rect = root_item->getBboxDesktop(bbox_type);
+                            _paths_to_snap_to->push_back(Inkscape::SnapCandidatePath(path, SNAPTARGET_BBOX_EDGE, rect));
                         }
-                        delete curve;
                     }
                 }
             }
         }
     }
+}
 
-    //Now we can finally do the real snapping, using the paths collected above
-    for (std::vector<Path*>::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
-        if (*k) {
-            if (first_point) {
-                (*k)->ConvertWithBackData(0.01); //This is extremely time consuming!
+void Inkscape::ObjectSnapper::_snapPaths(SnappedConstraints &sc,
+                                     Inkscape::SnapCandidatePoint const &p,
+                                     std::vector<Inkscape::SnapCandidatePoint> *unselected_nodes,
+                                     SPPath const *selected_path) const
+{
+    _collectPaths(p.getPoint(), p.getSourceType(), p.getSourceNum() <= 0);
+    // Now we can finally do the real snapping, using the paths collected above
+
+    g_assert(_snapmanager->getDesktop() != NULL);
+    Geom::Point const p_doc = _snapmanager->getDesktop()->dt2doc(p.getPoint());
+
+    bool const node_tool_active = _snapmanager->snapprefs.getSnapToItemPath() && selected_path != NULL;
+
+    if (p.getSourceNum() <= 0) {
+        /* findCandidates() is used for snapping to both paths and nodes. It ignores the path that is
+         * currently being edited, because that path requires special care: when snapping to nodes
+         * only the unselected nodes of that path should be considered, and these will be passed on separately.
+         * This path must not be ignored however when snapping to the paths, so we add it here
+         * manually when applicable.
+         * */
+        if (node_tool_active) {
+            SPCurve *curve = curve_for_item(SP_ITEM(selected_path));
+            if (curve) {
+                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
+                _paths_to_snap_to->push_back(Inkscape::SnapCandidatePath(pathv, SNAPTARGET_PATH, Geom::OptRect(), true));
+                curve->unref();
             }
+        }
+    }
 
-            /* Look for the nearest position on this SPItem to our snap point */
-            NR::Maybe<Path::cut_position> const o = get_nearest_position_on_Path(*k, p_doc);
-            if (o && o->t >= 0 && o->t <= 1) {
-
-                /* Convert the nearest point back to desktop coordinates */
-                NR::Point const o_it = get_point_on_Path(*k, o->piece, o->t);
-                NR::Point const o_dt = desktop->doc2dt(o_it);
+    int num_path = 0;
+    int num_segm = 0;
+
+    for (std::vector<Inkscape::SnapCandidatePath >::const_iterator it_p = _paths_to_snap_to->begin(); it_p != _paths_to_snap_to->end(); it_p++) {
+        bool const being_edited = node_tool_active && (*it_p).currently_being_edited;
+        //if true then this pathvector it_pv is currently being edited in the node tool
+
+        for(Geom::PathVector::iterator it_pv = (it_p->path_vector)->begin(); it_pv != (it_p->path_vector)->end(); ++it_pv) {
+            // Find a nearest point for each curve within this path
+            // n curves will return n time values with 0 <= t <= 1
+            std::vector<double> anp = (*it_pv).nearestPointPerCurve(p_doc);
+
+            std::vector<double>::const_iterator np = anp.begin();
+            unsigned int index = 0;
+            for (; np != anp.end(); np++, index++) {
+                Geom::Curve const *curve = &((*it_pv).at_index(index));
+                Geom::Point const sp_doc = curve->pointAt(*np);
+
+                bool c1 = true;
+                bool c2 = true;
+                if (being_edited) {
+                    /* If the path is being edited, then we should only snap though to stationary pieces of the path
+                     * and not to the pieces that are being dragged around. This way we avoid
+                     * self-snapping. For this we check whether the nodes at both ends of the current
+                     * piece are unselected; if they are then this piece must be stationary
+                     */
+                    g_assert(unselected_nodes != NULL);
+                    Geom::Point start_pt = _snapmanager->getDesktop()->doc2dt(curve->pointAt(0));
+                    Geom::Point end_pt = _snapmanager->getDesktop()->doc2dt(curve->pointAt(1));
+                    c1 = isUnselectedNode(start_pt, unselected_nodes);
+                    c2 = isUnselectedNode(end_pt, unselected_nodes);
+                    /* Unfortunately, this might yield false positives for coincident nodes. Inkscape might therefore mistakenly
+                     * snap to path segments that are not stationary. There are at least two possible ways to overcome this:
+                     * - Linking the individual nodes of the SPPath we have here, to the nodes of the NodePath::SubPath class as being
+                     *   used in sp_nodepath_selected_nodes_move. This class has a member variable called "selected". For this the nodes
+                     *   should be in the exact same order for both classes, so we can index them
+                     * - Replacing the SPPath being used here by the the NodePath::SubPath class; but how?
+                     */
+                }
 
-                NR::Coord const dist = NR::L2(o_dt - p);
-                if (dist < getDistance() && dist < s.getDistance()) {
-                    s = SnappedPoint(o_dt, dist);
-                    success = true;
+                Geom::Point const sp_dt = _snapmanager->getDesktop()->doc2dt(sp_doc);
+                if (!being_edited || (c1 && c2)) {
+                    Geom::Coord const dist = Geom::distance(sp_doc, p_doc);
+                    if (dist < getSnapperTolerance()) {
+                        sc.curves.push_back(Inkscape::SnappedCurve(sp_dt, num_path, num_segm, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, curve, p.getSourceType(), p.getSourceNum(), it_p->target_type, it_p->target_bbox));
+                    }
                 }
             }
+            num_segm++;
+        } // End of: for (Geom::PathVector::iterator ....)
+        num_path++;
+    }
+}
+
+/* Returns true if point is coincident with one of the unselected nodes */
+bool Inkscape::ObjectSnapper::isUnselectedNode(Geom::Point const &point, std::vector<Inkscape::SnapCandidatePoint> const *unselected_nodes) const
+{
+    if (unselected_nodes == NULL) {
+        return false;
+    }
+
+    if (unselected_nodes->size() == 0) {
+        return false;
+    }
+
+    for (std::vector<Inkscape::SnapCandidatePoint>::const_iterator i = unselected_nodes->begin(); i != unselected_nodes->end(); i++) {
+        if (Geom::L2(point - (*i).getPoint()) < 1e-4) {
+            return true;
         }
     }
 
-    return success;
+    return false;
 }
 
-
-void Inkscape::ObjectSnapper::_doFreeSnap(SnappedConstraints &sc,
-                                            Inkscape::Snapper::PointType const &t,
-                                            NR::Point const &p,
-                                            bool const &first_point,
-                                             std::vector<NR::Point> &points_to_snap,
-                                            std::list<SPItem const *> const &it) const
+void Inkscape::ObjectSnapper::_snapPathsConstrained(SnappedConstraints &sc,
+                                     Inkscape::SnapCandidatePoint const &p,
+                                     SnapConstraint const &c,
+                                     Geom::Point const &p_proj_on_constraint) const
 {
-    if ( NULL == _named_view ) {
-        return;
+
+    _collectPaths(p_proj_on_constraint, p.getSourceType(), p.getSourceNum() <= 0);
+
+    // Now we can finally do the real snapping, using the paths collected above
+
+    g_assert(_snapmanager->getDesktop() != NULL);
+    Geom::Point const p_doc = _snapmanager->getDesktop()->dt2doc(p_proj_on_constraint);
+
+    Geom::Point direction_vector = c.getDirection();
+    if (!is_zero(direction_vector)) {
+        direction_vector = Geom::unit_vector(direction_vector);
     }
 
-    /* Get a list of all the SPItems that we will try to snap to */
-    if (first_point) {
-        _findCandidates(sp_document_root(_named_view->document), it, first_point, points_to_snap, SNAP_XY);
+    // The intersection point of the constraint line with any path, must lie within two points on the
+    // SnapConstraint: p_min_on_cl and p_max_on_cl. The distance between those points is twice the snapping tolerance
+    Geom::Point const p_min_on_cl = _snapmanager->getDesktop()->dt2doc(p_proj_on_constraint - getSnapperTolerance() * direction_vector);
+    Geom::Point const p_max_on_cl = _snapmanager->getDesktop()->dt2doc(p_proj_on_constraint + getSnapperTolerance() * direction_vector);
+    Geom::Coord tolerance = getSnapperTolerance();
+
+    // PS: Because the paths we're about to snap to are all expressed relative to document coordinate system, we will have
+    // to convert the snapper coordinates from the desktop coordinates to document coordinates
+
+    std::vector<Geom::Path> constraint_path;
+    if (c.isCircular()) {
+        Geom::Circle constraint_circle(_snapmanager->getDesktop()->dt2doc(c.getPoint()), c.getRadius());
+        constraint_circle.getPath(constraint_path);
+    } else {
+        Geom::Path constraint_line;
+        constraint_line.start(p_min_on_cl);
+        constraint_line.appendNew<Geom::LineSegment>(p_max_on_cl);
+        constraint_path.push_back(constraint_line);
     }
+    // Length of constraint_path will always be one
+
+    // Find all intersections of the constrained path with the snap target candidates
+    std::vector<Geom::Point> intersections;
+    for (std::vector<Inkscape::SnapCandidatePath >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
+        if (k->path_vector) {
+            // Do the intersection math
+            Geom::CrossingSet cs = Geom::crossings(constraint_path, *(k->path_vector));
+            // Store the results as intersection points
+            unsigned int index = 0;
+            for (Geom::CrossingSet::const_iterator i = cs.begin(); i != cs.end(); i++) {
+                if (index >= constraint_path.size()) {
+                    break;
+                }
+                // Reconstruct and store the points of intersection
+                for (Geom::Crossings::const_iterator m = (*i).begin(); m != (*i).end(); m++) {
+                    intersections.push_back(constraint_path[index].pointAt((*m).ta));
+                }
+                index++;
+            }
 
-    SnappedPoint s(p, NR_HUGE);
-    bool snapped_to_node = false;
-    bool snapped_to_path = false;
+            //Geom::crossings will not consider the closing segment apparently, so we'll handle that separately here
+            //TODO: This should have been fixed in rev. #9859, which makes this workaround obsolete
+            for(Geom::PathVector::iterator it_pv = k->path_vector->begin(); it_pv != k->path_vector->end(); ++it_pv) {
+                if (it_pv->closed()) {
+                    // Get the closing linesegment and convert it to a path
+                    Geom::Path cls;
+                    cls.close(false);
+                    cls.append(it_pv->back_closed());
+                    // Intersect that closing path with the constrained path
+                    Geom::Crossings cs = Geom::crossings(constraint_path.front(), cls);
+                    // Reconstruct and store the points of intersection
+                    index = 0; // assuming the constraint path vector has only one path
+                    for (Geom::Crossings::const_iterator m = cs.begin(); m != cs.end(); m++) {
+                        intersections.push_back(constraint_path[index].pointAt((*m).ta));
+                    }
+                }
+            }
 
-    if (_snap_to_itemnode || _snap_to_bboxnode) {
-        snapped_to_node = _snapNodes(t, s, p, first_point, SNAP_XY);
+            // Convert the collected points of intersection to snapped points
+            for (std::vector<Geom::Point>::iterator p_inters = intersections.begin(); p_inters != intersections.end(); p_inters++) {
+                // Convert to desktop coordinates
+                (*p_inters) = _snapmanager->getDesktop()->doc2dt(*p_inters);
+                // Construct a snapped point
+                Geom::Coord dist = Geom::L2(p.getPoint() - *p_inters);
+                SnappedPoint s = SnappedPoint(*p_inters, p.getSourceType(), p.getSourceNum(), k->target_type, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), true, k->target_bbox);;
+                // Store the snapped point
+                if (dist <= tolerance) { // If the intersection is within snapping range, then we might snap to it
+                    sc.points.push_back(s);
+                }
+            }
+        }
     }
-    if (_snap_to_itempath || _snap_to_bboxpath) {
-        snapped_to_path = _snapPaths(t, s, p, first_point);
+}
+
+
+void Inkscape::ObjectSnapper::freeSnap(SnappedConstraints &sc,
+                                            Inkscape::SnapCandidatePoint const &p,
+                                            Geom::OptRect const &bbox_to_snap,
+                                            std::vector<SPItem const *> const *it,
+                                            std::vector<SnapCandidatePoint> *unselected_nodes) const
+{
+    if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(p.getSourceType()) == false ) {
+        return;
     }
 
-    if (snapped_to_node || snapped_to_path) {
-        sc.points.push_back(s);
+    /* Get a list of all the SPItems that we will try to snap to */
+    if (p.getSourceNum() <= 0) {
+        Geom::Rect const local_bbox_to_snap = bbox_to_snap ? *bbox_to_snap : Geom::Rect(p.getPoint(), p.getPoint());
+        _findCandidates(_snapmanager->getDocument()->getRoot(), it, p.getSourceNum() <= 0, local_bbox_to_snap, false, Geom::identity());
     }
-}
 
+    // TODO: Argh, UGLY! Get rid of this here, move this logic to the snap manager
+    bool snap_nodes = (_snapmanager->snapprefs.getSnapModeNode() && (
+                            _snapmanager->snapprefs.getSnapToItemNode() ||
+                            _snapmanager->snapprefs.getSnapSmoothNodes() ||
+                            _snapmanager->snapprefs.getSnapLineMidpoints() ||
+                            _snapmanager->snapprefs.getSnapObjectMidpoints()
+                        )) || (_snapmanager->snapprefs.getSnapModeBBox() && (
+                            _snapmanager->snapprefs.getSnapToBBoxNode() ||
+                            _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() ||
+                            _snapmanager->snapprefs.getSnapBBoxMidpoints()
+                        )) || (_snapmanager->snapprefs.getSnapModeBBoxOrNodes() && (
+                            _snapmanager->snapprefs.getIncludeItemCenter() ||
+                            _snapmanager->snapprefs.getSnapToPageBorder()
+                        ));
+
+    if (snap_nodes) {
+        _snapNodes(sc, p, unselected_nodes);
+    }
 
+    if ((_snapmanager->snapprefs.getSnapModeNode() && _snapmanager->snapprefs.getSnapToItemPath()) ||
+        (_snapmanager->snapprefs.getSnapModeBBox() && _snapmanager->snapprefs.getSnapToBBoxPath()) ||
+        (_snapmanager->snapprefs.getSnapModeBBoxOrNodes() && _snapmanager->snapprefs.getSnapToPageBorder())) {
+        unsigned n = (unselected_nodes == NULL) ? 0 : unselected_nodes->size();
+        if (n > 0) {
+            /* While editing a path in the node tool, findCandidates must ignore that path because
+             * of the node snapping requirements (i.e. only unselected nodes must be snapable).
+             * That path must not be ignored however when snapping to the paths, so we add it here
+             * manually when applicable
+             */
+            SPPath *path = NULL;
+            if (it != NULL) {
+                if (it->size() == 1 && SP_IS_PATH(*it->begin())) {
+                    path = SP_PATH(*it->begin());
+                } // else: *it->begin() might be a SPGroup, e.g. when editing a LPE of text that has been converted to a group of paths
+                // as reported in bug #356743. In that case we can just ignore it, i.e. not snap to this item
+            }
+            _snapPaths(sc, p, unselected_nodes, path);
+        } else {
+            _snapPaths(sc, p, NULL, NULL);
+        }
+    }
+}
 
-void Inkscape::ObjectSnapper::_doConstrainedSnap( SnappedConstraints &sc,
-                                                  Inkscape::Snapper::PointType const &t,
-                                                  NR::Point const &p,
-                                                  bool const &first_point,
-                                                  std::vector<NR::Point> &points_to_snap,
-                                                  ConstraintLine const &/*c*/,
-                                                  std::list<SPItem const *> const &it) const
+void Inkscape::ObjectSnapper::constrainedSnap( SnappedConstraints &sc,
+                                                  Inkscape::SnapCandidatePoint const &p,
+                                                  Geom::OptRect const &bbox_to_snap,
+                                                  SnapConstraint const &c,
+                                                  std::vector<SPItem const *> const *it,
+                                                  std::vector<SnapCandidatePoint> *unselected_nodes) const
 {
-    /* FIXME: this needs implementing properly; I think we have to do the
-    ** intersection of c with the objects.
-    */
-    _doFreeSnap(sc, t, p, first_point, points_to_snap, it);
-}
+    if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(p.getSourceType()) == false) {
+        return;
+    }
 
+    // project the mouse pointer onto the constraint. Only the projected point will be considered for snapping
+    Geom::Point pp = c.projection(p.getPoint());
 
+    /* Get a list of all the SPItems that we will try to snap to */
+    if (p.getSourceNum() <= 0) {
+        Geom::Rect const local_bbox_to_snap = bbox_to_snap ? *bbox_to_snap : Geom::Rect(pp, pp);
+        _findCandidates(_snapmanager->getDocument()->getRoot(), it, p.getSourceNum() <= 0, local_bbox_to_snap, false, Geom::identity());
+    }
 
-Inkscape::SnappedPoint Inkscape::ObjectSnapper::guideSnap(NR::Point const &p,
-                                                          DimensionToSnap const snap_dim) const
-{
-    if ( NULL == _named_view ) {
-        return SnappedPoint(p, NR_HUGE);
+    // A constrained snap, is a snap in only one degree of freedom (specified by the constraint line).
+    // This is useful for example when scaling an object while maintaining a fixed aspect ratio. It's
+    // nodes are only allowed to move in one direction (i.e. in one degree of freedom).
+
+    // TODO: Argh, UGLY! Get rid of this here, move this logic to the snap manager
+    bool snap_nodes = (_snapmanager->snapprefs.getSnapModeNode() && (
+                                _snapmanager->snapprefs.getSnapToItemNode() ||
+                                _snapmanager->snapprefs.getSnapSmoothNodes() ||
+                                _snapmanager->snapprefs.getSnapLineMidpoints() ||
+                                _snapmanager->snapprefs.getSnapObjectMidpoints()
+                            )) || (_snapmanager->snapprefs.getSnapModeBBox() && (
+                                _snapmanager->snapprefs.getSnapToBBoxNode() ||
+                                _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() ||
+                                _snapmanager->snapprefs.getSnapBBoxMidpoints()
+                            )) || (_snapmanager->snapprefs.getSnapModeBBoxOrNodes() && (
+                                _snapmanager->snapprefs.getIncludeItemCenter() ||
+                                _snapmanager->snapprefs.getSnapToPageBorder()
+                            ));
+
+    if (snap_nodes) {
+        _snapNodes(sc, p, unselected_nodes, c, pp);
     }
 
+    if (_snapmanager->snapprefs.getSnapToItemPath() || _snapmanager->snapprefs.getSnapToBBoxPath() || _snapmanager->snapprefs.getSnapToPageBorder()) {
+        _snapPathsConstrained(sc, p, c, pp);
+    }
+}
+
+
+// This method is used to snap a guide to nodes, while dragging the guide around
+void Inkscape::ObjectSnapper::guideFreeSnap(SnappedConstraints &sc,
+                                        Geom::Point const &p,
+                                        Geom::Point const &guide_normal) const
+{
     /* Get a list of all the SPItems that we will try to snap to */
     std::vector<SPItem*> cand;
-    std::list<SPItem const *> const it; //just an empty list
+    std::vector<SPItem const *> const it; //just an empty list
+
+    _findCandidates(_snapmanager->getDocument()->getRoot(), &it, true, Geom::Rect(p, p), false, Geom::identity());
+    _snapTranslatingGuide(sc, p, guide_normal);
 
-    std::vector<NR::Point> points_to_snap;
-    points_to_snap.push_back(p);
+}
 
-    _findCandidates(sp_document_root(_named_view->document), it, true, points_to_snap, snap_dim);
+// This method is used to snap the origin of a guide to nodes/paths, while dragging the origin along the guide
+void Inkscape::ObjectSnapper::guideConstrainedSnap(SnappedConstraints &sc,
+                                        Geom::Point const &p,
+                                        Geom::Point const &guide_normal,
+                                        SnapConstraint const &/*c*/) const
+{
+    /* Get a list of all the SPItems that we will try to snap to */
+    std::vector<SPItem*> cand;
+    std::vector<SPItem const *> const it; //just an empty list
 
-    SnappedPoint s(p, NR_HUGE);
-    _snapNodes(Inkscape::Snapper::SNAPPOINT_GUIDE, s, p, true, snap_dim);
+    _findCandidates(_snapmanager->getDocument()->getRoot(), &it, true, Geom::Rect(p, p), false, Geom::identity());
+    _snapTranslatingGuide(sc, p, guide_normal);
 
-    return s;
 }
 
 /**
@@ -401,10 +790,83 @@ Inkscape::SnappedPoint Inkscape::ObjectSnapper::guideSnap(NR::Point const &p,
  */
 bool Inkscape::ObjectSnapper::ThisSnapperMightSnap() const
 {
-    bool snap_to_something = _snap_to_itempath || _snap_to_itemnode || _snap_to_bboxpath || _snap_to_bboxnode;
-    return (_enabled && _snap_from != 0 && snap_to_something);
+    bool snap_to_something = (_snapmanager->snapprefs.getSnapModeNode() && (
+                                _snapmanager->snapprefs.getSnapToItemPath() ||
+                                _snapmanager->snapprefs.getSnapToItemNode() ||
+                                _snapmanager->snapprefs.getSnapSmoothNodes() ||
+                                _snapmanager->snapprefs.getSnapLineMidpoints() ||
+                                _snapmanager->snapprefs.getSnapObjectMidpoints()
+                            )) || (_snapmanager->snapprefs.getSnapModeBBox() && (
+                                _snapmanager->snapprefs.getSnapToBBoxPath() ||
+                                _snapmanager->snapprefs.getSnapToBBoxNode() ||
+                                _snapmanager->snapprefs.getSnapBBoxEdgeMidpoints() ||
+                                _snapmanager->snapprefs.getSnapBBoxMidpoints()
+                            )) || (_snapmanager->snapprefs.getSnapModeBBoxOrNodes() && (
+                                _snapmanager->snapprefs.getSnapToPageBorder() ||
+                                _snapmanager->snapprefs.getIncludeItemCenter()
+                            ));
+
+    return (_snap_enabled && snap_to_something);
+}
+
+void Inkscape::ObjectSnapper::_clear_paths() const
+{
+    for (std::vector<Inkscape::SnapCandidatePath >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); k++) {
+        delete k->path_vector;
+    }
+    _paths_to_snap_to->clear();
+}
+
+Geom::PathVector* Inkscape::ObjectSnapper::_getBorderPathv() const
+{
+    Geom::Rect const border_rect = Geom::Rect(Geom::Point(0,0), Geom::Point((_snapmanager->getDocument())->getWidth(),(_snapmanager->getDocument())->getHeight()));
+    return _getPathvFromRect(border_rect);
+}
+
+Geom::PathVector* Inkscape::ObjectSnapper::_getPathvFromRect(Geom::Rect const rect) const
+{
+    SPCurve const *border_curve = SPCurve::new_from_rect(rect, true);
+    if (border_curve) {
+        Geom::PathVector *dummy = new Geom::PathVector(border_curve->get_pathvector());
+        return dummy;
+    } else {
+        return NULL;
+    }
 }
 
+void Inkscape::ObjectSnapper::_getBorderNodes(std::vector<SnapCandidatePoint> *points) const
+{
+    Geom::Coord w = (_snapmanager->getDocument())->getWidth();
+    Geom::Coord h = (_snapmanager->getDocument())->getHeight();
+    points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(0,0), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
+    points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(0,h), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
+    points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(w,h), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
+    points->push_back(Inkscape::SnapCandidatePoint(Geom::Point(w,0), SNAPSOURCE_UNDEFINED, SNAPTARGET_PAGE_CORNER));
+}
+
+void Inkscape::getBBoxPoints(Geom::OptRect const bbox,
+                             std::vector<SnapCandidatePoint> *points,
+                             bool const /*isTarget*/,
+                             bool const includeCorners,
+                             bool const includeLineMidpoints,
+                             bool const includeObjectMidpoints)
+{
+    if (bbox) {
+        // collect the corners of the bounding box
+        for ( unsigned k = 0 ; k < 4 ; k++ ) {
+            if (includeCorners) {
+                points->push_back(Inkscape::SnapCandidatePoint(bbox->corner(k), Inkscape::SNAPSOURCE_BBOX_CORNER, -1, Inkscape::SNAPTARGET_BBOX_CORNER, *bbox));
+            }
+            // optionally, collect the midpoints of the bounding box's edges too
+            if (includeLineMidpoints) {
+                points->push_back(Inkscape::SnapCandidatePoint((bbox->corner(k) + bbox->corner((k+1) % 4))/2, Inkscape::SNAPSOURCE_BBOX_EDGE_MIDPOINT, -1, Inkscape::SNAPTARGET_BBOX_EDGE_MIDPOINT, *bbox));
+            }
+        }
+        if (includeObjectMidpoints) {
+            points->push_back(Inkscape::SnapCandidatePoint(bbox->midpoint(), Inkscape::SNAPSOURCE_BBOX_MIDPOINT, -1, Inkscape::SNAPTARGET_BBOX_MIDPOINT, *bbox));
+        }
+    }
+}
 
 /*
   Local Variables: