X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Fsnap.cpp;h=545607889c48e13f21da41c2e05150b2028be135;hb=d91c7044b45dde766203822b19e4affead5ce10f;hp=0d7a25ad6329bb1c42e0b6369338c31c5253b682;hpb=51e97ed360968cdba443d14c19d1da1caf194939;p=inkscape.git diff --git a/src/snap.cpp b/src/snap.cpp index 0d7a25ad6..545607889 100644 --- a/src/snap.cpp +++ b/src/snap.cpp @@ -9,10 +9,11 @@ * Frank Felfe * Nathan Hurst * Carl Hetherington + * Diederik van Lierop * * Copyright (C) 2006-2007 Johan Engelen * Copyrigth (C) 2004 Nathan Hurst - * Copyright (C) 1999-2002 Authors + * Copyright (C) 1999-2009 Authors * * Released under GNU GPL, read the file 'COPYING' for more information */ @@ -22,16 +23,16 @@ #include "sp-namedview.h" #include "snap.h" #include "snapped-line.h" - -#include -#include -#include +#include "snapped-curve.h" #include "display/canvas-grid.h" +#include "display/snap-indicator.h" #include "inkscape.h" #include "desktop.h" #include "sp-guide.h" +#include "preferences.h" +#include "event-context.h" using std::vector; /** @@ -41,19 +42,26 @@ using std::vector; */ SnapManager::SnapManager(SPNamedView const *v) : - guide(v, 0), - object(v, 0), - _named_view(v), - _include_item_center(false), - _snap_enabled_globally(true) -{ + guide(this, 0), + object(this, 0), + snapprefs(), + _named_view(v) +{ } - /** + * \brief Return a list of snappers + * + * Inkscape snaps to objects, grids, and guides. For each of these snap targets a + * separate class is used, which has been derived from the base Snapper class. The + * getSnappers() method returns a list of pointers to instances of this class. This + * list contains exactly one instance of the guide snapper and of the object snapper + * class, but any number of grid snappers (because each grid has its own snapper + * instance) + * * \return List of snappers that we use. */ -SnapManager::SnapperList +SnapManager::SnapperList SnapManager::getSnappers() const { SnapManager::SnapperList s; @@ -67,16 +75,21 @@ SnapManager::getSnappers() const } /** + * \brief Return a list of gridsnappers + * + * Each grid has its own instance of the snapper class. This way snapping can + * be enabled per grid individually. A list will be returned containing the + * pointers to these instances, but only for grids that are being displayed + * and for which snapping is enabled. + * * \return List of gridsnappers that we use. */ -SnapManager::SnapperList +SnapManager::SnapperList SnapManager::getGridSnappers() const { SnapperList s; - //FIXME: this code should actually do this: add new grid snappers that are active for this desktop. now it just adds all gridsnappers - SPDesktop* desktop = SP_ACTIVE_DESKTOP; - if (desktop && desktop->gridsEnabled()) { + if (_desktop && _desktop->gridsEnabled() && snapprefs.getSnapToGrids()) { for ( GSList const *l = _named_view->grids; l != NULL; l = l->next) { Inkscape::CanvasGrid *grid = (Inkscape::CanvasGrid*) l->data; s.push_back(grid->snapper); @@ -87,249 +100,428 @@ SnapManager::getGridSnappers() const } /** - * \return true if one of the snappers will try to snap something. + * \brief Return true if any snapping might occur, whether its to grids, guides or objects + * + * Each snapper instance handles its own snapping target, e.g. grids, guides or + * objects. This method iterates through all these snapper instances and returns + * true if any of the snappers might possible snap, considering only the relevant + * snapping preferences. + * + * \return true if one of the snappers will try to snap to something. */ -bool SnapManager::SomeSnapperMightSnap() const +bool SnapManager::someSnapperMightSnap() const { - if (!_snap_enabled_globally) { + if ( !snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally() ) { return false; } - + SnapperList const s = getSnappers(); SnapperList::const_iterator i = s.begin(); while (i != s.end() && (*i)->ThisSnapperMightSnap() == false) { i++; } - + return (i != s.end()); } -/* - * The snappers have too many parameters to adjust individually. Therefore only - * two snapping modes are presented to the user: snapping bounding box corners (to - * other bounding boxes, grids or guides), and/or snapping nodes (to other nodes, - * paths, grids or guides). To select either of these modes (or both), use the - * methods defined below: setSnapModeBBox() and setSnapModeNode(). - * - * */ - +/** + * \return true if one of the grids might be snapped to. + */ -void SnapManager::setSnapModeBBox(bool enabled) +bool SnapManager::gridSnapperMightSnap() const { - //The default values are being set in sp_namedview_set() (in sp-namedview.cpp) - guide.setSnapFrom(Inkscape::Snapper::SNAPPOINT_BBOX, enabled); - - for ( GSList const *l = _named_view->grids; l != NULL; l = l->next) { - Inkscape::CanvasGrid *grid = (Inkscape::CanvasGrid*) l->data; - grid->snapper->setSnapFrom(Inkscape::Snapper::SNAPPOINT_BBOX, enabled); - } - - object.setSnapFrom(Inkscape::Snapper::SNAPPOINT_BBOX, enabled); - //object.setSnapToBBoxNode(enabled); // On second thought, these should be controlled - //object.setSnapToBBoxPath(enabled); // separately by the snapping prefs dialog - object.setStrictSnapping(true); //don't snap bboxes to nodes/paths and vice versa -} + if ( !snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally() ) { + return false; + } -bool SnapManager::getSnapModeBBox() const -{ - return guide.getSnapFrom(Inkscape::Snapper::SNAPPOINT_BBOX); -} + SnapperList const s = getGridSnappers(); + SnapperList::const_iterator i = s.begin(); + while (i != s.end() && (*i)->ThisSnapperMightSnap() == false) { + i++; + } -void SnapManager::setSnapModeNode(bool enabled) -{ - guide.setSnapFrom(Inkscape::Snapper::SNAPPOINT_NODE, enabled); - - for ( GSList const *l = _named_view->grids; l != NULL; l = l->next) { - Inkscape::CanvasGrid *grid = (Inkscape::CanvasGrid*) l->data; - grid->snapper->setSnapFrom(Inkscape::Snapper::SNAPPOINT_NODE, enabled); - } - - object.setSnapFrom(Inkscape::Snapper::SNAPPOINT_NODE, enabled); - //object.setSnapToItemNode(enabled); // On second thought, these should be controlled - //object.setSnapToItemPath(enabled); // separately by the snapping prefs dialog - object.setStrictSnapping(true); + return (i != s.end()); } -bool SnapManager::getSnapModeNode() const -{ - return guide.getSnapFrom(Inkscape::Snapper::SNAPPOINT_NODE); -} +/** + * \brief Try to snap a point to grids, guides or objects. + * + * Try to snap a point to grids, guides or objects, in two degrees-of-freedom, + * i.e. snap in any direction on the two dimensional canvas to the nearest + * snap target. freeSnapReturnByRef() is equal in snapping behavior to + * freeSnap(), but the former returns the snapped point trough the referenced + * parameter p. This parameter p initially contains the position of the snap + * source and will we overwritten by the target position if snapping has occurred. + * This makes snapping transparent to the calling code. If this is not desired + * because either the calling code must know whether snapping has occurred, or + * because the original position should not be touched, then freeSnap() should be + * called instead. + * + * PS: SnapManager::setup() must have been called before calling this method, + * but only once for a set of points + * + * \param point_type Category of points to which the source point belongs: node, guide or bounding box + * \param p Current position of the snap source; will be overwritten by the position of the snap target if snapping has occurred + * \param source_type Detailed description of the source type, will be used by the snap indicator + * \param first_point If true then this point is the first one from a set of points, all from the same selection and having the same transformation + * \param bbox_to_snap Bounding box hulling the set of points, all from the same selection and having the same transformation + */ -void SnapManager::setSnapModeGuide(bool enabled) +void SnapManager::freeSnapReturnByRef(Inkscape::SnapPreferences::PointType point_type, + Geom::Point &p, + Inkscape::SnapSourceType const source_type, + bool first_point, + Geom::OptRect const &bbox_to_snap) const { - object.setSnapFrom(Inkscape::Snapper::SNAPPOINT_GUIDE, enabled); + //TODO: PointType and source_type are somewhat redundant; can't we get rid of the point_type parameter? + Inkscape::SnappedPoint const s = freeSnap(point_type, p, source_type, first_point, bbox_to_snap); + s.getPoint(p); } -bool SnapManager::getSnapModeGuide() const -{ - return object.getSnapFrom(Inkscape::Snapper::SNAPPOINT_GUIDE); -} /** - * Try to snap a point to any interested snappers. + * \brief Try to snap a point to grids, guides or objects. + * + * Try to snap a point to grids, guides or objects, in two degrees-of-freedom, + * i.e. snap in any direction on the two dimensional canvas to the nearest + * snap target. freeSnap() is equal in snapping behavior to + * freeSnapReturnByRef(). Please read the comments of the latter for more details * - * \param t Type of point. - * \param p Point. - * \param it Item to ignore when snapping. - * \return Snapped point. + * PS: SnapManager::setup() must have been called before calling this method, + * but only once for a set of points + * + * \param point_type Category of points to which the source point belongs: node, guide or bounding box + * \param p Current position of the snap source + * \param source_type Detailed description of the source type, will be used by the snap indicator + * \param first_point If true then this point is the first one from a set of points, all from the same selection and having the same transformation + * \param bbox_to_snap Bounding box hulling the set of points, all from the same selection and having the same transformation + * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics */ -Inkscape::SnappedPoint SnapManager::freeSnap(Inkscape::Snapper::PointType t, - NR::Point const &p, - SPItem const *it) const +Inkscape::SnappedPoint SnapManager::freeSnap(Inkscape::SnapPreferences::PointType point_type, + Geom::Point const &p, + Inkscape::SnapSourceType const &source_type, + bool first_point, + Geom::OptRect const &bbox_to_snap) const { - std::list lit; - lit.push_back(it); - - std::vector points_to_snap; - points_to_snap.push_back(p); - - return freeSnap(t, p, true, points_to_snap, lit); -} + if (!someSnapperMightSnap()) { + return Inkscape::SnappedPoint(p, source_type, Inkscape::SNAPTARGET_UNDEFINED, NR_HUGE, 0, false, false); + } -/** - * Try to snap a point to any of the specified snappers. - * - * \param t Type of point. - * \param p Point. - * \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 it List of items to ignore when snapping. - * \param snappers List of snappers to try to snap to - * \return Snapped point. - */ + std::vector *items_to_ignore; + if (_item_to_ignore) { // If we have only a single item to ignore + // then build a list containing this single item; + // This single-item list will prevail over any other _items_to_ignore list, should that exist + items_to_ignore = new std::vector; + items_to_ignore->push_back(_item_to_ignore); + } else { + items_to_ignore = _items_to_ignore; + } -Inkscape::SnappedPoint SnapManager::freeSnap(Inkscape::Snapper::PointType t, - NR::Point const &p, - bool const &first_point, - std::vector &points_to_snap, - std::list const &it) const -{ - - SnappedConstraints sc; - + SnappedConstraints sc; SnapperList const snappers = getSnappers(); for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) { - (*i)->freeSnap(sc, t, p, first_point, points_to_snap, it); + (*i)->freeSnap(sc, point_type, p, source_type, first_point, bbox_to_snap, items_to_ignore, _unselected_nodes); } - return findBestSnap(p, sc, false); + if (_item_to_ignore) { + delete items_to_ignore; + } + + return findBestSnap(p, source_type, sc, false); } /** - * Try to snap a point to any interested snappers. A snap will only occur along - * a line described by a Inkscape::Snapper::ConstraintLine. - * - * \param t Type of point. - * \param p Point. - * \param c Constraint line. - * \param it Item to ignore when snapping. - * \return Snapped point. + * \brief Snap to the closest multiple of a grid pitch + * + * When pasting, we would like to snap to the grid. Problem is that we don't know which + * nodes were aligned to the grid at the time of copying, so we don't know which nodes + * to snap. If we'd snap an unaligned node to the grid, previously aligned nodes would + * become unaligned. That's undesirable. Instead we will make sure that the offset + * between the source and its pasted copy is a multiple of the grid pitch. If the source + * was aligned, then the copy will therefore also be aligned. + * + * PS: Whether we really find a multiple also depends on the snapping range! Most users + * will have "always snap" enabled though, in which case a multiple will always be found. + * PS2: When multiple grids are present then the result will become ambiguous. There is no + * way to control to which grid this method will snap. + * + * \param t Vector that represents the offset of the pasted copy with respect to the original + * \return Offset vector after snapping to the closest multiple of a grid pitch */ -Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::Snapper::PointType t, - NR::Point const &p, - Inkscape::Snapper::ConstraintLine const &c, - SPItem const *it) const +Geom::Point SnapManager::multipleOfGridPitch(Geom::Point const &t) const { - std::list lit; - lit.push_back(it); - - std::vector points_to_snap; - points_to_snap.push_back(p); - - return constrainedSnap(t, p, true, points_to_snap, c, lit); + if (!snapprefs.getSnapEnabledGlobally()) // No need to check for snapprefs.getSnapPostponedGlobally() here + return t; + + if (_desktop && _desktop->gridsEnabled()) { + bool success = false; + Geom::Point nearest_multiple; + Geom::Coord nearest_distance = NR_HUGE; + + // It will snap to the grid for which we find the closest snap. This might be a different + // grid than to which the objects were initially aligned. I don't see an easy way to fix + // this, so when using multiple grids one can get unexpected results + + // Cannot use getGridSnappers() because we need both the grids AND their snappers + // Therefore we iterate through all grids manually + for (GSList const *l = _named_view->grids; l != NULL; l = l->next) { + Inkscape::CanvasGrid *grid = (Inkscape::CanvasGrid*) l->data; + const Inkscape::Snapper* snapper = grid->snapper; + if (snapper && snapper->ThisSnapperMightSnap()) { + // To find the nearest multiple of the grid pitch for a given translation t, we + // will use the grid snapper. Simply snapping the value t to the grid will do, but + // only if the origin of the grid is at (0,0). If it's not then compensate for this + // in the translation t + Geom::Point const t_offset = t + grid->origin; + SnappedConstraints sc; + // Only the first three parameters are being used for grid snappers + snapper->freeSnap(sc, Inkscape::SnapPreferences::SNAPPOINT_NODE, t_offset, Inkscape::SNAPSOURCE_UNDEFINED, TRUE, Geom::OptRect(), NULL, NULL); + // Find the best snap for this grid, including intersections of the grid-lines + Inkscape::SnappedPoint s = findBestSnap(t_offset, Inkscape::SNAPSOURCE_UNDEFINED, sc, false); + if (s.getSnapped() && (s.getSnapDistance() < nearest_distance)) { + // use getSnapDistance() instead of getWeightedDistance() here because the pointer's position + // doesn't tell us anything about which node to snap + success = true; + nearest_multiple = s.getPoint() - to_2geom(grid->origin); + nearest_distance = s.getSnapDistance(); + } + } + } + + if (success) + return nearest_multiple; + } + + return t; } +/** + * \brief Try to snap a point along a constraint line to grids, guides or objects. + * + * Try to snap a point to grids, guides or objects, in only one degree-of-freedom, + * i.e. snap in a specific direction on the two dimensional canvas to the nearest + * snap target. + * + * constrainedSnapReturnByRef() is equal in snapping behavior to + * constrainedSnap(), but the former returns the snapped point trough the referenced + * parameter p. This parameter p initially contains the position of the snap + * source and will we overwritten by the target position if snapping has occurred. + * This makes snapping transparent to the calling code. If this is not desired + * because either the calling code must know whether snapping has occurred, or + * because the original position should not be touched, then constrainedSnap() should + * be called instead. + * + * PS: SnapManager::setup() must have been called before calling this method, + * but only once for a set of points + * + * \param point_type Category of points to which the source point belongs: node, guide or bounding box + * \param p Current position of the snap source; will be overwritten by the position of the snap target if snapping has occurred + * \param source_type Detailed description of the source type, will be used by the snap indicator + * \param constraint The direction or line along which snapping must occur + * \param first_point If true then this point is the first one from a set of points, all from the same selection and having the same transformation + * \param bbox_to_snap Bounding box hulling the set of points, all from the same selection and having the same transformation + */ +void SnapManager::constrainedSnapReturnByRef(Inkscape::SnapPreferences::PointType point_type, + Geom::Point &p, + Inkscape::SnapSourceType const source_type, + Inkscape::Snapper::ConstraintLine const &constraint, + bool first_point, + Geom::OptRect const &bbox_to_snap) const +{ + Inkscape::SnappedPoint const s = constrainedSnap(point_type, p, source_type, constraint, first_point, bbox_to_snap); + s.getPoint(p); +} /** - * Try to snap a point to any interested snappers. A snap will only occur along - * a line described by a Inkscape::Snapper::ConstraintLine. - * - * \param t Type of point. - * \param p Point. - * \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 c Constraint line. - * \param it List of items to ignore when snapping. - * \return Snapped point. + * \brief Try to snap a point along a constraint line to grids, guides or objects. + * + * Try to snap a point to grids, guides or objects, in only one degree-of-freedom, + * i.e. snap in a specific direction on the two dimensional canvas to the nearest + * snap target. constrainedSnap is equal in snapping behavior to + * constrainedSnapReturnByRef(). Please read the comments of the latter for more details. + * + * PS: SnapManager::setup() must have been called before calling this method, + * but only once for a set of points + * + * \param point_type Category of points to which the source point belongs: node, guide or bounding box + * \param p Current position of the snap source + * \param source_type Detailed description of the source type, will be used by the snap indicator + * \param constraint The direction or line along which snapping must occur + * \param first_point If true then this point is the first one from a set of points, all from the same selection and having the same transformation + * \param bbox_to_snap Bounding box hulling the set of points, all from the same selection and having the same transformation */ -Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::Snapper::PointType t, - NR::Point const &p, - bool const &first_point, - std::vector &points_to_snap, - Inkscape::Snapper::ConstraintLine const &c, - std::list const &it) const +Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::SnapPreferences::PointType point_type, + Geom::Point const &p, + Inkscape::SnapSourceType const &source_type, + Inkscape::Snapper::ConstraintLine const &constraint, + bool first_point, + Geom::OptRect const &bbox_to_snap) const { - + if (!someSnapperMightSnap()) { + return Inkscape::SnappedPoint(p, source_type, Inkscape::SNAPTARGET_UNDEFINED, NR_HUGE, 0, false, false); + } + + std::vector *items_to_ignore; + if (_item_to_ignore) { // If we have only a single item to ignore + // then build a list containing this single item; + // This single-item list will prevail over any other _items_to_ignore list, should that exist + items_to_ignore = new std::vector; + items_to_ignore->push_back(_item_to_ignore); + } else { + items_to_ignore = _items_to_ignore; + } + + + // First project the mouse pointer onto the constraint + Geom::Point pp = constraint.projection(p); + // Then try to snap the projected point + SnappedConstraints sc; - SnapperList const snappers = getSnappers(); for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) { - (*i)->constrainedSnap(sc, t, p, first_point, points_to_snap, c, it); + (*i)->constrainedSnap(sc, point_type, pp, source_type, first_point, bbox_to_snap, constraint, items_to_ignore); } - return findBestSnap(p, sc, true); + if (_item_to_ignore) { + delete items_to_ignore; + } + + return findBestSnap(pp, source_type, sc, true); } -Inkscape::SnappedPoint SnapManager::guideSnap(NR::Point const &p, - NR::Point const &guide_normal) const +/** + * \brief Try to snap a point of a guide to another guide or to a node + * + * Try to snap a point of a guide to another guide or to a node in two degrees- + * of-freedom, i.e. snap in any direction on the two dimensional canvas to the + * nearest snap target. This method is used when dragging or rotating a guide + * + * PS: SnapManager::setup() must have been called before calling this method, + * + * \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 + * \param guide_normal Vector normal to the guide line + */ +void SnapManager::guideFreeSnap(Geom::Point &p, Geom::Point const &guide_normal, SPGuideDragType drag_type) const { - - // This method is used to snap a guide to nodes, while dragging the guide around - Inkscape::ObjectSnapper::DimensionToSnap snap_dim; - if (guide_normal == component_vectors[NR::Y]) { - snap_dim = Inkscape::ObjectSnapper::SNAP_Y; - } else if (guide_normal == component_vectors[NR::X]) { - snap_dim = Inkscape::ObjectSnapper::SNAP_X; - } else { - g_warning("WARNING: snapping of angled guides is not supported yet!"); - // this is because _snapnodes, called in object.guideSnap, cannot only handle - // vertical or horizontal lines for now.... - // Rotating an agled guide will require some additional code, as it would be great to - // have it rotate around a snapped point - snap_dim = Inkscape::ObjectSnapper::SNAP_XY; - } - + if (!snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally()) { + return; + } + + if (!(object.GuidesMightSnap() || snapprefs.getSnapToGuides())) { + return; + } + + Inkscape::SnapSourceType source_type = Inkscape::SNAPSOURCE_GUIDE_ORIGIN; + if (drag_type == SP_DRAG_ROTATE) { + source_type = Inkscape::SNAPSOURCE_GUIDE; + } + + // Snap to nodes SnappedConstraints sc; - object.guideSnap(sc, p, snap_dim); - - return findBestSnap(p, sc, false); + if (object.GuidesMightSnap()) { + object.guideFreeSnap(sc, p, guide_normal); + } + + // Snap to guides & grid lines + SnapperList snappers = getGridSnappers(); + snappers.push_back(&guide); + for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) { + (*i)->freeSnap(sc, Inkscape::SnapPreferences::SNAPPOINT_GUIDE, p, source_type, true, Geom::OptRect(), NULL, NULL); + } + + // Snap to intersections of curves, but not to the curves themselves! (see _snapTranslatingGuideToNodes in object-snapper.cpp) + Inkscape::SnappedPoint const s = findBestSnap(p, source_type, sc, false, true); + + s.getPoint(p); } +/** + * \brief Try to snap a point on a guide to the intersection with another guide or a path + * + * Try to snap a point on a guide to the intersection of that guide with another + * guide or with a path. The snapped point will lie somewhere on the guide-line, + * making this is a constrained snap, i.e. in only one degree-of-freedom. + * This method is used when dragging the origin of the guide along the guide itself. + * + * PS: SnapManager::setup() must have been called before calling this method, + * + * \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 + * \param guide_normal Vector normal to the guide line + */ + +void SnapManager::guideConstrainedSnap(Geom::Point &p, SPGuide const &guideline) const +{ + if (!snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally()) { + return; + } + + if (!(object.ThisSnapperMightSnap() || snapprefs.getSnapToGuides())) { + return; + } + + Inkscape::SnapSourceType source_type = Inkscape::SNAPSOURCE_GUIDE_ORIGIN; + + // Snap to nodes or paths + SnappedConstraints sc; + Inkscape::Snapper::ConstraintLine cl(guideline.point_on_line, Geom::rot90(guideline.normal_to_line)); + if (object.ThisSnapperMightSnap()) { + object.constrainedSnap(sc, Inkscape::SnapPreferences::SNAPPOINT_GUIDE, p, source_type, true, Geom::OptRect(), cl, NULL); + } + + // Snap to guides & grid lines + SnapperList snappers = getGridSnappers(); + snappers.push_back(&guide); + for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) { + (*i)->constrainedSnap(sc, Inkscape::SnapPreferences::SNAPPOINT_GUIDE, p, source_type, true, Geom::OptRect(), cl, NULL); + } + + Inkscape::SnappedPoint const s = findBestSnap(p, source_type, sc, false); + s.getPoint(p); +} /** - * Main internal snapping method, which is called by the other, friendlier, public - * methods. It's a bit hairy as it has lots of parameters, but it saves on a lot - * of duplicated code. - * - * \param type Type of points being snapped. - * \param points List of points to snap. - * \param ignore List of items to ignore while snapping. - * \param constrained true if the snap is constrained. - * \param constraint Constraint line to use, if `constrained' is true, otherwise undefined. + * \brief Method for snapping sets of points while they are being transformed + * + * Method for snapping sets of points while they are being transformed, when using + * for example the selector tool. This method is for internal use only, and should + * not have to be called directly. Use freeSnapTransalation(), constrainedSnapScale(), + * etc. instead. + * + * This is what is being done in this method: transform each point, find out whether + * a free snap or constrained snap is more appropriate, do the snapping, calculate + * some metrics to quantify the snap "distance", and see if it's better than the + * previous snap. Finally, the best ("nearest") snap from all these points is returned. + * + * \param type Category of points to which the source point belongs: node or bounding box. + * \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. + * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed). + * \param constrained true if the snap is constrained, e.g. for stretching or for purely horizontal translation. + * \param constraint The direction or line along which snapping must occur, if 'constrained' is true; otherwise undefined. * \param transformation_type Type of transformation to apply to points before trying to snap them. * \param transformation Description of the transformation; details depend on the type. * \param origin Origin of the transformation, if applicable. - * \param dim Dimension of the transformation, if applicable. - * \param uniform true if the transformation should be uniform, if applicable. + * \param dim Dimension to which the transformation applies, if applicable. + * \param uniform true if the transformation should be uniform; only applicable for stretching and scaling. + * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics. */ -std::pair SnapManager::_snapTransformed( - Inkscape::Snapper::PointType type, - std::vector const &points, - std::list const &ignore, +Inkscape::SnappedPoint SnapManager::_snapTransformed( + Inkscape::SnapPreferences::PointType type, + std::vector > const &points, + Geom::Point const &pointer, bool constrained, Inkscape::Snapper::ConstraintLine const &constraint, Transformation transformation_type, - NR::Point const &transformation, - NR::Point const &origin, - NR::Dim2 dim, + Geom::Point const &transformation, + Geom::Point const &origin, + Geom::Dim2 dim, bool uniform) const { /* We have a list of points, which we are proposing to transform in some way. We need to see @@ -338,354 +530,449 @@ std::pair SnapManager::_snapTransformed( */ /* Quick check to see if we have any snappers that are enabled - ** Also used to globally disable all snapping + ** Also used to globally disable all snapping */ - if (SomeSnapperMightSnap() == false) { - return std::make_pair(transformation, false); + if (someSnapperMightSnap() == false) { + return Inkscape::SnappedPoint(); } - - std::vector transformed_points; - - for (std::vector::const_iterator i = points.begin(); i != points.end(); i++) { + + std::vector > transformed_points; + Geom::Rect bbox; + + for (std::vector >::const_iterator i = points.begin(); i != points.end(); i++) { /* Work out the transformed version of this point */ - NR::Point transformed; - switch (transformation_type) { - case TRANSLATION: - transformed = *i + transformation; - break; - case SCALE: - transformed = ((*i - origin) * NR::scale(transformation[NR::X], transformation[NR::Y])) + origin; - break; - case STRETCH: - { - NR::scale s(1, 1); - if (uniform) - s[NR::X] = s[NR::Y] = transformation[dim]; - else { - s[dim] = transformation[dim]; - s[1 - dim] = 1; - } - transformed = ((*i - origin) * s) + origin; - break; - } - case SKEW: - transformed = *i; - transformed[dim] += transformation[dim] * ((*i)[1 - dim] - origin[1 - dim]); - break; - default: - g_assert_not_reached(); - } - + Geom::Point transformed = _transformPoint(*i, transformation_type, transformation, origin, dim, uniform); + // add the current transformed point to the box hulling all transformed points - transformed_points.push_back(transformed); - } - + if (i == points.begin()) { + bbox = Geom::Rect(transformed, transformed); + } else { + bbox.expandTo(transformed); + } + + transformed_points.push_back(std::make_pair(transformed, (*i).second)); + } + /* The current best transformation */ - NR::Point best_transformation = transformation; + Geom::Point best_transformation = transformation; /* The current best metric for the best transformation; lower is better, NR_HUGE ** means that we haven't snapped anything. */ - NR::Coord best_metric = NR_HUGE; - NR::Coord best_second_metric = NR_HUGE; - bool best_at_intersection = false; + Geom::Point best_scale_metric(NR_HUGE, NR_HUGE); + Inkscape::SnappedPoint best_snapped_point; + g_assert(best_snapped_point.getAlwaysSnap() == false); // Check initialization of snapped point + g_assert(best_snapped_point.getAtIntersection() == false); - std::vector::const_iterator j = transformed_points.begin(); + std::vector >::const_iterator j = transformed_points.begin(); - //std::cout << std::endl; + // std::cout << std::endl; + for (std::vector >::const_iterator i = points.begin(); i != points.end(); i++) { - for (std::vector::const_iterator i = points.begin(); i != points.end(); i++) { - /* Snap it */ - Inkscape::SnappedPoint const snapped = constrained ? - constrainedSnap(type, *j, i == points.begin(), transformed_points, constraint, ignore) : freeSnap(type, *j, i == points.begin(), transformed_points, ignore); - - NR::Point result; - NR::Coord metric = NR_HUGE; - NR::Coord second_metric = NR_HUGE; - - if (snapped.getDistance() < NR_HUGE) { + Inkscape::SnappedPoint snapped_point; + Inkscape::Snapper::ConstraintLine dedicated_constraint = constraint; + Geom::Point const b = ((*i).first - origin); // vector to original point + + if (constrained) { + if ((transformation_type == SCALE || transformation_type == STRETCH) && uniform) { + // When uniformly scaling, each point will have its own unique constraint line, + // running from the scaling origin to the original untransformed point. We will + // calculate that line here + dedicated_constraint = Inkscape::Snapper::ConstraintLine(origin, b); + } else if (transformation_type == STRETCH) { // when non-uniform stretching { + dedicated_constraint = Inkscape::Snapper::ConstraintLine((*i).first, component_vectors[dim]); + } else if (transformation_type == TRANSLATION) { + // When doing a constrained translation, all points will move in the same direction, i.e. + // either horizontally or vertically. The lines along which they move are therefore all + // parallel, but might not be colinear. Therefore we will have to set the point through + // which the constraint-line runs here, for each point individually. + dedicated_constraint.setPoint((*i).first); + } // else: leave the original constraint, e.g. for skewing + if (transformation_type == SCALE && !uniform) { + g_warning("Non-uniform constrained scaling is not supported!"); + } + snapped_point = constrainedSnap(type, (*j).first, static_cast((*j).second), dedicated_constraint, i == points.begin(), bbox); + } else { + bool const c1 = fabs(b[Geom::X]) < 1e-6; + bool const c2 = fabs(b[Geom::Y]) < 1e-6; + if (transformation_type == SCALE && (c1 || c2) && !(c1 && c2)) { + // When scaling, a point aligned either horizontally or vertically with the origin can only + // move in that specific direction; therefore it should only snap in that direction, otherwise + // we will get snapped points with an invalid transformation + dedicated_constraint = Inkscape::Snapper::ConstraintLine(origin, component_vectors[c1]); + snapped_point = constrainedSnap(type, (*j).first, static_cast((*j).second), dedicated_constraint, i == points.begin(), bbox); + } else { + snapped_point = freeSnap(type, (*j).first, static_cast((*j).second), i == points.begin(), bbox); + } + } + // std::cout << "dist = " << snapped_point.getSnapDistance() << std::endl; + snapped_point.setPointerDistance(Geom::L2(pointer - (*i).first)); + + Geom::Point result; + Geom::Point scale_metric(NR_HUGE, NR_HUGE); + + if (snapped_point.getSnapped()) { /* We snapped. Find the transformation that describes where the snapped point has ** ended up, and also the metric for this transformation. */ + Geom::Point const a = (snapped_point.getPoint() - origin); // vector to snapped point + //Geom::Point const b = (*i - origin); // vector to original point + switch (transformation_type) { case TRANSLATION: - result = snapped.getPoint() - *i; - /* Consider the case in which a box is almost aligned with a grid in both + result = snapped_point.getPoint() - (*i).first; + /* Consider the case in which a box is almost aligned with a grid in both * horizontal and vertical directions. The distance to the intersection of * the grid lines will always be larger then the distance to a single grid - * line. If we prefer snapping to an intersection instead of to a single - * grid line, then we cannot use "metric = NR::L2(result)". Therefore the + * line. If we prefer snapping to an intersection instead of to a single + * grid line, then we cannot use "metric = Geom::L2(result)". Therefore the * snapped distance will be used as a metric. Please note that the snapped * distance is defined as the distance to the nearest line of the intersection, - * and not to the intersection itself! + * and not to the intersection itself! */ - metric = snapped.getDistance(); //used to be: metric = NR::L2(result); - second_metric = snapped.getSecondDistance(); + // Only for translations, the relevant metric will be the real snapped distance, + // so we don't have to do anything special here break; case SCALE: { - NR::Point const a = (snapped.getPoint() - origin); - NR::Point const b = (*i - origin); - result = NR::Point(a[NR::X] / b[NR::X], a[NR::Y] / b[NR::Y]); - metric = std::abs(NR::L2(result) - NR::L2(transformation)); + result = Geom::Point(NR_HUGE, NR_HUGE); + // If this point *i is horizontally or vertically aligned with + // the origin of the scaling, then it will scale purely in X or Y + // We can therefore only calculate the scaling in this direction + // and the scaling factor for the other direction should remain + // untouched (unless scaling is uniform ofcourse) + for (int index = 0; index < 2; index++) { + if (fabs(b[index]) > 1e-6) { // if SCALING CAN occur in this direction + if (fabs(fabs(a[index]/b[index]) - fabs(transformation[index])) > 1e-12) { // if SNAPPING DID occur in this direction + result[index] = a[index] / b[index]; // then calculate it! + } + // we might leave result[1-index] = NR_HUGE + // if scaling didn't occur in the other direction + } + } + // Compare the resulting scaling with the desired scaling + scale_metric = result - transformation; // One or both of its components might be NR_HUGE break; } case STRETCH: - { - for (int a = 0; a < 2; a++) { - if (uniform || a == dim) { - result[a] = (snapped.getPoint()[dim] - origin[dim]) / ((*i)[dim] - origin[dim]); - } else { - result[a] = 1; + result = Geom::Point(NR_HUGE, NR_HUGE); + if (fabs(b[dim]) > 1e-6) { // if STRETCHING will occur for this point + result[dim] = a[dim] / b[dim]; + result[1-dim] = uniform ? result[dim] : 1; + } else { // STRETCHING might occur for this point, but only when the stretching is uniform + if (uniform && fabs(b[1-dim]) > 1e-6) { + result[1-dim] = a[1-dim] / b[1-dim]; + result[dim] = result[1-dim]; } } - metric = std::abs(result[dim] - transformation[dim]); + // Store the metric for this transformation as a virtual distance + snapped_point.setSnapDistance(std::abs(result[dim] - transformation[dim])); + snapped_point.setSecondSnapDistance(NR_HUGE); break; - } case SKEW: - result[dim] = (snapped.getPoint()[dim] - (*i)[dim]) / ((*i)[1 - dim] - origin[1 - dim]); - metric = std::abs(result[dim] - transformation[dim]); + result[0] = (snapped_point.getPoint()[dim] - ((*i).first)[dim]) / (((*i).first)[1 - dim] - origin[1 - dim]); // skew factor + result[1] = transformation[1]; // scale factor + // Store the metric for this transformation as a virtual distance + snapped_point.setSnapDistance(std::abs(result[0] - transformation[0])); + snapped_point.setSecondSnapDistance(NR_HUGE); break; default: g_assert_not_reached(); } - - /* Note it if it's the best so far */ - bool const c1 = metric < best_metric; - bool const c2 = metric == best_metric && snapped.getAtIntersection() == true && best_at_intersection == false; - bool const c3a = metric == best_metric && snapped.getAtIntersection() == true && best_at_intersection == true; - bool const c3b = second_metric < best_second_metric; - - if (c1 || c2 || c3a && c3b) { - best_transformation = result; - best_metric = metric; - best_second_metric = second_metric; - best_at_intersection = snapped.getAtIntersection(); - //std::cout << "SEL "; - } //else { std::cout << " ";} + + // When scaling, we're considering the best transformation in each direction separately. We will have a metric in each + // direction, whereas for all other transformation we only a single one-dimensional metric. That's why we need to handle + // the scaling metric differently + if (transformation_type == SCALE) { + for (int index = 0; index < 2; index++) { + if (fabs(scale_metric[index]) < fabs(best_scale_metric[index])) { + best_transformation[index] = result[index]; + best_scale_metric[index] = fabs(scale_metric[index]); + // When scaling, we're considering the best transformation in each direction separately + // Therefore two different snapped points might together make a single best transformation + // We will however return only a single snapped point (e.g. to display the snapping indicator) + best_snapped_point = snapped_point; + // std::cout << "SEL "; + } // else { std::cout << " ";} + } + if (uniform) { + if (best_scale_metric[0] < best_scale_metric[1]) { + best_transformation[1] = best_transformation[0]; + best_scale_metric[1] = best_scale_metric[0]; + } else { + best_transformation[0] = best_transformation[1]; + best_scale_metric[0] = best_scale_metric[1]; + } + } + } else { // For all transformations other than scaling + if (best_snapped_point.isOtherSnapBetter(snapped_point, true)) { + best_transformation = result; + best_snapped_point = snapped_point; + } + } } - - //std::cout << "P_orig = " << (*i) << " | metric = " << metric << " | distance = " << snapped.getDistance() << " | second metric = " << second_metric << " | P_snap = " << snapped.getPoint() << std::endl; + j++; } - + + Geom::Coord best_metric; + if (transformation_type == SCALE) { + // When scaling, don't ever exit with one of scaling components set to NR_HUGE + for (int index = 0; index < 2; index++) { + if (best_transformation[index] == NR_HUGE) { + if (uniform && best_transformation[1-index] < NR_HUGE) { + best_transformation[index] = best_transformation[1-index]; + } else { + best_transformation[index] = transformation[index]; + } + } + } + best_metric = std::min(best_scale_metric[0], best_scale_metric[1]); + } else { // For all transformations other than scaling + best_metric = best_snapped_point.getSnapDistance(); + } + + best_snapped_point.setTransformation(best_transformation); // Using " < 1e6" instead of " < NR_HUGE" for catching some rounding errors // These rounding errors might be caused by NRRects, see bug #1584301 - return std::make_pair(best_transformation, best_metric < 1e6); + best_snapped_point.setSnapDistance(best_metric < 1e6 ? best_metric : NR_HUGE); + return best_snapped_point; } /** - * Try to snap a list of points to any interested snappers after they have undergone - * a translation. - * - * \param t Type of points. - * \param p Points. - * \param it List of items to ignore when snapping. - * \param tr Proposed translation. - * \return Snapped translation, if a snap occurred, and a flag indicating whether a snap occurred. + * \brief Apply a translation to a set of points and try to snap freely in 2 degrees-of-freedom + * + * \param point_type Category of points to which the source point belongs: node or bounding box. + * \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. + * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed). + * \param tr Proposed translation; the final translation can only be calculated after snapping has occurred + * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics. */ -std::pair SnapManager::freeSnapTranslation(Inkscape::Snapper::PointType t, - std::vector const &p, - std::list const &it, - NR::Point const &tr) const +Inkscape::SnappedPoint SnapManager::freeSnapTranslation(Inkscape::SnapPreferences::PointType point_type, + std::vector > const &p, + Geom::Point const &pointer, + Geom::Point const &tr) const { - return _snapTransformed( - t, p, it, false, NR::Point(), TRANSLATION, tr, NR::Point(), NR::X, false - ); -} + if (p.size() == 1) { + _displaySnapsource(point_type, std::make_pair(_transformPoint(p.at(0), TRANSLATION, tr, Geom::Point(0,0), Geom::X, false), (p.at(0)).second)); + } + return _snapTransformed(point_type, p, pointer, false, Geom::Point(0,0), TRANSLATION, tr, Geom::Point(0,0), Geom::X, false); +} /** - * Try to snap a list of points to any interested snappers after they have undergone a - * translation. A snap will only occur along a line described by a - * Inkscape::Snapper::ConstraintLine. - * - * \param t Type of points. - * \param p Points. - * \param it List of items to ignore when snapping. - * \param c Constraint line. - * \param tr Proposed translation. - * \return Snapped translation, if a snap occurred, and a flag indicating whether a snap occurred. + * \brief Apply a translation to a set of points and try to snap along a constraint + * + * \param point_type Category of points to which the source point belongs: node or bounding box. + * \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. + * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed). + * \param constraint The direction or line along which snapping must occur. + * \param tr Proposed translation; the final translation can only be calculated after snapping has occurred. + * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics. */ -std::pair SnapManager::constrainedSnapTranslation(Inkscape::Snapper::PointType t, - std::vector const &p, - std::list const &it, - Inkscape::Snapper::ConstraintLine const &c, - NR::Point const &tr) const +Inkscape::SnappedPoint SnapManager::constrainedSnapTranslation(Inkscape::SnapPreferences::PointType point_type, + std::vector > const &p, + Geom::Point const &pointer, + Inkscape::Snapper::ConstraintLine const &constraint, + Geom::Point const &tr) const { - return _snapTransformed( - t, p, it, true, c, TRANSLATION, tr, NR::Point(), NR::X, false - ); + if (p.size() == 1) { + _displaySnapsource(point_type, std::make_pair(_transformPoint(p.at(0), TRANSLATION, tr, Geom::Point(0,0), Geom::X, false), (p.at(0)).second)); + } + + return _snapTransformed(point_type, p, pointer, true, constraint, TRANSLATION, tr, Geom::Point(0,0), Geom::X, false); } /** - * Try to snap a list of points to any interested snappers after they have undergone - * a scale. - * - * \param t Type of points. - * \param p Points. - * \param it List of items to ignore when snapping. - * \param s Proposed scale. - * \param o Origin of proposed scale. - * \return Snapped scale, if a snap occurred, and a flag indicating whether a snap occurred. + * \brief Apply a scaling to a set of points and try to snap freely in 2 degrees-of-freedom + * + * \param point_type Category of points to which the source point belongs: node or bounding box. + * \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. + * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed). + * \param s Proposed scaling; the final scaling can only be calculated after snapping has occurred + * \param o Origin of the scaling + * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics. */ -std::pair SnapManager::freeSnapScale(Inkscape::Snapper::PointType t, - std::vector const &p, - std::list const &it, - NR::scale const &s, - NR::Point const &o) const +Inkscape::SnappedPoint SnapManager::freeSnapScale(Inkscape::SnapPreferences::PointType point_type, + std::vector > const &p, + Geom::Point const &pointer, + Geom::Scale const &s, + Geom::Point const &o) const { - return _snapTransformed( - t, p, it, false, NR::Point(), SCALE, NR::Point(s[NR::X], s[NR::Y]), o, NR::X, false - ); + if (p.size() == 1) { + _displaySnapsource(point_type, std::make_pair(_transformPoint(p.at(0), SCALE, Geom::Point(s[Geom::X], s[Geom::Y]), o, Geom::X, false), (p.at(0)).second)); + } + + return _snapTransformed(point_type, p, pointer, false, Geom::Point(0,0), SCALE, Geom::Point(s[Geom::X], s[Geom::Y]), o, Geom::X, false); } /** - * Try to snap a list of points to any interested snappers after they have undergone - * a scale. A snap will only occur along a line described by a - * Inkscape::Snapper::ConstraintLine. - * - * \param t Type of points. - * \param p Points. - * \param it List of items to ignore when snapping. - * \param s Proposed scale. - * \param o Origin of proposed scale. - * \return Snapped scale, if a snap occurred, and a flag indicating whether a snap occurred. + * \brief Apply a scaling to a set of points and snap such that the aspect ratio of the selection is preserved + * + * \param point_type Category of points to which the source point belongs: node or bounding box. + * \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. + * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed). + * \param s Proposed scaling; the final scaling can only be calculated after snapping has occurred + * \param o Origin of the scaling + * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics. */ -std::pair SnapManager::constrainedSnapScale(Inkscape::Snapper::PointType t, - std::vector const &p, - std::list const &it, - Inkscape::Snapper::ConstraintLine const &c, - NR::scale const &s, - NR::Point const &o) const +Inkscape::SnappedPoint SnapManager::constrainedSnapScale(Inkscape::SnapPreferences::PointType point_type, + std::vector > const &p, + Geom::Point const &pointer, + Geom::Scale const &s, + Geom::Point const &o) const { - return _snapTransformed( - t, p, it, true, c, SCALE, NR::Point(s[NR::X], s[NR::Y]), o, NR::X, false - ); -} + // When constrained scaling, only uniform scaling is supported. + if (p.size() == 1) { + _displaySnapsource(point_type, std::make_pair(_transformPoint(p.at(0), SCALE, Geom::Point(s[Geom::X], s[Geom::Y]), o, Geom::X, true), (p.at(0)).second)); + } + return _snapTransformed(point_type, p, pointer, true, Geom::Point(0,0), SCALE, Geom::Point(s[Geom::X], s[Geom::Y]), o, Geom::X, true); +} /** - * Try to snap a list of points to any interested snappers after they have undergone - * a stretch. - * - * \param t Type of points. - * \param p Points. - * \param it List of items to ignore when snapping. - * \param s Proposed stretch. - * \param o Origin of proposed stretch. + * \brief Apply a stretch to a set of points and snap such that the direction of the stretch is preserved + * + * \param point_type Category of points to which the source point belongs: node or bounding box. + * \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. + * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed). + * \param s Proposed stretch; the final stretch can only be calculated after snapping has occurred + * \param o Origin of the stretching * \param d Dimension in which to apply proposed stretch. - * \param u true if the stretch should be uniform (ie to be applied equally in both dimensions) - * \return Snapped stretch, if a snap occurred, and a flag indicating whether a snap occurred. + * \param u true if the stretch should be uniform (i.e. to be applied equally in both dimensions) + * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics. */ -std::pair SnapManager::freeSnapStretch(Inkscape::Snapper::PointType t, - std::vector const &p, - std::list const &it, - NR::Coord const &s, - NR::Point const &o, - NR::Dim2 d, - bool u) const +Inkscape::SnappedPoint SnapManager::constrainedSnapStretch(Inkscape::SnapPreferences::PointType point_type, + std::vector > const &p, + Geom::Point const &pointer, + Geom::Coord const &s, + Geom::Point const &o, + Geom::Dim2 d, + bool u) const { - std::pair const r = _snapTransformed( - t, p, it, false, NR::Point(), STRETCH, NR::Point(s, s), o, d, u - ); + if (p.size() == 1) { + _displaySnapsource(point_type, std::make_pair(_transformPoint(p.at(0), STRETCH, Geom::Point(s, s), o, d, u), (p.at(0)).second)); + } - return std::make_pair(r.first[d], r.second); + return _snapTransformed(point_type, p, pointer, true, Geom::Point(0,0), STRETCH, Geom::Point(s, s), o, d, u); } - /** - * Try to snap a list of points to any interested snappers after they have undergone - * a skew. - * - * \param t Type of points. - * \param p Points. - * \param it List of items to ignore when snapping. - * \param s Proposed skew. - * \param o Origin of proposed skew. + * \brief Apply a skew to a set of points and snap such that the direction of the skew is preserved + * + * \param point_type Category of points to which the source point belongs: node or bounding box. + * \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. + * \param pointer Location of the mouse pointer at the time dragging started (i.e. when the selection was still untransformed). + * \param constraint The direction or line along which snapping must occur. + * \param s Proposed skew; the final skew can only be calculated after snapping has occurred + * \param o Origin of the proposed skew * \param d Dimension in which to apply proposed skew. - * \return Snapped skew, if a snap occurred, and a flag indicating whether a snap occurred. + * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics. */ -std::pair SnapManager::freeSnapSkew(Inkscape::Snapper::PointType t, - std::vector const &p, - std::list const &it, - NR::Coord const &s, - NR::Point const &o, - NR::Dim2 d) const +Inkscape::SnappedPoint SnapManager::constrainedSnapSkew(Inkscape::SnapPreferences::PointType point_type, + std::vector > const &p, + Geom::Point const &pointer, + Inkscape::Snapper::ConstraintLine const &constraint, + Geom::Point const &s, + Geom::Point const &o, + Geom::Dim2 d) const { - std::pair const r = _snapTransformed( - t, p, it, false, NR::Point(), SKEW, NR::Point(s, s), o, d, false - ); + // "s" contains skew factor in s[0], and scale factor in s[1] + + // Snapping the nodes of the bounding box of a selection that is being transformed, will only work if + // the transformation of the bounding box is equal to the transformation of the individual nodes. This is + // NOT the case for example when rotating or skewing. The bounding box itself cannot possibly rotate or skew, + // so it's corners have a different transformation. The snappers cannot handle this, therefore snapping + // of bounding boxes is not allowed here. + g_assert(!(point_type & Inkscape::SnapPreferences::SNAPPOINT_BBOX)); + + if (p.size() == 1) { + _displaySnapsource(point_type, std::make_pair(_transformPoint(p.at(0), SKEW, s, o, d, false), (p.at(0)).second)); + } - return std::make_pair(r.first[d], r.second); + return _snapTransformed(point_type, p, pointer, true, constraint, SKEW, s, o, d, false); } -Inkscape::SnappedPoint SnapManager::findBestSnap(NR::Point const &p, SnappedConstraints &sc, bool constrained) const +/** + * \brief Given a set of possible snap targets, find the best target (which is not necessarily + * also the nearest target), and show the snap indicator if requested + * + * \param p Current position of the snap source + * \param source_type Detailed description of the source type, will be used by the snap indicator + * \param sc A structure holding all snap targets that have been found so far + * \param constrained True if the snap is constrained, e.g. for stretching or for purely horizontal translation. + * \param noCurves If true, then do consider snapping to intersections of curves, but not to the curves themself + * \return An instance of the SnappedPoint class, which holds data on the snap source, snap target, and various metrics + */ + +Inkscape::SnappedPoint SnapManager::findBestSnap(Geom::Point const &p, + Inkscape::SnapSourceType const source_type, + SnappedConstraints &sc, + bool constrained, + bool noCurves) const { - NR::Coord const guide_sens = guide.getDistance(); - NR::Coord grid_sens = 0; - - SnapManager::SnapperList const gs = getGridSnappers(); - SnapperList::const_iterator i = gs.begin(); - if (i != gs.end()) { - grid_sens = (*i)->getDistance(); - } - - // Store all snappoints, optionally together with their specific snapping range - std::list > sp_list; - // Most of these snapped points are already within the snapping range, because - // they have already been filtered by their respective snappers. In that case - // we can set the snapping range to NR_HUGE here. If however we're looking at - // intersections of e.g. a grid and guide line, then we'll have to determine - // once again whether we're within snapping range. In this case we will set - // the snapping range to e.g. min(guide_sens, grid_sens) - + + /* + std::cout << "Type and number of snapped constraints: " << std::endl; + std::cout << " Points : " << sc.points.size() << std::endl; + std::cout << " Lines : " << sc.lines.size() << std::endl; + std::cout << " Grid lines : " << sc.grid_lines.size()<< std::endl; + std::cout << " Guide lines : " << sc.guide_lines.size()<< std::endl; + std::cout << " Curves : " << sc.curves.size()<< std::endl; + */ + + // Store all snappoints + std::list sp_list; + // search for the closest snapped point Inkscape::SnappedPoint closestPoint; if (getClosestSP(sc.points, closestPoint)) { - sp_list.push_back(std::make_pair(closestPoint, NR_HUGE)); - } - - // search for the closest snapped line segment - Inkscape::SnappedLineSegment closestLineSegment; - if (getClosestSLS(sc.lines, closestLineSegment)) { - sp_list.push_back(std::make_pair(Inkscape::SnappedPoint(closestLineSegment), NR_HUGE)); - } - - if (_intersectionLS) { - // search for the closest snapped intersection of line segments - Inkscape::SnappedPoint closestLineSegmentIntersection; - if (getClosestIntersectionSLS(sc.lines, closestLineSegmentIntersection)) { - sp_list.push_back(std::make_pair(closestLineSegmentIntersection, NR_HUGE)); - } - } + sp_list.push_back(closestPoint); + } + + // search for the closest snapped curve + if (!noCurves) { + Inkscape::SnappedCurve closestCurve; + if (getClosestCurve(sc.curves, closestCurve)) { + sp_list.push_back(Inkscape::SnappedPoint(closestCurve)); + } + } + + if (snapprefs.getSnapIntersectionCS()) { + // search for the closest snapped intersection of curves + Inkscape::SnappedPoint closestCurvesIntersection; + if (getClosestIntersectionCS(sc.curves, p, closestCurvesIntersection, _desktop->dt2doc())) { + closestCurvesIntersection.setSource(source_type); + sp_list.push_back(closestCurvesIntersection); + } + } // search for the closest snapped grid line Inkscape::SnappedLine closestGridLine; - if (getClosestSL(sc.grid_lines, closestGridLine)) { - sp_list.push_back(std::make_pair(Inkscape::SnappedPoint(closestGridLine), NR_HUGE)); + if (getClosestSL(sc.grid_lines, closestGridLine)) { + sp_list.push_back(Inkscape::SnappedPoint(closestGridLine)); } - + // search for the closest snapped guide line Inkscape::SnappedLine closestGuideLine; if (getClosestSL(sc.guide_lines, closestGuideLine)) { - sp_list.push_back(std::make_pair(Inkscape::SnappedPoint(closestGuideLine), NR_HUGE)); + sp_list.push_back(Inkscape::SnappedPoint(closestGuideLine)); } - + // When freely snapping to a grid/guide/path, only one degree of freedom is eliminated - // Therefore we will try get fully constrained by finding an intersection with another grid/guide/path - + // Therefore we will try get fully constrained by finding an intersection with another grid/guide/path + // When doing a constrained snap however, we're already at an intersection of the constrained line and // the grid/guide/path we're snapping to. This snappoint is therefore fully constrained, so there's // no need to look for additional intersections @@ -693,44 +980,199 @@ Inkscape::SnappedPoint SnapManager::findBestSnap(NR::Point const &p, SnappedCons // search for the closest snapped intersection of grid lines Inkscape::SnappedPoint closestGridPoint; if (getClosestIntersectionSL(sc.grid_lines, closestGridPoint)) { - sp_list.push_back(std::make_pair(closestGridPoint, NR_HUGE)); + closestGridPoint.setSource(source_type); + closestGridPoint.setTarget(Inkscape::SNAPTARGET_GRID_INTERSECTION); + sp_list.push_back(closestGridPoint); } - + // search for the closest snapped intersection of guide lines Inkscape::SnappedPoint closestGuidePoint; if (getClosestIntersectionSL(sc.guide_lines, closestGuidePoint)) { - sp_list.push_back(std::make_pair(closestGuidePoint, NR_HUGE)); + closestGuidePoint.setSource(source_type); + closestGuidePoint.setTarget(Inkscape::SNAPTARGET_GUIDE_INTERSECTION); + sp_list.push_back(closestGuidePoint); } - + // search for the closest snapped intersection of grid with guide lines - if (_intersectionGG) { - Inkscape::SnappedPoint closestGridGuidePoint; - if (getClosestIntersectionSL(sc.grid_lines, sc.guide_lines, closestGridGuidePoint)) { - sp_list.push_back(std::make_pair(closestGridGuidePoint, std::min(guide_sens, grid_sens))); - } + if (snapprefs.getSnapIntersectionGG()) { + Inkscape::SnappedPoint closestGridGuidePoint; + if (getClosestIntersectionSL(sc.grid_lines, sc.guide_lines, closestGridGuidePoint)) { + closestGridGuidePoint.setSource(source_type); + closestGridGuidePoint.setTarget(Inkscape::SNAPTARGET_GRID_GUIDE_INTERSECTION); + sp_list.push_back(closestGridGuidePoint); + } } } - + // now let's see which snapped point gets a thumbs up - Inkscape::SnappedPoint bestPoint(p, NR_HUGE); - for (std::list >::const_iterator i = sp_list.begin(); i != sp_list.end(); i++) { - // first find out if this snapped point is within snapping range - if ((*i).first.getDistance() <= (*i).second) { - // if it's the first point - bool c1 = (i == sp_list.begin()); - // or, if it's closer - bool c2 = (*i).first.getDistance() < bestPoint.getDistance(); - // or, if it's just as close then consider the second distance - // (which is only relevant for points at an intersection) - bool c3a = ((*i).first.getDistance() == bestPoint.getDistance()); - bool c3b = (*i).first.getSecondDistance() < bestPoint.getSecondDistance(); - // then prefer this point over the previous one - if (c1 || c2 || c3a && c3b) { - bestPoint = (*i).first; + Inkscape::SnappedPoint bestSnappedPoint = Inkscape::SnappedPoint(p, Inkscape::SNAPSOURCE_UNDEFINED, Inkscape::SNAPTARGET_UNDEFINED, NR_HUGE, 0, false, false); + // std::cout << "Finding the best snap..." << std::endl; + for (std::list::const_iterator i = sp_list.begin(); i != sp_list.end(); i++) { + // first find out if this snapped point is within snapping range + // std::cout << "sp = " << from_2geom((*i).getPoint()); + if ((*i).getSnapDistance() <= (*i).getTolerance()) { + // if it's the first point, or if it is closer than the best snapped point so far + if (i == sp_list.begin() || bestSnappedPoint.isOtherSnapBetter(*i, false)) { + // then prefer this point over the previous one + bestSnappedPoint = *i; + } + } + // std::cout << std::endl; + } + + // Update the snap indicator, if requested + if (_snapindicator) { + if (bestSnappedPoint.getSnapped()) { + _desktop->snapindicator->set_new_snaptarget(bestSnappedPoint); + } else { + _desktop->snapindicator->remove_snaptarget(); + } + } + + // std::cout << "findBestSnap = " << bestSnappedPoint.getPoint() << " | dist = " << bestSnappedPoint.getSnapDistance() << std::endl; + return bestSnappedPoint; +} + +/** + * \brief Prepare the snap manager for the actual snapping, which includes building a list of snap targets + * to ignore and toggling the snap indicator + * + * There are two overloaded setup() methods, of which this one only allows for a single item to be ignored + * whereas the other one will take a list of items to ignore + * + * \param desktop Reference to the desktop to which this snap manager is attached + * \param snapindicator If true then a snap indicator will be displayed automatically (when enabled in the preferences) + * \param item_to_ignore This item will not be snapped to, e.g. the item that is currently being dragged. This avoids "self-snapping" + * \param unselected_nodes Stationary nodes of the path that is currently being edited in the node tool and + * that can be snapped too. Nodes not in this list will not be snapped to, to avoid "self-snapping". Of each + * unselected node both the position (Geom::Point) and the type (Inkscape::SnapTargetType) will be stored + * \param guide_to_ignore Guide that is currently being dragged and should not be snapped to + */ + +void SnapManager::setup(SPDesktop const *desktop, + bool snapindicator, + SPItem const *item_to_ignore, + std::vector > *unselected_nodes, + SPGuide *guide_to_ignore) +{ + g_assert(desktop != NULL); + _item_to_ignore = item_to_ignore; + _items_to_ignore = NULL; + _desktop = desktop; + _snapindicator = snapindicator; + _unselected_nodes = unselected_nodes; + _guide_to_ignore = guide_to_ignore; +} + +/** + * \brief Prepare the snap manager for the actual snapping, which includes building a list of snap targets + * to ignore and toggling the snap indicator + * + * There are two overloaded setup() methods, of which the other one only allows for a single item to be ignored + * whereas this one will take a list of items to ignore + * + * \param desktop Reference to the desktop to which this snap manager is attached + * \param snapindicator If true then a snap indicator will be displayed automatically (when enabled in the preferences) + * \param items_to_ignore These items will not be snapped to, e.g. the items that are currently being dragged. This avoids "self-snapping" + * \param unselected_nodes Stationary nodes of the path that is currently being edited in the node tool and + * that can be snapped too. Nodes not in this list will not be snapped to, to avoid "self-snapping". Of each + * unselected node both the position (Geom::Point) and the type (Inkscape::SnapTargetType) will be stored + * \param guide_to_ignore Guide that is currently being dragged and should not be snapped to + */ + +void SnapManager::setup(SPDesktop const *desktop, + bool snapindicator, + std::vector &items_to_ignore, + std::vector > *unselected_nodes, + SPGuide *guide_to_ignore) +{ + g_assert(desktop != NULL); + _item_to_ignore = NULL; + _items_to_ignore = &items_to_ignore; + _desktop = desktop; + _snapindicator = snapindicator; + _unselected_nodes = unselected_nodes; + _guide_to_ignore = guide_to_ignore; +} + +SPDocument *SnapManager::getDocument() const +{ + return _named_view->document; +} + +/** + * \brief Takes an untransformed point, applies the given transformation, and returns the transformed point. Eliminates lots of duplicated code + * + * \param p The untransformed position of the point, paired with an identifier of the type of the snap source. + * \param transformation_type Type of transformation to apply. + * \param transformation Mathematical description of the transformation; details depend on the type. + * \param origin Origin of the transformation, if applicable. + * \param dim Dimension to which the transformation applies, if applicable. + * \param uniform true if the transformation should be uniform; only applicable for stretching and scaling. + * \return The position of the point after transformation + */ + +Geom::Point SnapManager::_transformPoint(std::pair const &p, + Transformation const transformation_type, + Geom::Point const &transformation, + Geom::Point const &origin, + Geom::Dim2 const dim, + bool const uniform) const +{ + /* Work out the transformed version of this point */ + Geom::Point transformed; + switch (transformation_type) { + case TRANSLATION: + transformed = p.first + transformation; + break; + case SCALE: + transformed = (p.first - origin) * Geom::Scale(transformation[Geom::X], transformation[Geom::Y]) + origin; + break; + case STRETCH: + { + Geom::Scale s(1, 1); + if (uniform) + s[Geom::X] = s[Geom::Y] = transformation[dim]; + else { + s[dim] = transformation[dim]; + s[1 - dim] = 1; } + transformed = ((p.first - origin) * s) + origin; + break; + } + case SKEW: + // Apply the skew factor + transformed[dim] = (p.first)[dim] + transformation[0] * ((p.first)[1 - dim] - origin[1 - dim]); + // While skewing, mirroring and scaling (by integer multiples) in the opposite direction is also allowed. + // Apply that scale factor here + transformed[1-dim] = (p.first - origin)[1 - dim] * transformation[1] + origin[1 - dim]; + break; + default: + g_assert_not_reached(); + } + + return transformed; +} + +/** + * \brief Mark the location of the snap source (not the snap target!) on the canvas by drawing a symbol + * + * \param point_type Category of points to which the source point belongs: node, guide or bounding box + * \param p The transformed position of the source point, paired with an identifier of the type of the snap source. + */ + +void SnapManager::_displaySnapsource(Inkscape::SnapPreferences::PointType point_type, std::pair const &p) const { + + Inkscape::Preferences *prefs = Inkscape::Preferences::get(); + if (prefs->getBool("/options/snapclosestonly/value")) { + bool p_is_a_node = point_type & Inkscape::SnapPreferences::SNAPPOINT_NODE; + bool p_is_a_bbox = point_type & Inkscape::SnapPreferences::SNAPPOINT_BBOX; + if (snapprefs.getSnapEnabledGlobally() && ((p_is_a_node && snapprefs.getSnapModeNode()) || (p_is_a_bbox && snapprefs.getSnapModeBBox()))) { + _desktop->snapindicator->set_new_snapsource(p); + } else { + _desktop->snapindicator->remove_snapsource(); } } - return bestPoint; } /*