X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Fsnap.cpp;h=cb4ea3f5882af10ed7bad80830513ccbb4935728;hb=80c9473a95dd9a83020a247201452e45ec9750c3;hp=111ef619f473ea7c7a3e35611d177e1d143cbf87;hpb=f951374eef04129c6a0d213e7ab4d9ed2095ca69;p=inkscape.git diff --git a/src/snap.cpp b/src/snap.cpp index 111ef619f..cb4ea3f58 100644 --- a/src/snap.cpp +++ b/src/snap.cpp @@ -2,44 +2,179 @@ /** * \file snap.cpp - * - * \brief Various snapping methods + * \brief SnapManager class. * * Authors: * Lauris Kaplinski * 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 * * Released under GNU GPL, read the file 'COPYING' for more information */ +#include + #include "sp-namedview.h" #include "snap.h" +#include "snapped-line.h" + #include #include #include +#include "display/canvas-grid.h" + +#include "inkscape.h" +#include "desktop.h" +#include "sp-guide.h" +using std::vector; + +/** + * Construct a SnapManager for a SPNamedView. + * + * \param v `Owning' SPNamedView. + */ + +SnapManager::SnapManager(SPNamedView const *v) : + guide(v, 0), + object(v, 0), + _named_view(v), + _include_item_center(false), + _snap_enabled_globally(true) +{ +} + + +/** + * \return List of snappers that we use. + */ +SnapManager::SnapperList +SnapManager::getSnappers() const +{ + SnapManager::SnapperList s; + s.push_back(&guide); + s.push_back(&object); + + SnapManager::SnapperList gs = getGridSnappers(); + s.splice(s.begin(), gs); + + return s; +} + +/** + * \return List of gridsnappers that we use. + */ +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()) { + for ( GSList const *l = _named_view->grids; l != NULL; l = l->next) { + Inkscape::CanvasGrid *grid = (Inkscape::CanvasGrid*) l->data; + s.push_back(grid->snapper); + } + } + + return s; +} /** * \return true if one of the snappers will try to snap something. */ -bool SnapManager::willSnapSomething() const + +bool SnapManager::SomeSnapperMightSnap() const { - SPNamedView::SnapperList s = namedview->getSnappers(); - SPNamedView::SnapperList::const_iterator i = s.begin(); - while (i != s.end() && (*i)->willSnapSomething() == false) { + if (!_snap_enabled_globally) { + 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(). + * + * */ -/* FIXME: lots of cut-and-paste here. This needs some -** functor voodoo to cut it all down a bit. -*/ + +void SnapManager::setSnapModeBBox(bool enabled) +{ + //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 +} + +bool SnapManager::getSnapModeBBox() const +{ + return guide.getSnapFrom(Inkscape::Snapper::SNAPPOINT_BBOX); +} + +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); +} + +bool SnapManager::getSnapModeNode() const +{ + return guide.getSnapFrom(Inkscape::Snapper::SNAPPOINT_NODE); +} + +void SnapManager::setSnapModeGuide(bool enabled) +{ + object.setSnapFrom(Inkscape::Snapper::SNAPPOINT_GUIDE, enabled); +} + +bool SnapManager::getSnapModeGuide() const +{ + return object.getSnapFrom(Inkscape::Snapper::SNAPPOINT_GUIDE); +} + +/** + * Try to snap a point to any interested snappers. + * + * \param t Type of point. + * \param p Point. + * \param it Item to ignore when snapping. + * \return Snapped point. + */ Inkscape::SnappedPoint SnapManager::freeSnap(Inkscape::Snapper::PointType t, NR::Point const &p, @@ -48,350 +183,615 @@ Inkscape::SnappedPoint SnapManager::freeSnap(Inkscape::Snapper::PointType t, { std::list lit; lit.push_back(it); - return freeSnap(t, p, lit); + + std::vector points_to_snap; + points_to_snap.push_back(p); + + return freeSnap(t, p, true, points_to_snap, lit); } +/** + * 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. + */ 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 { - Inkscape::SnappedPoint r(p, NR_HUGE); + if (!SomeSnapperMightSnap()) { + return Inkscape::SnappedPoint(p, NR_HUGE, 0, false); + } + + SnappedConstraints sc; + + SnapperList const snappers = getSnappers(); - SPNamedView::SnapperList snappers = namedview->getSnappers(); - for (SPNamedView::SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) { - Inkscape::SnappedPoint const s = (*i)->freeSnap(t, p, it); - if (s.getDistance() < r.getDistance()) { - r = s; - } + for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) { + (*i)->freeSnap(sc, t, p, first_point, points_to_snap, it); } - return r; + return findBestSnap(p, 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. + */ Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::Snapper::PointType t, NR::Point const &p, - NR::Point const &c, + Inkscape::Snapper::ConstraintLine const &c, SPItem const *it) const { std::list lit; lit.push_back(it); - return constrainedSnap(t, p, c, lit); + + std::vector points_to_snap; + points_to_snap.push_back(p); + + return constrainedSnap(t, p, true, points_to_snap, c, lit); } + +/** + * 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. + */ + Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::Snapper::PointType t, NR::Point const &p, - NR::Point const &c, + bool const &first_point, + std::vector &points_to_snap, + Inkscape::Snapper::ConstraintLine const &c, std::list const &it) const { - Inkscape::SnappedPoint r(p, NR_HUGE); - - SPNamedView::SnapperList snappers = namedview->getSnappers(); - for (SPNamedView::SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) { - Inkscape::SnappedPoint const s = (*i)->constrainedSnap(t, p, c, it); - if (s.getDistance() < r.getDistance()) { - r = s; - } + if (!SomeSnapperMightSnap()) { + return Inkscape::SnappedPoint(p, NR_HUGE, 0, false); + } + + 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); } - return r; + return findBestSnap(p, sc, true); } - -std::pair SnapManager::freeSnapTranslation(Inkscape::Snapper::PointType t, - std::vector const &p, - std::list const &it, - NR::Point const &tr) const +Inkscape::SnappedPoint SnapManager::guideSnap(NR::Point const &p, + NR::Point const &guide_normal) const { - if (willSnapSomething() == false) { - return std::make_pair(tr, false); - } - - NR::Point best_translation = tr; - NR::Coord best_distance = NR_HUGE; - - for (std::vector::const_iterator i = p.begin(); i != p.end(); i++) { - /* Translated version of this point */ - NR::Point const q = *i + tr; - /* Snap it */ - Inkscape::SnappedPoint s = freeSnap(t, q, it); - if (s.getDistance() < NR_HUGE) { - /* Resulting translation */ - NR::Point const r = s.getPoint() - *i; - NR::Coord const d = NR::L2(r); - if (d < best_distance) { - best_distance = d; - best_translation = r; - } - } + // This method is used to snap a guide to nodes, while dragging the guide around + + if (!(object.GuidesMightSnap() && _snap_enabled_globally)) { + return Inkscape::SnappedPoint(p, NR_HUGE, 0, false); } - - return std::make_pair(best_translation, best_distance < NR_HUGE); + + SnappedConstraints sc; + object.guideSnap(sc, p, guide_normal); + + return findBestSnap(p, sc, false); } +/** + * 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. + * \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; only applicable for stretching and scaling. + */ -std::pair SnapManager::constrainedSnapTranslation(Inkscape::Snapper::PointType t, - std::vector const &p, - NR::Point const &c, - std::list const &it, - NR::Point const &tr) const +std::pair SnapManager::_snapTransformed( + Inkscape::Snapper::PointType type, + std::vector const &points, + std::list const &ignore, + bool constrained, + Inkscape::Snapper::ConstraintLine const &constraint, + Transformation transformation_type, + NR::Point const &transformation, + NR::Point const &origin, + NR::Dim2 dim, + bool uniform) const { - if (willSnapSomething() == false) { - return std::make_pair(tr, false); + /* We have a list of points, which we are proposing to transform in some way. We need to see + ** if any of these points, when transformed, snap to anything. If they do, we return the + ** appropriate transformation with `true'; otherwise we return the original scale with `false'. + */ + + /* Quick check to see if we have any snappers that are enabled + ** Also used to globally disable all snapping + */ + if (SomeSnapperMightSnap() == false) { + return std::make_pair(transformation, false); } + + std::vector transformed_points; + + 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(); + } + + // add the current transformed point to the box hulling all transformed points + transformed_points.push_back(transformed); + } + + /* The current best transformation */ + NR::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; + NR::Point best_scale_metric(NR_HUGE, NR_HUGE); + bool best_at_intersection = false; + bool best_always_snap = false; + + std::vector::const_iterator j = transformed_points.begin(); + + //std::cout << std::endl; + + for (std::vector::const_iterator i = points.begin(); i != points.end(); i++) { + + /* Snap it */ + Inkscape::SnappedPoint snapped; + + if (constrained) { + Inkscape::Snapper::ConstraintLine dedicated_constraint = constraint; + 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, (*i) - origin); + } else if (transformation_type == STRETCH || transformation_type == SKEW) { // when skewing or non-uniform stretching { + dedicated_constraint = Inkscape::Snapper::ConstraintLine((*i), component_vectors[dim]); + } // else: leave the original constraint, e.g. for constrained translation + if (transformation_type == SCALE && !uniform) { + g_warning("Non-uniform constrained scaling is not supported!"); + } + snapped = constrainedSnap(type, *j, i == points.begin(), transformed_points, dedicated_constraint, ignore); + } else { + snapped = freeSnap(type, *j, i == points.begin(), transformed_points, ignore); + } - NR::Point best_translation = tr; - NR::Coord best_distance = NR_HUGE; - - for (std::vector::const_iterator i = p.begin(); i != p.end(); i++) { - /* Translated version of this point */ - NR::Point const q = *i + tr; - /* Snap it */ - Inkscape::SnappedPoint s = constrainedSnap(t, q, c, it); - if (s.getDistance() < NR_HUGE) { - /* Resulting translation */ - NR::Point const r = s.getPoint() - *i; - NR::Coord const d = NR::L2(r); - if (d < best_distance) { - best_distance = d; - best_translation = r; + NR::Point result; + NR::Coord metric = NR_HUGE; + NR::Coord second_metric = NR_HUGE; + NR::Point scale_metric(NR_HUGE, NR_HUGE); + + if (snapped.getDistance() < NR_HUGE) { + /* We snapped. Find the transformation that describes where the snapped point has + ** ended up, and also the metric for this transformation. + */ + NR::Point const a = (snapped.getPoint() - origin); // vector to snapped point + NR::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 + * 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 + * 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! + */ + metric = snapped.getDistance(); //used to be: metric = NR::L2(result); + second_metric = snapped.getSecondDistance(); + break; + case SCALE: + { + result = NR::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: + result = NR::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]); + break; + case SKEW: + result[dim] = (snapped.getPoint()[dim] - (*i)[dim]) / ((*i)[1 - dim] - origin[1 - dim]); + metric = std::abs(result[dim] - transformation[dim]); + break; + default: + g_assert_not_reached(); + } + + /* Note it if it's the best so far */ + 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]); + //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]; + } + } + best_metric = std::min(best_scale_metric[0], best_scale_metric[1]); + //std::cout << "P_orig = " << (*i) << " | scale_metric = " << scale_metric << " | distance = " << snapped.getDistance() << " | P_snap = " << snapped.getPoint() << std::endl; + } else { + 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; + bool const c4 = snapped.getAlwaysSnap() == true && best_always_snap == false; + bool const c4n = snapped.getAlwaysSnap() == false && best_always_snap == true; + + if ((c1 || c2 || (c3a && c3b) || c4) && !c4n) { + best_transformation = result; + best_metric = metric; + best_second_metric = second_metric; + best_at_intersection = snapped.getAtIntersection(); + best_always_snap = snapped.getAlwaysSnap(); + //std::cout << "SEL "; + } //else { std::cout << " ";} + //std::cout << "P_orig = " << (*i) << " | metric = " << metric << " | distance = " << snapped.getDistance() << " | second metric = " << second_metric << " | P_snap = " << snapped.getPoint() << std::endl; } } + + j++; } - - return std::make_pair(best_translation, best_distance < NR_HUGE); + + 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]; + } + } + } + } + + // 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); } - - - - -/// Minimal distance to norm before point is considered for snap. -static const double MIN_DIST_NORM = 1.0; - /** - * Try to snap \a req in one dimension. + * Try to snap a list of points to any interested snappers after they have undergone + * a translation. * - * \param nv NamedView to use. - * \param req Point to snap; updated to the snapped point if a snap occurred. - * \param dim Dimension to snap in. - * \return Distance to the snap point along the \a dim axis, or \c NR_HUGE - * if no snap occurred. + * \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. */ -NR::Coord namedview_dim_snap(SPNamedView const *nv, Inkscape::Snapper::PointType t, NR::Point &req, - NR::Dim2 const dim, SPItem const *it) -{ - return namedview_vector_snap(nv, t, req, component_vectors[dim], it); -} -NR::Coord namedview_dim_snap(SPNamedView const *nv, Inkscape::Snapper::PointType t, NR::Point &req, - NR::Dim2 const dim, std::list const &it) +std::pair SnapManager::freeSnapTranslation(Inkscape::Snapper::PointType t, + std::vector const &p, + std::list const &it, + NR::Point const &tr) const { - return namedview_vector_snap(nv, t, req, component_vectors[dim], it); + return _snapTransformed( + t, p, it, false, NR::Point(), TRANSLATION, tr, NR::Point(), NR::X, false + ); } -NR::Coord namedview_vector_snap(SPNamedView const *nv, Inkscape::Snapper::PointType t, - NR::Point &req, NR::Point const &d, - SPItem const *it) -{ - std::list lit; - lit.push_back(it); - return namedview_vector_snap(nv, t, req, d, lit); -} - /** - * Look for snap point along the line described by the point \a req - * and the direction vector \a d. - * Modifies req to the snap point, if one is found. - * \return The distance from \a req to the snap point along the vector \a d, - * or \c NR_HUGE if no snap point was found. + * 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. * - * \pre d â‰  (0, 0). + * \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. */ -NR::Coord namedview_vector_snap(SPNamedView const *nv, Inkscape::Snapper::PointType t, - NR::Point &req, NR::Point const &d, - std::list const &it) -{ - g_assert(nv != NULL); - g_assert(SP_IS_NAMEDVIEW(nv)); - SPNamedView::SnapperList snappers = nv->getSnappers(); - - NR::Coord best = NR_HUGE; - for (SPNamedView::SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); i++) { - Inkscape::SnappedPoint const s = (*i)->constrainedSnap(t, req, d, it); - if (s.getDistance() < best) { - req = s.getPoint(); - best = s.getDistance(); - } - } - - return best; +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 +{ + return _snapTransformed( + t, p, it, true, c, TRANSLATION, tr, NR::Point(), NR::X, false + ); } -/* - * functions for lists of points +/** + * Try to snap a list of points to any interested snappers after they have undergone + * a scale. * - * All functions take a list of NR::Point and parameter indicating the proposed transformation. - * They return the updated transformation parameter. + * \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. */ -/** - * Snap list of points in one dimension. - * \return Coordinate difference. - */ -std::pair namedview_dim_snap_list(SPNamedView const *nv, Inkscape::Snapper::PointType t, - const std::vector &p, - NR::Coord const dx, NR::Dim2 const dim, - std::list const &it - ) +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 { - NR::Coord dist = NR_HUGE; - NR::Coord xdist = dx; - - SnapManager const m(nv); - - if (m.willSnapSomething()) { - for (std::vector::const_iterator i = p.begin(); i != p.end(); i++) { - NR::Point q = *i; - NR::Coord const pre = q[dim]; - q[dim] += dx; - NR::Coord const d = namedview_dim_snap(nv, t, q, dim, it); - if (d < dist) { - xdist = q[dim] - pre; - dist = d; - } - } - } - - return std::make_pair(xdist, dist < NR_HUGE); + return _snapTransformed( + t, p, it, false, NR::Point(), SCALE, NR::Point(s[NR::X], s[NR::Y]), o, NR::X, false + ); } + /** - * Snap list of points in two dimensions. + * 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. */ -std::pair namedview_vector_snap_list(SPNamedView const *nv, Inkscape::Snapper::PointType t, - const std::vector &p, NR::Point const &norm, - NR::scale const &s, std::list const &it) -{ - using NR::X; - using NR::Y; - - SnapManager const m(nv); - if (m.willSnapSomething() == false) { - return std::make_pair(s[X], false); - } - - NR::Coord dist = NR_HUGE; - double ratio = fabs(s[X]); - for (std::vector::const_iterator i = p.begin(); i != p.end(); i++) { - NR::Point const &q = *i; - NR::Point check = ( q - norm ) * s + norm; - if (NR::LInfty( q - norm ) > MIN_DIST_NORM) { - NR::Coord d = namedview_vector_snap(nv, t, check, check - norm, it); - if (d < dist) { - dist = d; - NR::Dim2 const dominant = ( ( fabs( q[X] - norm[X] ) > - fabs( q[Y] - norm[Y] ) ) - ? X - : Y ); - ratio = ( ( check[dominant] - norm[dominant] ) - / ( q[dominant] - norm[dominant] ) ); - } - } - } - - return std::make_pair(ratio, dist < NR_HUGE); +std::pair SnapManager::constrainedSnapScale(Inkscape::Snapper::PointType t, + std::vector const &p, + std::list const &it, + NR::scale const &s, + NR::Point const &o) const +{ + // When constrained scaling, only uniform scaling is supported. + return _snapTransformed( + t, p, it, true, NR::Point(), SCALE, NR::Point(s[NR::X], s[NR::Y]), o, NR::X, true + ); } /** - * Try to snap points in \a p after they have been scaled by \a sx with respect to - * the origin \a norm. The best snap is the one that changes the scale least. + * Try to snap a list of points to any interested snappers after they have undergone + * a stretch. * - * \return Pair containing snapped scale and a flag which is true if a snap was made. + * \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. + * \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. */ -std::pair namedview_dim_snap_list_scale(SPNamedView const *nv, Inkscape::Snapper::PointType t, - const std::vector &p, NR::Point const &norm, - double const sx, NR::Dim2 dim, - std::list const &it) -{ - SnapManager const m(nv); - if (m.willSnapSomething() == false) { - return std::make_pair(sx, false); - } - - g_assert(dim < 2); - NR::Coord dist = NR_HUGE; - double scale = sx; +std::pair SnapManager::constrainedSnapStretch(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 +{ + std::pair const r = _snapTransformed( + t, p, it, true, NR::Point(), STRETCH, NR::Point(s, s), o, d, u + ); - for (std::vector::const_iterator i = p.begin(); i != p.end(); i++) { - NR::Point q = *i; - NR::Point check = q; + return std::make_pair(r.first[d], r.second); +} - /* Scaled version of the point we are looking at */ - check[dim] = (sx * (q - norm) + norm)[dim]; - if (fabs (q[dim] - norm[dim]) > MIN_DIST_NORM) { - /* Snap this point */ - const NR::Coord d = namedview_dim_snap (nv, t, check, dim, it); - /* Work out the resulting scale factor */ - double snapped_scale = (check[dim] - norm[dim]) / (q[dim] - norm[dim]); +/** + * 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. + * \param d Dimension in which to apply proposed skew. + * \return Snapped skew, if a snap occurred, and a flag indicating whether a snap occurred. + */ - if (dist == NR_HUGE || fabs(snapped_scale - sx) < fabs(scale - sx)) { - /* This is either the first point, or the snapped scale - ** is the closest yet to the original. - */ - scale = snapped_scale; - dist = d; - } - } - } +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 +{ + std::pair const r = _snapTransformed( + t, p, it, false, NR::Point(), SKEW, NR::Point(s, s), o, d, false + ); - return std::make_pair(scale, dist < NR_HUGE); + return std::make_pair(r.first[d], r.second); } -/** - * Try to snap points after they have been skewed. - */ -double namedview_dim_snap_list_skew(SPNamedView const *nv, Inkscape::Snapper::PointType t, - const std::vector &p, NR::Point const &norm, - double const sx, NR::Dim2 const dim) +Inkscape::SnappedPoint SnapManager::findBestSnap(NR::Point const &p, SnappedConstraints &sc, bool constrained) const { - SnapManager const m(nv); - - if (m.willSnapSomething() == false) { - return sx; + // 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(closestPoint); + } + + // search for the closest snapped line segment + Inkscape::SnappedLineSegment closestLineSegment; + if (getClosestSLS(sc.lines, closestLineSegment)) { + sp_list.push_back(Inkscape::SnappedPoint(closestLineSegment)); } - - g_assert(dim < 2); - - gdouble dist = NR_HUGE; - gdouble skew = sx; - - for (std::vector::const_iterator i = p.begin(); i != p.end(); i++) { - NR::Point q = *i; - NR::Point check = q; - // apply shear - check[dim] += sx * (q[!dim] - norm[!dim]); - if (fabs (q[!dim] - norm[!dim]) > MIN_DIST_NORM) { - const gdouble d = namedview_dim_snap (nv, t, check, dim, NULL); - if (d < fabs (dist)) { - dist = d; - skew = (check[dim] - q[dim]) / (q[!dim] - norm[!dim]); + + if (_intersectionLS) { + // search for the closest snapped intersection of line segments + Inkscape::SnappedPoint closestLineSegmentIntersection; + if (getClosestIntersectionSLS(sc.lines, closestLineSegmentIntersection)) { + sp_list.push_back(closestLineSegmentIntersection); + } + } + + // search for the closest snapped grid line + Inkscape::SnappedLine closestGridLine; + 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(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 + + // 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 + if (!constrained) { + // search for the closest snapped intersection of grid lines + Inkscape::SnappedPoint closestGridPoint; + if (getClosestIntersectionSL(sc.grid_lines, closestGridPoint)) { + 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(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(closestGridGuidePoint); + } + } + } + + // now let's see which snapped point gets a thumbs up + Inkscape::SnappedPoint bestSnappedPoint = Inkscape::SnappedPoint(p, NR_HUGE, 0, false); + 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).getDistance() <= (*i).getTolerance()) { + // if it's the first point + bool c1 = (i == sp_list.begin()); + // or, if it's closer + bool c2 = (*i).getDistance() < bestSnappedPoint.getDistance(); + // or, if it's for a snapper with "always snap" turned on, and the previous wasn't + bool c3 = (*i).getAlwaysSnap() && !bestSnappedPoint.getAlwaysSnap(); + // But in no case fall back from a snapper with "always snap" on to one with "always snap" off + bool c3n = !(*i).getAlwaysSnap() && bestSnappedPoint.getAlwaysSnap(); + // or, if it's just as close then consider the second distance + // (which is only relevant for points at an intersection) + bool c4a = ((*i).getDistance() == bestSnappedPoint.getDistance()); + bool c4b = (*i).getSecondDistance() < bestSnappedPoint.getSecondDistance(); + // then prefer this point over the previous one + if ((c1 || c2 || c3 || (c4a && c4b)) && !c3n) { + bestSnappedPoint = *i; } } } - - return skew; + + return bestSnappedPoint; } /*