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+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * SnapManager class.
+ *
+ * Authors:
+ * Lauris Kaplinski <lauris@kaplinski.com>
+ * Frank Felfe <innerspace@iname.com>
+ * Nathan Hurst <njh@njhurst.com>
+ * Carl Hetherington <inkscape@carlh.net>
+ * Diederik van Lierop <mail@diedenrezi.nl>
+ *
+ * Copyright (C) 2006-2007 Johan Engelen <johan@shouraizou.nl>
+ * Copyright (C) 2004 Nathan Hurst
+ * Copyright (C) 1999-2012 Authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <memory>
+#include <utility>
+#include <vector>
+
+#include <glibmm/timer.h>
+
+#include <2geom/transforms.h>
+
+#include "snap.h"
+#include "snap-enums.h"
+#include "preferences.h"
+#include "object/sp-use.h"
+#include "object/sp-mask.h"
+#include "live_effects/effect-enum.h"
+#include "object/sp-filter.h"
+#include "object/sp-object.h"
+#include "object/sp-page.h"
+#include "object/sp-clippath.h"
+#include "object/sp-root.h"
+#include "style.h"
+
+#include "desktop.h"
+#include "inkscape.h"
+#include "pure-transform.h"
+
+#include "display/control/canvas-grid.h"
+#include "display/control/snap-indicator.h"
+
+#include "helper/mathfns.h"
+
+#include "object/sp-namedview.h"
+#include "object/sp-guide.h"
+
+#include "ui/tools/tool-base.h"
+
+using Inkscape::Util::round_to_upper_multiple_plus;
+using Inkscape::Util::round_to_lower_multiple_plus;
+
+SnapManager::SnapManager(SPNamedView const *v, Inkscape::SnapPreferences& preferences) :
+ snapprefs(preferences),
+ guide(this, 0),
+ object(this, 0),
+ alignment(this, 0),
+ distribution(this, 0),
+ _named_view(v),
+ _rotation_center_source_items(std::vector<SPItem*>()),
+ _desktop(nullptr),
+ _snapindicator(true),
+ _unselected_nodes(nullptr)
+{
+ _obj_snapper_candidates = std::make_unique<std::vector<Inkscape::SnapCandidateItem>>();
+ _align_snapper_candidates = std::make_unique<std::vector<Inkscape::SnapCandidateItem>>();
+}
+
+SnapManager::~SnapManager()
+{
+ _obj_snapper_candidates->clear();
+ _align_snapper_candidates->clear();
+}
+
+SnapManager::SnapperList SnapManager::getSnappers() const
+{
+ SnapManager::SnapperList s;
+ s.push_back(&guide);
+ s.push_back(&object);
+ s.push_back(&alignment);
+ s.push_back(&distribution);
+
+ SnapManager::SnapperList gs = getGridSnappers();
+ s.splice(s.begin(), gs);
+
+ return s;
+}
+
+SnapManager::SnapperList SnapManager::getGridSnappers() const
+{
+ SnapperList s;
+
+ if (_desktop && _desktop->gridsEnabled() && snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_GRID)) {
+ for(auto grid : _named_view->grids) {
+ s.push_back(grid->snapper);
+ }
+ }
+
+ return s;
+}
+
+bool SnapManager::someSnapperMightSnap(bool immediately) const
+{
+ if ( !snapprefs.getSnapEnabledGlobally() ) {
+ return false;
+ }
+
+ // If we're asking if some snapper might snap RIGHT NOW (without the snap being postponed)...
+ if ( immediately && 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());
+}
+
+bool SnapManager::gridSnapperMightSnap() const
+{
+ if ( !snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally() ) {
+ return false;
+ }
+
+ SnapperList const s = getGridSnappers();
+ SnapperList::const_iterator i = s.begin();
+ while (i != s.end() && (*i)->ThisSnapperMightSnap() == false) {
+ ++i;
+ }
+
+ return (i != s.end());
+}
+
+void SnapManager::freeSnapReturnByRef(Geom::Point &p,
+ Inkscape::SnapSourceType const source_type,
+ Geom::OptRect const &bbox_to_snap) const
+{
+ Inkscape::SnappedPoint const s = freeSnap(Inkscape::SnapCandidatePoint(p, source_type, Inkscape::SNAPTARGET_PATH), bbox_to_snap);
+ s.getPointIfSnapped(p);
+}
+
+Inkscape::SnappedPoint SnapManager::freeSnap(Inkscape::SnapCandidatePoint const &p,
+ Geom::OptRect const &bbox_to_snap,
+ bool to_paths_only) const
+{
+ if (!someSnapperMightSnap()) {
+ return Inkscape::SnappedPoint(p, Inkscape::SNAPTARGET_UNDEFINED, Geom::infinity(), 0, false, false, false);
+ }
+
+ IntermSnapResults isr;
+ SnapperList const snappers = getSnappers();
+
+ for (auto snapper : snappers) {
+ snapper->freeSnap(isr, p, bbox_to_snap, &_objects_to_ignore, _unselected_nodes);
+ }
+
+ return findBestSnap(p, isr, false, false, to_paths_only);
+}
+
+void SnapManager::preSnap(Inkscape::SnapCandidatePoint const &p, bool to_paths_only)
+{
+ // setup() must have been called before calling this method!
+
+ if (_snapindicator) {
+ _snapindicator = false; // prevent other methods from drawing a snap indicator; we want to control this here
+ Inkscape::SnappedPoint s = freeSnap(p, Geom::OptRect(), to_paths_only);
+ g_assert(_desktop != nullptr);
+ if (s.getSnapped()) {
+ _desktop->snapindicator->set_new_snaptarget(s, true);
+ } else {
+ _desktop->snapindicator->remove_snaptarget(true);
+ }
+ _snapindicator = true; // restore the original value
+ }
+}
+
+Geom::Point SnapManager::multipleOfGridPitch(Geom::Point const &t, Geom::Point const &origin)
+{
+ if (!snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally())
+ return t;
+
+ if (_desktop && _desktop->gridsEnabled()) {
+ bool success = false;
+ Geom::Point nearest_multiple;
+ Geom::Coord nearest_distance = Geom::infinity();
+ Inkscape::SnappedPoint bestSnappedPoint(t);
+
+ // 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 (auto grid : _named_view->grids) {
+ 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;
+ IntermSnapResults isr;
+ // Only the first three parameters are being used for grid snappers
+ snapper->freeSnap(isr, Inkscape::SnapCandidatePoint(t_offset, Inkscape::SNAPSOURCE_GRID_PITCH),Geom::OptRect(), nullptr, nullptr);
+ // Find the best snap for this grid, including intersections of the grid-lines
+ bool old_val = _snapindicator;
+ _snapindicator = false;
+ Inkscape::SnappedPoint s = findBestSnap(Inkscape::SnapCandidatePoint(t_offset, Inkscape::SNAPSOURCE_GRID_PITCH), isr, false, true);
+ _snapindicator = old_val;
+ 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() - grid->origin;
+ nearest_distance = s.getSnapDistance();
+ bestSnappedPoint = s;
+ }
+ }
+ }
+
+ if (success) {
+ bestSnappedPoint.setPoint(origin + nearest_multiple);
+ _desktop->snapindicator->set_new_snaptarget(bestSnappedPoint);
+ return nearest_multiple;
+ }
+ }
+
+ return t;
+}
+
+void SnapManager::constrainedSnapReturnByRef(Geom::Point &p,
+ Inkscape::SnapSourceType const source_type,
+ Inkscape::Snapper::SnapConstraint const &constraint,
+ Geom::OptRect const &bbox_to_snap) const
+{
+ Inkscape::SnappedPoint const s = constrainedSnap(Inkscape::SnapCandidatePoint(p, source_type), constraint, bbox_to_snap);
+ p = s.getPoint(); // If we didn't snap, then we will return the point projected onto the constraint
+}
+
+Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::SnapCandidatePoint const &p,
+ Inkscape::Snapper::SnapConstraint const &constraint,
+ Geom::OptRect const &bbox_to_snap) const
+{
+ // First project the mouse pointer onto the constraint
+ Geom::Point pp = constraint.projection(p.getPoint());
+
+ Inkscape::SnappedPoint no_snap = Inkscape::SnappedPoint(pp, p.getSourceType(), p.getSourceNum(), Inkscape::SNAPTARGET_CONSTRAINT, Geom::infinity(), 0, false, true, false);
+
+ if (!someSnapperMightSnap()) {
+ // Always return point on constraint
+ return no_snap;
+ }
+
+ Inkscape::SnappedPoint result = no_snap;
+
+ Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+ if ((prefs->getBool("/options/snapmousepointer/value", false)) && p.isSingleHandle()) {
+ // Snapping the mouse pointer instead of the constrained position of the knot allows
+ // to snap to things which don't intersect with the constraint line; this is basically
+ // then just a freesnap with the constraint applied afterwards
+ // We'll only do this if we're dragging a single handle, and for example not when transforming an object in the selector tool
+ result = freeSnap(p, bbox_to_snap);
+ if (result.getSnapped()) {
+ // only change the snap indicator if we really snapped to something
+ if (_snapindicator && _desktop) {
+ _desktop->snapindicator->set_new_snaptarget(result);
+ }
+ // Apply the constraint
+ result.setPoint(constraint.projection(result.getPoint()));
+ return result;
+ }
+ return no_snap;
+ }
+
+ IntermSnapResults isr;
+ SnapperList const snappers = getSnappers();
+ for (auto snapper : snappers) {
+ snapper->constrainedSnap(isr, p, bbox_to_snap, constraint, &_objects_to_ignore, _unselected_nodes);
+ }
+
+ result = findBestSnap(p, isr, true);
+
+
+ if (result.getSnapped()) {
+ // only change the snap indicator if we really snapped to something
+ if (_snapindicator && _desktop) {
+ _desktop->snapindicator->set_new_snaptarget(result);
+ }
+ return result;
+ }
+ return no_snap;
+}
+
+/* See the documentation for constrainedSnap() directly above for more details.
+ * The difference is that multipleConstrainedSnaps() will take a list of constraints instead of a single one,
+ * and will try to snap the SnapCandidatePoint to only the closest constraint
+ * \param p Source point to be snapped
+ * \param constraints List of directions or lines along which snapping must occur
+ * \param dont_snap If true then we will only apply the constraint, without snapping
+ * \param bbox_to_snap Bounding box hulling the set of points, all from the same selection and having the same transformation
+ */
+
+
+Inkscape::SnappedPoint SnapManager::multipleConstrainedSnaps(Inkscape::SnapCandidatePoint const &p,
+ std::vector<Inkscape::Snapper::SnapConstraint> const &constraints,
+ bool dont_snap,
+ Geom::OptRect const &bbox_to_snap) const
+{
+
+ Inkscape::SnappedPoint no_snap = Inkscape::SnappedPoint(p.getPoint(), p.getSourceType(), p.getSourceNum(), Inkscape::SNAPTARGET_CONSTRAINT, Geom::infinity(), 0, false, true, false);
+ if (constraints.size() == 0) {
+ return no_snap;
+ }
+
+ // We haven't tried to snap yet; we will first determine which constraint is closest to where we are now,
+ // i.e. lets find out which of the constraints yields the closest projection of point p
+
+ // Project the mouse pointer on each of the constraints
+ std::vector<Geom::Point> projections;
+ for (const auto & constraint : constraints) {
+ // Project the mouse pointer onto the constraint; In case we don't snap then we will
+ // return the projection onto the constraint, such that the constraint is always enforced
+ Geom::Point pp = constraint.projection(p.getPoint());
+ projections.push_back(pp);
+ }
+
+ // Select the closest constraint
+ no_snap.setPoint(projections.front());
+ Inkscape::Snapper::SnapConstraint cc = constraints.front(); //closest constraint
+
+ std::vector<Inkscape::Snapper::SnapConstraint>::const_iterator c = constraints.begin();
+ std::vector<Geom::Point>::iterator pp = projections.begin();
+ for (; pp != projections.end(); ++pp) {
+ if (Geom::L2(*pp - p.getPoint()) < Geom::L2(no_snap.getPoint() - p.getPoint())) {
+ no_snap.setPoint(*pp); // Remember the projection onto the closest constraint
+ cc = *c; // Remember the closest constraint itself
+ }
+ ++c;
+ }
+
+ if (!someSnapperMightSnap() || dont_snap) {
+ return no_snap;
+ }
+
+ IntermSnapResults isr;
+ SnapperList const snappers = getSnappers();
+ Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+ bool snap_mouse = prefs->getBool("/options/snapmousepointer/value", false);
+
+ Inkscape::SnappedPoint result = no_snap;
+ if (snap_mouse && p.isSingleHandle()) {
+ // Snapping the mouse pointer instead of the constrained position of the knot allows
+ // to snap to things which don't intersect with the constraint line; this is basically
+ // then just a freesnap with the constraint applied afterwards
+ // We'll only to this if we're dragging a single handle, and for example not when transforming an object in the selector tool
+ result = freeSnap(p, bbox_to_snap);
+ // Now apply the constraint afterwards
+ result.setPoint(cc.projection(result.getPoint()));
+ } else {
+ // Try to snap along the closest constraint
+ for (auto snapper : snappers) {
+ snapper->constrainedSnap(isr, p, bbox_to_snap, cc, &_objects_to_ignore,_unselected_nodes);
+ }
+ result = findBestSnap(p, isr, true);
+ }
+
+ return result.getSnapped() ? result : no_snap;
+}
+
+Inkscape::SnappedPoint SnapManager::constrainedAngularSnap(Inkscape::SnapCandidatePoint const &p,
+ std::optional<Geom::Point> const &p_ref,
+ Geom::Point const &o,
+ unsigned const snaps) const
+{
+ Inkscape::SnappedPoint sp;
+ if (snaps > 0) { // 0 means no angular snapping
+ // p is at an arbitrary angle. Now we should snap this angle to specific increments.
+ // For this we'll calculate the closest two angles, one at each side of the current angle
+ Geom::Line y_axis(Geom::Point(0, 0), Geom::Point(0, 1));
+ Geom::Line p_line(o, p.getPoint());
+ double angle = Geom::angle_between(y_axis, p_line);
+ double angle_incr = M_PI / snaps;
+ double angle_offset = 0;
+ if (p_ref) {
+ Geom::Line p_line_ref(o, *p_ref);
+ angle_offset = Geom::angle_between(y_axis, p_line_ref);
+ }
+ double angle_ceil = round_to_upper_multiple_plus(angle, angle_incr, angle_offset);
+ double angle_floor = round_to_lower_multiple_plus(angle, angle_incr, angle_offset);
+ // We have two angles now. The constrained snapper will try each of them and return the closest
+
+ // Now do the snapping...
+ std::vector<Inkscape::Snapper::SnapConstraint> constraints;
+ constraints.emplace_back(Geom::Line(o, angle_ceil - M_PI/2));
+ constraints.emplace_back(Geom::Line(o, angle_floor - M_PI/2));
+ sp = multipleConstrainedSnaps(p, constraints); // Constraints will always be applied, even if we didn't snap
+ if (!sp.getSnapped()) { // If we haven't snapped then we only had the constraint applied;
+ sp.setTarget(Inkscape::SNAPTARGET_CONSTRAINED_ANGLE);
+ }
+ } else {
+ sp = freeSnap(p);
+ }
+ return sp;
+}
+
+void SnapManager::guideFreeSnap(Geom::Point &p, Geom::Point &origin_or_vector, bool origin, bool freeze_angle) const
+{
+ if (freeze_angle && origin) {
+ g_warning("Dear developer, when snapping guides you shouldn't ask me to freeze the guide's vector when you haven't specified one");
+ // You've supplied me with an origin instead of a vector
+ }
+
+ if (!snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally() || !snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_GUIDE)) {
+ return;
+ }
+
+ Inkscape::SnapCandidatePoint candidate(p, Inkscape::SNAPSOURCE_GUIDE);
+ if (origin) {
+ candidate.addOrigin(origin_or_vector);
+ } else {
+ candidate = Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_GUIDE_ORIGIN);
+ candidate.addVector(Geom::rot90(origin_or_vector));
+ }
+
+ IntermSnapResults isr;
+ SnapperList snappers = getSnappers();
+ for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); ++i) {
+ (*i)->freeSnap(isr, candidate, Geom::OptRect(), nullptr, nullptr);
+ }
+
+ Inkscape::SnappedPoint const s = findBestSnap(candidate, isr, false);
+
+ s.getPointIfSnapped(p);
+
+ if (!freeze_angle && s.getSnapped()) {
+ if (!Geom::are_near(s.getTangent(), Geom::Point(0,0))) { // If the tangent has been set ...
+ origin_or_vector = Geom::rot90(s.getTangent()); // then use it to update the normal of the guide
+ // PS: The tangent might not have been set if we snapped for example to a node
+ }
+ }
+}
+
+void SnapManager::guideConstrainedSnap(Geom::Point &p, SPGuide const &guideline) const
+{
+ if (!snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally() || !snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_GUIDE)) {
+ return;
+ }
+
+ Inkscape::SnapCandidatePoint candidate(p, Inkscape::SNAPSOURCE_GUIDE_ORIGIN, Inkscape::SNAPTARGET_UNDEFINED);
+
+ IntermSnapResults isr;
+ Inkscape::Snapper::SnapConstraint cl(guideline.getPoint(), Geom::rot90(guideline.getNormal()));
+
+ SnapperList snappers = getSnappers();
+ for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); ++i) {
+ (*i)->constrainedSnap(isr, candidate, Geom::OptRect(), cl, nullptr, nullptr);
+ }
+
+ Inkscape::SnappedPoint const s = findBestSnap(candidate, isr, false);
+ s.getPointIfSnapped(p);
+}
+
+void SnapManager::snapTransformed(
+ std::vector<Inkscape::SnapCandidatePoint> const &points,
+ Geom::Point const &pointer,
+ Inkscape::PureTransform &transform
+ )
+{
+ /* 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'.
+ */
+
+ if (points.size() == 0) {
+ transform.best_snapped_point = Inkscape::SnappedPoint(pointer);
+ return;
+ }
+
+ // We will try to snap a set of points, but we don't want to have a snap indicator displayed
+ // for each of them. That's why it's temporarily disabled here, and re-enabled again after we
+ // have finished calling the freeSnap() and constrainedSnap() methods
+ bool _orig_snapindicator_status = _snapindicator;
+ _snapindicator = false;
+
+ transform.snap(this, points, pointer);
+
+ // Allow the snapindicator to be displayed again
+ _snapindicator = _orig_snapindicator_status;
+
+ if (_snapindicator) {
+ if (transform.best_snapped_point.getSnapped()) {
+ _desktop->snapindicator->set_new_snaptarget(transform.best_snapped_point);
+ } else {
+ _desktop->snapindicator->remove_snaptarget();
+ }
+ }
+
+ if (points.size() == 1) {
+ displaySnapsource(Inkscape::SnapCandidatePoint(transform.best_snapped_point.getPoint(), points.at(0).getSourceType()));
+ }
+}
+
+Inkscape::SnappedPoint SnapManager::findBestSnap(Inkscape::SnapCandidatePoint const &p,
+ IntermSnapResults const &isr,
+ bool constrained,
+ bool allowOffScreen,
+ bool to_path_only) const
+{
+ g_assert(_desktop != nullptr);
+
+ /*
+ std::cout << "Type and number of snapped constraints: " << std::endl;
+ std::cout << " Points : " << isr.points.size() << std::endl;
+ std::cout << " Grid lines : " << isr.grid_lines.size()<< std::endl;
+ std::cout << " Guide lines : " << isr.guide_lines.size()<< std::endl;
+ std::cout << " Curves : " << isr.curves.size()<< std::endl;
+ */
+
+ /*
+ // Display all snap candidates on the canvas
+ _desktop->snapindicator->remove_debugging_points();
+ for (std::list<Inkscape::SnappedPoint>::const_iterator i = isr.points.begin(); i != isr.points.end(); i++) {
+ _desktop->snapindicator->set_new_debugging_point((*i).getPoint());
+ }
+ for (std::list<Inkscape::SnappedCurve>::const_iterator i = isr.curves.begin(); i != isr.curves.end(); i++) {
+ _desktop->snapindicator->set_new_debugging_point((*i).getPoint());
+ }
+ for (std::list<Inkscape::SnappedLine>::const_iterator i = isr.grid_lines.begin(); i != isr.grid_lines.end(); i++) {
+ _desktop->snapindicator->set_new_debugging_point((*i).getPoint());
+ }
+ for (std::list<Inkscape::SnappedLine>::const_iterator i = isr.guide_lines.begin(); i != isr.guide_lines.end(); i++) {
+ _desktop->snapindicator->set_new_debugging_point((*i).getPoint());
+ }
+ */
+
+ // Store all snappoints
+ std::list<Inkscape::SnappedPoint> sp_list;
+
+ // search for the closest snapped point
+ Inkscape::SnappedPoint closestPoint;
+ if (getClosestSP(isr.points, closestPoint)) {
+ sp_list.push_back(closestPoint);
+ }
+
+ // search for the closest snapped curve
+ Inkscape::SnappedCurve closestCurve;
+ // We might have collected the paths only to snap to their intersection, without the intention to snap to the paths themselves
+ // Therefore we explicitly check whether the paths should be considered as snap targets themselves
+ bool exclude_paths = !snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_PATH);
+ if (getClosestCurve(isr.curves, closestCurve, exclude_paths)) {
+ sp_list.emplace_back(closestCurve);
+ }
+
+ // search for the closest snapped grid line
+ Inkscape::SnappedLine closestGridLine;
+ if (getClosestSL(isr.grid_lines, closestGridLine)) {
+ sp_list.emplace_back(closestGridLine);
+ }
+
+ // search for the closest snapped guide line
+ Inkscape::SnappedLine closestGuideLine;
+ if (getClosestSL(isr.guide_lines, closestGuideLine)) {
+ sp_list.emplace_back(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) {
+ if (snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_PATH_INTERSECTION)) {
+ // search for the closest snapped intersection of curves
+ Inkscape::SnappedPoint closestCurvesIntersection;
+ if (getClosestIntersectionCS(isr.curves, p.getPoint(), closestCurvesIntersection, _desktop->dt2doc())) {
+ closestCurvesIntersection.setSource(p.getSourceType());
+ sp_list.push_back(closestCurvesIntersection);
+ }
+ }
+
+ if (snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_PATH_GUIDE_INTERSECTION)) {
+ // search for the closest snapped intersection of a guide with a curve
+ Inkscape::SnappedPoint closestCurveGuideIntersection;
+ if (getClosestIntersectionCL(isr.curves, isr.guide_lines, p.getPoint(), closestCurveGuideIntersection, _desktop->dt2doc())) {
+ closestCurveGuideIntersection.setSource(p.getSourceType());
+ sp_list.push_back(closestCurveGuideIntersection);
+ }
+ }
+
+ // search for the closest snapped intersection of grid lines
+ Inkscape::SnappedPoint closestGridPoint;
+ if (getClosestIntersectionSL(isr.grid_lines, closestGridPoint)) {
+ closestGridPoint.setSource(p.getSourceType());
+ 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(isr.guide_lines, closestGuidePoint)) {
+ closestGuidePoint.setSource(p.getSourceType());
+ closestGuidePoint.setTarget(Inkscape::SNAPTARGET_GUIDE_INTERSECTION);
+ sp_list.push_back(closestGuidePoint);
+ }
+
+ // search for the closest snapped intersection of grid with guide lines
+ if (snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_GRID_GUIDE_INTERSECTION)) {
+ Inkscape::SnappedPoint closestGridGuidePoint;
+ if (getClosestIntersectionSL(isr.grid_lines, isr.guide_lines, closestGridGuidePoint)) {
+ closestGridGuidePoint.setSource(p.getSourceType());
+ closestGridGuidePoint.setTarget(Inkscape::SNAPTARGET_GRID_GUIDE_INTERSECTION);
+ sp_list.push_back(closestGridGuidePoint);
+ }
+ }
+ }
+
+ // Filter out all snap targets that do NOT include a path; this is useful when we try to insert
+ // a node in a path (on doubleclick in the node tool). We don't want to change the shape of the
+ // path, so the snapped point must be on a path, and not e.g. on a grid intersection
+ if (to_path_only) {
+ std::list<Inkscape::SnappedPoint>::iterator i = sp_list.begin();
+
+ while (i != sp_list.end()) {
+ Inkscape::SnapTargetType t = (*i).getTarget();
+ if (t == Inkscape::SNAPTARGET_LINE_MIDPOINT ||
+ t == Inkscape::SNAPTARGET_PATH ||
+ t == Inkscape::SNAPTARGET_PATH_PERPENDICULAR ||
+ t == Inkscape::SNAPTARGET_PATH_TANGENTIAL ||
+ t == Inkscape::SNAPTARGET_PATH_INTERSECTION ||
+ t == Inkscape::SNAPTARGET_PATH_GUIDE_INTERSECTION ||
+ t == Inkscape::SNAPTARGET_PATH_CLIP ||
+ t == Inkscape::SNAPTARGET_PATH_MASK ||
+ t == Inkscape::SNAPTARGET_ELLIPSE_QUADRANT_POINT) {
+ ++i;
+ } else {
+ i = sp_list.erase(i);
+ }
+ }
+ }
+
+ // now let's see which snapped point gets a thumbs up
+ Inkscape::SnappedPoint bestSnappedPoint(p.getPoint());
+ // std::cout << "Finding the best snap..." << std::endl;
+ for (std::list<Inkscape::SnappedPoint>::const_iterator i = sp_list.begin(); i != sp_list.end(); ++i) {
+ // std::cout << "sp = " << (*i).getPoint() << " | source = " << (*i).getSource() << " | target = " << (*i).getTarget();
+ bool onScreen = _desktop->get_display_area().contains((*i).getPoint());
+ if (onScreen || allowOffScreen) { // Only snap to points which are not off the screen
+ if ((*i).getSnapDistance() <= (*i).getTolerance()) { // Only snap to points within snapping range
+ // 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;
+}
+
+void SnapManager::setup(SPDesktop const *desktop,
+ bool snapindicator,
+ SPObject const *item_to_ignore,
+ std::vector<Inkscape::SnapCandidatePoint> *unselected_nodes)
+{
+ g_assert(desktop != nullptr);
+ if (_desktop != nullptr) {
+ g_warning("The snapmanager has been set up before, but unSetup() hasn't been called afterwards. It possibly held invalid pointers");
+ }
+ _objects_to_ignore.clear();
+ if (item_to_ignore) {
+ _objects_to_ignore.push_back(item_to_ignore);
+ }
+ _desktop = desktop;
+ _snapindicator = snapindicator;
+ _unselected_nodes = unselected_nodes;
+ _rotation_center_source_items.clear();
+ _findCandidates_already_called = false;
+}
+
+void SnapManager::setup(SPDesktop const *desktop,
+ bool snapindicator,
+ std::vector<SPObject const *> &objects_to_ignore,
+ std::vector<Inkscape::SnapCandidatePoint> *unselected_nodes)
+{
+ g_assert(desktop != nullptr);
+ if (_desktop != nullptr) {
+ g_warning("The snapmanager has been set up before, but unSetup() hasn't been called afterwards. It possibly held invalid pointers");
+ }
+ _objects_to_ignore = objects_to_ignore;
+ _desktop = desktop;
+ _snapindicator = snapindicator;
+ _unselected_nodes = unselected_nodes;
+ _rotation_center_source_items.clear();
+ _findCandidates_already_called = false;
+}
+
+/// Setup, taking the list of items to ignore from the desktop's selection.
+void SnapManager::setupIgnoreSelection(SPDesktop const *desktop,
+ bool snapindicator,
+ std::vector<Inkscape::SnapCandidatePoint> *unselected_nodes)
+{
+ g_assert(desktop != nullptr);
+ if (_desktop != nullptr) {
+ // Someone has been naughty here! This is dangerous
+ g_warning("The snapmanager has been set up before, but unSetup() hasn't been called afterwards. It possibly held invalid pointers");
+ }
+ _desktop = desktop;
+ _snapindicator = snapindicator;
+ _unselected_nodes = unselected_nodes;
+ _rotation_center_source_items.clear();
+ _findCandidates_already_called = false;
+ _objects_to_ignore.clear();
+
+ Inkscape::Selection *sel = _desktop->selection;
+ auto items = sel->items();
+ for (auto i=items.begin();i!=items.end();++i) {
+ _objects_to_ignore.push_back(*i);
+ }
+}
+
+SPDocument *SnapManager::getDocument() const
+{
+ return _named_view->document;
+}
+
+//Geom::Point SnapManager::_transformPoint(Inkscape::SnapCandidatePoint 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 TRANSLATE:
+// transformed = p.getPoint() + transformation;
+// break;
+// case SCALE:
+// transformed = (p.getPoint() - 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.getPoint() - origin) * s) + origin;
+// break;
+// }
+// case SKEW:
+// // Apply the skew factor
+// transformed[dim] = (p.getPoint())[dim] + transformation[0] * ((p.getPoint())[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.getPoint() - origin)[1 - dim] * transformation[1] + origin[1 - dim];
+// break;
+// case ROTATE:
+// // for rotations: transformation[0] stores the angle in radians
+// transformed = (p.getPoint() - origin) * Geom::Rotate(transformation[0]) + origin;
+// break;
+// default:
+// g_assert_not_reached();
+// }
+//
+// return transformed;
+//}
+
+/**
+ * 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::SnapCandidatePoint const &p) const {
+ Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+ if (prefs->getBool("/options/snapclosestonly/value")) {
+ Inkscape::SnapSourceType t = p.getSourceType();
+ bool p_is_a_node = t & Inkscape::SNAPSOURCE_NODE_CATEGORY;
+ bool p_is_a_bbox = t & Inkscape::SNAPSOURCE_BBOX_CATEGORY;
+ bool p_is_other = (t & Inkscape::SNAPSOURCE_OTHERS_CATEGORY) || (t & Inkscape::SNAPSOURCE_DATUMS_CATEGORY);
+
+ g_assert(_desktop != nullptr);
+ if (snapprefs.getSnapEnabledGlobally() && (p_is_other || (p_is_a_node && snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_NODE_CATEGORY)) || (p_is_a_bbox && snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_BBOX_CATEGORY)))) {
+ _desktop->snapindicator->set_new_snapsource(p);
+ } else {
+ _desktop->snapindicator->remove_snapsource();
+ }
+ }
+}
+
+SPGuide const *SnapManager::getGuideToIgnore() const
+{
+ for (auto item : _objects_to_ignore) {
+ if (auto guide = dynamic_cast<SPGuide const *>(item)) {
+ return guide;
+ }
+ }
+ return nullptr;
+}
+SPPage const *SnapManager::getPageToIgnore() const
+{
+ for (auto item : _objects_to_ignore) {
+ if (auto page = dynamic_cast<SPPage const *>(item)) {
+ return page;
+ }
+ }
+ return nullptr;
+}
+
+
+void SnapManager::_findCandidates(SPObject* parent,
+ std::vector<SPObject const *> const *it,
+ Geom::Rect const &bbox_to_snap,
+ bool const clip_or_mask,
+ Geom::Affine const additional_affine)
+{
+ SPDesktop const *dt = getDesktop();
+ if (dt == nullptr) {
+ g_error("desktop == NULL, so we cannot snap; please inform the developers of this bug");
+ return;
+ // Apparently the setup() method from the SnapManager class hasn't been called before trying to snap.
+ }
+
+ static int recursion_level = 0;
+
+ if (recursion_level == 0) {
+ if (_findCandidates_already_called) { // In case we have already been called by another snapper,
+ return; // then we don't need to search for candidates again
+ }
+ _findCandidates_already_called = true;
+ _obj_snapper_candidates->clear();
+ _align_snapper_candidates->clear();
+ }
+ recursion_level++;
+
+ Geom::Rect bbox_to_snap_incl = bbox_to_snap; // _incl means: will include the snapper tolerance
+ bbox_to_snap_incl.expandBy(object.getSnapperTolerance()); // see?
+
+ for (auto& o: parent->children) {
+ SPItem *item = dynamic_cast<SPItem *>(&o);
+ if (item && !(dt->itemIsHidden(item) && !clip_or_mask)) {
+ // Fix LPE boolops self-snapping
+ bool stop = false;
+ if (item->style) {
+ SPFilter *filt = item->style->getFilter();
+ if (filt && filt->getId() && strcmp(filt->getId(), "selectable_hidder_filter") == 0) {
+ stop = true;
+ }
+ SPLPEItem *lpeitem = dynamic_cast<SPLPEItem *>(item);
+ if (lpeitem && lpeitem->hasPathEffectOfType(Inkscape::LivePathEffect::EffectType::BOOL_OP)) {
+ stop = true;
+ }
+ }
+ if (stop && it) {
+ stop = false;
+ for (auto skipitem : *it) {
+ if (skipitem && skipitem->style) {
+ SPItem *toskip = dynamic_cast<SPItem *>(const_cast<SPObject *>(skipitem));
+ if (toskip) {
+ SPFilter *filt = toskip->style->getFilter();
+ if (filt && filt->getId() && strcmp(filt->getId(), "selectable_hidder_filter") == 0) {
+ stop = true;
+ break;
+ }
+
+ SPLPEItem *lpeitem = dynamic_cast<SPLPEItem *>(toskip);
+ if (!stop && lpeitem &&
+ lpeitem->hasPathEffectOfType(Inkscape::LivePathEffect::EffectType::BOOL_OP)) {
+ stop = true;
+ break;
+ }
+ }
+ }
+ }
+ if (stop) {
+ continue;
+ }
+ }
+ // Snapping to items in a locked layer is allowed
+ // Don't snap to hidden objects, unless they're a clipped path or a mask
+ /* See if this item is on the ignore list */
+ std::vector<SPObject const *>::const_iterator i;
+ if (it != nullptr) {
+ i = it->begin();
+ while (i != it->end() && *i != &o) {
+ ++i;
+ }
+ }
+
+ if (it == nullptr || i == it->end()) {
+ if (item) {
+ if (!clip_or_mask) { // cannot clip or mask more than once
+ // The current item is not a clipping path or a mask, but might
+ // still be the subject of clipping or masking itself ; if so, then
+ // we should also consider that path or mask for snapping to
+ SPObject *obj = item->getClipObject();
+ if (obj && snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_PATH_CLIP)) {
+ _findCandidates(obj, it, bbox_to_snap, true, item->i2doc_affine());
+ }
+ obj = item->getMaskObject();
+ if (obj && snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_PATH_MASK)) {
+ _findCandidates(obj, it, bbox_to_snap, true, item->i2doc_affine());
+ }
+ }
+
+ if (dynamic_cast<SPGroup *>(item)) {
+ _findCandidates(&o, it, bbox_to_snap, clip_or_mask, additional_affine);
+ } else {
+ Geom::OptRect bbox_of_item;
+ Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+ int prefs_bbox = prefs->getBool("/tools/bounding_box", false);
+ // We'll only need to obtain the visual bounding box if the user preferences tell
+ // us to, AND if we are snapping to the bounding box itself. If we're snapping to
+ // paths only, then we can just as well use the geometric bounding box (which is faster)
+ SPItem::BBoxType bbox_type = (!prefs_bbox && snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_BBOX_CATEGORY)) ?
+ SPItem::VISUAL_BBOX : SPItem::GEOMETRIC_BBOX;
+ if (clip_or_mask) {
+ // Oh oh, this will get ugly. We cannot use sp_item_i2d_affine directly because we need to
+ // insert an additional transformation in document coordinates (code copied from sp_item_i2d_affine)
+ bbox_of_item = item->bounds(bbox_type, item->i2doc_affine() * additional_affine * dt->doc2dt());
+ } else {
+ bbox_of_item = item->desktopBounds(bbox_type);
+ }
+ if (bbox_of_item) {
+ bool overflow = false;
+ // See if the item is within range
+ auto display_area = getDesktop()->get_display_area().bounds();
+ if (display_area.intersects(*bbox_of_item)) {
+ // Finally add the object to _candidates.
+ _align_snapper_candidates->push_back(Inkscape::SnapCandidateItem(item, clip_or_mask, additional_affine));
+ // For debugging: print the id of the candidate to the console
+ // SPObject *obj = (SPObject*)item;
+ // std::cout << "Snap candidate added: " << obj->getId() << std::endl;
+
+ if (bbox_to_snap_incl.intersects(*bbox_of_item)
+ || (snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_ROTATION_CENTER) && bbox_to_snap_incl.contains(item->getCenter()))) { // rotation center might be outside of the bounding box
+ // This item is within snapping range, so record it as a candidate
+ _obj_snapper_candidates->push_back(Inkscape::SnapCandidateItem(item, clip_or_mask, additional_affine));
+ // For debugging: print the id of the candidate to the console
+ // SPObject *obj = (SPObject*)item;
+ // std::cout << "Snap candidate added: " << obj->getId() << std::endl;
+ }
+
+ if (_align_snapper_candidates->size() > 200) { // This makes Inkscape crawl already
+ overflow = true;
+ }
+ }
+
+ if (overflow) {
+ static Glib::Timer timer;
+ if (timer.elapsed() > 1.0) {
+ timer.reset();
+ std::cout << "Warning: limit of 200 snap target paths reached, some will be ignored" << std::endl;
+ }
+ break;
+ }
+ }
+ }
+ }
+ }
+ }
+ }
+
+ recursion_level--;
+}
+/*
+ Local Variables:
+ mode:c++
+ c-file-style:"stroustrup"
+ c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+ indent-tabs-mode:nil
+ fill-column:99
+ End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
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