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Diffstat (limited to 'src/snapped-point.cpp')
| -rw-r--r-- | src/snapped-point.cpp | 248 |
1 files changed, 248 insertions, 0 deletions
diff --git a/src/snapped-point.cpp b/src/snapped-point.cpp new file mode 100644 index 0000000..033713c --- /dev/null +++ b/src/snapped-point.cpp @@ -0,0 +1,248 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/** + * \file src/snapped-point.cpp + * SnappedPoint class. + * + * Authors: + * Mathieu Dimanche <mdimanche@free.fr> + * Diederik van Lierop <mail@diedenrezi.nl> + * + * Released under GNU GPL v2+, read the file 'COPYING' for more information. + */ + +#include <gtk/gtk.h> + +#include <utility> +#include "snapped-point.h" +#include "preferences.h" + +// overloaded constructor +Inkscape::SnappedPoint::SnappedPoint(Geom::Point const &p, SnapSourceType const &source, long source_num, SnapTargetType const &target, Geom::Coord const &d, Geom::Coord const &t, bool const &a, bool const &constrained_snap, bool const &fully_constrained, Geom::OptRect target_bbox) : + _point(p), + _tangent(Geom::Point(0,0)), + _source(source), + _source_num(source_num), + _target(target), + _at_intersection (false), + _constrained_snap (constrained_snap), + _fully_constrained (fully_constrained), + _distance(d), + _tolerance(std::max(t,1.0)),// tolerance should never be smaller than 1 px, as it is used for normalization in isOtherSnapBetter. We don't want a division by zero. + _always_snap(a), + _second_distance (Geom::infinity()), + _second_tolerance (1), + _second_always_snap (false), + _target_bbox(std::move(target_bbox)), + _pointer_distance (Geom::infinity()) +{ +} + +Inkscape::SnappedPoint::SnappedPoint(Inkscape::SnapCandidatePoint const &p, SnapTargetType const &target, Geom::Coord const &d, Geom::Coord const &t, bool const &a, bool const &constrained_snap, bool const &fully_constrained) : + _point (p.getPoint()), + _tangent (Geom::Point(0,0)), + _source (p.getSourceType()), + _source_num (p.getSourceNum()), + _target(target), + _at_intersection (false), + _constrained_snap (constrained_snap), + _fully_constrained (fully_constrained), + _distance(d), + _tolerance(std::max(t,1.0)), + _always_snap(a), + _second_distance (Geom::infinity()), + _second_tolerance (1), + _second_always_snap (false), + _target_bbox (p.getTargetBBox()), + _pointer_distance (Geom::infinity()) +{ +} + +Inkscape::SnappedPoint::SnappedPoint(Geom::Point const &p, SnapSourceType const &source, long source_num, SnapTargetType const &target, Geom::Coord const &d, Geom::Coord const &t, bool const &a, bool const &at_intersection, bool const &constrained_snap, bool const &fully_constrained, Geom::Coord const &d2, Geom::Coord const &t2, bool const &a2) : + _point(p), + _tangent (Geom::Point(0,0)), + _source(source), + _source_num(source_num), + _target(target), + _at_intersection(at_intersection), + _constrained_snap(constrained_snap), + _fully_constrained(fully_constrained), + _distance(d), + _tolerance(std::max(t,1.0)), + _always_snap(a), + _second_distance(d2), + _second_tolerance(std::max(t2,1.0)), + _second_always_snap(a2), + // tolerance should never be smaller than 1 px, as it is used for normalization in + // isOtherSnapBetter. We don't want a division by zero. + _target_bbox (Geom::OptRect()), + _pointer_distance (Geom::infinity()) +{ +} + +Inkscape::SnappedPoint::SnappedPoint(): + _point (Geom::Point(0,0)), + _tangent (Geom::Point(0,0)), + _source (SNAPSOURCE_UNDEFINED), + _source_num (-1), + _target (SNAPTARGET_UNDEFINED), + _at_intersection (false), + _constrained_snap (false), + _fully_constrained (false), + _distance (Geom::infinity()), + _tolerance (1), + _always_snap (false), + _second_distance (Geom::infinity()), + _second_tolerance (1), + _second_always_snap (false), + _target_bbox (Geom::OptRect()), + _pointer_distance (Geom::infinity()) +{ +} + +Inkscape::SnappedPoint::SnappedPoint(Geom::Point const &p): + _point (p), + _tangent (Geom::Point(0,0)), + _source (SNAPSOURCE_UNDEFINED), + _source_num (-1), + _target (SNAPTARGET_UNDEFINED), + _at_intersection (false), + _constrained_snap (false), + _fully_constrained (false), + _distance (Geom::infinity()), + _tolerance (1), + _always_snap (false), + _second_distance (Geom::infinity()), + _second_tolerance (1), + _second_always_snap (false), + _target_bbox (Geom::OptRect()), + _pointer_distance (Geom::infinity()) +{ +} + +Inkscape::SnappedPoint::~SnappedPoint() += default; + +void Inkscape::SnappedPoint::getPointIfSnapped(Geom::Point &p) const +{ + // When we have snapped + if (getSnapped()) { + // then return the snapped point by overwriting p + p = _point; + } //otherwise p will be left untouched; this way the caller doesn't have to check whether we've snapped +} + +// search for the closest snapped point +bool getClosestSP(std::list<Inkscape::SnappedPoint> const &list, Inkscape::SnappedPoint &result) +{ + bool success = false; + + for (std::list<Inkscape::SnappedPoint>::const_iterator i = list.begin(); i != list.end(); ++i) { + if ((i == list.begin()) || (*i).getSnapDistance() < result.getSnapDistance()) { + result = *i; + success = true; + } + } + + return success; +} + +bool Inkscape::SnappedPoint::isOtherSnapBetter(Inkscape::SnappedPoint const &other_one, bool weighted) const +{ + + if (getSnapped() && !other_one.getSnapped()) { + return false; + } + + if (!getSnapped() && other_one.getSnapped()) { + return true; + } + + double dist_other = other_one.getSnapDistance(); + double dist_this = getSnapDistance(); + + // The distance to the pointer should only be taken into account when finding the best snapped source node (when + // there's more than one). It is not useful when trying to find the best snapped target point. + // (both the snap distance and the pointer distance are measured in document pixels, not in screen pixels) + if (weighted) { + Geom::Coord const dist_pointer_other = other_one.getPointerDistance(); + Geom::Coord const dist_pointer_this = getPointerDistance(); + // Weight factor: controls which node should be preferred for snapping, which is either + // the node with the closest snap (w = 0), or the node closest to the mousepointer (w = 1) + Inkscape::Preferences *prefs = Inkscape::Preferences::get(); + double w = prefs->getDoubleLimited("/options/snapweight/value", 0.5, 0, 1); + if (prefs->getBool("/options/snapclosestonly/value", false)) { + w = 1; + } + if (w > 0) { + if (!(w == 1 && dist_pointer_this == dist_pointer_other)) { + // When accounting for the distance to the mouse pointer, then at least one of the snapped points should + // have that distance set. If not, then this is a bug. Either "weighted" must be set to false, or the + // mouse pointer distance must be set. + g_assert(dist_pointer_this != Geom::infinity() || dist_pointer_other != Geom::infinity()); + // The snap distance will always be smaller than the tolerance set for the snapper. The pointer distance can + // however be very large. To compare these in a fair way, we will have to normalize these metrics first + // The closest pointer distance will be normalized to 1.0; the other one will be > 1.0 + // The snap distance will be normalized to 1.0 if it's equal to the snapper tolerance + double const norm_p = std::min(dist_pointer_this, dist_pointer_other) + 1; + // make sure norm_p is never too close to zero (e.g. when snapping the bbox-corner that was grabbed), by incr. with 1 + double const norm_t_other = std::min(50.0, other_one.getTolerance()); + double const norm_t_this = std::min(50.0, getTolerance()); + dist_other = w * dist_pointer_other / norm_p + (1-w) * dist_other / norm_t_other; + dist_this = w * dist_pointer_this / norm_p + (1-w) * dist_this / norm_t_this; + } + } + } + + // When snapping to a constraint line only, which is not really a snap but merely a projection + // to the constraint line, then give this snap a very low priority. Basically, any other snap will do + if (other_one.getTarget() == SNAPTARGET_CONSTRAINT) { + dist_other += 1e6; + } + if (getTarget() == SNAPTARGET_CONSTRAINT) { + dist_this += 1e6; + } + + // If it's closer + bool c1 = dist_other < dist_this; + // or, if it's for a snapper with "always snap" turned on, and the previous wasn't + bool c2 = other_one.getAlwaysSnap() && !getAlwaysSnap(); + // But in no case fall back from a snapper with "always snap" on to one with "always snap" off + bool c2n = !other_one.getAlwaysSnap() && getAlwaysSnap(); + // or, if we have a fully constrained snappoint (e.g. to a node or an intersection), while the previous one was only partly constrained (e.g. to a line) + bool c3 = (other_one.getFullyConstrained() && !other_one.getConstrainedSnap()) && !getFullyConstrained(); // Do not consider constrained snaps here, because these will always be fully constrained anyway + // But in no case fall back; (has less priority than c3n, so it is allowed to fall back when c3 is true, see below) + bool c3n = !other_one.getFullyConstrained() && (getFullyConstrained() && !getConstrainedSnap()); + + // When both are fully constrained AND coincident, then prefer nodes over intersections + bool d = other_one.getFullyConstrained() && getFullyConstrained() && (Geom::L2(other_one.getPoint() - getPoint()) < 1e-9); + bool c4 = d && !other_one.getAtIntersection() && getAtIntersection(); + // But don't fall back... + bool c4n = d && other_one.getAtIntersection() && !getAtIntersection(); + + // or, if it's just as close then consider the second distance ... + bool c5a = (dist_other == dist_this); + bool c5b = (other_one.getSecondSnapDistance() < getSecondSnapDistance()) && (getSecondSnapDistance() < Geom::infinity()); + // ... or prefer free snaps over constrained snaps + bool c5c = !other_one.getConstrainedSnap() && getConstrainedSnap(); + + bool other_is_better = (c1 || c2 || c3 || c4 || (c5a && (c5b || c5c))) && !c2n && (!c3n || c2) && !c4n; + + /* + std::cout << other_one.getPoint() << " (Other one, dist = " << dist_other << ") vs. " << getPoint() << " (this one, dist = " << dist_this << ") ---> "; + std::cout << "c1 = " << c1 << " | c2 = " << c2 << " | c2n = " << c2n << " | c3 = " << c3 << " | c3n = " << c3n << " | c4 = " << c4 << " | c4n = " << c4n << " | c5a = " << c5a << " | c5b = " << c5b << " | c5c = " << c5c << std::endl; + std::cout << "Other one provides a better snap: " << other_is_better << std::endl; + */ + + return other_is_better; +} + +/* + 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 : |