// SPDX-License-Identifier: GPL-2.0-or-later /** * \file src/snapped-line.cpp * SnappedLine class. * * Authors: * Diederik van Lierop * * Released under GNU GPL v2+, read the file 'COPYING' for more information. */ #include "snapped-line.h" Inkscape::SnappedLineSegment::SnappedLineSegment(Geom::Point const &snapped_point, Geom::Coord const &snapped_distance, SnapSourceType const &source, long source_num, SnapTargetType const &target, Geom::Coord const &snapped_tolerance, bool const &always_snap, Geom::Point const &start_point_of_line, Geom::Point const &end_point_of_line) : _start_point_of_line(start_point_of_line), _end_point_of_line(end_point_of_line) { _point = snapped_point; _source = source; _source_num = source_num; _target = target; _distance = snapped_distance; _tolerance = std::max(snapped_tolerance, 1.0); _always_snap = always_snap; _at_intersection = false; _second_distance = Geom::infinity(); _second_tolerance = 1; _second_always_snap = false; } Inkscape::SnappedLineSegment::SnappedLineSegment() { _source = SNAPSOURCE_UNDEFINED; _source_num = -1; _target = SNAPTARGET_UNDEFINED; _distance = Geom::infinity(); _tolerance = 1; _always_snap = false; _at_intersection = false; _second_distance = Geom::infinity(); _second_tolerance = 1; _second_always_snap = false; } Inkscape::SnappedLineSegment::~SnappedLineSegment() = default; Inkscape::SnappedPoint Inkscape::SnappedLineSegment::intersect(SnappedLineSegment const &line) const { Geom::OptCrossing inters = Geom::OptCrossing(); // empty by default try { inters = Geom::intersection(getLineSegment(), line.getLineSegment()); } catch (Geom::InfiniteSolutions &e) { // We're probably dealing with parallel lines, so they don't really cross inters = Geom::OptCrossing(); } if (inters) { Geom::Point inters_pt = getLineSegment().pointAt((*inters).ta); /* If a snapper has been told to "always snap", then this one should be preferred * over the other, if that other one has not been told so. (The preferred snapper * will be labeled "primary" below) */ bool const c1 = this->getAlwaysSnap() && !line.getAlwaysSnap(); //do not use _tolerance directly! /* If neither or both have been told to "always snap", then cast a vote based on * the snapped distance. For this we should consider the distance to the snapped * line, not the distance to the intersection. * See the comment in Inkscape::SnappedLine::intersect */ bool const c2 = _distance < line.getSnapDistance(); bool const use_this_as_primary = c1 || c2; Inkscape::SnappedLineSegment const *primarySLS = use_this_as_primary ? this : &line; Inkscape::SnappedLineSegment const *secondarySLS = use_this_as_primary ? &line : this; Geom::Coord primaryDist = use_this_as_primary ? Geom::L2(inters_pt - this->getPoint()) : Geom::L2(inters_pt - line.getPoint()); Geom::Coord secondaryDist = use_this_as_primary ? Geom::L2(inters_pt - line.getPoint()) : Geom::L2(inters_pt - this->getPoint()); return SnappedPoint(inters_pt, SNAPSOURCE_UNDEFINED, primarySLS->getSourceNum(), SNAPTARGET_PATH_INTERSECTION, primaryDist, primarySLS->getTolerance(), primarySLS->getAlwaysSnap(), true, false, true, secondaryDist, secondarySLS->getTolerance(), secondarySLS->getAlwaysSnap()); } // No intersection return SnappedPoint(Geom::Point(Geom::infinity(), Geom::infinity()), SNAPSOURCE_UNDEFINED, 0, SNAPTARGET_UNDEFINED, Geom::infinity(), 0, false, false, false, false, Geom::infinity(), 0, false); }; Inkscape::SnappedLine::SnappedLine(Geom::Point const &snapped_point, Geom::Coord const &snapped_distance, SnapSourceType const &source, long source_num, SnapTargetType const &target, Geom::Coord const &snapped_tolerance, bool const &always_snap, Geom::Point const &normal_to_line, Geom::Point const &point_on_line) : _normal_to_line(normal_to_line), _point_on_line(point_on_line) { _source = source; _source_num = source_num; _target = target; _distance = snapped_distance; _tolerance = std::max(snapped_tolerance, 1.0); _always_snap = always_snap; _second_distance = Geom::infinity(); _second_tolerance = 1; _second_always_snap = false; _point = snapped_point; _at_intersection = false; } Inkscape::SnappedLine::SnappedLine() { _source = SNAPSOURCE_UNDEFINED; _source_num = -1; _target = SNAPTARGET_UNDEFINED; _distance = Geom::infinity(); _tolerance = 1; _always_snap = false; _second_distance = Geom::infinity(); _second_tolerance = 1; _second_always_snap = false; _at_intersection = false; } Inkscape::SnappedLine::~SnappedLine() = default; Inkscape::SnappedPoint Inkscape::SnappedLine::intersect(SnappedLine const &line) const { // Calculate the intersection of two lines, which are both within snapping range // One could be a grid line, whereas the other could be a guide line // The point of intersection should be considered for snapping, but might be outside the snapping range Geom::OptCrossing inters = Geom::OptCrossing(); // empty by default try { inters = Geom::intersection(getLine(), line.getLine()); } catch (Geom::InfiniteSolutions &e) { // We're probably dealing with parallel lines, so they don't really cross inters = Geom::OptCrossing(); } if (inters) { Geom::Point inters_pt = getLine().pointAt((*inters).ta); /* If a snapper has been told to "always snap", then this one should be preferred * over the other, if that other one has not been told so. (The preferred snapper * will be labelled "primary" below) */ bool const c1 = this->getAlwaysSnap() && !line.getAlwaysSnap(); /* If neither or both have been told to "always snap", then cast a vote based on * the snapped distance. For this we should consider the distance to the snapped * line or to the intersection */ bool const c2 = _distance < line.getSnapDistance(); bool const use_this_as_primary = c1 || c2; Inkscape::SnappedLine const *primarySL = use_this_as_primary ? this : &line; Inkscape::SnappedLine const *secondarySL = use_this_as_primary ? &line : this; Geom::Coord primaryDist = use_this_as_primary ? Geom::L2(inters_pt - this->getPoint()) : Geom::L2(inters_pt - line.getPoint()); Geom::Coord secondaryDist = use_this_as_primary ? Geom::L2(inters_pt - line.getPoint()) : Geom::L2(inters_pt - this->getPoint()); return SnappedPoint(inters_pt, Inkscape::SNAPSOURCE_UNDEFINED, primarySL->getSourceNum(), Inkscape::SNAPTARGET_UNDEFINED, primaryDist, primarySL->getTolerance(), primarySL->getAlwaysSnap(), true, false, true, secondaryDist, secondarySL->getTolerance(), secondarySL->getAlwaysSnap()); // The type of the snap target is yet undefined, as we cannot tell whether // we're snapping to grid or the guide lines; must be set by on a higher level } // No intersection return SnappedPoint(Geom::Point(Geom::infinity(), Geom::infinity()), SNAPSOURCE_UNDEFINED, 0, SNAPTARGET_UNDEFINED, Geom::infinity(), 0, false, false, false, false, Geom::infinity(), 0, false); } // search for the closest snapped line segment bool getClosestSLS(std::list const &list, Inkscape::SnappedLineSegment &result) { bool success = false; for (std::list::const_iterator i = list.begin(); i != list.end(); ++i) { if ((i == list.begin()) || (*i).getSnapDistance() < result.getSnapDistance()) { result = *i; success = true; } } return success; } // search for the closest intersection of two snapped line segments, which are both member of the same collection bool getClosestIntersectionSLS(std::list const &list, Inkscape::SnappedPoint &result) { bool success = false; for (std::list::const_iterator i = list.begin(); i != list.end(); ++i) { std::list::const_iterator j = i; ++j; for (; j != list.end(); ++j) { Inkscape::SnappedPoint sp = (*i).intersect(*j); if (sp.getAtIntersection()) { // if it's the first point bool const c1 = !success; // or, if it's closer bool const c2 = sp.getSnapDistance() < result.getSnapDistance(); // or, if it's just then look at the other distance // (only relevant for snapped points which are at an intersection bool const c3 = (sp.getSnapDistance() == result.getSnapDistance()) && (sp.getSecondSnapDistance() < result.getSecondSnapDistance()); // then prefer this point over the previous one if (c1 || c2 || c3) { result = sp; success = true; } } } } return success; } // search for the closest snapped line bool getClosestSL(std::list const &list, Inkscape::SnappedLine &result) { bool success = false; for (std::list::const_iterator i = list.begin(); i != list.end(); ++i) { if ((i == list.begin()) || (*i).getSnapDistance() < result.getSnapDistance()) { result = *i; success = true; } } return success; } // search for the closest intersection of two snapped lines, which are both member of the same collection bool getClosestIntersectionSL(std::list const &list, Inkscape::SnappedPoint &result) { bool success = false; for (std::list::const_iterator i = list.begin(); i != list.end(); ++i) { std::list::const_iterator j = i; ++j; for (; j != list.end(); ++j) { Inkscape::SnappedPoint sp = (*i).intersect(*j); if (sp.getAtIntersection()) { // if it's the first point bool const c1 = !success; // or, if it's closer bool const c2 = sp.getSnapDistance() < result.getSnapDistance(); // or, if it's just then look at the other distance // (only relevant for snapped points which are at an intersection bool const c3 = (sp.getSnapDistance() == result.getSnapDistance()) && (sp.getSecondSnapDistance() < result.getSecondSnapDistance()); // then prefer this point over the previous one if (c1 || c2 || c3) { result = sp; success = true; } } } } return success; } // search for the closest intersection of two snapped lines, which are in two different collections bool getClosestIntersectionSL(std::list const &list1, std::list const &list2, Inkscape::SnappedPoint &result) { bool success = false; for (const auto & i : list1) { for (const auto & j : list2) { Inkscape::SnappedPoint sp = i.intersect(j); if (sp.getAtIntersection()) { // if it's the first point bool const c1 = !success; // or, if it's closer bool const c2 = sp.getSnapDistance() < result.getSnapDistance(); // or, if it's just then look at the other distance // (only relevant for snapped points which are at an intersection bool const c3 = (sp.getSnapDistance() == result.getSnapDistance()) && (sp.getSecondSnapDistance() < result.getSecondSnapDistance()); // then prefer this point over the previous one if (c1 || c2 || c3) { result = sp; success = true; } } } } return success; } /* 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 :