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Diffstat (limited to 'src/snapped-line.cpp')
| -rw-r--r-- | src/snapped-line.cpp | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/src/snapped-line.cpp b/src/snapped-line.cpp new file mode 100644 index 0000000..799fda7 --- /dev/null +++ b/src/snapped-line.cpp @@ -0,0 +1,293 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/** + * \file src/snapped-line.cpp + * SnappedLine class. + * + * Authors: + * Diederik van Lierop <mail@diedenrezi.nl> + * + * 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<Inkscape::SnappedLineSegment> const &list, Inkscape::SnappedLineSegment &result) +{ + bool success = false; + + for (std::list<Inkscape::SnappedLineSegment>::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<Inkscape::SnappedLineSegment> const &list, Inkscape::SnappedPoint &result) +{ + bool success = false; + + for (std::list<Inkscape::SnappedLineSegment>::const_iterator i = list.begin(); i != list.end(); ++i) { + std::list<Inkscape::SnappedLineSegment>::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<Inkscape::SnappedLine> const &list, Inkscape::SnappedLine &result) +{ + bool success = false; + + for (std::list<Inkscape::SnappedLine>::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<Inkscape::SnappedLine> const &list, Inkscape::SnappedPoint &result) +{ + bool success = false; + + for (std::list<Inkscape::SnappedLine>::const_iterator i = list.begin(); i != list.end(); ++i) { + std::list<Inkscape::SnappedLine>::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<Inkscape::SnappedLine> const &list1, std::list<Inkscape::SnappedLine> 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 : |