X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Fline-snapper.cpp;h=f2f02533246a8d6b90a20fb73db4694db4ffc678;hb=99f8079bc0a32aef279e4af06de4cbf4bd853563;hp=a2c6b944bcc28ff10c36963b8fbb1bb142901cda;hpb=b7313eac22048276ef96257c67805fc94ad7d6ab;p=inkscape.git diff --git a/src/line-snapper.cpp b/src/line-snapper.cpp index a2c6b944b..f2f025332 100644 --- a/src/line-snapper.cpp +++ b/src/line-snapper.cpp @@ -1,69 +1,129 @@ -#include "libnr/nr-values.h" -#include "libnr/nr-point-fns.h" -#include "geom.h" +/** + * \file line-snapper.cpp + * \brief LineSnapper class. + * + * Authors: + * Diederik van Lierop + * And others... + * + * Copyright (C) 1999-2008 Authors + * + * Released under GNU GPL, read the file 'COPYING' for more information + */ + +#include <2geom/line.h> #include "line-snapper.h" +#include "snapped-line.h" +//#include +#include "snap.h" -Inkscape::LineSnapper::LineSnapper(SPNamedView const *nv, NR::Coord const d) : Snapper(nv, d) +Inkscape::LineSnapper::LineSnapper(SnapManager *sm, Geom::Coord const d) : Snapper(sm, d) { - } -Inkscape::SnappedPoint Inkscape::LineSnapper::_doFreeSnap(NR::Point const &p, - std::list const &it) const +void Inkscape::LineSnapper::freeSnap(SnappedConstraints &sc, + Inkscape::SnapCandidatePoint const &p, + Geom::OptRect const &/*bbox_to_snap*/, + std::vector const */*it*/, + std::vector */*unselected_nodes*/) const { - /* Snap along x (ie to vertical lines) */ - Inkscape::SnappedPoint const v = _doConstrainedSnap(p, component_vectors[NR::X], it); - /* Snap along y (ie to horizontal lines) */ - Inkscape::SnappedPoint const h = _doConstrainedSnap(p, component_vectors[NR::Y], it); - - /* If we snapped to both, combine the two results. This is so that, for example, - ** we snap nicely to the intersection of two guidelines. - */ - if (v.getDistance() < NR_HUGE && h.getDistance() < NR_HUGE) { - return SnappedPoint(NR::Point(v.getPoint()[NR::X], h.getPoint()[NR::Y]), hypot(v.getDistance(), h.getDistance())); + if (!(_snap_enabled && _snapmanager->snapprefs.getSnapFrom(p.getSourceType())) ) { + return; } - /* If we snapped to a vertical line, return that */ - if (v.getDistance() < NR_HUGE) { - return v; - } + /* Get the lines that we will try to snap to */ + const LineList lines = _getSnapLines(p.getPoint()); - /* Otherwise just return any horizontal snap; if we didn't snap to that either - ** we haven't snapped to anything. - */ - return h; + for (LineList::const_iterator i = lines.begin(); i != lines.end(); i++) { + Geom::Point const p1 = i->second; // point at guide/grid line + Geom::Point const p2 = p1 + Geom::rot90(i->first); // 2nd point at guide/grid line + // std::cout << " line through " << i->second << " with normal " << i->first; + g_assert(i->first != Geom::Point(0,0)); // we cannot project on an linesegment of zero length + + Geom::Point const p_proj = Geom::projection(p.getPoint(), Geom::Line(p1, p2)); + Geom::Coord const dist = Geom::L2(p_proj - p.getPoint()); + //Store any line that's within snapping range + if (dist < getSnapperTolerance()) { + _addSnappedLine(sc, p_proj, dist, p.getSourceType(), p.getSourceNum(), i->first, i->second); + // For any line that's within range, we will also look at it's "point on line" p1. For guides + // this point coincides with its origin; for grids this is of no use, but we cannot + // discern between grids and guides here + Geom::Coord const dist_p1 = Geom::L2(p1 - p.getPoint()); + if (dist_p1 < getSnapperTolerance()) { + _addSnappedLinesOrigin(sc, p1, dist_p1, p.getSourceType(), p.getSourceNum()); + // Only relevant for guides; grids don't have an origin per line + // Therefore _addSnappedLinesOrigin() will only be implemented for guides + } + // std::cout << " -> distance = " << dist; + } + // std::cout << std::endl; + } } -Inkscape::SnappedPoint Inkscape::LineSnapper::_doConstrainedSnap(NR::Point const &p, - ConstraintLine const &c, - std::list const &it) const +void Inkscape::LineSnapper::constrainedSnap(SnappedConstraints &sc, + Inkscape::SnapCandidatePoint const &p, + Geom::OptRect const &/*bbox_to_snap*/, + ConstraintLine const &c, + std::vector const */*it*/) const + { - Inkscape::SnappedPoint s = SnappedPoint(p, NR_HUGE); + if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(p.getSourceType()) == false) { + return; + } /* Get the lines that we will try to snap to */ - const LineList lines = _getSnapLines(p); + const LineList lines = _getSnapLines(p.getPoint()); for (LineList::const_iterator i = lines.begin(); i != lines.end(); i++) { + if (Geom::L2(c.getDirection()) > 0) { // Can't do a constrained snap without a constraint + // constraint line + Geom::Point const point_on_line = c.hasPoint() ? c.getPoint() : p.getPoint(); + Geom::Line line1(point_on_line, point_on_line + c.getDirection()); - /* Normal to the line we're trying to snap along */ - NR::Point const n(NR::rot90(NR::unit_vector(c.getDirection()))); - - /* Constant term of the line we're trying to snap along */ - NR::Coord const q = dot(n, c.hasPoint() ? c.getPoint() : p); + // grid/guide line + Geom::Point const p1 = i->second; // point at guide/grid line + Geom::Point const p2 = p1 + Geom::rot90(i->first); // 2nd point at guide/grid line + Geom::Line line2(p1, p2); - /* Try to intersect this line with the target line */ - NR::Point t = p; - IntersectorKind const k = intersector_line_intersection(n, q, component_vectors[i->first], i->second, t); + Geom::OptCrossing inters = Geom::OptCrossing(); // empty by default + try + { + inters = Geom::intersection(line1, line2); + } + catch (Geom::InfiniteSolutions e) + { + // We're probably dealing with parallel lines, so snapping doesn't make any sense here + continue; // jump to the next iterator in the for-loop + } - if (k == INTERSECTS) { - const NR::Coord dist = L2(t - p); - if (dist < getDistance() && dist < s.getDistance() ) { - s = SnappedPoint(t, dist); + if (inters) { + Geom::Point t = line1.pointAt((*inters).ta); + const Geom::Coord dist = Geom::L2(t - p.getPoint()); + if (dist < getSnapperTolerance()) { + // When doing a constrained snap, we're already at an intersection. + // This snappoint is therefore fully constrained, so there's no need + // to look for additional intersections; just return the snapped point + // and forget about the line + _addSnappedPoint(sc, t, dist, p.getSourceType(), p.getSourceNum()); + // For any line that's within range, we will also look at it's "point on line" p1. For guides + // this point coincides with its origin; for grids this is of no use, but we cannot + // discern between grids and guides here + Geom::Coord const dist_p1 = Geom::L2(p1 - p.getPoint()); + if (dist_p1 < getSnapperTolerance()) { + _addSnappedLinesOrigin(sc, p1, dist_p1, p.getSourceType(), p.getSourceNum()); + // Only relevant for guides; grids don't have an origin per line + // Therefore _addSnappedLinesOrigin() will only be implemented for guides + } + } } } } +} - return s; +// Will only be overridden in the guide-snapper class, because grid lines don't have an origin; the +// grid-snapper classes will use this default empty method +void Inkscape::LineSnapper::_addSnappedLinesOrigin(SnappedConstraints &/*sc*/, Geom::Point const /*origin*/, Geom::Coord const /*snapped_distance*/, SnapSourceType const &/*source_type*/, long /*source_num*/) const +{ } /*