X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Fline-snapper.cpp;h=be64438ed503d5b6282b77fed33348822f4b79b6;hb=e454b92b3d16b0909892cddef064b745898c924d;hp=be35ec2db930b1faaf717ecad13bb2f7d379853e;hpb=bbbe9eebaeb94bab65295acc609a7c98544c4f4c;p=inkscape.git diff --git a/src/line-snapper.cpp b/src/line-snapper.cpp index be35ec2db..be64438ed 100644 --- a/src/line-snapper.cpp +++ b/src/line-snapper.cpp @@ -1,69 +1,143 @@ -#include "libnr/nr-values.h" -#include "libnr/nr-point-fns.h" -#include <2geom/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.cpp" +#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) { - } -void Inkscape::LineSnapper::_doFreeSnap(SnappedConstraints &sc, - Inkscape::Snapper::PointType const &t, - NR::Point const &p, - bool const &f, - std::vector &points_to_snap, - 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 (i.e. to vertical lines) */ - _doConstrainedSnap(sc, t, p, f, points_to_snap, component_vectors[NR::X], it); - /* Snap along y (i.e. to horizontal lines) */ - _doConstrainedSnap(sc, t, p, f, points_to_snap, component_vectors[NR::Y], it); + if (!(_snap_enabled && _snapmanager->snapprefs.getSnapFrom(p.getSourceType())) ) { + return; + } + /* Get the lines that we will try to snap to */ + const LineList lines = _getSnapLines(p.getPoint()); + + 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(), false); + // 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; + } } -void Inkscape::LineSnapper::_doConstrainedSnap(SnappedConstraints &sc, - Inkscape::Snapper::PointType const &/*t*/, - NR::Point const &p, - bool const &/*f*/, - std::vector &/*points_to_snap*/, - ConstraintLine const &c, - std::list const &/*it*/) const +void Inkscape::LineSnapper::constrainedSnap(SnappedConstraints &sc, + Inkscape::SnapCandidatePoint const &p, + Geom::OptRect const &/*bbox_to_snap*/, + SnapConstraint const &c, + std::vector const */*it*/, + std::vector */*unselected_nodes*/) const { - Inkscape::SnappedPoint s = SnappedPoint(p, NR_HUGE); + if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(p.getSourceType()) == false) { + return; + } + + // project the mouse pointer onto the constraint. Only the projected point will be considered for snapping + Geom::Point pp = c.projection(p.getPoint()); /* Get the lines that we will try to snap to */ - const LineList lines = _getSnapLines(p); + const LineList lines = _getSnapLines(pp); for (LineList::const_iterator i = lines.begin(); i != lines.end(); i++) { + Geom::Point const point_on_line = c.hasPoint() ? c.getPoint() : pp; + Geom::Line gridguide_line(i->second, i->second + Geom::rot90(i->first)); - /* Normal to the line we're trying to snap along */ - NR::Point const n(NR::rot90(NR::unit_vector(c.getDirection()))); - - NR::Point const point_on_line = c.hasPoint() ? c.getPoint() : p; - - /* Constant term of the line we're trying to snap along */ - NR::Coord const q = dot(n, point_on_line); - - /* Try to intersect this line with the target line */ - Geom::Point t_2geom(NR_HUGE, NR_HUGE); - Geom::IntersectorKind const k = Geom::line_intersection(n.to_2geom(), q, component_vectors[i->first].to_2geom(), i->second, t_2geom); - NR::Point t(t_2geom); + if (c.isCircular()) { + // Find the intersections between the line and the circular constraint + // First, project the origin of the circle onto the line + Geom::Point const origin = c.getPoint(); + Geom::Point const p_proj = Geom::projection(origin, gridguide_line); + Geom::Coord dist = Geom::L2(p_proj - origin); // distance from circle origin to constraint line + Geom::Coord radius = c.getRadius(); + if (dist == radius) { + // Only one point of intersection; + _addSnappedPoint(sc, p_proj, Geom::L2(pp - p_proj), p.getSourceType(), p.getSourceNum(), true); + } else if (dist < radius) { + // Two points of intersection, symmetrical with respect to the projected point + // Calculate half the length of the linesegment between the two points of intersection + Geom::Coord l = sqrt(radius*radius - dist*dist); + Geom::Coord d = Geom::L2(gridguide_line.versor()); // length of versor, needed to normalize the versor + if (d > 0) { + Geom::Point v = l*gridguide_line.versor()/d; + _addSnappedPoint(sc, p_proj + v, Geom::L2(pp - (p_proj + v)), p.getSourceType(), p.getSourceNum(), true); + _addSnappedPoint(sc, p_proj - v, Geom::L2(pp - (p_proj - v)), p.getSourceType(), p.getSourceNum(), true); + } + } + } else { + // Find the intersections between the line and the linear constraint + Geom::Line constraint_line(point_on_line, point_on_line + c.getDirection()); + Geom::OptCrossing inters = Geom::OptCrossing(); // empty by default + try + { + inters = Geom::intersection(constraint_line, gridguide_line); + } + 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 == Geom::intersects) { - const NR::Coord dist = L2(t - p); - //Store any line that's within snapping range - if (dist < getDistance()) { - _addSnappedLine(sc, t, dist, c.getDirection(), t); - //SnappedLine dummy = SnappedLine(t, dist, c.getDirection(), t); - //sc.infinite_lines.push_back(dummy); + if (inters) { + Geom::Point t = constraint_line.pointAt((*inters).ta); + const Geom::Coord dist = Geom::L2(t - pp); + 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(), true); + } } } } } +// 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*/, bool /*constrained_snap*/) const +{ +} + /* Local Variables: mode:c++