src/line-snapper.cpp

   1 #include "libnr/nr-values.h"
   2 #include "libnr/nr-point-fns.h"
   3 #include <2geom/geom.h>
   4 #include "line-snapper.h"
   5 #include "snapped-line.cpp"
   6
   7 Inkscape::LineSnapper::LineSnapper(SPNamedView const *nv, NR::Coord const d) : Snapper(nv, d)
   8 {
   9
  10 }
  11
  12 void Inkscape::LineSnapper::_doFreeSnap(SnappedConstraints &sc,
  13                                                     Inkscape::Snapper::PointType const &t,
  14                                                     NR::Point const &p,
  15                                                     bool const &f,
  16                                                      std::vector<NR::Point> &points_to_snap,
  17                                                     std::list<SPItem const *> const &it) const
  18 {
  19     /* Snap along x (i.e. to vertical lines) */
  20     _doConstrainedSnap(sc, t, p, f, points_to_snap, component_vectors[NR::X], it);
  21     /* Snap along y (i.e. to horizontal lines) */
  22     _doConstrainedSnap(sc, t, p, f, points_to_snap, component_vectors[NR::Y], it);
  23
  24 }
  25
  26 void Inkscape::LineSnapper::_doConstrainedSnap(SnappedConstraints &sc,
  27                                                Inkscape::Snapper::PointType const &/*t*/,
  28                                                NR::Point const &p,
  29                                                bool const &/*f*/,
  30                                                std::vector<NR::Point> &/*points_to_snap*/,
  31                                                ConstraintLine const &c,
  32                                                std::list<SPItem const *> const &/*it*/) const
  33
  34 {
  35     Inkscape::SnappedPoint s = SnappedPoint(p, NR_HUGE);
  36
  37     /* Get the lines that we will try to snap to */
  38     const LineList lines = _getSnapLines(p);
  39
  40     for (LineList::const_iterator i = lines.begin(); i != lines.end(); i++) {
  41
  42         /* Normal to the line we're trying to snap along */
  43         NR::Point const n(NR::rot90(NR::unit_vector(c.getDirection())));
  44
  45         NR::Point const point_on_line = c.hasPoint() ? c.getPoint() : p;
  46
  47         /* Constant term of the line we're trying to snap along */
  48         NR::Coord const q = dot(n, point_on_line);
  49
  50         /* Try to intersect this line with the target line */
  51         Geom::Point t_2geom(NR_HUGE, NR_HUGE);
  52         Geom::IntersectorKind const k = Geom::line_intersection(n.to_2geom(), q, component_vectors[i->first].to_2geom(), i->second, t_2geom);
  53         NR::Point t(t_2geom);
  54
  55         if (k == Geom::intersects) {
  56             const NR::Coord dist = L2(t - p);
  57             //Store any line that's within snapping range
  58             if (dist < getDistance()) {
  59                                 _addSnappedLine(sc, t, dist, c.getDirection(), t);
  60                 //SnappedLine dummy = SnappedLine(t, dist, c.getDirection(), t);
  61                 //sc.infinite_lines.push_back(dummy);
  62             }
  63         }
  64     }
  65 }
  66
  67 /*
  68   Local Variables:
  69   mode:c++
  70   c-file-style:"stroustrup"
  71   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
  72   indent-tabs-mode:nil
  73   fill-column:99
  74   End:
  75 */
  76 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :