src/snapper.cpp

   1 /**
   2  *  \file src/snapper.cpp
   3  *  \brief Snapper class.
   4  *
   5  *  Authors:
   6  *    Carl Hetherington <inkscape@carlh.net>
   7  *    Diederik van Lierop <mail@diedenrezi.nl>
   8  *
   9  *  Released under GNU GPL, read the file 'COPYING' for more information.
  10  */
  11
  12 #include "libnr/nr-values.h"
  13 #include "sp-namedview.h"
  14 #include "inkscape.h"
  15 #include "desktop.h"
  16
  17 Inkscape::Snapper::PointType const Inkscape::Snapper::SNAPPOINT_BBOX = 0x1;
  18 Inkscape::Snapper::PointType const Inkscape::Snapper::SNAPPOINT_NODE = 0x2;
  19 Inkscape::Snapper::PointType const Inkscape::Snapper::SNAPPOINT_GUIDE = 0x4;
  20
  21 /**
  22  *  Construct new Snapper for named view.
  23  *  \param nv Named view.
  24  *  \param d Snap tolerance.
  25  */
  26 Inkscape::Snapper::Snapper(SPNamedView const *nv, NR::Coord const t) : _named_view(nv), _snap_enabled(true), _snapper_tolerance(t)
  27 {
  28     g_assert(_named_view != NULL);
  29     g_assert(SP_IS_NAMEDVIEW(_named_view));
  30
  31     setSnapFrom(SNAPPOINT_BBOX | SNAPPOINT_NODE, true); //Snap any point. In v0.45 and earlier, this was controlled in the preferences tab
  32 }
  33
  34 /**
  35  *  Set snap tolerance.
  36  *  \param d New snap tolerance (desktop coordinates)
  37  */
  38 void Inkscape::Snapper::setSnapperTolerance(NR::Coord const d)
  39 {
  40     _snapper_tolerance = d;
  41 }
  42
  43 /**
  44  *  \return Snap tolerance (desktop coordinates); depends on current zoom so that it's always the same in screen pixels
  45  */
  46 NR::Coord Inkscape::Snapper::getSnapperTolerance() const
  47 {
  48     return _snapper_tolerance / SP_ACTIVE_DESKTOP->current_zoom();
  49 }
  50
  51 bool Inkscape::Snapper::getSnapperAlwaysSnap() const
  52 {
  53     return _snapper_tolerance == 10000; //TODO: Replace this threshold of 10000 by a constant; see also tolerance-slider.cpp
  54 }
  55
  56 /**
  57  *  Turn on/off snapping of specific point types.
  58  *  \param t Point type.
  59  *  \param s true to snap to this point type, otherwise false;
  60  */
  61 void Inkscape::Snapper::setSnapFrom(PointType t, bool s)
  62 {
  63     if (s) {
  64         _snap_from |= t;
  65     } else {
  66         _snap_from &= ~t;
  67     }
  68 }
  69
  70 /**
  71  *  \param t Point type.
  72  *  \return true if snapper will snap this type of point, otherwise false.
  73  */
  74 bool Inkscape::Snapper::getSnapFrom(PointType t) const
  75 {
  76     return (_snap_from & t);
  77 }
  78
  79 /**
  80  *  \param s true to enable this snapper, otherwise false.
  81  */
  82
  83 void Inkscape::Snapper::setEnabled(bool s)
  84 {
  85     _snap_enabled = s;
  86 }
  87
  88
  89 /**
  90  *  Try to snap a point to whatever this snapper is interested in.  Any
  91  *  snap that occurs will be to the nearest "interesting" thing (e.g. a
  92  *  grid or guide line)
  93  *
  94  *  \param t Point type.
  95  *  \param p Point to snap (desktop coordinates).
  96  *  \param it Item that should not be snapped to.
  97  *  \return Snapped point.
  98  */
  99
 100 void Inkscape::Snapper::freeSnap(SnappedConstraints &sc,
 101                                                    PointType const &t,
 102                                                    NR::Point const &p,
 103                                                    bool const &first_point,
 104                                                    std::vector<NR::Point> &points_to_snap,
 105                                                    SPItem const *it) const
 106 {
 107     std::list<SPItem const *> lit;
 108     if (it) {
 109         lit.push_back(it);
 110     }
 111
 112     freeSnap(sc, t, p, first_point, points_to_snap, lit, NULL);
 113 }
 114
 115 /**
 116  *  Try to snap a point to whatever this snapper is interested in.  Any
 117  *  snap that occurs will be to the nearest "interesting" thing (e.g. a
 118  *  grid or guide line)
 119  *
 120  *  \param t Point type.
 121  *  \param p Point to snap (desktop coordinates).
 122  *  \param it Items that should not be snapped to.
 123  *  \return Snapped point.
 124  */
 125
 126 void Inkscape::Snapper::freeSnap(SnappedConstraints &sc,
 127                                                    PointType const &t,
 128                                                    NR::Point const &p,
 129                                                    bool const &first_point,
 130                                                    std::vector<NR::Point> &points_to_snap,
 131                                                    std::list<SPItem const *> const &it,
 132                                                    std::vector<NR::Point> *unselected_nodes) const
 133 {
 134     if (_snap_enabled == false || getSnapFrom(t) == false) {
 135         return;
 136     }
 137
 138     _doFreeSnap(sc, t, p, first_point, points_to_snap, it, unselected_nodes);
 139 }
 140
 141
 142
 143
 144 /**
 145  *  Try to snap a point to whatever this snapper is interested in, where
 146  *  the snap point is constrained to lie along a specified vector from the
 147  *  original point.
 148  *
 149  *  \param p Point to snap (desktop coordinates).
 150  *  \param c Vector to constrain the snap to.
 151  *  \param it Items that should not be snapped to.
 152  *  \return Snapped point.
 153  */
 154
 155 void Inkscape::Snapper::constrainedSnap(SnappedConstraints &sc,
 156                                                           PointType const &t,
 157                                                           NR::Point const &p,
 158                                                           bool const &first_point,
 159                                                           std::vector<NR::Point> &points_to_snap,
 160                                                           ConstraintLine const &c,
 161                                                           SPItem const *it) const
 162 {
 163     std::list<SPItem const *> lit;
 164     lit.push_back(it);
 165     constrainedSnap(sc, t, p, first_point, points_to_snap, c, lit);
 166 }
 167
 168
 169 /**
 170  *  Try to snap a point to whatever this snapper is interested in, where
 171  *  the snap point is constrained to lie along a specified vector from the
 172  *  original point.
 173  *
 174  *  \param p Point to snap (desktop coordinates).
 175  *  \param c Vector to constrain the snap to.
 176  *  \param it Items that should not be snapped to.
 177  *  \return Snapped point.
 178  */
 179
 180 void Inkscape::Snapper::constrainedSnap(SnappedConstraints &sc,
 181                                                           PointType const &t,
 182                                                           NR::Point const &p,
 183                                                           bool const &first_point,
 184                                                           std::vector<NR::Point> &points_to_snap,
 185                                                           ConstraintLine const &c,
 186                                                           std::list<SPItem const *> const &it) const
 187 {
 188     if (_snap_enabled == false || getSnapFrom(t) == false) {
 189         return;
 190     }
 191
 192     _doConstrainedSnap(sc, t, p, first_point, points_to_snap, c, it);
 193 }
 194
 195 /*
 196   Local Variables:
 197   mode:c++
 198   c-file-style:"stroustrup"
 199   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 200   indent-tabs-mode:nil
 201   fill-column:99
 202   End:
 203 */
 204 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :