src/guide-snapper.cpp

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  Snapping things to guides.
   4  *
   5  * Authors:
   6  *   Lauris Kaplinski <lauris@kaplinski.com>
   7  *   Frank Felfe <innerspace@iname.com>
   8  *   Carl Hetherington <inkscape@carlh.net>
   9  *
  10  * Copyright (C) 1999-2002 Authors
  11  *
  12  * Released under GNU GPL v2+, read the file 'COPYING' for more information.
  13  */
  14
  15 #include "desktop.h"
  16 #include "preferences.h"
  17
  18 #include "object/sp-guide.h"
  19 #include "object/sp-namedview.h"
  20
  21 Inkscape::GuideSnapper::GuideSnapper(SnapManager *sm, Geom::Coord const d) : LineSnapper(sm, d)
  22 {}
  23
  24 /**
  25  *  \return Snap tolerance (desktop coordinates); depends on current zoom so that it's always the same in screen pixels
  26  */
  27 Geom::Coord Inkscape::GuideSnapper::getSnapperTolerance() const
  28 {
  29     SPDesktop const *dt = _snapmanager->getDesktop();
  30     double const zoom =  dt ? dt->current_zoom() : 1;
  31     return _snapmanager->snapprefs.getGuideTolerance() / zoom;
  32 }
  33
  34 bool Inkscape::GuideSnapper::getSnapperAlwaysSnap(SnapSourceType const &source) const
  35 {
  36     if (source == SNAPSOURCE_GUIDE || source == SNAPSOURCE_GUIDE_ORIGIN)
  37         return false; // Don't always snap to other guides
  38     return Preferences::get()->getBool("/options/snap/guide/always", false);
  39 }
  40
  41 Inkscape::GuideSnapper::LineList Inkscape::GuideSnapper::_getSnapLines(Geom::Point const &/*p*/) const
  42 {
  43     LineList s;
  44
  45     if ( nullptr == _snapmanager->getNamedView() || ThisSnapperMightSnap() == false) {
  46         return s;
  47     }
  48
  49     SPGuide const *guide_to_ignore = _snapmanager->getGuideToIgnore();
  50     std::vector<SPGuide *> guides = _snapmanager->getNamedView()->guides;
  51     for(auto guide : guides) {
  52         if (guide != guide_to_ignore) {
  53             s.emplace_back(guide->getNormal(), guide->getPoint());
  54         }
  55     }
  56
  57     return s;
  58 }
  59
  60 /**
  61  *  \return true if this Snapper will snap at least one kind of point.
  62  */
  63 bool Inkscape::GuideSnapper::ThisSnapperMightSnap() const
  64 {
  65     if (_snapmanager->getNamedView() == nullptr) {
  66         return false;
  67     }
  68
  69     return (_snap_enabled && _snapmanager->snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_GUIDE) && _snapmanager->getNamedView()->showguides);
  70 }
  71
  72 void Inkscape::GuideSnapper::_addSnappedLine(IntermSnapResults &isr, Geom::Point const &snapped_point, Geom::Coord const &snapped_distance, SnapSourceType const &source, long source_num, Geom::Point const &normal_to_line, Geom::Point const &point_on_line) const
  73 {
  74     SnappedLine dummy = SnappedLine(snapped_point, snapped_distance, source, source_num, Inkscape::SNAPTARGET_GUIDE, getSnapperTolerance(), getSnapperAlwaysSnap(source), normal_to_line, point_on_line);
  75     isr.guide_lines.push_back(dummy);
  76 }
  77
  78 void Inkscape::GuideSnapper::_addSnappedLinesOrigin(IntermSnapResults &isr, Geom::Point const &origin, Geom::Coord const &snapped_distance, SnapSourceType const &source, long source_num, bool constrained_snap) const
  79 {
  80     SnappedPoint dummy = SnappedPoint(origin, source, source_num, Inkscape::SNAPTARGET_GUIDE_ORIGIN, snapped_distance, getSnapperTolerance(), getSnapperAlwaysSnap(source), constrained_snap, true);
  81     isr.points.push_back(dummy);
  82 }
  83
  84 void Inkscape::GuideSnapper::_addSnappedLinePerpendicularly(IntermSnapResults &isr, Geom::Point const &snapped_point, Geom::Coord const &snapped_distance, SnapSourceType const &source, long source_num, bool constrained_snap) const
  85 {
  86     SnappedPoint dummy = SnappedPoint(snapped_point, source, source_num, Inkscape::SNAPTARGET_GUIDE_PERPENDICULAR, snapped_distance, getSnapperTolerance(), getSnapperAlwaysSnap(source), constrained_snap, true);
  87     isr.points.push_back(dummy);
  88 }
  89
  90 void Inkscape::GuideSnapper::_addSnappedPoint(IntermSnapResults &isr, Geom::Point const &snapped_point, Geom::Coord const &snapped_distance, SnapSourceType const &source, long source_num, bool constrained_snap) const
  91 {
  92     SnappedPoint dummy = SnappedPoint(snapped_point, source, source_num, Inkscape::SNAPTARGET_GUIDE, snapped_distance, getSnapperTolerance(), getSnapperAlwaysSnap(source), constrained_snap, true);
  93     isr.points.push_back(dummy);
  94 }
  95
  96 /*
  97   Local Variables:
  98   mode:c++
  99   c-file-style:"stroustrup"
 100   c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
 101   indent-tabs-mode:nil
 102   fill-column:99
 103   End:
 104 */
 105 // vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :