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/**
* \file line-snapper.cpp
* \brief LineSnapper class.
*
* Authors:
* Diederik van Lierop <mail@diedenrezi.nl>
* 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 <gtk/gtk.h>
#include "snap.h"
Inkscape::LineSnapper::LineSnapper(SnapManager *sm, Geom::Coord const d) : Snapper(sm, d)
{
}
void Inkscape::LineSnapper::freeSnap(SnappedConstraints &sc,
Inkscape::SnapPreferences::PointType const &t,
Geom::Point const &p,
SnapSourceType const &source_type,
bool const &/*f*/,
Geom::OptRect const &/*bbox_to_snap*/,
std::vector<SPItem const *> const */*it*/,
std::vector<std::pair<Geom::Point, int> > */*unselected_nodes*/) const
{
if (!(_snap_enabled && _snapmanager->snapprefs.getSnapFrom(t)) ) {
return;
}
/* Get the lines that we will try to snap to */
const LineList lines = _getSnapLines(p);
// std::cout << "snap point " << p << " to: " << std::endl;
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, Geom::Line(p1, p2));
Geom::Coord const dist = Geom::L2(p_proj - p);
//Store any line that's within snapping range
if (dist < getSnapperTolerance()) {
_addSnappedLine(sc, p_proj, dist, source_type, i->first, i->second);
// std::cout << " -> distance = " << dist;
}
// std::cout << std::endl;
}
}
void Inkscape::LineSnapper::constrainedSnap(SnappedConstraints &sc,
Inkscape::SnapPreferences::PointType const &t,
Geom::Point const &p,
SnapSourceType const &source_type,
bool const &/*f*/,
Geom::OptRect const &/*bbox_to_snap*/,
ConstraintLine const &c,
std::vector<SPItem const *> const */*it*/) const
{
if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(t) == false) {
return;
}
/* Get the lines that we will try to snap to */
const LineList lines = _getSnapLines(p);
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
Geom::Point const point_on_line = c.hasPoint() ? c.getPoint() : p;
Geom::Line line1(point_on_line, point_on_line + c.getDirection());
Geom::Line line2(i->second, i->second + Geom::rot90(i->first));
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 (inters) {
Geom::Point t = line1.pointAt((*inters).ta);
const Geom::Coord dist = Geom::L2(t - p);
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, source_type);
}
}
}
}
}
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
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