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diff --git a/src/line-snapper.cpp b/src/line-snapper.cpp
index 3b91fb015df57c6b73d12eaf511c98e40972f668..22a964d43487e2b1e7c20851b0e43b458c532917 100644 (file)
--- a/src/line-snapper.cpp
+++ b/src/line-snapper.cpp
-#include "libnr/nr-values.h"
-#include "libnr/nr-point-fns.h"
-#include "geom.h"
+/**
+ * \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.cpp"
+#include "snapped-line.h"
+//#include <gtk/gtk.h>
+#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<NR::Point> &points_to_snap,
- std::list<SPItem const *> const &it) const
+void Inkscape::LineSnapper::freeSnap(SnappedConstraints &sc,
+ Inkscape::SnapCandidatePoint const &p,
+ Geom::OptRect const &/*bbox_to_snap*/,
+ std::vector<SPItem const *> const */*it*/,
+ std::vector<Inkscape::SnapCandidatePoint> */*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<NR::Point> &points_to_snap,
- ConstraintLine const &c,
- std::list<SPItem const *> const &it) const
+void Inkscape::LineSnapper::constrainedSnap(SnappedConstraints &sc,
+ Inkscape::SnapCandidatePoint const &p,
+ Geom::OptRect const &/*bbox_to_snap*/,
+ SnapConstraint const &c,
+ std::vector<SPItem const *> const */*it*/,
+ std::vector<SnapCandidatePoint> */*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);
-
- for (LineList::const_iterator i = lines.begin(); i != lines.end(); i++) {
+ const LineList lines = _getSnapLines(pp);
- /* Normal to the line we're trying to snap along */
- NR::Point const n(NR::rot90(NR::unit_vector(c.getDirection())));
+ 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));
- 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);
+ 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(p.getPoint() - (p_proj + v)), p.getSourceType(), p.getSourceNum(), true);
+ _addSnappedPoint(sc, p_proj - v, Geom::L2(p.getPoint() - (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
+ }
- /* Try to intersect this line with the target line */
- NR::Point t = NR::Point(NR_HUGE, NR_HUGE);
- IntersectorKind const k = intersector_line_intersection(n, q, component_vectors[i->first], i->second, t);
-
- if (k == 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);
- //SnappedInfiniteLine dummy = SnappedInfiniteLine(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 - p.getPoint());
+ 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++