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diff --git a/src/line-snapper.cpp b/src/line-snapper.cpp
index 446ec73e73deab0c57eafa6545f2b9533597f350..22a964d43487e2b1e7c20851b0e43b458c532917 100644 (file)
--- a/src/line-snapper.cpp
+++ b/src/line-snapper.cpp
* Authors:
* Diederik van Lierop <mail@diedenrezi.nl>
* And others...
- *
- * Copyright (C) 1999-2007 Authors
+ *
+ * Copyright (C) 1999-2008 Authors
*
* Released under GNU GPL, read the file 'COPYING' for more information
*/
-#include "libnr/nr-values.h"
-#include "libnr/nr-point-fns.h"
-#include <2geom/geom.h>
+#include <2geom/line.h>
#include "line-snapper.h"
-#include "snapped-line.cpp"
-#include <gtk/gtk.h>
+#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
{
- Inkscape::SnappedPoint s = SnappedPoint(p, NR_HUGE);
+ if (!(_snap_enabled && _snapmanager->snapprefs.getSnapFrom(p.getSourceType())) ) {
+ return;
+ }
/* Get the lines that we will try to snap to */
- const LineList lines = _getSnapLines(p);
-
- // std::cout << "snap point " << p << " to: " << std::endl;
+ const LineList lines = _getSnapLines(p.getPoint());
for (LineList::const_iterator i = lines.begin(); i != lines.end(); i++) {
- NR::Point const p1 = i->second; // point at guide/grid line
- NR::Point const p2 = p1 + NR::rot90(i->first); // 2nd point at guide/grid line
-
+ 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 != NR::Point(0,0)); // otherwise we'll have div. by zero because NR::L2(d2) = 0
-
- // p_proj = projection of p on the grid/guide line running from p1 to p2
- // p_proj = p1 + u (p2 - p1)
- // calculate u according to "Minimum Distance between a Point and a Line"
- // see http://local.wasp.uwa.edu.au/~pbourke/geometry/pointline/
- NR::Point const d1(p-p1); // delta 1
- NR::Point const d2(p2-p1); // delta 1
- double const u = (d1[NR::X] * d2[NR::X] + d1[NR::Y] * d2[NR::Y]) / (NR::L2(d2) * NR::L2(d2));
-
- NR::Point const p_proj(p1 + u*(p2-p1));
- NR::Coord const dist = NR::L2(p_proj - p);
+ 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 < getDistance()) {
- _addSnappedLine(sc, p_proj, dist, i->first, i->second);
- // std::cout << " -> distance = " << dist;
- }
+ 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);
+ const LineList lines = _getSnapLines(pp);
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));
+
+ 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
+ }
- /* Normal to the line we're trying to snap along */
- NR::Point const n(NR::rot90(NR::unit_vector(c.getDirection())));
-
- 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 q0 = dot(n, point_on_line);
- /* Constant term of the grid or guide line */
- NR::Coord const q1 = dot(i->first, i->second);
-
- /* Try to intersect this line with the target line */
- Geom::Point t_2geom(NR_HUGE, NR_HUGE);
- Geom::IntersectorKind const k = Geom::line_intersection(n.to_2geom(), q0, i->first.to_2geom(), q1, t_2geom);
- NR::Point t(t_2geom);
-
- if (k == Geom::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);
+ 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++