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diff --git a/src/line-snapper.cpp b/src/line-snapper.cpp
index f2f02533246a8d6b90a20fb73db4694db4ffc678..22a964d43487e2b1e7c20851b0e43b458c532917 100644 (file)
--- a/src/line-snapper.cpp
+++ b/src/line-snapper.cpp
// 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());
+ _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
}
void Inkscape::LineSnapper::constrainedSnap(SnappedConstraints &sc,
Inkscape::SnapCandidatePoint const &p,
Geom::OptRect const &/*bbox_to_snap*/,
- ConstraintLine const &c,
- std::vector<SPItem const *> const */*it*/) const
+ SnapConstraint const &c,
+ std::vector<SPItem const *> const */*it*/,
+ std::vector<SnapCandidatePoint> */*unselected_nodes*/) const
{
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.getPoint());
+ const LineList lines = _getSnapLines(pp);
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
- // constraint line
- Geom::Point const point_on_line = c.hasPoint() ? c.getPoint() : p.getPoint();
- Geom::Line line1(point_on_line, point_on_line + c.getDirection());
-
- // grid/guide 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
- Geom::Line line2(p1, p2);
+ 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(line1, line2);
+ inters = Geom::intersection(constraint_line, gridguide_line);
}
catch (Geom::InfiniteSolutions e)
{
}
if (inters) {
- Geom::Point t = line1.pointAt((*inters).ta);
+ 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());
- // 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());
- // Only relevant for guides; grids don't have an origin per line
- // Therefore _addSnappedLinesOrigin() will only be implemented for guides
- }
+ _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*/) const
+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
{
}