Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::SnapCandidatePoint const &p,
Inkscape::Snapper::SnapConstraint const &constraint,
Geom::OptRect const &bbox_to_snap) const
{
// First project the mouse pointer onto the constraint
Geom::Point pp = constraint.projection(p.getPoint());
Inkscape::SnappedPoint no_snap = Inkscape::SnappedPoint(pp, p.getSourceType(), p.getSourceNum(), Inkscape::SNAPTARGET_CONSTRAINT, Geom::infinity(), 0, false, true, false);
if (!someSnapperMightSnap()) {
// Always return point on constraint
return no_snap;
}
Inkscape::SnappedPoint result = no_snap;
Inkscape::Preferences *prefs = Inkscape::Preferences::get();
if ((prefs->getBool("/options/snapmousepointer/value", false)) && p.isSingleHandle()) {
// Snapping the mouse pointer instead of the constrained position of the knot allows
// to snap to things which don't intersect with the constraint line; this is basically
// then just a freesnap with the constraint applied afterwards
// We'll only do this if we're dragging a single handle, and for example not when transforming an object in the selector tool
result = freeSnap(p, bbox_to_snap);
if (result.getSnapped()) {
// only change the snap indicator if we really snapped to something
if (_snapindicator && _desktop) {
_desktop->snapindicator->set_new_snaptarget(result);
}
// Apply the constraint
result.setPoint(constraint.projection(result.getPoint()));
return result;
}
return no_snap;
}
IntermSnapResults isr;
SnapperList const snappers = getSnappers();
for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); ++i) {
(*i)->constrainedSnap(isr, p, bbox_to_snap, constraint, &_items_to_ignore, _unselected_nodes);
}
result = findBestSnap(p, isr, true);
if (result.getSnapped()) {
// only change the snap indicator if we really snapped to something
if (_snapindicator && _desktop) {
_desktop->snapindicator->set_new_snaptarget(result);
}
return result;
}
return no_snap;
}
Inkscape::SnappedPoint SnapManager::multipleConstrainedSnaps(Inkscape::SnapCandidatePoint const &p,
std::vector<Inkscape::Snapper::SnapConstraint> const &constraints,
bool dont_snap,
Geom::OptRect const &bbox_to_snap) const
{
Inkscape::SnappedPoint no_snap = Inkscape::SnappedPoint(p.getPoint(), p.getSourceType(), p.getSourceNum(), Inkscape::SNAPTARGET_CONSTRAINT, Geom::infinity(), 0, false, true, false);
if (constraints.size() == 0) {
return no_snap;
}
// We haven't tried to snap yet; we will first determine which constraint is closest to where we are now,
// i.e. lets find out which of the constraints yields the closest projection of point p
// Project the mouse pointer on each of the constraints
std::vector<Geom::Point> projections;
for (std::vector<Inkscape::Snapper::SnapConstraint>::const_iterator c = constraints.begin(); c != constraints.end(); ++c) {
// Project the mouse pointer onto the constraint; In case we don't snap then we will
// return the projection onto the constraint, such that the constraint is always enforced
Geom::Point pp = (*c).projection(p.getPoint());
projections.push_back(pp);
}
// Select the closest constraint
no_snap.setPoint(projections.front());
Inkscape::Snapper::SnapConstraint cc = constraints.front(); //closest constraint
std::vector<Inkscape::Snapper::SnapConstraint>::const_iterator c = constraints.begin();
std::vector<Geom::Point>::iterator pp = projections.begin();
for (; pp != projections.end(); ++pp) {
if (Geom::L2(*pp - p.getPoint()) < Geom::L2(no_snap.getPoint() - p.getPoint())) {
no_snap.setPoint(*pp); // Remember the projection onto the closest constraint
cc = *c; // Remember the closest constraint itself
}
++c;
}
if (!someSnapperMightSnap() || dont_snap) {
return no_snap;
}
IntermSnapResults isr;
SnapperList const snappers = getSnappers();
Inkscape::Preferences *prefs = Inkscape::Preferences::get();
bool snap_mouse = prefs->getBool("/options/snapmousepointer/value", false);
Inkscape::SnappedPoint result = no_snap;
if (snap_mouse && p.isSingleHandle()) {
// Snapping the mouse pointer instead of the constrained position of the knot allows
// to snap to things which don't intersect with the constraint line; this is basically
// then just a freesnap with the constraint applied afterwards
// We'll only to this if we're dragging a single handle, and for example not when transforming an object in the selector tool
result = freeSnap(p, bbox_to_snap);
// Now apply the constraint afterwards
result.setPoint(cc.projection(result.getPoint()));
} else {
// Try to snap along the closest constraint
for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); ++i) {
(*i)->constrainedSnap(isr, p, bbox_to_snap, cc, &_items_to_ignore,_unselected_nodes);
}
result = findBestSnap(p, isr, true);
}
return result.getSnapped() ? result : no_snap;
}