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
{
if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(p.getSourceType()) == false) {
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++) {
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::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.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);
// 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(), true);
// Only relevant for guides; grids don't have an origin per line
// Therefore _addSnappedLinesOrigin() will only be implemented for guides
}
}
}
}
}
}
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
{
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::freeSnap(IntermSnapResults &isr,
Inkscape::SnapCandidatePoint const &p,
Geom::OptRect const &/*bbox_to_snap*/,
std::vector<SPItem const *> const */*it*/,
std::vector<Inkscape::SnapCandidatePoint> */*unselected_nodes*/) const
{
if (!(_snap_enabled && _snapmanager->snapprefs.isSourceSnappable(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;
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(isr, 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(isr, 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
}
// Here we will try to snap either tangentially or perpendicularly to a grid/guide line
// For this we need to know where the origin is located of the line that is currently being rotated,
std::vector<std::pair<Geom::Point, bool> > const origins_and_vectors = p.getOriginsAndVectors();
// Now we will iterate over all the origins and vectors and see which of these will get use a tangential or perpendicular snap
for (std::vector<std::pair<Geom::Point, bool> >::const_iterator it_origin_or_vector = origins_and_vectors.begin(); it_origin_or_vector != origins_and_vectors.end(); ++it_origin_or_vector) {
if ((*it_origin_or_vector).second) { // if "second" is true then "first" is a vector, otherwise it's a point
// When snapping a line with a constant vector (constant direction) to a guide or grid line,
// then either all points will be perpendicular/tangential or none at all. This is not very useful
continue;
}
//Geom::Point origin_doc = _snapmanager->getDesktop()->dt2doc((*it_origin_or_vector).first); // "first" contains a Geom::Point, denoting either a point
Geom::Point origin = (*it_origin_or_vector).first; // "first" contains a Geom::Point, denoting either a point
// We won't try to snap tangentially; a line being tangential to another line can be achieved by snapping both its endpoints
// individually to the other line. There's no need to have an explicit tangential snap here, that would be redundant
if (_snapmanager->snapprefs.getSnapPerp()) { // Find the point that leads to a perpendicular snap
Geom::Point const origin_proj = Geom::projection(origin, Geom::Line(p1, p2));
Geom::Coord dist = Geom::L2(origin_proj - p.getPoint());
if (dist < getSnapperTolerance()) {
_addSnappedLinePerpendicularly(isr, origin_proj, dist, p.getSourceType(), p.getSourceNum(), false);
}
}
}
// std::cout << " -> distance = " << dist;
}
// std::cout << std::endl;
}
}
