void Inkscape::ObjectSnapper::_snapPathsTangPerp(bool snap_tang, bool snap_perp, IntermSnapResults &isr, SnapCandidatePoint const &p, Geom::Curve const *curve, SPDesktop const *dt) const
{
// Here we will try to snap either tangentially or perpendicularly to a single path; for this we need to know where the origin is located of the line that is currently being rotated,
// or we need to know the vector of the guide which is currently being translated
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) {
Geom::Point origin_or_vector_doc = dt->dt2doc((*it_origin_or_vector).first); // "first" contains a Geom::Point, denoting either a point or vector
if ((*it_origin_or_vector).second) { // if "second" is true then "first" is a vector, otherwise it's a point
// So we have a vector, which tells us what tangential or perpendicular direction we're looking for
if (curve->degreesOfFreedom() <= 2) { // A LineSegment has order one, and therefore 2 DOF
// When snapping to a point of a line segment that has a specific tangential or normal vector, then either all point
// along that line will be snapped to or no points at all will be snapped to. This is not very useful, so let's skip
// any line segments and lets only snap to higher order curves
continue;
}
// The vector is being treated as a point (relative to the origin), and has been translated to document coordinates accordingly
// We need however to make it a vector again, because also the origin has been transformed
origin_or_vector_doc -= dt->dt2doc(Geom::Point(0,0));
}
Geom::Point point_dt;
Geom::Coord dist;
std::vector<double> ts;
if (snap_tang) { // Find all points that lead to a tangential snap
if ((*it_origin_or_vector).second) { // if "second" is true then "first" is a vector, otherwise it's a point
ts = find_tangents_by_vector(origin_or_vector_doc, curve->toSBasis());
} else {
ts = find_tangents(origin_or_vector_doc, curve->toSBasis());
}
for (std::vector<double>::const_iterator t = ts.begin(); t != ts.end(); ++t) {
point_dt = dt->doc2dt(curve->pointAt(*t));
dist = Geom::distance(point_dt, p.getPoint());
isr.points.push_back(SnappedPoint(point_dt, p.getSourceType(), p.getSourceNum(), SNAPTARGET_PATH_TANGENTIAL, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, true));
}
}
if (snap_perp) { // Find all points that lead to a perpendicular snap
if ((*it_origin_or_vector).second) {
ts = find_normals_by_vector(origin_or_vector_doc, curve->toSBasis());
} else {
ts = find_normals(origin_or_vector_doc, curve->toSBasis());
}
for (std::vector<double>::const_iterator t = ts.begin(); t != ts.end(); ++t) {
point_dt = dt->doc2dt(curve->pointAt(*t));
dist = Geom::distance(point_dt, p.getPoint());
isr.points.push_back(SnappedPoint(point_dt, p.getSourceType(), p.getSourceNum(), SNAPTARGET_PATH_PERPENDICULAR, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, true));
}
}
}
}
void Inkscape::ObjectSnapper::_snapTranslatingGuide(IntermSnapResults &isr,
Geom::Point const &p,
Geom::Point const &guide_normal) const
{
// Iterate through all nodes, find out which one is the closest to this guide, and snap to it!
_collectNodes(SNAPSOURCE_GUIDE, true);
if (_snapmanager->snapprefs.isTargetSnappable(SNAPTARGET_PATH, SNAPTARGET_PATH_INTERSECTION, SNAPTARGET_BBOX_EDGE, SNAPTARGET_PAGE_BORDER, SNAPTARGET_TEXT_BASELINE)) {
_collectPaths(p, SNAPSOURCE_GUIDE, true);
_snapPaths(isr, SnapCandidatePoint(p, SNAPSOURCE_GUIDE), NULL, NULL);
}
SnappedPoint s;
Geom::Coord tol = getSnapperTolerance();
for (std::vector<SnapCandidatePoint>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); ++k) {
Geom::Point target_pt = (*k).getPoint();
// Project each node (*k) on the guide line (running through point p)
Geom::Point p_proj = Geom::projection(target_pt, Geom::Line(p, p + Geom::rot90(guide_normal)));
Geom::Coord dist = Geom::L2(target_pt - p_proj); // distance from node to the guide
Geom::Coord dist2 = Geom::L2(p - p_proj); // distance from projection of node on the guide, to the mouse location
if ((dist < tol && dist2 < tol) || getSnapperAlwaysSnap()) {
s = SnappedPoint(target_pt, SNAPSOURCE_GUIDE, 0, (*k).getTargetType(), dist, tol, getSnapperAlwaysSnap(), false, true, (*k).getTargetBBox());
isr.points.push_back(s);
}
}
}
void Inkscape::LineSnapper::constrainedSnap(SnappedConstraints &sc,
Inkscape::SnapPreferences::PointType const &t,
Geom::Point const &p,
bool const &/*f*/,
Geom::OptRect const &/*bbox_to_snap*/,
ConstraintLine const &c,
std::vector<SPItem const *> const */*it*/) const
{
if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(t) == false) {
return;
}
/* 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++) {
if (Geom::L2(c.getDirection()) > 0) { // Can't do a constrained snap without a constraint
/* Normal to the line we're trying to snap along */
Geom::Point const n(Geom::rot90(Geom::unit_vector(c.getDirection())));
Geom::Point const point_on_line = c.hasPoint() ? c.getPoint() : p;
/* Constant term of the line we're trying to snap along */
Geom::Coord const q0 = dot(n, point_on_line);
/* Constant term of the grid or guide line */
Geom::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, q0, i->first, q1, t_2geom);
Geom::Point t(t_2geom);
if (k == Geom::intersects) {
const Geom::Coord dist = L2(t - p);
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
sc.points.push_back(SnappedPoint(t, Inkscape::SNAPTARGET_UNDEFINED, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), true));
// The type of the snap target is yet undefined, as we cannot tell whether
// we're snapping to grid or the guide lines; must be set by on a higher level
}
}
}
}
}
void Inkscape::ObjectSnapper::_snapNodes(IntermSnapResults &isr,
SnapCandidatePoint const &p,
std::vector<SnapCandidatePoint> *unselected_nodes,
SnapConstraint const &c,
Geom::Point const &p_proj_on_constraint) const
{
// Iterate through all nodes, find out which one is the closest to p, and snap to it!
_collectNodes(p.getSourceType(), p.getSourceNum() <= 0);
if (unselected_nodes != NULL && unselected_nodes->size() > 0) {
g_assert(_points_to_snap_to != NULL);
_points_to_snap_to->insert(_points_to_snap_to->end(), unselected_nodes->begin(), unselected_nodes->end());
}
SnappedPoint s;
bool success = false;
bool strict_snapping = _snapmanager->snapprefs.getStrictSnapping();
for (std::vector<SnapCandidatePoint>::const_iterator k = _points_to_snap_to->begin(); k != _points_to_snap_to->end(); ++k) {
if (_allowSourceToSnapToTarget(p.getSourceType(), (*k).getTargetType(), strict_snapping)) {
Geom::Point target_pt = (*k).getPoint();
Geom::Coord dist = Geom::infinity();
if (!c.isUndefined()) {
// We're snapping to nodes along a constraint only, so find out if this node
// is at the constraint, while allowing for a small margin
if (Geom::L2(target_pt - c.projection(target_pt)) > 1e-9) {
// The distance from the target point to its projection on the constraint
// is too large, so this point is not on the constraint. Skip it!
continue;
}
dist = Geom::L2(target_pt - p_proj_on_constraint);
} else {
// Free (unconstrained) snapping
dist = Geom::L2(target_pt - p.getPoint());
}
if (dist < getSnapperTolerance() && dist < s.getSnapDistance()) {
s = SnappedPoint(target_pt, p.getSourceType(), p.getSourceNum(), (*k).getTargetType(), dist, getSnapperTolerance(), getSnapperAlwaysSnap(), false, true, (*k).getTargetBBox());
success = true;
}
}
}
if (success) {
isr.points.push_back(s);
}
}
void Inkscape::GuideSnapper::_addSnappedPoint(IntermSnapResults &isr, Geom::Point const &snapped_point, Geom::Coord const &snapped_distance, SnapSourceType const &source, long source_num, bool constrained_snap) const
{
SnappedPoint dummy = SnappedPoint(snapped_point, source, source_num, Inkscape::SNAPTARGET_GUIDE, snapped_distance, getSnapperTolerance(), getSnapperAlwaysSnap(), constrained_snap, true);
isr.points.push_back(dummy);
}
void Inkscape::ObjectSnapper::_snapPathsConstrained(IntermSnapResults &isr,
SnapCandidatePoint const &p,
SnapConstraint const &c,
Geom::Point const &p_proj_on_constraint) const
{
_collectPaths(p_proj_on_constraint, p.getSourceType(), p.getSourceNum() <= 0);
// Now we can finally do the real snapping, using the paths collected above
SPDesktop const *dt = _snapmanager->getDesktop();
g_assert(dt != NULL);
Geom::Point direction_vector = c.getDirection();
if (!is_zero(direction_vector)) {
direction_vector = Geom::unit_vector(direction_vector);
}
// The intersection point of the constraint line with any path, must lie within two points on the
// SnapConstraint: p_min_on_cl and p_max_on_cl. The distance between those points is twice the snapping tolerance
Geom::Point const p_min_on_cl = dt->dt2doc(p_proj_on_constraint - getSnapperTolerance() * direction_vector);
Geom::Point const p_max_on_cl = dt->dt2doc(p_proj_on_constraint + getSnapperTolerance() * direction_vector);
Geom::Coord tolerance = getSnapperTolerance();
// PS: Because the paths we're about to snap to are all expressed relative to document coordinate system, we will have
// to convert the snapper coordinates from the desktop coordinates to document coordinates
std::vector<Geom::Path> constraint_path;
if (c.isCircular()) {
Geom::Circle constraint_circle(dt->dt2doc(c.getPoint()), c.getRadius());
constraint_circle.getPath(constraint_path);
} else {
Geom::Path constraint_line;
constraint_line.start(p_min_on_cl);
constraint_line.appendNew<Geom::LineSegment>(p_max_on_cl);
constraint_path.push_back(constraint_line);
}
// Length of constraint_path will always be one
bool strict_snapping = _snapmanager->snapprefs.getStrictSnapping();
// Find all intersections of the constrained path with the snap target candidates
std::vector<Geom::Point> intersections;
for (std::vector<SnapCandidatePath >::const_iterator k = _paths_to_snap_to->begin(); k != _paths_to_snap_to->end(); ++k) {
if (k->path_vector && _allowSourceToSnapToTarget(p.getSourceType(), (*k).target_type, strict_snapping)) {
// Do the intersection math
Geom::CrossingSet cs = Geom::crossings(constraint_path, *(k->path_vector));
// Store the results as intersection points
unsigned int index = 0;
for (Geom::CrossingSet::const_iterator i = cs.begin(); i != cs.end(); ++i) {
if (index >= constraint_path.size()) {
break;
}
// Reconstruct and store the points of intersection
for (Geom::Crossings::const_iterator m = (*i).begin(); m != (*i).end(); ++m) {
intersections.push_back(constraint_path[index].pointAt((*m).ta));
}
index++;
}
//Geom::crossings will not consider the closing segment apparently, so we'll handle that separately here
//TODO: This should have been fixed in rev. #9859, which makes this workaround obsolete
for(Geom::PathVector::iterator it_pv = k->path_vector->begin(); it_pv != k->path_vector->end(); ++it_pv) {
if (it_pv->closed()) {
// Get the closing linesegment and convert it to a path
Geom::Path cls;
cls.close(false);
cls.append(it_pv->back_closed());
// Intersect that closing path with the constrained path
Geom::Crossings cs = Geom::crossings(constraint_path.front(), cls);
// Reconstruct and store the points of intersection
index = 0; // assuming the constraint path vector has only one path
for (Geom::Crossings::const_iterator m = cs.begin(); m != cs.end(); ++m) {
intersections.push_back(constraint_path[index].pointAt((*m).ta));
}
}
}
// Convert the collected points of intersection to snapped points
for (std::vector<Geom::Point>::iterator p_inters = intersections.begin(); p_inters != intersections.end(); ++p_inters) {
// Convert to desktop coordinates
(*p_inters) = dt->doc2dt(*p_inters);
// Construct a snapped point
Geom::Coord dist = Geom::L2(p.getPoint() - *p_inters);
SnappedPoint s = SnappedPoint(*p_inters, p.getSourceType(), p.getSourceNum(), k->target_type, dist, getSnapperTolerance(), getSnapperAlwaysSnap(), true, k->target_bbox);;
// Store the snapped point
if (dist <= tolerance) { // If the intersection is within snapping range, then we might snap to it
isr.points.push_back(s);
}
}
}
}
}