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); } } } } }
void SPShape::snappoints(std::vector<Inkscape::SnapCandidatePoint> &p, Inkscape::SnapPreferences const *snapprefs) const { if (this->_curve == NULL) { return; } Geom::PathVector const &pathv = this->_curve->get_pathvector(); if (pathv.empty()) { return; } Geom::Affine const i2dt (this->i2dt_affine ()); if (snapprefs->isTargetSnappable(Inkscape::SNAPTARGET_OBJECT_MIDPOINT)) { Geom::OptRect bbox = this->desktopVisualBounds(); if (bbox) { p.push_back(Inkscape::SnapCandidatePoint(bbox->midpoint(), Inkscape::SNAPSOURCE_OBJECT_MIDPOINT, Inkscape::SNAPTARGET_OBJECT_MIDPOINT)); } } for(Geom::PathVector::const_iterator path_it = pathv.begin(); path_it != pathv.end(); ++path_it) { if (snapprefs->isTargetSnappable(Inkscape::SNAPTARGET_NODE_CUSP)) { // Add the first point of the path p.push_back(Inkscape::SnapCandidatePoint(path_it->initialPoint() * i2dt, Inkscape::SNAPSOURCE_NODE_CUSP, Inkscape::SNAPTARGET_NODE_CUSP)); } Geom::Path::const_iterator curve_it1 = path_it->begin(); // incoming curve Geom::Path::const_iterator curve_it2 = ++(path_it->begin()); // outgoing curve while (curve_it1 != path_it->end_default()) { // For each path: consider midpoints of line segments for snapping if (snapprefs->isTargetSnappable(Inkscape::SNAPTARGET_LINE_MIDPOINT)) { if (Geom::LineSegment const* line_segment = dynamic_cast<Geom::LineSegment const*>(&(*curve_it1))) { p.push_back(Inkscape::SnapCandidatePoint(Geom::middle_point(*line_segment) * i2dt, Inkscape::SNAPSOURCE_LINE_MIDPOINT, Inkscape::SNAPTARGET_LINE_MIDPOINT)); } } if (curve_it2 == path_it->end_default()) { // Test will only pass for the last iteration of the while loop if (snapprefs->isTargetSnappable(Inkscape::SNAPTARGET_NODE_CUSP) && !path_it->closed()) { // Add the last point of the path, but only for open paths // (for closed paths the first and last point will coincide) p.push_back(Inkscape::SnapCandidatePoint((*curve_it1).finalPoint() * i2dt, Inkscape::SNAPSOURCE_NODE_CUSP, Inkscape::SNAPTARGET_NODE_CUSP)); } } else { /* Test whether to add the node between curve_it1 and curve_it2. * Loop to end_default (so only iterating through the stroked part); */ Geom::NodeType nodetype = Geom::get_nodetype(*curve_it1, *curve_it2); bool c1 = snapprefs->isTargetSnappable(Inkscape::SNAPTARGET_NODE_CUSP) && (nodetype == Geom::NODE_CUSP || nodetype == Geom::NODE_NONE); bool c2 = snapprefs->isTargetSnappable(Inkscape::SNAPTARGET_NODE_SMOOTH) && (nodetype == Geom::NODE_SMOOTH || nodetype == Geom::NODE_SYMM); if (c1 || c2) { Inkscape::SnapSourceType sst; Inkscape::SnapTargetType stt; switch (nodetype) { case Geom::NODE_CUSP: sst = Inkscape::SNAPSOURCE_NODE_CUSP; stt = Inkscape::SNAPTARGET_NODE_CUSP; break; case Geom::NODE_SMOOTH: case Geom::NODE_SYMM: sst = Inkscape::SNAPSOURCE_NODE_SMOOTH; stt = Inkscape::SNAPTARGET_NODE_SMOOTH; break; default: sst = Inkscape::SNAPSOURCE_UNDEFINED; stt = Inkscape::SNAPTARGET_UNDEFINED; break; } p.push_back(Inkscape::SnapCandidatePoint(curve_it1->finalPoint() * i2dt, sst, stt)); } } ++curve_it1; ++curve_it2; } // Find the internal intersections of each path and consider these for snapping // (using "Method 1" as described in Inkscape::ObjectSnapper::_collectNodes()) if (snapprefs->isTargetSnappable(Inkscape::SNAPTARGET_PATH_INTERSECTION) || snapprefs->isSourceSnappable(Inkscape::SNAPSOURCE_PATH_INTERSECTION)) { Geom::Crossings cs; try { cs = self_crossings(*path_it); // This can be slow! if (!cs.empty()) { // There might be multiple intersections... for (Geom::Crossings::const_iterator i = cs.begin(); i != cs.end(); ++i) { Geom::Point p_ix = (*path_it).pointAt((*i).ta); p.push_back(Inkscape::SnapCandidatePoint(p_ix * i2dt, Inkscape::SNAPSOURCE_PATH_INTERSECTION, Inkscape::SNAPTARGET_PATH_INTERSECTION)); } } } catch (Geom::RangeError &e) { // do nothing // The exception could be Geom::InfiniteSolutions: then no snappoints should be added } } } }