X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Fline-snapper.cpp;h=22a964d43487e2b1e7c20851b0e43b458c532917;hb=1b7827f2519b38d72174d744f9795392d538d64f;hp=72a6cc33d54d5a7b1a2b784bbbf16732abd6e823;hpb=c123991dbc3ceab027b9e876e848c41833140318;p=inkscape.git diff --git a/src/line-snapper.cpp b/src/line-snapper.cpp index 72a6cc33d..22a964d43 100644 --- a/src/line-snapper.cpp +++ b/src/line-snapper.cpp @@ -11,12 +11,10 @@ * Released under GNU GPL, read the file 'COPYING' for more information */ -#include "libnr/nr-values.h" -#include "libnr/nr-point-fns.h" -#include <2geom/geom.h> +#include <2geom/line.h> #include "line-snapper.h" #include "snapped-line.h" -#include +//#include #include "snap.h" Inkscape::LineSnapper::LineSnapper(SnapManager *sm, Geom::Coord const d) : Snapper(sm, d) @@ -24,22 +22,17 @@ Inkscape::LineSnapper::LineSnapper(SnapManager *sm, Geom::Coord const d) : Snapp } void Inkscape::LineSnapper::freeSnap(SnappedConstraints &sc, - Inkscape::SnapPreferences::PointType const &t, - Geom::Point const &p, - SnapSourceType const &source_type, - bool const &/*f*/, + Inkscape::SnapCandidatePoint const &p, Geom::OptRect const &/*bbox_to_snap*/, std::vector const */*it*/, - std::vector > */*unselected_nodes*/) const + std::vector */*unselected_nodes*/) const { - if (!(_snap_enabled && _snapmanager->snapprefs.getSnapFrom(t)) ) { + if (!(_snap_enabled && _snapmanager->snapprefs.getSnapFrom(p.getSourceType())) ) { return; } /* Get the lines that we will try to snap to */ - const LineList lines = _getSnapLines(p); - - // std::cout << "snap point " << p << " to: " << std::endl; + 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 @@ -47,11 +40,20 @@ void Inkscape::LineSnapper::freeSnap(SnappedConstraints &sc, // 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 = project_on_linesegment(p, p1, p2); - Geom::Coord const dist = Geom::L2(p_proj - p); + 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, source_type, i->first, i->second); + _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; @@ -59,53 +61,83 @@ void Inkscape::LineSnapper::freeSnap(SnappedConstraints &sc, } void Inkscape::LineSnapper::constrainedSnap(SnappedConstraints &sc, - Inkscape::SnapPreferences::PointType const &t, - Geom::Point const &p, - SnapSourceType const &source_type, - bool const &/*f*/, + Inkscape::SnapCandidatePoint const &p, Geom::OptRect const &/*bbox_to_snap*/, - ConstraintLine const &c, - std::vector const */*it*/) const + SnapConstraint const &c, + std::vector const */*it*/, + std::vector */*unselected_nodes*/) const { - if (_snap_enabled == false || _snapmanager->snapprefs.getSnapFrom(t) == false) { + 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); + 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 - /* 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); + 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(constraint_line, gridguide_line); + } + 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 (k == Geom::intersects) { - const Geom::Coord dist = L2(t - p); + if (inters) { + 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. + // 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, source_type); + _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*/, bool /*constrained_snap*/) const +{ +} + /* Local Variables: mode:c++