diff options
Diffstat (limited to 'src/snap.cpp')
| -rw-r--r-- | src/snap.cpp | 56 |
1 files changed, 51 insertions, 5 deletions
diff --git a/src/snap.cpp b/src/snap.cpp index 1f3753600..46bd01f4d 100644 --- a/src/snap.cpp +++ b/src/snap.cpp @@ -34,6 +34,7 @@ #include "sp-guide.h" #include "preferences.h" #include "event-context.h" +#include "util/mathfns.h" using std::vector; /** @@ -471,12 +472,8 @@ Inkscape::SnappedPoint SnapManager::multipleConstrainedSnaps(Inkscape::SnapCandi } if (result.getSnapped()) { - // only change the snap indicator if we really snapped to something - if (_snapindicator && _desktop) { - _desktop->snapindicator->set_new_snaptarget(result); - } if (snap_mouse) { - // We still have to apply the constraint, because so far we only tried a freeSnap + // If "snap_mouse" then we still have to apply the constraint, because so far we only tried a freeSnap Geom::Point result_closest; 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 @@ -507,6 +504,55 @@ Inkscape::SnappedPoint SnapManager::multipleConstrainedSnaps(Inkscape::SnapCandi } /** + * \brief Try to snap a point to something at a specific angle + * + * When drawing a straight line or modifying a gradient, it will snap to specific angle increments + * if CTRL is being pressed. This method will enforce this angular constraint (even if there is nothing + * to snap to) + * + * \param p Source point to be snapped + * \param p_ref Optional original point, relative to which the angle should be calculated. If empty then + * the angle will be calculated relative to the y-axis + * \param snaps Number of angular increments per PI radians; E.g. if snaps = 2 then we will snap every PI/2 = 90 degrees + */ + +Inkscape::SnappedPoint SnapManager::constrainedAngularSnap(Inkscape::SnapCandidatePoint const &p, + boost::optional<Geom::Point> const &p_ref, + Geom::Point const &o, + unsigned const snaps) const +{ + Inkscape::SnappedPoint sp; + if (snaps > 0) { // 0 means no angular snapping + // p is at an arbitrary angle. Now we should snap this angle to specific increments. + // For this we'll calculate the closest two angles, one at each side of the current angle + Geom::Line y_axis(Geom::Point(0, 0), Geom::Point(0, 1)); + Geom::Line p_line(o, p.getPoint()); + double angle = Geom::angle_between(y_axis, p_line); + double angle_incr = M_PI / snaps; + double angle_offset = 0; + if (p_ref) { + Geom::Line p_line_ref(o, *p_ref); + angle_offset = Geom::angle_between(y_axis, p_line_ref); + } + double angle_ceil = round_to_upper_multiple_plus(angle, angle_incr, angle_offset); + double angle_floor = round_to_lower_multiple_plus(angle, angle_incr, angle_offset); + // We have two angles now. The constrained snapper will try each of them and return the closest + + // Now do the snapping... + std::vector<Inkscape::Snapper::SnapConstraint> constraints; + constraints.push_back(Inkscape::Snapper::SnapConstraint(Geom::Line(o, angle_ceil - M_PI/2))); + constraints.push_back(Inkscape::Snapper::SnapConstraint(Geom::Line(o, angle_floor - M_PI/2))); + sp = multipleConstrainedSnaps(p, constraints); // Constraints will always be applied, even if we didn't snap + if (!sp.getSnapped()) { // If we haven't snapped then we only had the constraint applied; + sp.setTarget(Inkscape::SNAPTARGET_CONSTRAINED_ANGLE); + } + } else { + sp = freeSnap(p); + } + return sp; +} + +/** * \brief Try to snap a point of a guide to another guide or to a node * * Try to snap a point of a guide to another guide or to a node in two degrees- |