diff options
Diffstat (limited to 'src/draw-context.cpp')
| -rw-r--r-- | src/draw-context.cpp | 69 |
1 files changed, 34 insertions, 35 deletions
diff --git a/src/draw-context.cpp b/src/draw-context.cpp index 9bd67c3dd..ca68b3f6d 100644 --- a/src/draw-context.cpp +++ b/src/draw-context.cpp @@ -42,6 +42,7 @@ #include "sp-namedview.h" #include "live_effects/lpe-patternalongpath.h" #include "style.h" +#include "util/mathfns.h" static void sp_draw_context_class_init(SPDrawContextClass *klass); static void sp_draw_context_init(SPDrawContext *dc); @@ -468,7 +469,7 @@ spdc_attach_selection(SPDrawContext *dc, Inkscape::Selection */*sel*/) * \param dc draw context * \param p cursor point (to be changed by snapping) * \param o origin point - * \param state keyboard state to check if ctrl was pressed + * \param state keyboard state to check if ctrl or shift was pressed */ void spdc_endpoint_snap_rotation(SPEventContext const *const ec, Geom::Point &p, Geom::Point const &o, @@ -476,43 +477,41 @@ void spdc_endpoint_snap_rotation(SPEventContext const *const ec, Geom::Point &p, { Inkscape::Preferences *prefs = Inkscape::Preferences::get(); unsigned const snaps = abs(prefs->getInt("/options/rotationsnapsperpi/value", 12)); - /* 0 means no snapping. */ - - /* mirrored by fabs, so this corresponds to 15 degrees */ - Geom::Point best; /* best solution */ - double bn = NR_HUGE; /* best normal */ - double bdot = 0; - Geom::Point v = Geom::Point(0, 1); - double const r00 = cos(M_PI / snaps), r01 = sin(M_PI / snaps); - double const r10 = -r01, r11 = r00; - - Geom::Point delta = p - o; - - for (unsigned i = 0; i < snaps; i++) { - double const ndot = fabs(dot(v,Geom::rot90(delta))); - Geom::Point t(r00*v[Geom::X] + r01*v[Geom::Y], - r10*v[Geom::X] + r11*v[Geom::Y]); - if (ndot < bn) { - /* I think it is better numerically to use the normal, rather than the dot product - * to assess solutions, but I haven't proven it. */ - bn = ndot; - best = v; - bdot = dot(v, delta); + + if (snaps > 0) { // 0 means no 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); + double angle = Geom::angle_between(y_axis, p_line); + double angle_incr = M_PI / snaps; + double angle_ceil = round_to_upper_multiple_plus(angle, angle_incr); + double angle_floor = round_to_lower_multiple_plus(angle, angle_incr); + // We have to angles now. The constrained snapper will try each of them and return the closest + // But first we should setup the snapper + + SnapManager &m = SP_EVENT_CONTEXT_DESKTOP(ec)->namedview->snap_manager; + m.setup(SP_EVENT_CONTEXT_DESKTOP(ec)); + bool snap_enabled = m.snapprefs.getSnapEnabledGlobally(); + if (state & GDK_SHIFT_MASK) { + // SHIFT disables all snapping, except the angular snapping. After all, the user explicitly asked for angular + // snapping by pressing CTRL, otherwise we wouldn't have arrived here. But although we temporarily disable + // the snapping here, we must still call for a constrained snap in order to apply the constraints (i.e. round + // to the nearest angle increment) + m.snapprefs.setSnapEnabledGlobally(false); } - v = t; - } - if (fabs(bdot) > 0) { - p = o + bdot * best; + // 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))); + + Inkscape::SnappedPoint sp = m.multipleConstrainedSnaps(Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_NODE_HANDLE), constraints); + p = sp.getPoint(); - if (!(state & GDK_SHIFT_MASK)) { //SHIFT disables all snapping, except the angular snapping above - //After all, the user explicitly asked for angular snapping by - //pressing CTRL - /* Snap it along best vector */ - SnapManager &m = SP_EVENT_CONTEXT_DESKTOP(ec)->namedview->snap_manager; - m.setup(SP_EVENT_CONTEXT_DESKTOP(ec)); - m.constrainedSnapReturnByRef(p, Inkscape::SNAPSOURCE_NODE_HANDLE, Inkscape::Snapper::SnapConstraint(o, best)); - m.unSetup(); + m.unSetup(); + if (state & GDK_SHIFT_MASK) { + m.snapprefs.setSnapEnabledGlobally(snap_enabled); // restore the original setting } } } |