Exemple #1
0
Inkscape::SnappedPoint SnapManager::constrainedSnap(Inkscape::SnapCandidatePoint const &p,
                                                    Inkscape::Snapper::SnapConstraint const &constraint,
                                                    Geom::OptRect const &bbox_to_snap) const
{
    // First project the mouse pointer onto the constraint
    Geom::Point pp = constraint.projection(p.getPoint());

    Inkscape::SnappedPoint no_snap = Inkscape::SnappedPoint(pp, p.getSourceType(), p.getSourceNum(), Inkscape::SNAPTARGET_CONSTRAINT, Geom::infinity(), 0, false, true, false);

    if (!someSnapperMightSnap()) {
        // Always return point on constraint
        return no_snap;
    }

    Inkscape::SnappedPoint result = no_snap;

    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
    if ((prefs->getBool("/options/snapmousepointer/value", false)) && p.isSingleHandle()) {
        // Snapping the mouse pointer instead of the constrained position of the knot allows
        // to snap to things which don't intersect with the constraint line; this is basically
        // then just a freesnap with the constraint applied afterwards
        // We'll only do this if we're dragging a single handle, and for example not when transforming an object in the selector tool
        result = freeSnap(p, bbox_to_snap);
        if (result.getSnapped()) {
            // only change the snap indicator if we really snapped to something
            if (_snapindicator && _desktop) {
                _desktop->snapindicator->set_new_snaptarget(result);
            }
            // Apply the constraint
            result.setPoint(constraint.projection(result.getPoint()));
            return result;
        }
        return no_snap;
    }

    IntermSnapResults isr;
    SnapperList const snappers = getSnappers();
    for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); ++i) {
        (*i)->constrainedSnap(isr, p, bbox_to_snap, constraint, &_items_to_ignore, _unselected_nodes);
    }

    result = findBestSnap(p, isr, true);


    if (result.getSnapped()) {
        // only change the snap indicator if we really snapped to something
        if (_snapindicator && _desktop) {
            _desktop->snapindicator->set_new_snaptarget(result);
        }
        return result;
    }
    return no_snap;
}
Exemple #2
0
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;
}
Exemple #3
0
Geom::Point SnapManager::multipleOfGridPitch(Geom::Point const &t, Geom::Point const &origin)
{
    if (!snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally())
        return t;

    if (_desktop && _desktop->gridsEnabled()) {
        bool success = false;
        Geom::Point nearest_multiple;
        Geom::Coord nearest_distance = Geom::infinity();
        Inkscape::SnappedPoint bestSnappedPoint(t);

        // It will snap to the grid for which we find the closest snap. This might be a different
        // grid than to which the objects were initially aligned. I don't see an easy way to fix
        // this, so when using multiple grids one can get unexpected results

        // Cannot use getGridSnappers() because we need both the grids AND their snappers
        // Therefore we iterate through all grids manually
        for (std::vector<Inkscape::CanvasGrid *>::const_iterator it = _named_view->grids.begin(); it != _named_view->grids.end(); ++it) {
            Inkscape::CanvasGrid *grid = (*it); 
            const Inkscape::Snapper* snapper = grid->snapper;
            if (snapper && snapper->ThisSnapperMightSnap()) {
                // To find the nearest multiple of the grid pitch for a given translation t, we
                // will use the grid snapper. Simply snapping the value t to the grid will do, but
                // only if the origin of the grid is at (0,0). If it's not then compensate for this
                // in the translation t
                Geom::Point const t_offset = t + grid->origin;
                IntermSnapResults isr;
                // Only the first three parameters are being used for grid snappers
                snapper->freeSnap(isr, Inkscape::SnapCandidatePoint(t_offset, Inkscape::SNAPSOURCE_GRID_PITCH),Geom::OptRect(), NULL, NULL);
                // Find the best snap for this grid, including intersections of the grid-lines
                bool old_val = _snapindicator;
                _snapindicator = false;
                Inkscape::SnappedPoint s = findBestSnap(Inkscape::SnapCandidatePoint(t_offset, Inkscape::SNAPSOURCE_GRID_PITCH), isr, false, true);
                _snapindicator = old_val;
                if (s.getSnapped() && (s.getSnapDistance() < nearest_distance)) {
                    // use getSnapDistance() instead of getWeightedDistance() here because the pointer's position
                    // doesn't tell us anything about which node to snap
                    success = true;
                    nearest_multiple = s.getPoint() - grid->origin;
                    nearest_distance = s.getSnapDistance();
                    bestSnappedPoint = s;
                }
            }
        }

        if (success) {
            bestSnappedPoint.setPoint(origin + nearest_multiple);
            _desktop->snapindicator->set_new_snaptarget(bestSnappedPoint);
            return nearest_multiple;
        }
    }

    return t;
}
Exemple #4
0
void SnapManager::preSnap(Inkscape::SnapCandidatePoint const &p, bool to_paths_only)
{
    // setup() must have been called before calling this method!

    if (_snapindicator) {
        _snapindicator = false; // prevent other methods from drawing a snap indicator; we want to control this here
        Inkscape::SnappedPoint s = freeSnap(p, Geom::OptRect(), to_paths_only);
        g_assert(_desktop != NULL);
        if (s.getSnapped()) {
            _desktop->snapindicator->set_new_snaptarget(s, true);
        } else {
            _desktop->snapindicator->remove_snaptarget(true);
        }
        _snapindicator = true; // restore the original value
    }
}
Exemple #5
0
void SnapManager::guideFreeSnap(Geom::Point &p, Geom::Point &origin_or_vector, bool origin, bool freeze_angle) const
{
    if (freeze_angle && origin) {
        g_warning("Dear developer, when snapping guides you shouldn't ask me to freeze the guide's vector when you haven't specified one");
        // You've supplied me with an origin instead of a vector
    }

    if (!snapprefs.getSnapEnabledGlobally() || snapprefs.getSnapPostponedGlobally() || !snapprefs.isTargetSnappable(Inkscape::SNAPTARGET_GUIDE)) {
        return;
    }

    Inkscape::SnapCandidatePoint candidate(p, Inkscape::SNAPSOURCE_GUIDE);
    if (origin) {
        candidate.addOrigin(origin_or_vector);
    } else {
        candidate = Inkscape::SnapCandidatePoint(p, Inkscape::SNAPSOURCE_GUIDE_ORIGIN);
        candidate.addVector(Geom::rot90(origin_or_vector));
    }

    IntermSnapResults isr;
    SnapperList snappers = getSnappers();
    for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); ++i) {
        (*i)->freeSnap(isr, candidate, Geom::OptRect(), NULL, NULL);
    }

    Inkscape::SnappedPoint const s = findBestSnap(candidate, isr, false);

    s.getPointIfSnapped(p);

    if (!freeze_angle && s.getSnapped()) {
        if (!Geom::are_near(s.getTangent(), Geom::Point(0,0))) { // If the tangent has been set ...
            origin_or_vector = Geom::rot90(s.getTangent()); // then use it to update the normal of the guide
            // PS: The tangent might not have been set if we snapped for example to a node
        }
    }
}
Exemple #6
0
Geom::Rect Inkscape::snap_rectangular_box(SPDesktop const *desktop, SPItem *item,
                                        Geom::Point const &pt, Geom::Point const &center, int state)
{
    Geom::Point p[2];

    bool const shift = state & GDK_SHIFT_MASK;
    bool const control = state & GDK_CONTROL_MASK;

    SnapManager &m = desktop->namedview->snap_manager;
    m.setup(desktop, false, item);
    Inkscape::SnappedPoint snappoint;

    if (control) {

        /* Control is down: we are constrained to producing integer-ratio rectangles */

        /* Vector from the centre of the box to the point we are dragging to */
        Geom::Point delta = pt - center;

        /* Round it so that we have an integer-ratio (or golden ratio) box */
        if (fabs(delta[Geom::X]) > fabs(delta[Geom::Y]) && (delta[Geom::Y] != 0.0)) {
            double ratio = delta[Geom::X] / delta[Geom::Y];
            double ratioabs = fabs (ratio);
            double sign = (ratio < 0 ? -1 : 1);
            if (midpt_1_goldenratio < ratioabs && ratioabs < midpt_goldenratio_2) {
                delta[Geom::X] = sign * goldenratio * delta[Geom::Y];
            } else {
                delta[Geom::X] = floor(ratio + 0.5) * delta[Geom::Y];
            }
        } else if (delta[Geom::X] != 0.0) {
            double ratio = delta[Geom::Y] / delta[Geom::X];
            double ratioabs = fabs (ratio);
            double sign = (ratio < 0 ? -1 : 1);
            if (midpt_1_goldenratio < ratioabs && ratioabs < midpt_goldenratio_2) {
                delta[Geom::Y] = sign * goldenratio * delta[Geom::X];
            } else {
                delta[Geom::Y] = floor(delta[Geom::Y] / delta[Geom::X] + 0.5) * delta[Geom::X];
            }
        }

        /* p[1] is the dragged point with the integer-ratio constraint */
        p[1] = center + delta;

        if (shift) {

            /* Shift is down, so our origin is the centre point rather than the corner
            ** point; this means that corner-point movements are bound to each other.
            */

            /* p[0] is the opposite corner of our box */
            p[0] = center - delta;

            Inkscape::SnappedPoint s[2];

            /* Try to snap p[0] (the opposite corner) along the constraint vector */
            s[0] = m.constrainedSnap(Inkscape::SnapCandidatePoint(p[0], Inkscape::SNAPSOURCE_NODE_HANDLE),
                                     Inkscape::Snapper::ConstraintLine(p[0] - p[1]));

            /* Try to snap p[1] (the dragged corner) along the constraint vector */
            s[1] = m.constrainedSnap(Inkscape::SnapCandidatePoint(p[1], Inkscape::SNAPSOURCE_NODE_HANDLE),
                                     Inkscape::Snapper::ConstraintLine(p[1] - p[0]));

            /* Choose the best snap and update points accordingly */
            if (s[0].getSnapDistance() < s[1].getSnapDistance()) {
                if (s[0].getSnapped()) {
                    p[0] = s[0].getPoint();
                    p[1] = 2 * center - s[0].getPoint();
                    snappoint = s[0];
                }
            } else {
                if (s[1].getSnapped()) {
                    p[0] = 2 * center - s[1].getPoint();
                    p[1] = s[1].getPoint();
                    snappoint = s[1];
                }
            }
        } else {

            /* Our origin is the opposite corner.  Snap the drag point along the constraint vector */
            p[0] = center;
            snappoint = m.constrainedSnap(Inkscape::SnapCandidatePoint(p[1], Inkscape::SNAPSOURCE_NODE_HANDLE),
                                          Inkscape::Snapper::ConstraintLine(p[1] - p[0]));
            if (snappoint.getSnapped()) {
                p[1] = snappoint.getPoint();
            }
        }

    } else if (shift) {

        /* Shift is down, so our origin is the centre point rather than the corner point;
        ** this means that corner-point movements are bound to each other.
        */

        p[1] = pt;
        p[0] = 2 * center - p[1];

        Inkscape::SnappedPoint s[2];

        s[0] = m.freeSnap(Inkscape::SnapCandidatePoint(p[0], Inkscape::SNAPSOURCE_NODE_HANDLE));
        s[1] = m.freeSnap(Inkscape::SnapCandidatePoint(p[1], Inkscape::SNAPSOURCE_NODE_HANDLE));

        if (s[0].getSnapDistance() < s[1].getSnapDistance()) {
            if (s[0].getSnapped()) {
                p[0] = s[0].getPoint();
                p[1] = 2 * center - s[0].getPoint();
                snappoint = s[0];
            }
        } else {
            if (s[1].getSnapped()) {
                p[0] = 2 * center - s[1].getPoint();
                p[1] = s[1].getPoint();
                snappoint = s[1];
            }
        }

    } else {

        /* There's no constraint on the corner point, so just snap it to anything */
        p[0] = center;
        p[1] = pt;
        snappoint = m.freeSnap(Inkscape::SnapCandidatePoint(pt, Inkscape::SNAPSOURCE_NODE_HANDLE));
        if (snappoint.getSnapped()) {
            p[1] = snappoint.getPoint();
        }
    }

    if (snappoint.getSnapped()) {
        desktop->snapindicator->set_new_snaptarget(snappoint);
    }

    p[0] *= desktop->dt2doc();
    p[1] *= desktop->dt2doc();

    return Geom::Rect(Geom::Point(MIN(p[0][Geom::X], p[1][Geom::X]), MIN(p[0][Geom::Y], p[1][Geom::Y])),
                    Geom::Point(MAX(p[0][Geom::X], p[1][Geom::X]), MAX(p[0][Geom::Y], p[1][Geom::Y])));
}
Exemple #7
0
Inkscape::SnappedPoint SnapManager::multipleConstrainedSnaps(Inkscape::SnapCandidatePoint const &p,
                                                    std::vector<Inkscape::Snapper::SnapConstraint> const &constraints,
                                                    bool dont_snap,
                                                    Geom::OptRect const &bbox_to_snap) const
{

    Inkscape::SnappedPoint no_snap = Inkscape::SnappedPoint(p.getPoint(), p.getSourceType(), p.getSourceNum(), Inkscape::SNAPTARGET_CONSTRAINT, Geom::infinity(), 0, false, true, false);
    if (constraints.size() == 0) {
        return no_snap;
    }

    // We haven't tried to snap yet; we will first determine which constraint is closest to where we are now,
    // i.e. lets find out which of the constraints yields the closest projection of point p

    // Project the mouse pointer on each of the constraints
    std::vector<Geom::Point> projections;
    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
        // return the projection onto the constraint, such that the constraint is always enforced
        Geom::Point pp = (*c).projection(p.getPoint());
        projections.push_back(pp);
    }

    // Select the closest constraint
    no_snap.setPoint(projections.front());
    Inkscape::Snapper::SnapConstraint cc = constraints.front(); //closest constraint

    std::vector<Inkscape::Snapper::SnapConstraint>::const_iterator c = constraints.begin();
    std::vector<Geom::Point>::iterator pp = projections.begin();
    for (; pp != projections.end(); ++pp) {
        if (Geom::L2(*pp - p.getPoint()) < Geom::L2(no_snap.getPoint() - p.getPoint())) {
            no_snap.setPoint(*pp); // Remember the projection onto the closest constraint
            cc = *c; // Remember the closest constraint itself
        }
        ++c;
    }

    if (!someSnapperMightSnap() || dont_snap) {
        return no_snap;
    }

    IntermSnapResults isr;
    SnapperList const snappers = getSnappers();
    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
    bool snap_mouse = prefs->getBool("/options/snapmousepointer/value", false);

    Inkscape::SnappedPoint result = no_snap;
    if (snap_mouse && p.isSingleHandle()) {
        // Snapping the mouse pointer instead of the constrained position of the knot allows
        // to snap to things which don't intersect with the constraint line; this is basically
        // then just a freesnap with the constraint applied afterwards
        // We'll only to this if we're dragging a single handle, and for example not when transforming an object in the selector tool
        result = freeSnap(p, bbox_to_snap);
        // Now apply the constraint afterwards
        result.setPoint(cc.projection(result.getPoint()));
    } else {
        // Try to snap along the closest constraint
        for (SnapperList::const_iterator i = snappers.begin(); i != snappers.end(); ++i) {
            (*i)->constrainedSnap(isr, p, bbox_to_snap, cc, &_items_to_ignore,_unselected_nodes);
        }
        result = findBestSnap(p, isr, true);
    }

    return result.getSnapped() ? result : no_snap;
}
Exemple #8
0
static gint
pencil_handle_motion_notify(SPPencilContext *const pc, GdkEventMotion const &mevent)
{
    if ((mevent.state & GDK_CONTROL_MASK) && (mevent.state & GDK_BUTTON1_MASK)) {
        // mouse was accidentally moved during Ctrl+click;
        // ignore the motion and create a single point
        pc->is_drawing = false;
        return TRUE;
    }
    gint ret = FALSE;
    SPDesktop *const dt = pc->desktop;

    SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
    if (event_context->space_panning || mevent.state & GDK_BUTTON2_MASK || mevent.state & GDK_BUTTON3_MASK) {
        // allow scrolling
        return FALSE;
    }

    if ( ( mevent.state & GDK_BUTTON1_MASK ) && !pc->grab && pc->is_drawing) {
        /* Grab mouse, so release will not pass unnoticed */
        pc->grab = SP_CANVAS_ITEM(dt->acetate);
        sp_canvas_item_grab(pc->grab, ( GDK_KEY_PRESS_MASK | GDK_BUTTON_PRESS_MASK   |
                                        GDK_BUTTON_RELEASE_MASK |
                                        GDK_POINTER_MOTION_MASK  ),
                            NULL, mevent.time);
    }

    /* Find desktop coordinates */
    Geom::Point p = dt->w2d(Geom::Point(mevent.x, mevent.y));

    /* Test whether we hit any anchor. */
    SPDrawAnchor *anchor = spdc_test_inside(pc, Geom::Point(mevent.x, mevent.y));

    if (pencil_within_tolerance) {
        Inkscape::Preferences *prefs = Inkscape::Preferences::get();
        gint const tolerance = prefs->getIntLimited("/options/dragtolerance/value", 0, 0, 100);
        if ( Geom::LInfty( Geom::Point(mevent.x,mevent.y) - pencil_drag_origin_w ) < tolerance ) {
            return FALSE;   // Do not drag if we're within tolerance from origin.
        }
    }

    // Once the user has moved farther than tolerance from the original location
    // (indicating they intend to move the object, not click), then always process the
    // motion notify coordinates as given (no snapping back to origin)
    pencil_within_tolerance = false;

    switch (pc->state) {
        case SP_PENCIL_CONTEXT_ADDLINE:
            /* Set red endpoint */
            if (anchor) {
                p = anchor->dp;
            } else {
                Geom::Point ptnr(p);
                spdc_endpoint_snap(pc, ptnr, mevent.state);
                p = ptnr;
            }
            spdc_set_endpoint(pc, p);
            ret = TRUE;
            break;
        default:
            /* We may be idle or already freehand */
            if ( mevent.state & GDK_BUTTON1_MASK && pc->is_drawing ) {
                pc->state = SP_PENCIL_CONTEXT_FREEHAND;
                if ( !pc->sa && !pc->green_anchor ) {
                    /* Create green anchor */
                    pc->green_anchor = sp_draw_anchor_new(pc, pc->green_curve, TRUE, pc->p[0]);
                }
                /** \todo
                 * fixme: I am not sure whether we want to snap to anchors
                 * in middle of freehand (Lauris)
                 */
                SnapManager &m = dt->namedview->snap_manager;
                
                if (anchor) {
                    p = anchor->dp;
                } else if ((mevent.state & GDK_SHIFT_MASK) == 0) {
                    m.setup(dt);
                    Inkscape::SnappedPoint const s = m.freeSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, p);
                    if (s.getSnapped()) {
                    	s.getPoint(p);
                    	pc->prev_snap_was_succesful = true;
                    } else {
                    	pc->prev_snap_was_succesful = false;
                    }
                }
                if ( pc->npoints != 0) { // buttonpress may have happened before we entered draw context!
                	if (!(pc->prev_snap_was_succesful && m.snapprefs.getSnapPostponedGlobally())) {
	                    // When snapping is enabled but temporarily on hold because the mouse is moving 
                        // fast, then we don't want to add nodes off-grid
                        spdc_add_freehand_point(pc, p, mevent.state);
	                    ret = TRUE;
                	}
                }

                if (anchor && !pc->anchor_statusbar) {
                    pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Release</b> here to close and finish the path."));
                    pc->anchor_statusbar = true;
                } else if (!anchor && pc->anchor_statusbar) {
                    pc->_message_context->clear();
                    pc->anchor_statusbar = false;
                } else if (!anchor) {
                    pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("Drawing a freehand path"));
                }

            } else {
                if (anchor && !pc->anchor_statusbar) {
                    pc->_message_context->set(Inkscape::NORMAL_MESSAGE, _("<b>Drag</b> to continue the path from this point."));
                    pc->anchor_statusbar = true;
                } else if (!anchor && pc->anchor_statusbar) {
                    pc->_message_context->clear();
                    pc->anchor_statusbar = false;
                }
            }
            break;
    }
    return ret;
}
Exemple #9
0
static gint
pencil_handle_button_press(SPPencilContext *const pc, GdkEventButton const &bevent)
{
    gint ret = FALSE;
    SPEventContext *event_context = SP_EVENT_CONTEXT(pc);
    if ( bevent.button == 1  && !event_context->space_panning) {

        SPDrawContext *dc = SP_DRAW_CONTEXT (pc);
        SPDesktop *desktop = SP_EVENT_CONTEXT_DESKTOP(dc);
        Inkscape::Selection *selection = sp_desktop_selection(desktop);

        if (Inkscape::have_viable_layer(desktop, dc->_message_context) == false) {
            return TRUE;
        }

        Geom::Point const button_w(bevent.x, bevent.y);

        /* Find desktop coordinates */
        Geom::Point p = pc->desktop->w2d(button_w);

        /* Test whether we hit any anchor. */
        SPDrawAnchor *anchor = spdc_test_inside(pc, button_w);

        pencil_drag_origin_w = Geom::Point(bevent.x,bevent.y);
        pencil_within_tolerance = true;

        switch (pc->state) {
            case SP_PENCIL_CONTEXT_ADDLINE:
                /* Current segment will be finished with release */
                ret = TRUE;
                break;
            default:
                /* Set first point of sequence */
                if (bevent.state & GDK_CONTROL_MASK) {
                    spdc_create_single_dot(event_context, p, "/tools/freehand/pencil", bevent.state);
                    ret = true;
                    break;
                }
                if (anchor) {
                    p = anchor->dp;
                    desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Continuing selected path"));
                } else {

                    if (!(bevent.state & GDK_SHIFT_MASK)) {

                        // This is the first click of a new curve; deselect item so that
                        // this curve is not combined with it (unless it is drawn from its
                        // anchor, which is handled by the sibling branch above)
                        selection->clear();
                        desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Creating new path"));
                        SnapManager &m = desktop->namedview->snap_manager;
                        m.setup(desktop);
                        Inkscape::SnappedPoint const s = m.freeSnap(Inkscape::SnapPreferences::SNAPPOINT_NODE, p);
                        if (s.getSnapped()) {
                        	s.getPoint(p);
                        	pc->prev_snap_was_succesful = true;
                        } else {
                        	pc->prev_snap_was_succesful = false;
                        }
                    } else if (selection->singleItem() && SP_IS_PATH(selection->singleItem())) {
                        desktop->messageStack()->flash(Inkscape::NORMAL_MESSAGE, _("Appending to selected path"));
                    }
                }
                pc->sa = anchor;
                spdc_set_startpoint(pc, p);
                ret = TRUE;
                break;
        }

        pc->is_drawing = true;
    }
    return ret;
}