Move classes derived from SPObject to own directory.

A lot of header clean-up.

1 files changed, 0 insertions, 1359 deletions

diff --git a/src/box3d.cpp b/src/box3d.cpp
deleted file mode 100644
index af1d00b0f..000000000
--- a/src/box3d.cpp
+++ /dev/null
@@ -1,1359 +0,0 @@
-/*
- * SVG <box3d> implementation
- *
- * Authors:
- *   Maximilian Albert <Anhalter42@gmx.de>
- *   Lauris Kaplinski <lauris@kaplinski.com>
- *   bulia byak <buliabyak@users.sf.net>
- *   Abhishek Sharma
- *   Jon A. Cruz <jon@joncruz.org>
- *
- * Copyright (C) 2007      Authors
- * Copyright (C) 1999-2002 Lauris Kaplinski
- * Copyright (C) 2000-2001 Ximian, Inc.
- *
- * Released under GNU GPL, read the file 'COPYING' for more information
- */
-
-#include "box3d.h"
-
-#include <glibmm/i18n.h>
-#include "attributes.h"
-#include "xml/document.h"
-#include "xml/repr.h"
-
-#include "bad-uri-exception.h"
-#include "box3d-side.h"
-#include "ui/tools/box3d-tool.h"
-#include "perspective-line.h"
-#include "persp3d-reference.h"
-#include "uri.h"
-#include <2geom/line.h>
-#include "sp-guide.h"
-#include "sp-namedview.h"
-
-#include "desktop.h"
-
-#include "macros.h"
-
-static void box3d_ref_changed(SPObject *old_ref, SPObject *ref, SPBox3D *box);
-
-static gint counter = 0;
-
-SPBox3D::SPBox3D() : SPGroup() {
-    this->my_counter = 0;
-    this->swapped = Box3D::NONE;
-
-    this->persp_href = NULL;
-    this->persp_ref = new Persp3DReference(this);
-
-    /* we initialize the z-orders to zero so that they are updated during dragging */
-    for (int i = 0; i < 6; ++i) {
-        z_orders[i] = 0;
-    }
-}
-
-SPBox3D::~SPBox3D() {
-}
-
-void SPBox3D::build(SPDocument *document, Inkscape::XML::Node *repr) {
-    SPGroup::build(document, repr);
-
-    my_counter = counter++;
-
-    /* we initialize the z-orders to zero so that they are updated during dragging */
-    for (int i = 0; i < 6; ++i) {
-        z_orders[i] = 0;
-    }
-
-    // TODO: Create/link to the correct perspective
-
-    if ( document ) {
-        persp_ref->changedSignal().connect(sigc::bind(sigc::ptr_fun(box3d_ref_changed), this));
-
-        readAttr( "inkscape:perspectiveID" );
-        readAttr( "inkscape:corner0" );
-        readAttr( "inkscape:corner7" );
-    }
-}
-
-void SPBox3D::release() {
-    SPBox3D* object = this;
-    SPBox3D *box = object;
-
-    if (box->persp_href) {
-        g_free(box->persp_href);
-    }
-
-    // We have to store this here because the Persp3DReference gets destroyed below, but we need to
-    // access it to call persp3d_remove_box(), which cannot be called earlier because the reference
-    // needs to be destroyed first.
-    Persp3D *persp = box3d_get_perspective(box);
-
-    if (box->persp_ref) {
-        box->persp_ref->detach();
-        delete box->persp_ref;
-        box->persp_ref = NULL;
-    }
-
-    if (persp) {
-        persp3d_remove_box (persp, box);
-        /*
-        // TODO: This deletes a perspective when the last box referring to it is gone. Eventually,
-        // it would be nice to have this but currently it crashes when undoing/redoing box deletion
-        // Reason: When redoing a box deletion, the associated perspective is deleted twice, first
-        // by the following code and then again by the redo mechanism! Perhaps we should perform
-        // deletion of the perspective from another location "outside" the undo/redo mechanism?
-        if (persp->perspective_impl->boxes.empty()) {
-            SPDocument *doc = box->document;
-            persp->deleteObject();
-            doc->setCurrentPersp3D(persp3d_document_first_persp(doc));
-        }
-        */
-    }
-
-    SPGroup::release();
-}
-
-void SPBox3D::set(unsigned int key, const gchar* value) {
-    SPBox3D* object = this;
-    SPBox3D *box = object;
-
-    switch (key) {
-        case SP_ATTR_INKSCAPE_BOX3D_PERSPECTIVE_ID:
-            if ( value && box->persp_href && ( strcmp(value, box->persp_href) == 0 ) ) {
-                /* No change, do nothing. */
-            } else {
-                if (box->persp_href) {
-                    g_free(box->persp_href);
-                    box->persp_href = NULL;
-                }
-                if (value) {
-                    box->persp_href = g_strdup(value);
-
-                    // Now do the attaching, which emits the changed signal.
-                    try {
-                        box->persp_ref->attach(Inkscape::URI(value));
-                    } catch (Inkscape::BadURIException &e) {
-                        g_warning("%s", e.what());
-                        box->persp_ref->detach();
-                    }
-                } else {
-                    // Detach, which emits the changed signal.
-                    box->persp_ref->detach();
-                }
-            }
-
-            // FIXME: Is the following update doubled by some call in either persp3d.cpp or vanishing_point_new.cpp?
-            box3d_position_set(box);
-            break;
-        case SP_ATTR_INKSCAPE_BOX3D_CORNER0:
-            if (value && strcmp(value, "0 : 0 : 0 : 0")) {
-                box->orig_corner0 = Proj::Pt3(value);
-                box->save_corner0 = box->orig_corner0;
-                box3d_position_set(box);
-            }
-            break;
-        case SP_ATTR_INKSCAPE_BOX3D_CORNER7:
-            if (value && strcmp(value, "0 : 0 : 0 : 0")) {
-                box->orig_corner7 = Proj::Pt3(value);
-                box->save_corner7 = box->orig_corner7;
-                box3d_position_set(box);
-            }
-            break;
-        default:
-            SPGroup::set(key, value);
-            break;
-    }
-}
-
-/**
- * Gets called when (re)attached to another perspective.
- */
-static void
-box3d_ref_changed(SPObject *old_ref, SPObject *ref, SPBox3D *box)
-{
-    if (old_ref) {
-        sp_signal_disconnect_by_data(old_ref, box);
-        Persp3D *oldPersp = dynamic_cast<Persp3D *>(old_ref);
-        if (oldPersp) {
-            persp3d_remove_box(oldPersp, box);
-        }
-    }
-    Persp3D *persp = dynamic_cast<Persp3D *>(ref);
-    if ( persp && (ref != box) ) // FIXME: Comparisons sane?
-    {
-        persp3d_add_box(persp, box);
-    }
-}
-
-void SPBox3D::update(SPCtx *ctx, guint flags) {
-    if (flags & (SP_OBJECT_MODIFIED_FLAG | SP_OBJECT_STYLE_MODIFIED_FLAG | SP_OBJECT_VIEWPORT_MODIFIED_FLAG)) {
-
-        /* FIXME?: Perhaps the display updates of box sides should be instantiated from here, but this
-           causes evil update loops so it's all done from box3d_position_set, which is called from
-           various other places (like the handlers in shape-editor-knotholders.cpp, vanishing-point.cpp, etc. */
-
-    }
-
-    // Invoke parent method
-    SPGroup::update(ctx, flags);
-}
-
-Inkscape::XML::Node* SPBox3D::write(Inkscape::XML::Document *xml_doc, Inkscape::XML::Node *repr, guint flags) {
-    SPBox3D* object = this;
-    SPBox3D *box = object;
-
-    if ((flags & SP_OBJECT_WRITE_BUILD) && !repr) {
-        // this is where we end up when saving as plain SVG (also in other circumstances?)
-        // thus we don' set "sodipodi:type" so that the box is only saved as an ordinary svg:g
-        repr = xml_doc->createElement("svg:g");
-    }
-
-    if (flags & SP_OBJECT_WRITE_EXT) {
-
-        if (box->persp_href) {
-            repr->setAttribute("inkscape:perspectiveID", box->persp_href);
-        } else {
-            /* box is not yet linked to a perspective; use the document's current perspective */
-            SPDocument *doc = object->document;
-            if (box->persp_ref->getURI()) {
-                gchar *uri_string = box->persp_ref->getURI()->toString();
-                repr->setAttribute("inkscape:perspectiveID", uri_string);
-                g_free(uri_string);
-            } else {
-                Glib::ustring href = "#";
-                href += doc->getCurrentPersp3D()->getId();
-                repr->setAttribute("inkscape:perspectiveID", href.c_str());
-            }
-        }
-
-        gchar *coordstr0 = box->orig_corner0.coord_string();
-        gchar *coordstr7 = box->orig_corner7.coord_string();
-        repr->setAttribute("inkscape:corner0", coordstr0);
-        repr->setAttribute("inkscape:corner7", coordstr7);
-        g_free(coordstr0);
-        g_free(coordstr7);
-
-        box->orig_corner0.normalize();
-        box->orig_corner7.normalize();
-
-        box->save_corner0 = box->orig_corner0;
-        box->save_corner7 = box->orig_corner7;
-    }
-
-    SPGroup::write(xml_doc, repr, flags);
-
-    return repr;
-}
-
-const char* SPBox3D::display_name() {
-    return _("3D Box");
-}
-
-void box3d_position_set(SPBox3D *box)
-{
-    /* This draws the curve and calls requestDisplayUpdate() for each side (the latter is done in
-       box3d_side_position_set() to avoid update conflicts with the parent box) */
-    for (auto& obj: box->children) {
-        Box3DSide *side = dynamic_cast<Box3DSide *>(&obj);
-        if (side) {
-            box3d_side_position_set(side);
-        }
-    }
-}
-
-Geom::Affine SPBox3D::set_transform(Geom::Affine const &xform) {
-    // We don't apply the transform to the box directly but instead to its perspective (which is
-    // done in sp_selection_apply_affine). Here we only adjust strokes, patterns, etc.
-
-    Geom::Affine ret(Geom::Affine(xform).withoutTranslation());
-    gdouble const sw = hypot(ret[0], ret[1]);
-    gdouble const sh = hypot(ret[2], ret[3]);
-
-    for (auto& child: children) {
-        SPItem *childitem = dynamic_cast<SPItem *>(&child);
-        if (childitem) {
-            // Adjust stroke width
-            childitem->adjust_stroke(sqrt(fabs(sw * sh)));
-
-            // Adjust pattern fill
-            childitem->adjust_pattern(xform);
-
-            // Adjust gradient fill
-            childitem->adjust_gradient(xform);
-
-            // Adjust LPE
-            childitem->adjust_livepatheffect(xform);
-        }
-    }
-
-    return Geom::identity();
-}
-
-static Proj::Pt3
-box3d_get_proj_corner (guint id, Proj::Pt3 const &c0, Proj::Pt3 const &c7) {
-    return Proj::Pt3 ((id & Box3D::X) ? c7[Proj::X] : c0[Proj::X],
-                      (id & Box3D::Y) ? c7[Proj::Y] : c0[Proj::Y],
-                      (id & Box3D::Z) ? c7[Proj::Z] : c0[Proj::Z],
-                      1.0);
-}
-
-Proj::Pt3
-box3d_get_proj_corner (SPBox3D const *box, guint id) {
-    return Proj::Pt3 ((id & Box3D::X) ? box->orig_corner7[Proj::X] : box->orig_corner0[Proj::X],
-                      (id & Box3D::Y) ? box->orig_corner7[Proj::Y] : box->orig_corner0[Proj::Y],
-                      (id & Box3D::Z) ? box->orig_corner7[Proj::Z] : box->orig_corner0[Proj::Z],
-                      1.0);
-}
-
-Geom::Point
-box3d_get_corner_screen (SPBox3D const *box, guint id, bool item_coords) {
-    Proj::Pt3 proj_corner (box3d_get_proj_corner (box, id));
-    if (!box3d_get_perspective(box)) {
-        return Geom::Point (Geom::infinity(), Geom::infinity());
-    }
-    Geom::Affine const i2d(box->i2dt_affine ());
-    if (item_coords) {
-        return box3d_get_perspective(box)->perspective_impl->tmat.image(proj_corner).affine() * i2d.inverse();
-    } else {
-        return box3d_get_perspective(box)->perspective_impl->tmat.image(proj_corner).affine();
-    }
-}
-
-Proj::Pt3
-box3d_get_proj_center (SPBox3D *box) {
-    box->orig_corner0.normalize();
-    box->orig_corner7.normalize();
-    return Proj::Pt3 ((box->orig_corner0[Proj::X] + box->orig_corner7[Proj::X]) / 2,
-                      (box->orig_corner0[Proj::Y] + box->orig_corner7[Proj::Y]) / 2,
-                      (box->orig_corner0[Proj::Z] + box->orig_corner7[Proj::Z]) / 2,
-                      1.0);
-}
-
-Geom::Point
-box3d_get_center_screen (SPBox3D *box) {
-    Proj::Pt3 proj_center (box3d_get_proj_center (box));
-    if (!box3d_get_perspective(box)) {
-        return Geom::Point (Geom::infinity(), Geom::infinity());
-    }
-    Geom::Affine const i2d( box->i2dt_affine() );
-    return box3d_get_perspective(box)->perspective_impl->tmat.image(proj_center).affine() * i2d.inverse();
-}
-
-/*
- * To keep the snappoint from jumping randomly between the two lines when the mouse pointer is close to
- * their intersection, we remember the last snapped line and keep snapping to this specific line as long
- * as the distance from the intersection to the mouse pointer is less than remember_snap_threshold.
- */
-
-// Should we make the threshold settable in the preferences?
-static double remember_snap_threshold = 30;
-static guint remember_snap_index = 0;
-
-// constant for sizing the array of points to be considered:
-static const int MAX_POINT_COUNT = 4;
-
-static Proj::Pt3
-box3d_snap (SPBox3D *box, int id, Proj::Pt3 const &pt_proj, Proj::Pt3 const &start_pt) {
-    double z_coord = start_pt[Proj::Z];
-    double diff_x = box->save_corner7[Proj::X] - box->save_corner0[Proj::X];
-    double diff_y = box->save_corner7[Proj::Y] - box->save_corner0[Proj::Y];
-    double x_coord = start_pt[Proj::X];
-    double y_coord = start_pt[Proj::Y];
-    Proj::Pt3 A_proj (x_coord,          y_coord,          z_coord, 1.0);
-    Proj::Pt3 B_proj (x_coord + diff_x, y_coord,          z_coord, 1.0);
-    Proj::Pt3 C_proj (x_coord + diff_x, y_coord + diff_y, z_coord, 1.0);
-    Proj::Pt3 D_proj (x_coord,          y_coord + diff_y, z_coord, 1.0);
-    Proj::Pt3 E_proj (x_coord - diff_x, y_coord + diff_y, z_coord, 1.0);
-
-    Persp3DImpl *persp_impl = box3d_get_perspective(box)->perspective_impl;
-    Geom::Point A = persp_impl->tmat.image(A_proj).affine();
-    Geom::Point B = persp_impl->tmat.image(B_proj).affine();
-    Geom::Point C = persp_impl->tmat.image(C_proj).affine();
-    Geom::Point D = persp_impl->tmat.image(D_proj).affine();
-    Geom::Point E = persp_impl->tmat.image(E_proj).affine();
-    Geom::Point pt = persp_impl->tmat.image(pt_proj).affine();
-
-    // TODO: Replace these lines between corners with lines from a corner to a vanishing point
-    //       (this might help to prevent rounding errors if the box is small)
-    Box3D::Line pl1(A, B);
-    Box3D::Line pl2(A, D);
-    Box3D::Line diag1(A, (id == -1 || (!(id & Box3D::X) == !(id & Box3D::Y))) ? C : E);
-    Box3D::Line diag2(A, E); // diag2 is only taken into account if id equals -1, i.e., if we are snapping the center
-
-    int num_snap_lines = (id != -1) ? 3 : 4;
-    Geom::Point snap_pts[MAX_POINT_COUNT];
-
-    snap_pts[0] = pl1.closest_to (pt);
-    snap_pts[1] = pl2.closest_to (pt);
-    snap_pts[2] = diag1.closest_to (pt);
-    if (id == -1) {
-        snap_pts[3] = diag2.closest_to (pt);
-    }
-
-    gdouble const zoom = SP_ACTIVE_DESKTOP->current_zoom();
-
-    // determine the distances to all potential snapping points
-    double snap_dists[MAX_POINT_COUNT];
-    for (int i = 0; i < num_snap_lines; ++i) {
-        snap_dists[i] = Geom::L2 (snap_pts[i] - pt) * zoom;
-    }
-
-    // while we are within a given tolerance of the starting point,
-    // keep snapping to the same point to avoid jumping
-    bool within_tolerance = true;
-    for (int i = 0; i < num_snap_lines; ++i) {
-        if (snap_dists[i] > remember_snap_threshold) {
-            within_tolerance = false;
-            break;
-        }
-    }
-
-    // find the closest snapping point
-    int snap_index = -1;
-    double snap_dist = Geom::infinity();
-    for (int i = 0; i < num_snap_lines; ++i) {
-        if (snap_dists[i] < snap_dist) {
-            snap_index = i;
-            snap_dist = snap_dists[i];
-        }
-    }
-
-    // snap to the closest point (or the previously remembered one
-    // if we are within tolerance of the starting point)
-    Geom::Point result;
-    if (within_tolerance) {
-        result = snap_pts[remember_snap_index];
-    } else {
-        remember_snap_index = snap_index;
-        result = snap_pts[snap_index];
-    }
-    return box3d_get_perspective(box)->perspective_impl->tmat.preimage (result, z_coord, Proj::Z);
-}
-
-SPBox3D * SPBox3D::createBox3D(SPItem * parent)
-{
-    SPBox3D *box3d = 0;
-    Inkscape::XML::Document *xml_doc = parent->document->rdoc;
-    Inkscape::XML::Node *repr = xml_doc->createElement("svg:g");
-    repr->setAttribute("sodipodi:type", "inkscape:box3d");
-    box3d = reinterpret_cast<SPBox3D *>(parent->appendChildRepr(repr));
-    return box3d;
-}
-
-void
-box3d_set_corner (SPBox3D *box, const guint id, Geom::Point const &new_pos, const Box3D::Axis movement, bool constrained) {
-    g_return_if_fail ((movement != Box3D::NONE) && (movement != Box3D::XYZ));
-
-    box->orig_corner0.normalize();
-    box->orig_corner7.normalize();
-
-    /* update corners 0 and 7 according to which handle was moved and to the axes of movement */
-    if (!(movement & Box3D::Z)) {
-        Persp3DImpl *persp_impl = box3d_get_perspective(box)->perspective_impl;
-        Proj::Pt3 pt_proj (persp_impl->tmat.preimage (new_pos, (id < 4) ? box->orig_corner0[Proj::Z] :
-                                                      box->orig_corner7[Proj::Z], Proj::Z));
-        if (constrained) {
-            pt_proj = box3d_snap (box, id, pt_proj, box3d_get_proj_corner (id, box->save_corner0, box->save_corner7));
-        }
-
-        // normalizing pt_proj is essential because we want to mingle affine coordinates
-        pt_proj.normalize();
-        box->orig_corner0 = Proj::Pt3 ((id & Box3D::X) ? box->save_corner0[Proj::X] : pt_proj[Proj::X],
-                                       (id & Box3D::Y) ? box->save_corner0[Proj::Y] : pt_proj[Proj::Y],
-                                       box->save_corner0[Proj::Z],
-                                       1.0);
-        box->orig_corner7 = Proj::Pt3 ((id & Box3D::X) ? pt_proj[Proj::X] : box->save_corner7[Proj::X],
-                                       (id & Box3D::Y) ? pt_proj[Proj::Y] : box->save_corner7[Proj::Y],
-                                       box->save_corner7[Proj::Z],
-                                       1.0);
-    } else {
-        Persp3D *persp = box3d_get_perspective(box);
-        Persp3DImpl *persp_impl = box3d_get_perspective(box)->perspective_impl;
-        Box3D::PerspectiveLine pl(persp_impl->tmat.image(
-                                      box3d_get_proj_corner (id, box->save_corner0, box->save_corner7)).affine(),
-                                  Proj::Z, persp);
-        Geom::Point new_pos_snapped(pl.closest_to(new_pos));
-        Proj::Pt3 pt_proj (persp_impl->tmat.preimage (new_pos_snapped,
-                                      box3d_get_proj_corner (box, id)[(movement & Box3D::Y) ? Proj::X : Proj::Y],
-                                                      (movement & Box3D::Y) ? Proj::X : Proj::Y));
-        bool corner0_move_x = !(id & Box3D::X) && (movement & Box3D::X);
-        bool corner0_move_y = !(id & Box3D::Y) && (movement & Box3D::Y);
-        bool corner7_move_x =  (id & Box3D::X) && (movement & Box3D::X);
-        bool corner7_move_y =  (id & Box3D::Y) && (movement & Box3D::Y);
-        // normalizing pt_proj is essential because we want to mingle affine coordinates
-        pt_proj.normalize();
-        box->orig_corner0 = Proj::Pt3 (corner0_move_x ? pt_proj[Proj::X] : box->orig_corner0[Proj::X],
-                                       corner0_move_y ? pt_proj[Proj::Y] : box->orig_corner0[Proj::Y],
-                                       (id & Box3D::Z) ? box->orig_corner0[Proj::Z] : pt_proj[Proj::Z],
-                                       1.0);
-        box->orig_corner7 = Proj::Pt3 (corner7_move_x ? pt_proj[Proj::X] : box->orig_corner7[Proj::X],
-                                       corner7_move_y ? pt_proj[Proj::Y] : box->orig_corner7[Proj::Y],
-                                       (id & Box3D::Z) ? pt_proj[Proj::Z] : box->orig_corner7[Proj::Z],
-                                       1.0);
-    }
-    // FIXME: Should we update the box here? If so, how?
-}
-
-void box3d_set_center (SPBox3D *box, Geom::Point const &new_pos, Geom::Point const &old_pos, const Box3D::Axis movement, bool constrained) {
-    g_return_if_fail ((movement != Box3D::NONE) && (movement != Box3D::XYZ));
-
-    box->orig_corner0.normalize();
-    box->orig_corner7.normalize();
-
-    Persp3D *persp = box3d_get_perspective(box);
-    if (!(movement & Box3D::Z)) {
-        double coord = (box->orig_corner0[Proj::Z] + box->orig_corner7[Proj::Z]) / 2;
-        double radx = (box->orig_corner7[Proj::X] - box->orig_corner0[Proj::X]) / 2;
-        double rady = (box->orig_corner7[Proj::Y] - box->orig_corner0[Proj::Y]) / 2;
-
-        Proj::Pt3 pt_proj (persp->perspective_impl->tmat.preimage (new_pos, coord, Proj::Z));
-        if (constrained) {
-            Proj::Pt3 old_pos_proj (persp->perspective_impl->tmat.preimage (old_pos, coord, Proj::Z));
-            old_pos_proj.normalize();
-            pt_proj = box3d_snap (box, -1, pt_proj, old_pos_proj);
-        }
-        // normalizing pt_proj is essential because we want to mingle affine coordinates
-        pt_proj.normalize();
-        box->orig_corner0 = Proj::Pt3 ((movement & Box3D::X) ? pt_proj[Proj::X] - radx : box->orig_corner0[Proj::X],
-                                       (movement & Box3D::Y) ? pt_proj[Proj::Y] - rady : box->orig_corner0[Proj::Y],
-                                       box->orig_corner0[Proj::Z],
-                                       1.0);
-        box->orig_corner7 = Proj::Pt3 ((movement & Box3D::X) ? pt_proj[Proj::X] + radx : box->orig_corner7[Proj::X],
-                                       (movement & Box3D::Y) ? pt_proj[Proj::Y] + rady : box->orig_corner7[Proj::Y],
-                                       box->orig_corner7[Proj::Z],
-                                       1.0);
-    } else {
-        double coord = (box->orig_corner0[Proj::X] + box->orig_corner7[Proj::X]) / 2;
-        double radz = (box->orig_corner7[Proj::Z] - box->orig_corner0[Proj::Z]) / 2;
-
-        Box3D::PerspectiveLine pl(old_pos, Proj::Z, persp);
-        Geom::Point new_pos_snapped(pl.closest_to(new_pos));
-        Proj::Pt3 pt_proj (persp->perspective_impl->tmat.preimage (new_pos_snapped, coord, Proj::X));
-
-        /* normalizing pt_proj is essential because we want to mingle affine coordinates */
-        pt_proj.normalize();
-        box->orig_corner0 = Proj::Pt3 (box->orig_corner0[Proj::X],
-                                       box->orig_corner0[Proj::Y],
-                                       pt_proj[Proj::Z] - radz,
-                                       1.0);
-        box->orig_corner7 = Proj::Pt3 (box->orig_corner7[Proj::X],
-                                       box->orig_corner7[Proj::Y],
-                                       pt_proj[Proj::Z] + radz,
-                                       1.0);
-    }
-}
-
-/*
- * Manipulates corner1 through corner4 to contain the indices of the corners
- * from which the perspective lines in the direction of 'axis' emerge
- */
-void box3d_corners_for_PLs (const SPBox3D * box, Proj::Axis axis,
-                            Geom::Point &corner1, Geom::Point &corner2, Geom::Point &corner3, Geom::Point &corner4)
-{
-    Persp3D *persp = box3d_get_perspective(box);
-    g_return_if_fail (persp);
-    Persp3DImpl *persp_impl = persp->perspective_impl;
-    //box->orig_corner0.normalize();
-    //box->orig_corner7.normalize();
-    double coord = (box->orig_corner0[axis] > box->orig_corner7[axis]) ?
-        box->orig_corner0[axis] :
-        box->orig_corner7[axis];
-
-    Proj::Pt3 c1, c2, c3, c4;
-    // FIXME: This can certainly be done more elegantly/efficiently than by a case-by-case analysis.
-    switch (axis) {
-        case Proj::X:
-            c1 = Proj::Pt3 (coord, box->orig_corner0[Proj::Y], box->orig_corner0[Proj::Z], 1.0);
-            c2 = Proj::Pt3 (coord, box->orig_corner7[Proj::Y], box->orig_corner0[Proj::Z], 1.0);
-            c3 = Proj::Pt3 (coord, box->orig_corner7[Proj::Y], box->orig_corner7[Proj::Z], 1.0);
-            c4 = Proj::Pt3 (coord, box->orig_corner0[Proj::Y], box->orig_corner7[Proj::Z], 1.0);
-            break;
-        case Proj::Y:
-            c1 = Proj::Pt3 (box->orig_corner0[Proj::X], coord, box->orig_corner0[Proj::Z], 1.0);
-            c2 = Proj::Pt3 (box->orig_corner7[Proj::X], coord, box->orig_corner0[Proj::Z], 1.0);
-            c3 = Proj::Pt3 (box->orig_corner7[Proj::X], coord, box->orig_corner7[Proj::Z], 1.0);
-            c4 = Proj::Pt3 (box->orig_corner0[Proj::X], coord, box->orig_corner7[Proj::Z], 1.0);
-            break;
-        case Proj::Z:
-            c1 = Proj::Pt3 (box->orig_corner7[Proj::X], box->orig_corner7[Proj::Y], coord, 1.0);
-            c2 = Proj::Pt3 (box->orig_corner7[Proj::X], box->orig_corner0[Proj::Y], coord, 1.0);
-            c3 = Proj::Pt3 (box->orig_corner0[Proj::X], box->orig_corner0[Proj::Y], coord, 1.0);
-            c4 = Proj::Pt3 (box->orig_corner0[Proj::X], box->orig_corner7[Proj::Y], coord, 1.0);
-            break;
-        default:
-            return;
-    }
-    corner1 = persp_impl->tmat.image(c1).affine();
-    corner2 = persp_impl->tmat.image(c2).affine();
-    corner3 = persp_impl->tmat.image(c3).affine();
-    corner4 = persp_impl->tmat.image(c4).affine();
-}
-
-/* Auxiliary function: Checks whether the half-line from A to B crosses the line segment joining C and D */
-static bool
-box3d_half_line_crosses_joining_line (Geom::Point const &A, Geom::Point const &B,
-                                      Geom::Point const &C, Geom::Point const &D) {
-    Geom::Point n0 = (B - A).ccw();
-    double d0 = dot(n0,A);
-
-    Geom::Point n1 = (D - C).ccw();
-    double d1 = dot(n1,C);
-
-    Geom::Line lineAB(A,B);
-    Geom::Line lineCD(C,D);
-
-    Geom::OptCrossing inters = Geom::OptCrossing(); // empty by default
-    try
-    {
-        inters = Geom::intersection(lineAB, lineCD);
-    }
-    catch (Geom::InfiniteSolutions& e)
-    {
-        // We're probably dealing with parallel lines, so they don't really cross
-        return false;
-    }
-
-    if (!inters) {
-        return false;
-    }
-
-    Geom::Point E = lineAB.pointAt((*inters).ta); // the point of intersection
-
-    if ((dot(C,n0) < d0) == (dot(D,n0) < d0)) {
-        // C and D lie on the same side of the line AB
-        return false;
-    }
-    if ((dot(A,n1) < d1) != (dot(B,n1) < d1)) {
-        // A and B lie on different sides of the line CD
-        return true;
-    } else if (Geom::distance(E,A) < Geom::distance(E,B)) {
-        // The line CD passes on the "wrong" side of A
-        return false;
-    }
-
-    // The line CD passes on the "correct" side of A
-    return true;
-}
-
-static bool
-box3d_XY_axes_are_swapped (SPBox3D *box) {
-    Persp3D *persp = box3d_get_perspective(box);
-    g_return_val_if_fail(persp, false);
-    Box3D::PerspectiveLine l1(box3d_get_corner_screen(box, 3, false), Proj::X, persp);
-    Box3D::PerspectiveLine l2(box3d_get_corner_screen(box, 3, false), Proj::Y, persp);
-    Geom::Point v1(l1.direction());
-    Geom::Point v2(l2.direction());
-    v1.normalize();
-    v2.normalize();
-
-    return (v1[Geom::X]*v2[Geom::Y] - v1[Geom::Y]*v2[Geom::X] > 0);
-}
-
-static inline void
-box3d_aux_set_z_orders (int z_orders[6], int a, int b, int c, int d, int e, int f) {
-    z_orders[0] = a;
-    z_orders[1] = b;
-    z_orders[2] = c;
-    z_orders[3] = d;
-    z_orders[4] = e;
-    z_orders[5] = f;
-}
-
-
-/*
- * In standard perspective we have:
- * 2 = front face
- * 1 = top face
- * 0 = left face
- * 3 = right face
- * 4 = bottom face
- * 5 = rear face
- */
-
-/* All VPs infinite */
-static void
-box3d_set_new_z_orders_case0 (SPBox3D *box, int z_orders[6], Box3D::Axis central_axis) {
-    bool swapped = box3d_XY_axes_are_swapped(box);
-
-    switch(central_axis) {
-        case Box3D::X:
-            if (!swapped) {
-                box3d_aux_set_z_orders (z_orders, 2, 0, 4, 1, 3, 5);
-            } else {
-                box3d_aux_set_z_orders (z_orders, 3, 1, 5, 2, 4, 0);
-            }
-            break;
-        case Box3D::Y:
-            if (!swapped) {
-                box3d_aux_set_z_orders (z_orders, 2, 3, 1, 4, 0, 5);
-            } else {
-                box3d_aux_set_z_orders (z_orders, 5, 0, 4, 1, 3, 2);
-            }
-            break;
-        case Box3D::Z:
-            if (!swapped) {
-                box3d_aux_set_z_orders (z_orders, 2, 0, 1, 4, 3, 5);
-            } else {
-                box3d_aux_set_z_orders (z_orders, 5, 3, 4, 1, 0, 2);
-            }
-            break;
-        case Box3D::NONE:
-            if (!swapped) {
-                box3d_aux_set_z_orders (z_orders, 2, 3, 4, 1, 0, 5);
-            } else {
-                box3d_aux_set_z_orders (z_orders, 5, 0, 1, 4, 3, 2);
-            }
-            break;
-        default:
-            g_assert_not_reached();
-            break;
-    }
-}
-
-/* Precisely one finite VP */
-static void
-box3d_set_new_z_orders_case1 (SPBox3D *box, int z_orders[6], Box3D::Axis central_axis, Box3D::Axis fin_axis) {
-    Persp3D *persp = box3d_get_perspective(box);
-    Geom::Point vp(persp3d_get_VP(persp, Box3D::toProj(fin_axis)).affine());
-
-    // note: in some of the case distinctions below we rely upon the fact that oaxis1 and oaxis2 are ordered
-    Box3D::Axis oaxis1 = Box3D::get_remaining_axes(fin_axis).first;
-    Box3D::Axis oaxis2 = Box3D::get_remaining_axes(fin_axis).second;
-    int inside1 = 0;
-    int inside2 = 0;
-    inside1 = box3d_pt_lies_in_PL_sector (box, vp, 3, 3 ^ oaxis2, oaxis1);
-    inside2 = box3d_pt_lies_in_PL_sector (box, vp, 3, 3 ^ oaxis1, oaxis2);
-
-    bool swapped = box3d_XY_axes_are_swapped(box);
-
-    switch(central_axis) {
-        case Box3D::X:
-            if (!swapped) {
-                box3d_aux_set_z_orders (z_orders, 2, 4, 0, 1, 3, 5);
-            } else {
-                box3d_aux_set_z_orders (z_orders, 5, 3, 1, 0, 2, 4);
-            }
-            break;
-        case Box3D::Y:
-            if (inside2 > 0) {
-                box3d_aux_set_z_orders (z_orders, 1, 2, 3, 0, 5, 4);
-            } else if (inside2 < 0) {
-                box3d_aux_set_z_orders (z_orders, 2, 3, 1, 4, 0, 5);
-            } else {
-                if (!swapped) {
-                    box3d_aux_set_z_orders (z_orders, 2, 3, 1, 5, 0, 4);
-                } else {
-                    box3d_aux_set_z_orders (z_orders, 5, 0, 4, 1, 3, 2);
-                }
-            }
-            break;
-        case Box3D::Z:
-            if (inside2) {
-                if (!swapped) {
-                    box3d_aux_set_z_orders (z_orders, 2, 1, 3, 0, 4, 5);
-                } else {
-                    box3d_aux_set_z_orders (z_orders, 5, 3, 4, 0, 1, 2);
-                }
-            } else if (inside1) {
-                if (!swapped) {
-                    box3d_aux_set_z_orders (z_orders, 2, 0, 1, 4, 3, 5);
-                } else {
-                    box3d_aux_set_z_orders (z_orders, 5, 3, 4, 1, 0, 2);
-                }
-            } else {
-                // "regular" case
-                if (!swapped) {
-                    box3d_aux_set_z_orders (z_orders, 0, 1, 2, 5, 4, 3);
-                } else {
-                    box3d_aux_set_z_orders (z_orders, 5, 3, 4, 0, 2, 1);
-                }
-            }
-            break;
-        case Box3D::NONE:
-            if (!swapped) {
-                box3d_aux_set_z_orders (z_orders, 2, 3, 4, 5, 0, 1);
-            } else {
-                box3d_aux_set_z_orders (z_orders, 5, 0, 1, 3, 2, 4);
-            }
-            break;
-        default:
-            g_assert_not_reached();
-    }
-}
-
-/* Precisely 2 finite VPs */
-static void
-box3d_set_new_z_orders_case2 (SPBox3D *box, int z_orders[6], Box3D::Axis central_axis, Box3D::Axis /*infinite_axis*/) {
-    Geom::Point c3(box3d_get_corner_screen(box, 3, false));
-
-    bool swapped = box3d_XY_axes_are_swapped(box);
-
-    int insidexy = box3d_VP_lies_in_PL_sector (box, Proj::X, 3, 3 ^ Box3D::Z, Box3D::Y);
-    //int insidexz = box3d_VP_lies_in_PL_sector (box, Proj::X, 3, 3 ^ Box3D::Y, Box3D::Z);
-
-    int insideyx = box3d_VP_lies_in_PL_sector (box, Proj::Y, 3, 3 ^ Box3D::Z, Box3D::X);
-    int insideyz = box3d_VP_lies_in_PL_sector (box, Proj::Y, 3, 3 ^ Box3D::X, Box3D::Z);
-
-    //int insidezx = box3d_VP_lies_in_PL_sector (box, Proj::Z, 3, 3 ^ Box3D::Y, Box3D::X);
-    int insidezy = box3d_VP_lies_in_PL_sector (box, Proj::Z, 3, 3 ^ Box3D::X, Box3D::Y);
-
-    switch(central_axis) {
-        case Box3D::X:
-            if (!swapped) {
-                if (insidezy == -1) {
-                    box3d_aux_set_z_orders (z_orders, 2, 4, 0, 1, 3, 5);
-                } else if (insidexy == 1) {
-                    box3d_aux_set_z_orders (z_orders, 2, 4, 0, 5, 1, 3);
-                } else {
-                    box3d_aux_set_z_orders (z_orders, 2, 4, 0, 1, 3, 5);
-                }
-            } else {
-                if (insideyz == -1) {
-                    box3d_aux_set_z_orders (z_orders, 3, 1, 5, 0, 2, 4);
-                } else {
-                    if (!swapped) {
-                        box3d_aux_set_z_orders (z_orders, 3, 1, 5, 2, 4, 0);
-                    } else {
-                        if (insidexy == 0) {
-                            box3d_aux_set_z_orders (z_orders, 3, 5, 1, 0, 2, 4);
-                        } else {
-                            box3d_aux_set_z_orders (z_orders, 3, 1, 5, 0, 2, 4);
-                        }
-                    }
-                }
-            }
-            break;
-        case Box3D::Y:
-            if (!swapped) {
-                if (insideyz == 1) {
-                    box3d_aux_set_z_orders (z_orders, 2, 3, 1, 0, 5, 4);
-                } else {
-                    box3d_aux_set_z_orders (z_orders, 2, 3, 1, 5, 0, 4);
-                }
-            } else {
-                if (insideyx == 1) {
-                    box3d_aux_set_z_orders (z_orders, 4, 0, 5, 1, 3, 2);
-                } else {
-                    box3d_aux_set_z_orders (z_orders, 5, 0, 4, 1, 3, 2);
-                }
-            }
-            break;
-        case Box3D::Z:
-            if (!swapped) {
-                if (insidezy == 1) {
-                    box3d_aux_set_z_orders (z_orders, 2, 1, 0, 4, 3, 5);
-                } else if (insidexy == -1) {
-                    box3d_aux_set_z_orders (z_orders, 2, 1, 0, 5, 4, 3);
-                } else {
-                    box3d_aux_set_z_orders (z_orders, 2, 0, 1, 5, 3, 4);
-                }
-            } else {
-                box3d_aux_set_z_orders (z_orders, 3, 4, 5, 1, 0, 2);
-            }
-            break;
-        case Box3D::NONE:
-            if (!swapped) {
-                box3d_aux_set_z_orders (z_orders, 2, 3, 4, 1, 0, 5);
-            } else {
-                box3d_aux_set_z_orders (z_orders, 5, 0, 1, 4, 3, 2);
-            }
-            break;
-        default:
-            g_assert_not_reached();
-            break;
-    }
-}
-
-/*
- * It can happen that during dragging the box is everted.
- * In this case the opposite sides in this direction need to be swapped
- */
-static Box3D::Axis
-box3d_everted_directions (SPBox3D *box) {
-    Box3D::Axis ev = Box3D::NONE;
-
-    box->orig_corner0.normalize();
-    box->orig_corner7.normalize();
-
-    if (box->orig_corner0[Proj::X] < box->orig_corner7[Proj::X])
-        ev = (Box3D::Axis) (ev ^ Box3D::X);
-    if (box->orig_corner0[Proj::Y] < box->orig_corner7[Proj::Y])
-        ev = (Box3D::Axis) (ev ^ Box3D::Y);
-    if (box->orig_corner0[Proj::Z] > box->orig_corner7[Proj::Z]) // FIXME: Remove the need to distinguish signs among the cases
-        ev = (Box3D::Axis) (ev ^ Box3D::Z);
-
-    return ev;
-}
-
-static void
-box3d_swap_sides(int z_orders[6], Box3D::Axis axis) {
-    int pos1 = -1;
-    int pos2 = -1;
-
-    for (int i = 0; i < 6; ++i) {
-        if (!(Box3D::int_to_face(z_orders[i]) & axis)) {
-            if (pos1 == -1) {
-                pos1 = i;
-            } else {
-                pos2 = i;
-                break;
-            }
-        }
-    }
-
-    if ((pos1 != -1) && (pos2 != -1)){
-        int tmp = z_orders[pos1];
-        z_orders[pos1] = z_orders[pos2];
-        z_orders[pos2] = tmp;
-    }
-}
-
-
-bool
-box3d_recompute_z_orders (SPBox3D *box) {
-    Persp3D *persp = box3d_get_perspective(box);
-
-    if (!persp)
-        return false;
-
-    int z_orders[6];
-
-    Geom::Point c3(box3d_get_corner_screen(box, 3, false));
-
-    // determine directions from corner3 to the VPs
-    int num_finite = 0;
-    Box3D::Axis axis_finite = Box3D::NONE;
-    Box3D::Axis axis_infinite = Box3D::NONE;
-    Geom::Point dirs[3];
-    for (int i = 0; i < 3; ++i) {
-        dirs[i] = persp3d_get_PL_dir_from_pt(persp, c3, Box3D::toProj(Box3D::axes[i]));
-        if (persp3d_VP_is_finite(persp->perspective_impl, Proj::axes[i])) {
-            num_finite++;
-            axis_finite = Box3D::axes[i];
-        } else {
-            axis_infinite = Box3D::axes[i];
-        }
-    }
-
-    // determine the "central" axis (if there is one)
-    Box3D::Axis central_axis = Box3D::NONE;
-    if(Box3D::lies_in_sector(dirs[0], dirs[1], dirs[2])) {
-        central_axis = Box3D::Z;
-    } else if(Box3D::lies_in_sector(dirs[1], dirs[2], dirs[0])) {
-        central_axis = Box3D::X;
-    } else if(Box3D::lies_in_sector(dirs[2], dirs[0], dirs[1])) {
-        central_axis = Box3D::Y;
-    }
-
-    switch (num_finite) {
-        case 0:
-            // TODO: Remark: In this case (and maybe one of the others, too) the z-orders for all boxes
-            //               coincide, hence only need to be computed once in a more central location.
-            box3d_set_new_z_orders_case0(box, z_orders, central_axis);
-            break;
-        case 1:
-            box3d_set_new_z_orders_case1(box, z_orders, central_axis, axis_finite);
-            break;
-        case 2:
-        case 3:
-            box3d_set_new_z_orders_case2(box, z_orders, central_axis, axis_infinite);
-            break;
-        default:
-        /*
-         * For each VP F, check whether the half-line from the corner3 to F crosses the line segment
-         * joining the other two VPs. If this is the case, it determines the "central" corner from
-         * which the visible sides can be deduced. Otherwise, corner3 is the central corner.
-         */
-        // FIXME: We should eliminate the use of Geom::Point altogether
-        Box3D::Axis central_axis = Box3D::NONE;
-        Geom::Point vp_x = persp3d_get_VP(persp, Proj::X).affine();
-        Geom::Point vp_y = persp3d_get_VP(persp, Proj::Y).affine();
-        Geom::Point vp_z = persp3d_get_VP(persp, Proj::Z).affine();
-        Geom::Point vpx(vp_x[Geom::X], vp_x[Geom::Y]);
-        Geom::Point vpy(vp_y[Geom::X], vp_y[Geom::Y]);
-        Geom::Point vpz(vp_z[Geom::X], vp_z[Geom::Y]);
-
-        Geom::Point c3 = box3d_get_corner_screen(box, 3, false);
-        Geom::Point corner3(c3[Geom::X], c3[Geom::Y]);
-
-        if (box3d_half_line_crosses_joining_line (corner3, vpx, vpy, vpz)) {
-            central_axis = Box3D::X;
-        } else if (box3d_half_line_crosses_joining_line (corner3, vpy, vpz, vpx)) {
-            central_axis = Box3D::Y;
-        } else if (box3d_half_line_crosses_joining_line (corner3, vpz, vpx, vpy)) {
-            central_axis = Box3D::Z;
-        }
-
-        // FIXME: At present, this is not used.  Why is it calculated?
-        /*
-        unsigned int central_corner = 3 ^ central_axis;
-        if (central_axis == Box3D::Z) {
-            central_corner = central_corner ^ Box3D::XYZ;
-        }
-        if (box3d_XY_axes_are_swapped(box)) {
-            central_corner = central_corner ^ Box3D::XYZ;
-        }
-        */
-
-        Geom::Point c1(box3d_get_corner_screen(box, 1, false));
-        Geom::Point c2(box3d_get_corner_screen(box, 2, false));
-        Geom::Point c7(box3d_get_corner_screen(box, 7, false));
-
-        Geom::Point corner1(c1[Geom::X], c1[Geom::Y]);
-        Geom::Point corner2(c2[Geom::X], c2[Geom::Y]);
-        Geom::Point corner7(c7[Geom::X], c7[Geom::Y]);
-        // FIXME: At present we don't use the information about central_corner computed above.
-        switch (central_axis) {
-            case Box3D::Y:
-                if (!box3d_half_line_crosses_joining_line(vpz, vpy, corner3, corner2)) {
-                    box3d_aux_set_z_orders (z_orders, 2, 3, 1, 5, 0, 4);
-                } else {
-                    // degenerate case
-                    box3d_aux_set_z_orders (z_orders, 2, 1, 3, 0, 5, 4);
-                }
-                break;
-
-            case Box3D::Z:
-                if (box3d_half_line_crosses_joining_line(vpx, vpz, corner3, corner1)) {
-                    // degenerate case
-                    box3d_aux_set_z_orders (z_orders, 2, 0, 1, 4, 3, 5);
-                } else if (box3d_half_line_crosses_joining_line(vpx, vpy, corner3, corner7)) {
-                    // degenerate case
-                    box3d_aux_set_z_orders (z_orders, 2, 1, 0, 5, 3, 4);
-                } else {
-                    box3d_aux_set_z_orders (z_orders, 2, 1, 0, 3, 4, 5);
-                }
-                break;
-
-            case Box3D::X:
-                if (box3d_half_line_crosses_joining_line(vpz, vpx, corner3, corner1)) {
-                    // degenerate case
-                    box3d_aux_set_z_orders (z_orders, 2, 1, 0, 4, 5, 3);
-                } else {
-                    box3d_aux_set_z_orders (z_orders, 2, 4, 0, 5, 1, 3);
-                }
-                break;
-
-            case Box3D::NONE:
-                box3d_aux_set_z_orders (z_orders, 2, 3, 4, 1, 0, 5);
-                break;
-
-            default:
-                g_assert_not_reached();
-                break;
-        } // end default case
-    }
-
-    // TODO: If there are still errors in z-orders of everted boxes, we need to choose a variable corner
-    //       instead of the hard-coded corner #3 in the computations above
-    Box3D::Axis ev = box3d_everted_directions(box);
-    for (int i = 0; i < 3; ++i) {
-        if (ev & Box3D::axes[i]) {
-            box3d_swap_sides(z_orders, Box3D::axes[i]);
-        }
-    }
-
-    // Check whether anything actually changed
-    for (int i = 0; i < 6; ++i) {
-        if (box->z_orders[i] != z_orders[i]) {
-            for (int j = i; j < 6; ++j) {
-                box->z_orders[j] = z_orders[j];
-            }
-            return true;
-        }
-    }
-    return false;
-}
-
-static std::map<int, Box3DSide *> box3d_get_sides(SPBox3D *box)
-{
-    std::map<int, Box3DSide *> sides;
-    for (auto& obj: box->children) {
-        Box3DSide *side = dynamic_cast<Box3DSide *>(&obj);
-        if (side) {
-            sides[Box3D::face_to_int(side->getFaceId())] = side;
-        }
-    }
-    sides.erase(-1);
-    return sides;
-}
-
-
-// TODO: Check whether the box is everted in any direction and swap the sides opposite to this direction
-void
-box3d_set_z_orders (SPBox3D *box) {
-    // For efficiency reasons, we only set the new z-orders if something really changed
-    if (box3d_recompute_z_orders (box)) {
-        std::map<int, Box3DSide *> sides = box3d_get_sides(box);
-        std::map<int, Box3DSide *>::iterator side;
-        for (unsigned int i = 0; i < 6; ++i) {
-            side = sides.find(box->z_orders[i]);
-            if (side != sides.end()) {
-                ((*side).second)->lowerToBottom();
-            }
-        }
-    }
-}
-
-/*
- * Auxiliary function for z-order recomputing:
- * Determines whether \a pt lies in the sector formed by the two PLs from the corners with IDs
- * \a i21 and \a id2 to the VP in direction \a axis. If the VP is infinite, we say that \a pt
- * lies in the sector if it lies between the two (parallel) PLs.
- * \ret *  0 if \a pt doesn't lie in the sector
- *      *  1 if \a pt lies in the sector and either VP is finite of VP is infinite and the direction
- *           from the edge between the two corners to \a pt points towards the VP
- *      * -1 otherwise
- */
-// TODO: Maybe it would be useful to have a similar method for projective points pt because then we
-//       can use it for VPs and perhaps merge the case distinctions during z-order recomputation.
-int
-box3d_pt_lies_in_PL_sector (SPBox3D const *box, Geom::Point const &pt, int id1, int id2, Box3D::Axis axis) {
-    Persp3D *persp = box3d_get_perspective(box);
-
-    // the two corners
-    Geom::Point c1(box3d_get_corner_screen(box, id1, false));
-    Geom::Point c2(box3d_get_corner_screen(box, id2, false));
-
-    int ret = 0;
-    if (persp3d_VP_is_finite(persp->perspective_impl, Box3D::toProj(axis))) {
-        Geom::Point vp(persp3d_get_VP(persp, Box3D::toProj(axis)).affine());
-        Geom::Point v1(c1 - vp);
-        Geom::Point v2(c2 - vp);
-        Geom::Point w(pt - vp);
-        ret = static_cast<int>(Box3D::lies_in_sector(v1, v2, w));
-    } else {
-        Box3D::PerspectiveLine pl1(c1, Box3D::toProj(axis), persp);
-        Box3D::PerspectiveLine pl2(c2, Box3D::toProj(axis), persp);
-        if (pl1.lie_on_same_side(pt, c2) && pl2.lie_on_same_side(pt, c1)) {
-            // test whether pt lies "towards" or "away from" the VP
-            Box3D::Line edge(c1,c2);
-            Geom::Point c3(box3d_get_corner_screen(box, id1 ^ axis, false));
-            if (edge.lie_on_same_side(pt, c3)) {
-                ret = 1;
-            } else {
-                ret = -1;
-            }
-        }
-    }
-    return ret;
-}
-
-int
-box3d_VP_lies_in_PL_sector (SPBox3D const *box, Proj::Axis vpdir, int id1, int id2, Box3D::Axis axis) {
-    Persp3D *persp = box3d_get_perspective(box);
-
-    if (!persp3d_VP_is_finite(persp->perspective_impl, vpdir)) {
-        return 0;
-    } else {
-        return box3d_pt_lies_in_PL_sector(box, persp3d_get_VP(persp, vpdir).affine(), id1, id2, axis);
-    }
-}
-
-/* swap the coordinates of corner0 and corner7 along the specified axis */
-static void
-box3d_swap_coords(SPBox3D *box, Proj::Axis axis, bool smaller = true) {
-    box->orig_corner0.normalize();
-    box->orig_corner7.normalize();
-    if ((box->orig_corner0[axis] < box->orig_corner7[axis]) != smaller) {
-        double tmp = box->orig_corner0[axis];
-        box->orig_corner0[axis] = box->orig_corner7[axis];
-        box->orig_corner7[axis] = tmp;
-    }
-    // Should we also swap the coordinates of save_corner0 and save_corner7?
-}
-
-/* ensure that the coordinates of corner0 and corner7 are in the correct order (to prevent everted boxes) */
-void
-box3d_relabel_corners(SPBox3D *box) {
-    box3d_swap_coords(box, Proj::X, false);
-    box3d_swap_coords(box, Proj::Y, false);
-    box3d_swap_coords(box, Proj::Z, true);
-}
-
-static void
-box3d_check_for_swapped_coords(SPBox3D *box, Proj::Axis axis, bool smaller) {
-    box->orig_corner0.normalize();
-    box->orig_corner7.normalize();
-
-    if ((box->orig_corner0[axis] < box->orig_corner7[axis]) != smaller) {
-        box->swapped = (Box3D::Axis) (box->swapped | Proj::toAffine(axis));
-    } else {
-        box->swapped = (Box3D::Axis) (box->swapped & ~Proj::toAffine(axis));
-    }
-}
-
-static void
-box3d_exchange_coords(SPBox3D *box) {
-    box->orig_corner0.normalize();
-    box->orig_corner7.normalize();
-
-    for (int i = 0; i < 3; ++i) {
-        if (box->swapped & Box3D::axes[i]) {
-            double tmp = box->orig_corner0[i];
-            box->orig_corner0[i] = box->orig_corner7[i];
-            box->orig_corner7[i] = tmp;
-        }
-    }
-}
-
-void
-box3d_check_for_swapped_coords(SPBox3D *box) {
-    box3d_check_for_swapped_coords(box, Proj::X, false);
-    box3d_check_for_swapped_coords(box, Proj::Y, false);
-    box3d_check_for_swapped_coords(box, Proj::Z, true);
-
-    box3d_exchange_coords(box);
-}
-
-static void box3d_extract_boxes_rec(SPObject *obj, std::list<SPBox3D *> &boxes) {
-    SPBox3D *box = dynamic_cast<SPBox3D *>(obj);
-    if (box) {
-        boxes.push_back(box);
-    } else if (dynamic_cast<SPGroup *>(obj)) {
-        for (auto& child: obj->children) {
-            box3d_extract_boxes_rec(&child, boxes);
-        }
-    }
-}
-
-std::list<SPBox3D *>
-box3d_extract_boxes(SPObject *obj) {
-    std::list<SPBox3D *> boxes;
-    box3d_extract_boxes_rec(obj, boxes);
-    return boxes;
-}
-
-Persp3D *
-box3d_get_perspective(SPBox3D const *box) {
-    return box->persp_ref->getObject();
-}
-
-void
-box3d_switch_perspectives(SPBox3D *box, Persp3D *old_persp, Persp3D *new_persp, bool recompute_corners) {
-    if (recompute_corners) {
-        box->orig_corner0.normalize();
-        box->orig_corner7.normalize();
-        double z0 = box->orig_corner0[Proj::Z];
-        double z7 = box->orig_corner7[Proj::Z];
-        Geom::Point corner0_screen = box3d_get_corner_screen(box, 0, false);
-        Geom::Point corner7_screen = box3d_get_corner_screen(box, 7, false);
-
-        box->orig_corner0 = new_persp->perspective_impl->tmat.preimage(corner0_screen, z0, Proj::Z);
-        box->orig_corner7 = new_persp->perspective_impl->tmat.preimage(corner7_screen, z7, Proj::Z);
-    }
-
-    persp3d_remove_box (old_persp, box);
-    persp3d_add_box (new_persp, box);
-
-    Glib::ustring href = "#";
-    href += new_persp->getId();
-    box->setAttribute("inkscape:perspectiveID", href.c_str());
-}
-
-/* Converts the 3D box to an ordinary SPGroup, adds it to the XML tree at the same position as
-   the original box and deletes the latter */
-SPGroup *box3d_convert_to_group(SPBox3D *box)
-{
-    SPDocument *doc = box->document;
-    Inkscape::XML::Document *xml_doc = doc->getReprDoc();
-
-    // remember position of the box
-    int pos = box->getPosition();
-
-    // remember important attributes
-    gchar const *id = box->getAttribute("id");
-    gchar const *style = box->getAttribute("style");
-    gchar const *mask = box->getAttribute("mask");
-    gchar const *clip_path = box->getAttribute("clip-path");
-
-    // create a new group and add the sides (converted to ordinary paths) as its children
-    Inkscape::XML::Node *grepr = xml_doc->createElement("svg:g");
-
-    for (auto& obj: box->children) {
-        Box3DSide *side = dynamic_cast<Box3DSide *>(&obj);
-        if (side) {
-            Inkscape::XML::Node *repr = box3d_side_convert_to_path(side);
-            grepr->appendChild(repr);
-        } else {
-            g_warning("Non-side item encountered as child of a 3D box.");
-        }
-    }
-
-    // add the new group to the box's parent and set remembered position
-    SPObject *parent = box->parent;
-    parent->appendChild(grepr);
-    grepr->setPosition(pos);
-    grepr->setAttribute("style", style);
-    if (mask)
-       grepr->setAttribute("mask", mask);
-    if (clip_path)
-       grepr->setAttribute("clip-path", clip_path);
-
-    box->deleteObject(true);
-
-    grepr->setAttribute("id", id);
-
-    SPGroup *group = dynamic_cast<SPGroup *>(doc->getObjectByRepr(grepr));
-    g_assert(group != NULL);
-    return group;
-}
-
-const char *SPBox3D::displayName() const {
-    return _("3D Box");
-}
-
-gchar *SPBox3D::description() const {
-    // We could put more details about the 3d box here
-    return g_strdup("");
-}
-
-static inline void
-box3d_push_back_corner_pair(SPBox3D const *box, std::list<std::pair<Geom::Point, Geom::Point> > &pts, int c1, int c2) {
-    pts.push_back(std::make_pair(box3d_get_corner_screen(box, c1, false),
-                                 box3d_get_corner_screen(box, c2, false)));
-}
-
-void SPBox3D::convert_to_guides() const {
-    Inkscape::Preferences *prefs = Inkscape::Preferences::get();
-
-    if (!prefs->getBool("/tools/shapes/3dbox/convertguides", true)) {
-        this->convert_to_guides();
-        return;
-    }
-
-    std::list<std::pair<Geom::Point, Geom::Point> > pts;
-
-    /* perspective lines in X direction */
-    box3d_push_back_corner_pair(this, pts, 0, 1);
-    box3d_push_back_corner_pair(this, pts, 2, 3);
-    box3d_push_back_corner_pair(this, pts, 4, 5);
-    box3d_push_back_corner_pair(this, pts, 6, 7);
-
-    /* perspective lines in Y direction */
-    box3d_push_back_corner_pair(this, pts, 0, 2);
-    box3d_push_back_corner_pair(this, pts, 1, 3);
-    box3d_push_back_corner_pair(this, pts, 4, 6);
-    box3d_push_back_corner_pair(this, pts, 5, 7);
-
-    /* perspective lines in Z direction */
-    box3d_push_back_corner_pair(this, pts, 0, 4);
-    box3d_push_back_corner_pair(this, pts, 1, 5);
-    box3d_push_back_corner_pair(this, pts, 2, 6);
-    box3d_push_back_corner_pair(this, pts, 3, 7);
-
-    sp_guide_pt_pairs_to_guides(this->document, pts);
-}
-
-/*
-  Local Variables:
-  mode:c++
-  c-file-style:"stroustrup"
-  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
-  indent-tabs-mode:nil
-  fill-column:99
-  End:
-*/
-// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :