1 files changed, 226 insertions, 0 deletions
diff --git a/src/vanishing-point.h b/src/vanishing-point.h
new file mode 100644
index 0000000..c6c280d
--- /dev/null
+++ b/src/vanishing-point.h
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Vanishing point for 3D perspectives
+ *
+ * Authors:
+ *   Maximilian Albert <Anhalter42@gmx.de>
+ *
+ * Copyright (C) 2007 authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef SEEN_VANISHING_POINT_H
+#define SEEN_VANISHING_POINT_H
+
+#include <2geom/point.h>
+#include <list>
+#include <set>
+
+#include "selection.h"
+
+#include "display/control/canvas-item-enums.h"
+
+#include "object/persp3d.h"
+
+class SPBox3D;
+class SPKnot;
+
+namespace Inkscape {
+class CanvasItemCurve;
+}
+
+namespace Box3D {
+
+enum VPState {
+    VP_FINITE = 0, // perspective lines meet in the VP
+    VP_INFINITE    // perspective lines are parallel
+};
+
+/* VanishingPoint is a simple wrapper class to easily extract VP data from perspectives.
+ * A VanishingPoint represents a VP in a certain direction (X, Y, Z) of a single perspective.
+ * In particular, it can potentially have more than one box linked to it (although in facth they
+ * are rather linked to the parent perspective).
+ */
+// FIXME: Don't store the box in the VP but rather the perspective (and link the box to it)!!
+class VanishingPoint {
+public:
+    VanishingPoint() : my_counter(VanishingPoint::global_counter++), _persp(nullptr), _axis(Proj::NONE) {}
+    VanishingPoint(Persp3D *persp, Proj::Axis axis) : my_counter(VanishingPoint::global_counter++), _persp(persp), _axis(axis) {}
+    VanishingPoint(const VanishingPoint &other) : my_counter(VanishingPoint::global_counter++), _persp(other._persp), _axis(other._axis) {}
+
+    inline VanishingPoint &operator=(VanishingPoint const &rhs) = default;
+    inline bool operator==(VanishingPoint const &rhs) const {
+        /* vanishing points coincide if they belong to the same perspective */
+        return (_persp == rhs._persp && _axis == rhs._axis);
+    }
+
+    inline bool operator<(VanishingPoint const &rhs) const {
+        return my_counter < rhs.my_counter;
+    }
+
+    inline void set(Persp3D *persp, Proj::Axis axis) {
+        _persp = persp;
+        _axis = axis;
+    }
+    void set_pos(Proj::Pt2 const &pt);
+    inline bool is_finite() const {
+        g_return_val_if_fail (_persp, false);
+        return _persp->get_VP (_axis).is_finite();
+    }
+    inline Geom::Point get_pos() const {
+        g_return_val_if_fail (_persp, Geom::Point (Geom::infinity(), Geom::infinity()));
+        return _persp->get_VP (_axis).affine();
+    }
+    inline Persp3D * get_perspective() const {
+        return _persp;
+    }
+    inline Persp3D * set_perspective(Persp3D *persp) {
+        return _persp = persp;
+    }
+
+    inline bool hasBox (SPBox3D *box) {
+        return _persp->has_box(box);
+    }
+    inline unsigned int numberOfBoxes() const {
+        return _persp->num_boxes();
+    }
+
+    /* returns all selected boxes sharing this perspective */
+    std::list<SPBox3D *> selectedBoxes(Inkscape::Selection *sel);
+
+    inline void updateBoxDisplays() const {
+        g_return_if_fail (_persp);
+        _persp->update_box_displays();
+    }
+    inline void updateBoxReprs() const {
+        g_return_if_fail (_persp);
+        _persp->update_box_reprs();
+    }
+    inline void updatePerspRepr() const {
+        g_return_if_fail (_persp);
+        _persp->updateRepr(SP_OBJECT_WRITE_EXT);
+    }
+    inline void printPt() const {
+        g_return_if_fail (_persp);
+        _persp->get_VP (_axis).print("");
+    }
+    inline char const *axisString () { return Proj::string_from_axis(_axis); }
+
+    unsigned int my_counter;
+    static unsigned int global_counter; // FIXME: Only to implement operator< so that we can merge lists. Do this in a better way!!
+private:
+    Persp3D *_persp;
+    Proj::Axis _axis;
+};
+
+struct VPDrag;
+
+struct VPDragger {
+public:
+    VPDragger(VPDrag *parent, Geom::Point p, VanishingPoint &vp);
+    ~VPDragger();
+
+    VPDrag *parent;
+    SPKnot *knot;
+
+    // position of the knot, desktop coords
+    Geom::Point point;
+    // position of the knot before it began to drag; updated when released
+    Geom::Point point_original;
+
+    bool dragging_started;
+
+    std::list<VanishingPoint> vps;
+
+    void addVP(VanishingPoint &vp, bool update_pos = false);
+    void removeVP(const VanishingPoint &vp);
+
+    void updateTip();
+
+    unsigned int numberOfBoxes(); // the number of boxes linked to all VPs of the dragger
+    VanishingPoint *findVPWithBox(SPBox3D *box);
+    std::set<VanishingPoint*> VPsOfSelectedBoxes();
+
+    bool hasPerspective(const Persp3D *persp);
+    void mergePerspectives(); // remove duplicate perspectives
+
+    void updateBoxDisplays();
+    void updateVPs(Geom::Point const &pt);
+    void updateZOrders();
+
+    void printVPs();
+
+private:
+    sigc::connection _moved_connection;
+    sigc::connection _grabbed_connection;
+    sigc::connection _ungrabbed_connection;
+};
+
+struct VPDrag {
+public:
+    VPDrag(SPDocument *document);
+    ~VPDrag();
+
+    VPDragger *getDraggerFor (VanishingPoint const &vp);
+
+    bool dragging;
+
+    SPDocument *document;
+    std::vector<VPDragger *> draggers;
+    std::vector<Inkscape::CanvasItemCurve *> item_curves;
+
+    void printDraggers(); // convenience for debugging
+    /*
+     * FIXME: Should the following functions be merged?
+     *        Also, they should make use of the info in a VanishingPoint structure (regarding boxes
+     *        and perspectives) rather than each time iterating over the whole list of selected items?
+     */
+    void updateDraggers ();
+    void updateLines ();
+    void updateBoxHandles ();
+    void updateBoxReprs ();
+    void updateBoxDisplays ();
+    void drawLinesForFace (const SPBox3D *box, Proj::Axis axis); //, guint corner1, guint corner2, guint corner3, guint corner4);
+    bool show_lines; /* whether perspective lines are drawn at all */
+    unsigned int front_or_rear_lines; /* whether we draw perspective lines from all corners or only the
+                                  front/rear corners (indicated by the first/second bit, respectively  */
+
+
+    inline bool hasEmptySelection() { return this->selection->isEmpty(); }
+    bool allBoxesAreSelected (VPDragger *dragger);
+
+    // FIXME: Should this be private? (It's the case with the corresponding function in gradient-drag.h)
+    //        But vp_knot_grabbed_handler
+    void addDragger (VanishingPoint &vp);
+
+    void swap_perspectives_of_VPs(Persp3D *persp2, Persp3D *persp1);
+
+private:
+    //void deselect_all();
+
+    /**
+     * Create a line from p1 to p2 and add it to the item_curves list.
+     */
+    void addCurve(Geom::Point const &p1, Geom::Point const &p2, Inkscape::CanvasItemColor color);
+
+    Inkscape::Selection *selection;
+    sigc::connection sel_changed_connection;
+    sigc::connection sel_modified_connection;
+};
+
+} // namespace Box3D
+
+
+#endif /* !SEEN_VANISHING_POINT_H */
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :