Adding upstream version 1.2.2.upstream/1.2.2upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 166 insertions, 0 deletions

diff --git a/src/snapper.h b/src/snapper.h
new file mode 100644
index 0000000..18f324c
--- /dev/null
+++ b/src/snapper.h
@@ -0,0 +1,166 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_SNAPPER_H
+#define SEEN_SNAPPER_H
+
+/**
+ *    \file src/snapper.h
+ *    \brief Snapper class.
+ *
+ *    Authors:
+ *      Carl Hetherington <inkscape@carlh.net>
+ *      Diederik van Lierop <mail@diedenrezi.nl>
+ *
+ *    Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <optional>
+#include <cstdio>
+#include <list>
+
+#include "snap-candidate.h"
+#include "snapped-point.h"
+#include "snapped-line.h"
+#include "snapped-curve.h"
+
+struct IntermSnapResults {
+    std::list<Inkscape::SnappedPoint> points;
+    std::list<Inkscape::SnappedLine> grid_lines;
+    std::list<Inkscape::SnappedLine> guide_lines;
+    std::list<Inkscape::SnappedCurve> curves;
+};
+
+class SnapManager;
+class SPObject;
+
+namespace Inkscape
+{
+/// Parent for classes that can snap points to something
+class Snapper
+{
+public:
+    //Snapper() {} //does not seem to be used somewhere
+    Snapper(SnapManager *sm, ::Geom::Coord const t);
+    virtual ~Snapper() = default;
+
+    virtual Geom::Coord getSnapperTolerance() const = 0; //returns the tolerance of the snapper in screen pixels (i.e. independent of zoom)
+    virtual bool getSnapperAlwaysSnap() const = 0; //if true, then the snapper will always snap, regardless of its tolerance
+
+    /**
+    *  \return true if this Snapper will snap at least one kind of point.
+    */
+    virtual bool ThisSnapperMightSnap() const {return _snap_enabled;} // will likely be overridden by derived classes
+
+    // These four methods are only used for grids, for which snapping can be enabled individually
+    void setEnabled(bool s);
+    void setSnapVisibleOnly(bool s);
+    bool getEnabled() const {return _snap_enabled;}
+    bool getSnapVisibleOnly() const {return _snap_visible_only;}
+
+    virtual void freeSnap(IntermSnapResults &/*isr*/,
+                          Inkscape::SnapCandidatePoint const &/*p*/,
+                          Geom::OptRect const &/*bbox_to_snap*/,
+                          std::vector<SPObject const *> const */*it*/,
+                          std::vector<SnapCandidatePoint> */*unselected_nodes*/) const {};
+
+    // Class for storing the constraint for constrained snapping; can be
+    // - a line (infinite line with origin, running through _point pointing in _direction)
+    // - a direction (infinite line without origin, i.e. only a direction vector, stored in _direction)
+    // - a circle (_point denotes the center, _radius doesn't need an explanation, _direction contains
+    //      the vector from the origin to the original untransformed point);
+    class SnapConstraint
+    {
+    private:
+        enum SnapConstraintType {LINE, DIRECTION, CIRCLE, UNDEFINED};
+
+    public:
+        // Constructs a direction constraint, e.g. horizontal or vertical but without a specified point
+        SnapConstraint(Geom::Point const &d) : _point(), _direction(d), _radius(0), _type(DIRECTION) {}
+        // Constructs a linear constraint
+        SnapConstraint(Geom::Point const &p, Geom::Point const &d) : _point(p), _direction(d), _radius(0), _type(LINE) {}
+        // Orthogonal version
+        SnapConstraint(Geom::Point const &p, Geom::Dim2 const &d) : _point(p), _direction(), _radius(0), _type(LINE) {_direction[d] = 1.;}
+        SnapConstraint(Geom::Line const &l) : _point(l.origin()), _direction(l.versor()), _radius(0), _type(LINE) {}
+        // Constructs a circular constraint
+        SnapConstraint(Geom::Point const &p, Geom::Point const &d, Geom::Coord const &r) : _point(p), _direction(d), _radius(r), _type(CIRCLE) {}
+        // Undefined, or empty constraint
+        SnapConstraint() : _point(), _direction(), _radius(0), _type(UNDEFINED) {}
+
+        bool hasPoint() const {return _type != DIRECTION && _type != UNDEFINED;}
+
+        Geom::Point getPoint() const {
+            assert(_type != DIRECTION && _type != UNDEFINED);
+            return _point;
+        }
+
+        Geom::Point getDirection() const {
+            return _direction;
+        }
+
+        Geom::Coord getRadius() const {
+            assert(_type == CIRCLE);
+            return _radius;
+        }
+
+        bool isCircular() const { return _type == CIRCLE; }
+        bool isLinear() const { return _type == LINE; }
+        bool isDirection() const { return _type == DIRECTION; }
+        bool isUndefined() const { return _type == UNDEFINED; }
+
+        Geom::Point projection(Geom::Point const &p) const { // returns the projection of p on this constraint
+            if (_type == CIRCLE) {
+                // project on to a circular constraint
+                Geom::Point v_orig = p - _point;
+                Geom::Coord l = Geom::L2(v_orig);
+                if (l > 0) {
+                    return _point + _radius * v_orig/l; // Length of _direction is equal to the radius
+                } else {
+                    // point to be projected is exactly at the center of the circle, so any point on the circle is a projection
+                    return _point + Geom::Point(_radius, 0);
+                }
+            } else if (_type != UNDEFINED){
+                // project on to a linear constraint
+                Geom::Point const p1_on_cl = (_type == LINE) ? _point : p;
+                Geom::Point const p2_on_cl = p1_on_cl + _direction;
+                return Geom::projection(p, Geom::Line(p1_on_cl, p2_on_cl));
+            } else {
+                printf("WARNING: Bug: trying to find the projection onto an undefined constraint");
+                return Geom::Point();
+            }
+        }
+
+    private:
+        Geom::Point _point;
+        Geom::Point _direction;
+        Geom::Coord _radius;
+        SnapConstraintType _type;
+    };
+
+    virtual void constrainedSnap(IntermSnapResults &/*isr*/,
+                                 Inkscape::SnapCandidatePoint const &/*p*/,
+                                 Geom::OptRect const &/*bbox_to_snap*/,
+                                 SnapConstraint const &/*c*/,
+                                 std::vector<SPObject const *> const */*it*/,
+                                 std::vector<SnapCandidatePoint> */*unselected_nodes*/) const {};
+
+protected:
+    SnapManager *_snapmanager;
+
+    // This is only used for grids, for which snapping can be enabled individually
+    bool _snap_enabled; ///< true if this snapper is enabled, otherwise false
+    bool _snap_visible_only;
+};
+
+}
+
+#endif /* !SEEN_SNAPPER_H */
+
+/*
+  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 :