From af1c59f0fdf3df1a2e105519f59180b7a37cbee0 Mon Sep 17 00:00:00 2001
From: Daniel Bailey <d@nielbailey.com>
Date: Sun, 15 May 2016 21:44:44 +0100
Subject: [PATCH] Add support for editing arc segments in the node editor

---
 .../node-segment-elliptical-arc-bulge.svg     | 125 +++++++++++
 .../node-segment-elliptical-arc-flip.svg      | 137 ++++++++++++
 .../node-segment-elliptical-arc-shallow.svg   | 125 +++++++++++
 .../actions/node-segment-elliptical-arc.svg   | 132 +++++++++++
 share/ui/toolbar-node.ui                      |  67 ++++++
 src/helper/geom.cpp                           |  40 ++++
 src/helper/geom.h                             |   1 +
 src/ui/tool/curve-drag-point.cpp              |  14 ++
 src/ui/tool/curve-drag-point.h                |   1 +
 src/ui/tool/multi-path-manipulator.cpp        |  36 ++-
 src/ui/tool/multi-path-manipulator.h          |   3 +
 src/ui/tool/node-types.h                      |   3 +-
 src/ui/tool/node.cpp                          | 192 ++++++++++++++--
 src/ui/tool/node.h                            |  29 ++-
 src/ui/tool/path-manipulator.cpp              | 205 ++++++++++++++++--
 src/ui/tool/path-manipulator.h                |   5 +
 src/ui/toolbar/node-toolbar.cpp               |  32 +++
 src/ui/toolbar/node-toolbar.h                 |   4 +
 18 files changed, 1111 insertions(+), 40 deletions(-)
 create mode 100644 share/icons/hicolor/scalable/actions/node-segment-elliptical-arc-bulge.svg
 create mode 100644 share/icons/hicolor/scalable/actions/node-segment-elliptical-arc-flip.svg
 create mode 100644 share/icons/hicolor/scalable/actions/node-segment-elliptical-arc-shallow.svg
 create mode 100644 share/icons/hicolor/scalable/actions/node-segment-elliptical-arc.svg

diff --git a/share/icons/hicolor/scalable/actions/node-segment-elliptical-arc-bulge.svg b/share/icons/hicolor/scalable/actions/node-segment-elliptical-arc-bulge.svg
new file mode 100644
index 0000000000..e70bdf2d5e
--- /dev/null
+++ b/share/icons/hicolor/scalable/actions/node-segment-elliptical-arc-bulge.svg
@@ -0,0 +1,125 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg
+   xmlns:dc="http://purl.org/dc/elements/1.1/"
+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
+   id="svg1"
+   width="16"
+   height="16.002623"
+   version="1.1"
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+   viewBox="0 0 16 16.002623"
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diff --git a/share/icons/hicolor/scalable/actions/node-segment-elliptical-arc-flip.svg b/share/icons/hicolor/scalable/actions/node-segment-elliptical-arc-flip.svg
new file mode 100644
index 0000000000..35c22141c5
--- /dev/null
+++ b/share/icons/hicolor/scalable/actions/node-segment-elliptical-arc-flip.svg
@@ -0,0 +1,137 @@
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+<svg
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+   xmlns:cc="http://creativecommons.org/ns#"
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+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
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diff --git a/share/icons/hicolor/scalable/actions/node-segment-elliptical-arc-shallow.svg b/share/icons/hicolor/scalable/actions/node-segment-elliptical-arc-shallow.svg
new file mode 100644
index 0000000000..73040fc2aa
--- /dev/null
+++ b/share/icons/hicolor/scalable/actions/node-segment-elliptical-arc-shallow.svg
@@ -0,0 +1,125 @@
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+   xmlns:cc="http://creativecommons.org/ns#"
+   xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+   xmlns:svg="http://www.w3.org/2000/svg"
+   xmlns="http://www.w3.org/2000/svg"
+   xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
+   xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
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+   width="16"
+   height="16.002623"
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diff --git a/share/icons/hicolor/scalable/actions/node-segment-elliptical-arc.svg b/share/icons/hicolor/scalable/actions/node-segment-elliptical-arc.svg
new file mode 100644
index 0000000000..60c120877d
--- /dev/null
+++ b/share/icons/hicolor/scalable/actions/node-segment-elliptical-arc.svg
@@ -0,0 +1,132 @@
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+       width="16"
+       height="16"
+       x="-31.299295"
+       y="-17.947935" />
+    <rect
+       y="-6.3165879"
+       x="-26.745646"
+       height="3.970665"
+       width="3.9574931"
+       id="use5745-8"
+       style="color:#000000;fill:#6464ff;fill-opacity:0.39215692;fill-rule:evenodd;stroke:#0000ff;stroke-width:1.00000036;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:0" />
+    <rect
+       y="-11.811461"
+       x="-19.674295"
+       height="3.970665"
+       width="3.9574931"
+       id="use5747-9"
+       style="color:#000000;fill:#6464ff;fill-opacity:0.39215692;fill-rule:evenodd;stroke:#0000ff;stroke-width:1.00000036;stroke-linecap:round;stroke-linejoin:round;stroke-miterlimit:0" />
+  </g>
+</svg>
diff --git a/share/ui/toolbar-node.ui b/share/ui/toolbar-node.ui
index f48308e340..edbb229ff0 100644
--- a/share/ui/toolbar-node.ui
+++ b/share/ui/toolbar-node.ui
@@ -271,6 +271,73 @@
         </child>
       </object>
     </child>
+    <child>
+      <object class="GtkButton" id="arc_btn">
+        <property name="focusable">True</property>
+        <property name="tooltip-text" translatable="yes">Make selected segments elliptical arcs</property>
+        <property name="has-frame">False</property>
+        <style>
+            <class name="priority2"/>
+        </style>
+        <child>
+          <object class="GtkImage">
+            <property name="icon-name">node-segment-elliptical-arc</property>
+          </object>
+        </child>
+      </object>
+    </child>
+    <child>
+      <object class="GtkSeparator">
+        <style>
+            <class name="priority2"/>
+        </style>
+      </object>
+    </child>
+    <child>
+      <object class="GtkButton" id="arc_shallow_btn">
+        <property name="focusable">True</property>
+        <property name="tooltip-text" translatable="yes">Make selected elliptical arc segments shallow</property>
+        <property name="has-frame">False</property>
+        <style>
+            <class name="priority2"/>
+        </style>
+        <child>
+          <object class="GtkImage">
+            <property name="icon-name">node-segment-elliptical-arc-shallow</property>
+          </object>
+        </child>
+      </object>
+    </child>
+    <child>
+      <object class="GtkButton" id="arc_bulge_btn">
+        <property name="focusable">True</property>
+        <property name="tooltip-text" translatable="yes">Make selected elliptical arc segments bulge</property>
+        <property name="has-frame">False</property>
+        <style>
+            <class name="priority2"/>
+        </style>
+        <child>
+          <object class="GtkImage">
+            <property name="icon-name">node-segment-elliptical-arc-bulge</property>
+          </object>
+        </child>
+      </object>
+    </child>
+    <child>
+      <object class="GtkButton" id="arc_flip_btn">
+        <property name="focusable">True</property>
+        <property name="tooltip-text" translatable="yes">Flip selected elliptical arc segments</property>
+        <property name="has-frame">False</property>
+        <style>
+            <class name="priority2"/>
+        </style>
+        <child>
+          <object class="GtkImage">
+            <property name="icon-name">node-segment-elliptical-arc-flip</property>
+          </object>
+        </child>
+      </object>
+    </child>
     <child>
       <object class="GtkSeparator">
         <style>
diff --git a/src/helper/geom.cpp b/src/helper/geom.cpp
index 54d88aa791..e467c93d79 100644
--- a/src/helper/geom.cpp
+++ b/src/helper/geom.cpp
@@ -544,6 +544,46 @@ bool pathvs_have_nonempty_overlap(Geom::PathVector const &a, Geom::PathVector co
     return false;
 }
 
+/**
+ * Converts all segments in all paths to Geom::LineSegment or Geom::HLineSegment or
+ * Geom::VLineSegment or Geom::CubicBezier or Geom::EllipticalArc.
+ */
+Geom::PathVector pathv_to_linear_and_cubic_beziers_and_arcs(Geom::PathVector const &pathv)
+{
+    Geom::PathVector output;
+
+    for (const auto &pit : pathv) {
+        output.push_back(Geom::Path());
+        output.back().setStitching(true);
+        output.back().start(pit.initialPoint());
+
+        for (Geom::Path::const_iterator cit = pit.begin(); cit != pit.end_open(); ++cit) {
+            if (is_straight_curve(*cit)) {
+                Geom::LineSegment l(cit->initialPoint(), cit->finalPoint());
+                output.back().append(l);
+            } else {
+                Geom::EllipticalArc const *arc = dynamic_cast<Geom::EllipticalArc const *>(&*cit);
+                if (arc) {
+                    output.back().append(arc->duplicate());
+                } else {
+                    Geom::BezierCurve const *curve = dynamic_cast<Geom::BezierCurve const *>(&*cit);
+                    if (curve && curve->order() == 3) {
+                        Geom::CubicBezier b((*curve)[0], (*curve)[1], (*curve)[2], (*curve)[3]);
+                        output.back().append(b);
+                    } else {
+                        // convert all other curve types to cubicbeziers
+                        Geom::Path cubicbezier_path = Geom::cubicbezierpath_from_sbasis(cit->toSBasis(), 0.1);
+                        cubicbezier_path.close(false);
+                        output.back().append(cubicbezier_path);
+                    }
+                }
+            }
+        }
+        output.back().close(pit.closed());
+    }
+    return output;
+}
+
 /**
  * Checks whether the filled region defined by pathvector @a a and fill rule @a fill_rule
  * completely contains pathvector @a b.
diff --git a/src/helper/geom.h b/src/helper/geom.h
index 6ad0319d81..4377375807 100644
--- a/src/helper/geom.h
+++ b/src/helper/geom.h
@@ -39,6 +39,7 @@ size_t count_path_curves(Geom::Path const &path);
 size_t count_pathvector_degenerations(Geom::PathVector const &pathv );
 size_t count_path_degenerations(Geom::Path const &path);
 bool pointInTriangle(Geom::Point const &p, Geom::Point const &p1, Geom::Point const &p2, Geom::Point const &p3);
+Geom::PathVector pathv_to_linear_and_cubic_beziers_and_arcs(Geom::PathVector const &pathv);
 Geom::PathVector pathv_to_linear_and_cubic_beziers( Geom::PathVector const &pathv );
 Geom::PathVector pathv_to_linear( Geom::PathVector const &pathv, double maxdisp );
 Geom::PathVector pathv_to_cubicbezier( Geom::PathVector const &pathv, bool nolines);
diff --git a/src/ui/tool/curve-drag-point.cpp b/src/ui/tool/curve-drag-point.cpp
index 99944c75e6..2d55591b9b 100644
--- a/src/ui/tool/curve-drag-point.cpp
+++ b/src/ui/tool/curve-drag-point.cpp
@@ -23,6 +23,7 @@ namespace UI {
 
 bool CurveDragPoint::_drags_stroke = false;
 bool CurveDragPoint::_segment_was_degenerate = false;
+bool CurveDragPoint::_can_drag = true;
 
 CurveDragPoint::CurveDragPoint(PathManipulator &pm) :
     ControlPoint(pm._multi_path_manipulator._path_data.node_data.desktop, Geom::Point(), SP_ANCHOR_CENTER,
@@ -49,6 +50,15 @@ bool CurveDragPoint::grabbed(MotionEvent const &/*event*/)
     _pm._selection.hideTransformHandles();
     NodeList::iterator second = first.next();
 
+    _can_drag = true;
+
+    if (!first->arc_rx()->isDegenerate() && !first->arc_ry()->isDegenerate()) {
+        // This is an arc node
+        // TODO implement dragging of elliptical arc nodes
+        _can_drag = false;
+        return false;
+    }
+
     // move the handles to 1/3 the length of the segment for line segments
     if (first->front()->isDegenerate() && second->back()->isDegenerate()) {
         _segment_was_degenerate = true;
@@ -72,6 +82,10 @@ void CurveDragPoint::dragged(Geom::Point &new_pos, MotionEvent const &event)
     if (!first || !first.next()) return;
     NodeList::iterator second = first.next();
 
+    if (!_can_drag) {
+        return;
+    }
+
     // special cancel handling - retract handles when if the segment was degenerate
     if (_is_drag_cancelled(event) && _segment_was_degenerate) {
         first->front()->retract();
diff --git a/src/ui/tool/curve-drag-point.h b/src/ui/tool/curve-drag-point.h
index ada9fd2b7b..2bcdceb249 100644
--- a/src/ui/tool/curve-drag-point.h
+++ b/src/ui/tool/curve-drag-point.h
@@ -54,6 +54,7 @@ private:
 
     static bool _drags_stroke;
     static bool _segment_was_degenerate;
+    static bool _can_drag;
     static Geom::Point _stroke_drag_origin;
     void _insertNode(bool take_selection);
 };
diff --git a/src/ui/tool/multi-path-manipulator.cpp b/src/ui/tool/multi-path-manipulator.cpp
index 448c802d85..d0b8a7a876 100644
--- a/src/ui/tool/multi-path-manipulator.cpp
+++ b/src/ui/tool/multi-path-manipulator.cpp
@@ -317,11 +317,41 @@ void MultiPathManipulator::setSegmentType(SegmentType type)
 {
     if (_selection.empty()) return;
     invokeForAll(&PathManipulator::setSegmentType, type);
-    if (type == SEGMENT_STRAIGHT) {
-        _done(_("Straighten segments"));
+    switch (type) {
+        case SEGMENT_STRAIGHT:
+            _done(_("Straighten segments"));
+            break;
+        case SEGMENT_CUBIC_BEZIER:
+            _done(_("Make segments curves"));
+            break;
+        case SEGMENT_ELLIPTICAL_ARC:
+            _done(_("Make segments arcs"));
+            break;
+        default:
+            g_error("Unknown segment type");
+    }
+}
+
+void MultiPathManipulator::setArcSegmentLarge(bool large)
+{
+    if (_selection.empty()) {
+        return;
+    }
+    invokeForAll(&PathManipulator::setArcSegmentLarge, large);
+    if (large) {
+        _done(_("Make arc segments bulge"));
     } else {
-        _done(_("Make segments curves"));
+        _done(_("Make arc segments shallow"));
+    }
+}
+
+void MultiPathManipulator::toggleArcSegmentSweep()
+{
+    if (_selection.empty()) {
+        return;
     }
+    invokeForAll(&PathManipulator::toggleArcSegmentSweep);
+    _done(_("Flip arc segments"));
 }
 
 void MultiPathManipulator::insertNodes()
diff --git a/src/ui/tool/multi-path-manipulator.h b/src/ui/tool/multi-path-manipulator.h
index 2c3ac8aa61..aa082da3a1 100644
--- a/src/ui/tool/multi-path-manipulator.h
+++ b/src/ui/tool/multi-path-manipulator.h
@@ -53,6 +53,9 @@ public:
     void setNodeType(NodeType t);
     void setSegmentType(SegmentType t);
 
+    void setArcSegmentLarge(bool large);
+    void toggleArcSegmentSweep();
+
     void insertNodesAtExtrema(ExtremumType extremum);
     void insertNodes();
     void insertNode(Geom::Point pt);
diff --git a/src/ui/tool/node-types.h b/src/ui/tool/node-types.h
index bad6a5c52c..1cd98a3eea 100644
--- a/src/ui/tool/node-types.h
+++ b/src/ui/tool/node-types.h
@@ -29,7 +29,8 @@ enum NodeType {
 /** Types of segments supported in the node tool. */
 enum SegmentType {
     SEGMENT_STRAIGHT, ///< Straight linear segment
-    SEGMENT_CUBIC_BEZIER ///< Bezier curve with two control points
+    SEGMENT_CUBIC_BEZIER, ///< Bezier curve with two control points
+    SEGMENT_ELLIPTICAL_ARC ///< Eliptical arc (two radii, rotation, size flag, direction flag)
 };
 
 enum class AlignTargetNode {
diff --git a/src/ui/tool/node.cpp b/src/ui/tool/node.cpp
index 34e7e07711..14dee031e1 100644
--- a/src/ui/tool/node.cpp
+++ b/src/ui/tool/node.cpp
@@ -179,6 +179,7 @@ Handle::Handle(NodeSharedData const &data, Geom::Point const &initial_pos, Node
     , _handle_line(make_canvasitem<CanvasItemCurve>(data.handle_line_group))
     , _parent(parent)
     , _degenerate(true)
+    , _offset(Geom::Point()) // Start with 0 offset
 {
     setVisible(false);
 }
@@ -247,8 +248,8 @@ void Handle::move(Geom::Point const &new_pos)
 
     if (_parent->type() == NODE_SMOOTH && Node::_is_line_segment(_parent, node_away)) {
         // restrict movement to the line joining the nodes
-        Geom::Point direction = _parent->position() - node_away->position();
-        Geom::Point delta = new_pos - _parent->position();
+        Geom::Point direction = _parent->position() + _offset - node_away->position();
+        Geom::Point delta = new_pos - _parent->position() + _offset;
         // project the relative position on the direction line
         Geom::Coord direction_length = Geom::L2sq(direction);
         Geom::Point new_delta;
@@ -277,7 +278,7 @@ void Handle::move(Geom::Point const &new_pos)
         } break;
         case NODE_SYMMETRIC:
             // for symmetric nodes, place the other handle on the opposite side
-            other->setRelativePos(-(new_pos - _parent->position()));
+            other->setRelativePos(-(new_pos - _parent->position() + _offset));
             break;
         default:
             break;
@@ -292,10 +293,10 @@ void Handle::move(Geom::Point const &new_pos)
 void Handle::setPosition(Geom::Point const &p)
 {
     ControlPoint::setPosition(p);
-    _handle_line->set_coords(_parent->position(), position());
+    _handle_line->set_coords(_parent->position() + _offset, position());
 
     // update degeneration info and visibility
-    if (Geom::are_near(position(), _parent->position()))
+    if (Geom::are_near(position(), _parent->position() + _offset))
         _degenerate = true;
     else
         _degenerate = false;
@@ -307,6 +308,16 @@ void Handle::setPosition(Geom::Point const &p)
     }
 }
 
+/** Set the offset between the parent node and the origin */
+void Handle::setOffset(Geom::Point const &offset)
+{
+    _offset = offset;
+    _handle_line->set_coords(_parent->position() + _offset, position());
+}
+
+/** Set the length of the handle, if the handle is degenerate then
+    the function returns without changing the handle position as
+    it cannot determine the desired direction of the handle */
 void Handle::setLength(double len)
 {
     if (isDegenerate())
@@ -315,11 +326,33 @@ void Handle::setLength(double len)
     setRelativePos(dir * len);
 }
 
-void Handle::retract()
+/** Set the angle of the handle, if the handle is degenerate then
+    the function returns without changing the handle position as
+    it is not possible to set the orientation of a zero length line */
+void Handle::setAngle(Geom::Angle a)
+{
+    if (isDegenerate()) {
+        return;
+    }
+    setRelativePos(Geom::Point::polar(a, length()));
+}
+
+/** Set the angle and the length of the handle by moving the handle position
+    unlike Handle::setLength and Handle::setAngle, this function works for
+    degenerate handles as both the desired length and angle are known*/
+void Handle::setAngleAndLength(Geom::Angle a, double len)
 {
-    move(_parent->position());
+    // Degenerate case can be handled by setting the handle relative position
+    // to be any vector of non-zero length. A unit vector is used here.
+    if (isDegenerate()) {
+        setRelativePos(Geom::Point(0, 1));
+    }
+    setAngle(a);
+    setLength(len);
 }
 
+void Handle::retract() { move(_parent->position() + _offset); }
+
 void Handle::setDirection(Geom::Point const &from, Geom::Point const &to)
 {
     setDirection(to - from);
@@ -551,6 +584,7 @@ void Handle::dragged(Geom::Point &new_pos, MotionEvent const &event)
     if (_pm()._isBSpline() && !mod_shift(event) && !mod_ctrl(event)) {
         new_pos = _last_drag_origin();
     }
+    _parent->updateArcHandleConstriants(this);
     _pm().update();
 }
 
@@ -753,6 +787,10 @@ Node::Node(NodeSharedData const &data, Geom::Point const &initial_pos)
                              *data.selection, data.node_group)
     , _front(data, initial_pos, this)
     , _back(data, initial_pos, this)
+    , _arc_rx(data, initial_pos, this)
+    , _arc_ry(data, initial_pos, this)
+    , _arc_large(true)
+    , _arc_sweep(false)
     , _type(NODE_CUSP)
     , _handles_shown(false)
 {
@@ -791,6 +829,57 @@ Node *Node::_prev()
     }
 }
 
+/** Update constrained arc handles given a new constraint.
+    This is used to keep the arc radius handles at right angles
+    @param constraint Pointer to the handle that was forced to a new position.
+        If the constraint is anything other than _arc_rx or _arc_ry then this function does nothing */
+void Node::updateArcHandleConstriants(Handle *constraint)
+{
+    Handle *updateTarget = NULL;
+    Geom::Angle rotation = 0.0;
+    // Check which handle moved and set the update target and rotation
+    if (constraint == &_arc_rx) {
+        updateTarget = &_arc_ry;
+        rotation = Geom::rad_from_deg(90.0);
+    } else if (constraint == &_arc_ry) {
+        updateTarget = &_arc_rx;
+        rotation = Geom::rad_from_deg(-90.0);
+    } else {
+        return;
+    }
+    // Calculate the new position and move the constrained handle (updateTarget)
+    Geom::Angle newAngle = constraint->angle() + rotation;
+    Geom::Coord newLength = updateTarget->length();
+    Geom::Point newPos = Geom::Point::polar(newAngle, newLength);
+    updateTarget->setRelativePos(newPos);
+}
+
+/** Move the arc handles so that their origin is half way along the line between the nodes */
+void Node::moveArcHandles(Geom::Point lineBetweenNodes, double lenX, double lenY, Geom::Angle rotX, Geom::Angle rotY)
+{
+    // Calculate the mid point between the two nodes, put the origin of the handles there.
+    // This usually changes the length and angle of the handle lines
+    Geom::Point midPointOffset = lineBetweenNodes / 2.0;
+    _arc_rx.setOffset(midPointOffset);
+    _arc_ry.setOffset(midPointOffset);
+
+    _arc_rx.setPosition(position());
+    _arc_ry.setPosition(position());
+
+    // Apply the stored angle and length
+    _arc_rx.setAngleAndLength(rotX, lenX);
+    _arc_ry.setAngleAndLength(rotY, lenY);
+}
+
+/** Retract this node's handles for controling arcs */
+void Node::retractArcHandles()
+{
+    _arc_rx.setOffset(Geom::Point());
+    _arc_ry.setOffset(Geom::Point());
+    _arc_rx.retract();
+    _arc_ry.retract();
+}
+
 void Node::move(Geom::Point const &new_pos)
 {
     // move handles when the node moves.
@@ -811,13 +900,50 @@ void Node::move(Geom::Point const &new_pos)
         nextNodeWeight = _pm()._bsplineHandlePosition(nextNode->back());
     }
 
+    // Save the lengths and angles of the two arc handles to apply again after the node is moved.
+    double lenX, lenY;
+    Geom::Angle rotX, rotY;
+    lenX = _arc_rx.length();
+    lenY = _arc_ry.length();
+    rotX = _arc_rx.angle();
+    rotY = _arc_ry.angle();
+
     // Save original position for post-processing
     _unfixed_pos = std::optional<Geom::Point>(position());
 
     setPosition(new_pos);
+
+    // _front and _back are translated with the node to which they belong.
+    // This means that if they were degenrate then they are still degenerate.
     _front.setPosition(_front.position() + delta);
     _back.setPosition(_back.position() + delta);
 
+    // For arc manipulation handles, the position relative to their parent nodes
+    // may change as the node moves. For this reason, the degenerate case must be
+    // handled as a special case.
+    if (nextNode) { // Must have a next node for this to be an arc segment
+        if (_arc_rx.isDegenerate() || _arc_ry.isDegenerate()) {
+            retractArcHandles();
+        } else {
+            moveArcHandles(nextNode->position() - position(), lenX, lenY, rotX, rotY);
+        }
+    }
+    // If this is the end of an arc segment then the arc data for prevNode needs updating
+    if (prevNode) {
+        if (prevNode->arc_rx()->isDegenerate() || prevNode->arc_ry()->isDegenerate()) {
+            prevNode->retractArcHandles();
+        } else {
+            // In this case, the parent node for the arc handles hasn't moved,
+            // for this reason, we didn't need to save the length and rotation earlier,
+            // we can get the length and rotation now.
+            lenX = prevNode->arc_rx()->length();
+            lenY = prevNode->arc_ry()->length();
+            rotX = prevNode->arc_rx()->angle();
+            rotY = prevNode->arc_ry()->angle();
+            prevNode->moveArcHandles(n->position() - prevNode->position(), lenX, lenY, rotX, rotY);
+        }
+    }
+
     // move the affected handles. First the node ones, later the adjoining ones.
     if (_pm()._isBSpline()) {
         _front.setPosition(_pm()._bsplineHandleReposition(this->front(), nodeWeight));
@@ -849,6 +975,14 @@ void Node::transform(Geom::Affine const &m)
         nextNodeWeight = _pm()._bsplineHandlePosition(nextNode->back());
     }
 
+    // Save the lengths and angles of the two arc handles to apply again after the node is moved.
+    double lenX, lenY;
+    Geom::Angle rotX, rotY;
+    lenX = _arc_rx.length();
+    lenY = _arc_ry.length();
+    rotX = _arc_rx.angle();
+    rotY = _arc_ry.angle();
+
     // Save original position for post-processing
     _unfixed_pos = std::optional<Geom::Point>(position());
 
@@ -856,6 +990,14 @@ void Node::transform(Geom::Affine const &m)
     _front.setPosition(_front.position() * m);
     _back.setPosition(_back.position() * m);
 
+    if (nextNode) {
+        if (_arc_rx.isDegenerate() || _arc_ry.isDegenerate()) {
+            retractArcHandles();
+        } else {
+            moveArcHandles(nextNode->position() - position(), lenX, lenY, rotX, rotY);
+        }
+    }
+
     // move the involved handles. First the node ones, later the adjoining ones.
     if (_pm()._isBSpline()) {
         _front.setPosition(_pm()._bsplineHandleReposition(this->front(), nodeWeight));
@@ -969,6 +1111,12 @@ void Node::showHandles(bool v)
     if (!_back.isDegenerate()) {
         _back.setVisible(v);
     }
+    if (!_arc_rx.isDegenerate()) {
+        _arc_rx.setVisible(v);
+    }
+    if (!_arc_ry.isDegenerate()) {
+        _arc_ry.setVisible(v);
+    }
 }
 
 void Node::updateHandles()
@@ -977,6 +1125,8 @@ void Node::updateHandles()
 
     _front._handleControlStyling();
     _back._handleControlStyling();
+    _arc_rx._handleControlStyling();
+    _arc_ry._handleControlStyling();
 }
 
 void Node::setType(NodeType type, bool update_handles)
@@ -1559,6 +1709,18 @@ Inkscape::SnapCandidatePoint Node::snapCandidatePoint()
     return SnapCandidatePoint(position(), _snapSourceType(), _snapTargetType());
 }
 
+Geom::EllipticalArc Node::getEllipticalArc()
+{
+    // Must have a next node for this to be an arc
+    if (not _next()) {
+        return Geom::EllipticalArc();
+    }
+    Geom::Point r = Geom::Point(_arc_rx.length(), _arc_ry.length());
+    Geom::Coord rot = _arc_rx.angle();
+    // Create an arc and return it
+    return Geom::EllipticalArc(position(), r, rot, _arc_large, _arc_sweep, _next()->position());
+}
+
 Handle *Node::handleToward(Node *to)
 {
     if (_next() == to) {
@@ -1576,7 +1738,7 @@ Node *Node::nodeToward(Handle *dir)
     if (front() == dir) {
         return _next();
     }
-    if (back() == dir) {
+    if ((back() == dir) || (arc_rx() == dir) || (arc_ry() == dir)) {
         return _prev();
     }
     g_error("Node::nodeToward(): handle is not a child of this node!");
@@ -1600,7 +1762,7 @@ Node *Node::nodeAwayFrom(Handle *h)
     if (front() == h) {
         return _prev();
     }
-    if (back() == h) {
+    if ((back() == h) || (arc_rx() == h) || (arc_ry() == h)) {
         return _next();
     }
     g_error("Node::nodeAwayFrom(): handle is not a child of this node!");
@@ -1726,10 +1888,14 @@ bool Node::_is_line_segment(Node *first, Node *second)
 {
     if (!first || !second)
         return false;
-    if (first->_next() == second)
-        return first->_front.isDegenerate() && second->_back.isDegenerate();
-    if (second->_next() == first)
-        return second->_front.isDegenerate() && first->_back.isDegenerate();
+    if (first->_next() == second) {
+        return first->_front.isDegenerate() && second->_back.isDegenerate() && first->_arc_rx.isDegenerate() &&
+               first->_arc_ry.isDegenerate();
+    }
+    if (second->_next() == first) {
+        return second->_front.isDegenerate() && first->_back.isDegenerate() && second->_arc_rx.isDegenerate() &&
+               second->_arc_ry.isDegenerate();
+    }
     return false;
 }
 
diff --git a/src/ui/tool/node.h b/src/ui/tool/node.h
index 792d5991bd..e49b5a0cef 100644
--- a/src/ui/tool/node.h
+++ b/src/ui/tool/node.h
@@ -21,6 +21,8 @@
 #include <2geom/point.h>
 #include <boost/noncopyable.hpp>
 
+#include <2geom/elliptical-arc.h>
+
 #include "snap-candidate.h"
 #include "ui/tool/selectable-control-point.h"
 #include "ui/tool/node-types.h"
@@ -65,6 +67,7 @@ public:
 
     inline Geom::Point relativePos() const;
     inline double length() const;
+    inline Geom::Angle angle() const;
     bool isDegenerate() const { return _degenerate; } // True if the handle is retracted, i.e. has zero length.
 
     void setVisible(bool) override;
@@ -72,7 +75,10 @@ public:
 
     void setPosition(Geom::Point const &p) override;
     inline void setRelativePos(Geom::Point const &p);
+    void setOffset(Geom::Point const &offset); // Needs override?
     void setLength(double len);
+    void setAngle(Geom::Angle a);
+    void setAngleAndLength(Geom::Angle a, double len);
     void retract();
     void setDirection(Geom::Point const &from, Geom::Point const &to);
     void setDirection(Geom::Point const &dir);
@@ -105,6 +111,8 @@ private:
     CanvasItemPtr<CanvasItemCurve> _handle_line;
     bool _degenerate; // True if the handle is retracted, i.e. has zero length. This is used often internally so it makes sense to cache this
 
+    Geom::Point _offset;
+
     /**
      * Control point of a cubic Bezier curve in a path.
      *
@@ -152,6 +160,10 @@ public:
     void showHandles(bool v);
 
     void updateHandles();
+    void updateArcHandleConstriants(Handle *constraint);
+    void moveArcHandles(Geom::Point lineBetweenNodes, double lenX, double lenY, Geom::Angle rotX, Geom::Angle rotY);
+
+    void retractArcHandles();
 
     /**
      * Pick the best type for this node, based on the position of its handles.
@@ -163,6 +175,11 @@ public:
     bool isEndNode() const;
     Handle *front() { return &_front; }
     Handle *back()  { return &_back;  }
+    Handle *arc_rx() { return &_arc_rx; }
+    Handle *arc_ry() { return &_arc_ry; }
+    bool *arc_large() { return &_arc_large; }
+    bool *arc_sweep() { return &_arc_sweep; }
+    Geom::EllipticalArc getEllipticalArc();
 
     /**
      * Gets the handle that faces the given adjacent node.
@@ -242,6 +259,11 @@ private:
     // as a line segment
     Handle _front; ///< Node handle in the backward direction of the path
     Handle _back; ///< Node handle in the forward direction of the path
+    // The arc control points and flags relate to an arc starting at this node and ending at the next node
+    Handle _arc_rx; ///< Handle for controling the x radius and rotation of the elipse (in eliptical arc mode)
+    Handle _arc_ry; ///< Handle for controling the y radius and rotation of the elipse (in eliptical arc mode)
+    bool _arc_large; ///< Flag that determines if arc mode is shallow or bulge
+    bool _arc_sweep; ///< Flag that determines the direction of an arc's sweep
     NodeType _type; ///< Type of node - cusp, smooth...
     bool _handles_shown;
 
@@ -458,14 +480,17 @@ private:
 
 // define inline Handle funcs after definition of Node
 inline Geom::Point Handle::relativePos() const {
-    return position() - _parent->position();
+    return position() - (_parent->position() + _offset);
 }
 inline void Handle::setRelativePos(Geom::Point const &p) {
-    setPosition(_parent->position() + p);
+    setPosition(_parent->position() + _offset + p);
 }
 inline double Handle::length() const {
     return relativePos().length();
 }
+inline Geom::Angle Handle::angle() const {
+    return Geom::Angle(position() - _parent->position() - _offset);
+}
 inline PathManipulator &Handle::_pm() {
     return _parent->_pm();
 }
diff --git a/src/ui/tool/path-manipulator.cpp b/src/ui/tool/path-manipulator.cpp
index fe70deeec4..b4475dcee8 100644
--- a/src/ui/tool/path-manipulator.cpp
+++ b/src/ui/tool/path-manipulator.cpp
@@ -911,27 +911,111 @@ void PathManipulator::reverseSubpaths(bool selected_only)
 void PathManipulator::setSegmentType(SegmentType type)
 {
     if (_selection.empty()) return;
+
+    // Changing arc segments to cubic beziers can introduce new nodes.
+    // For these non-trivial updates we record the changes required and apply them at the end.
+    std::vector<std::tuple<NodeList::iterator, Geom::Path>> nontrivial_replacements;
+
     for (auto & _subpath : _subpaths) {
         for (NodeList::iterator j = _subpath->begin(); j != _subpath->end(); ++j) {
             NodeList::iterator k = j.next();
             if (!(k && j->selected() && k->selected())) continue;
             switch (type) {
             case SEGMENT_STRAIGHT:
-                if (j->front()->isDegenerate() && k->back()->isDegenerate())
+                if ((j->front()->isDegenerate() && k->back()->isDegenerate()) &&
+                    (j->arc_rx()->isDegenerate() && j->arc_ry()->isDegenerate()))
                     break;
                 j->front()->move(j->position());
                 k->back()->move(k->position());
+                j->retractArcHandles();
                 break;
             case SEGMENT_CUBIC_BEZIER:
-                if (!j->front()->isDegenerate() || !k->back()->isDegenerate())
+                if (!j->front()->isDegenerate() || !k->back()->isDegenerate()) {
+                    // Already a cubic bezier
+                    break;
+                }
+                if (!j->arc_rx()->isDegenerate() || !j->arc_ry()->isDegenerate()) {
+                    // This is an elliptical arc that is being converted to a cubic bezier
+                    // Generate the bezier path and use it to replace the current segment
+                    Geom::Path cubicbezier_path =
+                        Geom::cubicbezierpath_from_sbasis(j->getEllipticalArc().toSBasis(), 0.1);
+                    std::tuple<NodeList::iterator, Geom::Path> replacement = std::make_tuple(j, cubicbezier_path);
+                    nontrivial_replacements.push_back(replacement);
                     break;
+                }
+
                 // move both handles to 1/3 of the line
                 j->front()->move(j->position() + (k->position() - j->position()) / 3);
                 k->back()->move(k->position() + (j->position() - k->position()) / 3);
+                j->retractArcHandles();
+                break;
+            case SEGMENT_ELLIPTICAL_ARC:
+                if (!(j->front()->isDegenerate() && k->back()->isDegenerate())) {
+                    j->front()->move(j->position());
+                    k->back()->move(k->position());
+                }
+
+                if (j->arc_rx()->isDegenerate() && j->arc_ry()->isDegenerate()) {
+                    Geom::Point midPointOffset = ((k->position() - j->position()) / 2);
+                    Geom::Point handleOrigin = j->position() + midPointOffset;
+
+                    j->arc_rx()->setOffset(midPointOffset);
+                    j->arc_ry()->setOffset(midPointOffset);
+                    j->arc_rx()->move(j->position() + ((k->position() - handleOrigin) / 2));
+                    j->updateArcHandleConstriants(j->arc_rx());
+                }
                 break;
             }
         }
     }
+
+    for (auto r : nontrivial_replacements) {
+        auto j = std::get<0>(r);
+        auto cubicbezier_path = std::get<1>(r);
+        replaceSegmentWithPath(j, cubicbezier_path);
+    }
+}
+
+/** Set the large flag on selected arcs */
+void PathManipulator::setArcSegmentLarge(bool large)
+{
+    if (_selection.empty()) {
+        return;
+    }
+    for (auto i : _subpaths) {
+        for (NodeList::iterator j = i->begin(); j != i->end(); ++j) {
+            NodeList::iterator k = j.next();
+            if (!(k && j->selected() && k->selected())) {
+                continue;
+            }
+            // This code executes for every selected segment
+            if (!j->arc_rx()->isDegenerate() || !j->arc_ry()->isDegenerate()) {
+                // This code executes for every selected ARC segment
+                *(j->arc_large()) = large;
+            }
+        }
+    }
+}
+
+/** Set the sweep flag on selected arcs */
+void PathManipulator::toggleArcSegmentSweep()
+{
+    if (_selection.empty()) {
+        return;
+    }
+    for (auto i : _subpaths) {
+        for (NodeList::iterator j = i->begin(); j != i->end(); ++j) {
+            NodeList::iterator k = j.next();
+            if (!(k && j->selected() && k->selected())) {
+                continue;
+            }
+            // This code executes for every selected segment
+            if (!j->arc_rx()->isDegenerate() || !j->arc_ry()->isDegenerate()) {
+                // This code executes for every selected ARC segment
+                *(j->arc_sweep()) = !*j->arc_sweep();
+            }
+        }
+    }
 }
 
 void PathManipulator::scaleHandle(Node *n, int which, int dir, bool pixel)
@@ -1191,6 +1275,72 @@ NodeList::iterator PathManipulator::extremeNode(NodeList::iterator origin, bool
     return match;
 }
 
+/** Replace a segment with a path.
+ * @param segment The segment to replace
+ * @param newPath The path to insert in place of 'segment'
+ *
+ * Currently, newPath must be composed only of cubic beziers, the caller must
+ * ensure that the path only contains cubic beziers (until other segments are
+ * implemented in this function)  */
+void PathManipulator::replaceSegmentWithPath(NodeList::iterator segment, Geom::Path newPath)
+{
+    if (!segment) {
+        throw std::invalid_argument("Invalid iterator for replacement");
+    }
+    NodeList &list = NodeList::get(segment);
+    NodeList::iterator insert_at = segment.next();
+    if (!insert_at) {
+        throw std::invalid_argument("Replace after last node in open path");
+    }
+
+    // Retract all handles relating to this segment
+    segment->retractArcHandles();
+    segment->front()->retract();
+
+    // Path is to be inserted in reverse order
+    Geom::Path reversedPath = newPath.reversed();
+
+    // Iterate over the path
+    for (Geom::Path::iterator i = reversedPath.begin(); i != reversedPath.end(); ++i) {
+        const Geom::Curve &thisCurve = *i;
+
+        // Try converting to a bezier
+        const Geom::BezierCurve *bezier = dynamic_cast<const Geom::BezierCurve *>(&thisCurve);
+        if (bezier) {
+            // Check order of bezier (currently only cubic beziers are supported)
+            if (bezier->order() == 3) {
+                auto bez = *bezier;
+                if (std::next(i) == reversedPath.end()) {
+                    (*insert_at).back()->setPosition((*bezier)[1]);
+                    insert_at.prev()->front()->setPosition((*bezier)[2]);
+                } else {
+                    // Create one new node
+                    Node *newNode = new Node(_multi_path_manipulator._path_data.node_data, bezier->finalPoint());
+                    newNode->front()->setPosition((*bezier)[2]);
+                    auto p = (*bezier)[1];
+                    auto b = insert_at->back();
+                    b->setPosition(p);
+                    // All new nodes are smooth
+                    newNode->setType(NODE_SMOOTH, false);
+
+                    // Insert new node
+                    list.insert(insert_at, newNode);
+                    // Move along to next node
+                    insert_at--;
+                }
+            } else {
+                throw std::invalid_argument(
+                    "Only cubic bezier curves are implemented in PathManipulator::replaceSegment."
+                    " newPath contains beziers with order!=3.");
+            }
+        } else {
+            // Not a bezier
+            throw std::invalid_argument("Only cubic bezier curves are implemented in PathManipulator::replaceSegment."
+                                        " newPath contains non-bezier segments.");
+        }
+    }
+}
+
 /* Called when a process updates the path in-situe */
 void PathManipulator::updatePath()
 {
@@ -1264,8 +1414,9 @@ void PathManipulator::_createControlPointsFromGeometry()
     if (_is_bspline) {
         pathv = pathv_to_cubicbezier(_spcurve, false);
     } else {
-        pathv = pathv_to_linear_and_cubic_beziers(_spcurve);
+        pathv = pathv_to_linear_and_cubic_beziers_and_arcs(_spcurve);
     }
+
     for (Geom::PathVector::iterator i = pathv.begin(); i != pathv.end(); ) {
         // NOTE: this utilizes the fact that Geom::PathVector is an std::vector.
         // When we erase an element, the next one slides into position,
@@ -1309,15 +1460,20 @@ void PathManipulator::_createControlPointsFromGeometry()
                 subpath->push_back(current_node);
             }
             // if this is a bezier segment, move handles appropriately
-            // TODO: I don't know why the dynamic cast below doesn't want to work
-            //       when I replace BezierCurve with CubicBezier. Might be a bug
-            //       somewhere in pathv_to_linear_and_cubic_beziers
-            Geom::BezierCurve const *bezier = dynamic_cast<Geom::BezierCurve const*>(&*cit);
-            if (bezier && bezier->order() == 3)
-            {
+            Geom::BezierCurve const *bezier = dynamic_cast<Geom::BezierCurve const *>(&*cit);
+            if (bezier && bezier->order() == 3) {
                 previous_node->front()->setPosition((*bezier)[1]);
                 current_node ->back() ->setPosition((*bezier)[2]);
             }
+            Geom::EllipticalArc const *arc = dynamic_cast<Geom::EllipticalArc const *>(&*cit);
+            if (arc) {
+                Geom::Coord angleX = arc->rotationAngle();
+                Geom::Coord angleY = angleX + Geom::rad_from_deg(90);
+                previous_node->moveArcHandles(current_node->position() - previous_node->position(), arc->ray(Geom::X),
+                                              arc->ray(Geom::Y), angleX, angleY);
+                *(previous_node->arc_large()) = arc->largeArc();
+                *(previous_node->arc_sweep()) = arc->sweep();
+            }
             previous_node = current_node;
         }
         // If the path is closed, make the list cyclic
@@ -1455,8 +1611,9 @@ void PathManipulator::_createGeometryFromControlPoints(bool alert_LPE)
         }
         if (subpath->closed()) {
             // Here we link the last and first node if the path is closed.
-            // If the last segment is Bezier, we add it.
-            if (!prev->front()->isDegenerate() || !subpath->begin()->back()->isDegenerate()) {
+            // If the last segment is Bezier or arc, we add it.
+            if (!prev->front()->isDegenerate() || !subpath->begin()->back()->isDegenerate() ||
+                !prev->arc_rx()->isDegenerate() || !prev->arc_ry()->isDegenerate()) {
                 build_segment(builder, prev.ptr(), subpath->begin().ptr());
             }
             // if that segment is linear, we just call closePath().
@@ -1508,17 +1665,23 @@ void PathManipulator::_createGeometryFromControlPoints(bool alert_LPE)
  * @relates PathManipulator */
 void build_segment(Geom::PathBuilder &builder, Node *prev_node, Node *cur_node)
 {
-    if (cur_node->back()->isDegenerate() && prev_node->front()->isDegenerate())
-    {
-        // NOTE: It seems like the renderer cannot correctly handle vline / hline segments,
-        // and trying to display a path using them results in funny artifacts.
-        builder.lineTo(cur_node->position());
+    if (prev_node->arc_rx()->isDegenerate() || prev_node->arc_ry()->isDegenerate()) {
+        // This is not an eliptical arc, check if it is a straight line or bezier
+        if (cur_node->back()->isDegenerate() && prev_node->front()->isDegenerate()) {
+            // NOTE: It seems like the renderer cannot correctly handle vline / hline segments,
+            // and trying to display a path using them results in funny artifacts.
+            builder.lineTo(cur_node->position());
+        } else {
+            // this is a bezier segment
+            builder.curveTo(prev_node->front()->position(), cur_node->back()->position(), cur_node->position());
+        }
     } else {
-        // this is a bezier segment
-        builder.curveTo(
-            prev_node->front()->position(),
-            cur_node->back()->position(),
-            cur_node->position());
+        // This is an eliptical arc, get the x and y set by the xy handle
+        Geom::Coord rx = prev_node->arc_rx()->length();
+        Geom::Coord ry = prev_node->arc_ry()->length();
+        Geom::Angle rot = prev_node->arc_rx()->angle();
+
+        builder.arcTo(rx, ry, rot, *prev_node->arc_large(), *prev_node->arc_sweep(), cur_node->position());
     }
 }
 
diff --git a/src/ui/tool/path-manipulator.h b/src/ui/tool/path-manipulator.h
index 80957428ea..7eabf78be3 100644
--- a/src/ui/tool/path-manipulator.h
+++ b/src/ui/tool/path-manipulator.h
@@ -17,6 +17,7 @@
 #include <2geom/pathvector.h>
 #include <2geom/path-sink.h>
 #include <2geom/affine.h>
+#include <2geom/sbasis-to-bezier.h>
 #include "ui/tool/node.h"
 #include "ui/tool/manipulator.h"
 
@@ -97,6 +98,9 @@ public:
     void reverseSubpaths(bool selected_only);
     void setSegmentType(SegmentType);
 
+    void setArcSegmentLarge(bool large);
+    void toggleArcSegmentSweep();
+
     void scaleHandle(Node *n, int which, int dir, bool pixel);
     void rotateHandle(Node *n, int which, int dir, bool pixel);
 
@@ -114,6 +118,7 @@ public:
     NodeList::iterator subdivideSegment(NodeList::iterator after, double t);
     NodeList::iterator extremeNode(NodeList::iterator origin, bool search_selected,
     bool search_unselected, bool closest);
+    void replaceSegmentWithPath(NodeList::iterator segment, Geom::Path newPath);
 
     int _bsplineGetSteps() const;
     // this is necessary for Tab-selection in MultiPathManipulator
diff --git a/src/ui/toolbar/node-toolbar.cpp b/src/ui/toolbar/node-toolbar.cpp
index 12dd786d44..dad4a1c1a9 100644
--- a/src/ui/toolbar/node-toolbar.cpp
+++ b/src/ui/toolbar/node-toolbar.cpp
@@ -108,6 +108,10 @@ NodeToolbar::NodeToolbar(Glib::RefPtr<Gtk::Builder> const &builder)
         {"auto_btn", &NodeToolbar::edit_auto},
         {"line_btn", &NodeToolbar::edit_toline},
         {"curve_btn", &NodeToolbar::edit_tocurve},
+        {"arc_btn", &NodeToolbar::edit_toarc},
+        {"arc_shallow_btn", &NodeToolbar::edit_arc_shallow},
+        {"arc_bulge_btn", &NodeToolbar::edit_arc_bulge},
+        {"arc_flip_btn", &NodeToolbar::edit_arc_flip},
     };
 
     for (auto const &button_info : button_mapping) {
@@ -438,6 +442,34 @@ void NodeToolbar::edit_tocurve()
     }
 }
 
+void NodeToolbar::edit_toarc()
+{
+    if (auto nt = get_node_tool()) {
+        nt->_multipath->setSegmentType(SEGMENT_ELLIPTICAL_ARC);
+    }
+}
+
+void NodeToolbar::edit_arc_shallow()
+{
+    if (auto nt = get_node_tool()) {
+        nt->_multipath->setArcSegmentLarge(false);
+    }
+}
+
+void NodeToolbar::edit_arc_bulge()
+{
+    if (auto nt = get_node_tool()) {
+        nt->_multipath->setArcSegmentLarge(true);
+    }
+}
+
+void NodeToolbar::edit_arc_flip()
+{
+    if (auto nt = get_node_tool()) {
+        nt->_multipath->toggleArcSegmentSweep();
+    }
+}
+
 void NodeToolbar::on_pref_toggled(Gtk::ToggleButton *item, Glib::ustring const &path)
 {
     Preferences::get()->setBool(path, item->get_active());
diff --git a/src/ui/toolbar/node-toolbar.h b/src/ui/toolbar/node-toolbar.h
index 1518dc7061..3676486a93 100644
--- a/src/ui/toolbar/node-toolbar.h
+++ b/src/ui/toolbar/node-toolbar.h
@@ -114,6 +114,10 @@ private:
     void edit_auto();
     void edit_toline();
     void edit_tocurve();
+    void edit_toarc();
+    void edit_arc_shallow();
+    void edit_arc_bulge();
+    void edit_arc_flip();
     void on_pref_toggled(Gtk::ToggleButton *item, Glib::ustring const &path);
 
     void setup_derived_spin_button(UI::Widget::SpinButton &btn, Glib::ustring const &name);
-- 
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