Getting instancing working.

example/lib/example_animation.dart

@@ -35,7 +35,7 @@ class _ExampleAnimationState extends State<ExampleAnimation> {
 
         // The artboard is the root of the animation and gets drawn in the
         // Rive widget.
-        final artboard = file.mainArtboard;
+        final artboard = file.mainArtboard.instance();
         // Add a controller to play back a known animation on the main/default
         // artboard. We store a reference to it so we can toggle playback.
         artboard.addController(_controller = SimpleAnimation('idle'));

lib/src/core/core.dart

@@ -1,5 +1,6 @@
 import 'dart:collection';
 
+import 'package:flutter/foundation.dart';
 import 'package:rive/src/rive_core/runtime/exceptions/rive_format_error_exception.dart';
 export 'package:rive/src/animation_list.dart';
 export 'package:rive/src/state_machine_components.dart';
@@ -37,6 +38,21 @@ abstract class Core<T extends CoreContext> {
   bool import(ImportStack stack) => true;
 
   bool validate() => true;
+
+  /// Make a duplicate of this core object, N.B. that all properties including
+  /// id's are copied.
+  K? clone<K extends Core>() {
+    var object = context.makeCoreInstance(coreType);
+    object?.copy(this);
+    return object is K ? object : null;
+  }
+
+  /// Copies property values, currently doesn't trigger change callbacks. It's
+  /// meant to be a helper for [clone].
+  @protected
+  void copy(covariant Core source) {
+    id = source.id;
+  }
 }
 
 class InternalCoreHelper {

lib/src/generated/animation/animation_base.dart

@@ -34,4 +34,9 @@ abstract class AnimationBase<T extends CoreContext> extends Core<T> {
   }
 
   void nameChanged(String from, String to);
+
+  @override
+  void copy(AnimationBase source) {
+    _name = source._name;
+  }
 }

lib/src/generated/animation/animation_state_base.dart

@@ -41,4 +41,10 @@ abstract class AnimationStateBase extends LayerState {
   }
 
   void animationIdChanged(int from, int to);
+
+  @override
+  void copy(AnimationStateBase source) {
+    super.copy(source);
+    _animationId = source._animationId;
+  }
 }

lib/src/generated/animation/blend_animation_1d_base.dart

@@ -34,4 +34,10 @@ abstract class BlendAnimation1DBase extends BlendAnimation {
   }
 
   void valueChanged(double from, double to);
+
+  @override
+  void copy(BlendAnimation1DBase source) {
+    super.copy(source);
+    _value = source._value;
+  }
 }

lib/src/generated/animation/blend_animation_base.dart

@@ -35,4 +35,9 @@ abstract class BlendAnimationBase<T extends CoreContext> extends Core<T> {
   }
 
   void animationIdChanged(int from, int to);
+
+  @override
+  void copy(BlendAnimationBase source) {
+    _animationId = source._animationId;
+  }
 }

lib/src/generated/animation/blend_animation_direct_base.dart

@@ -36,4 +36,10 @@ abstract class BlendAnimationDirectBase extends BlendAnimation {
   }
 
   void inputIdChanged(int from, int to);
+
+  @override
+  void copy(BlendAnimationDirectBase source) {
+    super.copy(source);
+    _inputId = source._inputId;
+  }
 }

lib/src/generated/animation/blend_state_1d_base.dart

@@ -43,4 +43,10 @@ abstract class BlendState1DBase extends BlendState<BlendAnimation1D> {
   }
 
   void inputIdChanged(int from, int to);
+
+  @override
+  void copy(BlendState1DBase source) {
+    super.copy(source);
+    _inputId = source._inputId;
+  }
 }

lib/src/generated/animation/blend_state_transition_base.dart

@@ -41,4 +41,10 @@ abstract class BlendStateTransitionBase extends StateTransition {
   }
 
   void exitBlendAnimationIdChanged(int from, int to);
+
+  @override
+  void copy(BlendStateTransitionBase source) {
+    super.copy(source);
+    _exitBlendAnimationId = source._exitBlendAnimationId;
+  }
 }

lib/src/generated/animation/cubic_interpolator_base.dart

@@ -98,4 +98,12 @@ abstract class CubicInterpolatorBase<T extends CoreContext> extends Core<T> {
   }
 
   void y2Changed(double from, double to);
+
+  @override
+  void copy(CubicInterpolatorBase source) {
+    _x1 = source._x1;
+    _y1 = source._y1;
+    _x2 = source._x2;
+    _y2 = source._y2;
+  }
 }

lib/src/generated/animation/keyed_object_base.dart

@@ -34,4 +34,9 @@ abstract class KeyedObjectBase<T extends CoreContext> extends Core<T> {
   }
 
   void objectIdChanged(int from, int to);
+
+  @override
+  void copy(KeyedObjectBase source) {
+    _objectId = source._objectId;
+  }
 }

lib/src/generated/animation/keyed_property_base.dart

@@ -35,4 +35,9 @@ abstract class KeyedPropertyBase<T extends CoreContext> extends Core<T> {
   }
 
   void propertyKeyChanged(int from, int to);
+
+  @override
+  void copy(KeyedPropertyBase source) {
+    _propertyKey = source._propertyKey;
+  }
 }

lib/src/generated/animation/keyframe_base.dart

@@ -85,4 +85,11 @@ abstract class KeyFrameBase<T extends CoreContext> extends Core<T> {
   }
 
   void interpolatorIdChanged(int from, int to);
+
+  @override
+  void copy(KeyFrameBase source) {
+    _frame = source._frame;
+    _interpolationType = source._interpolationType;
+    _interpolatorId = source._interpolatorId;
+  }
 }

lib/src/generated/animation/keyframe_color_base.dart

@@ -33,4 +33,10 @@ abstract class KeyFrameColorBase extends KeyFrame {
   }
 
   void valueChanged(int from, int to);
+
+  @override
+  void copy(KeyFrameColorBase source) {
+    super.copy(source);
+    _value = source._value;
+  }
 }

lib/src/generated/animation/keyframe_double_base.dart

@@ -33,4 +33,10 @@ abstract class KeyFrameDoubleBase extends KeyFrame {
   }
 
   void valueChanged(double from, double to);
+
+  @override
+  void copy(KeyFrameDoubleBase source) {
+    super.copy(source);
+    _value = source._value;
+  }
 }

lib/src/generated/animation/keyframe_id_base.dart

@@ -33,4 +33,10 @@ abstract class KeyFrameIdBase extends KeyFrame {
   }
 
   void valueChanged(int from, int to);
+
+  @override
+  void copy(KeyFrameIdBase source) {
+    super.copy(source);
+    _value = source._value;
+  }
 }

lib/src/generated/animation/linear_animation_base.dart

@@ -182,4 +182,16 @@ abstract class LinearAnimationBase extends Animation {
   }
 
   void enableWorkAreaChanged(bool from, bool to);
+
+  @override
+  void copy(LinearAnimationBase source) {
+    super.copy(source);
+    _fps = source._fps;
+    _duration = source._duration;
+    _speed = source._speed;
+    _loopValue = source._loopValue;
+    _workStart = source._workStart;
+    _workEnd = source._workEnd;
+    _enableWorkArea = source._enableWorkArea;
+  }
 }

lib/src/generated/animation/state_machine_bool_base.dart

@@ -38,4 +38,10 @@ abstract class StateMachineBoolBase extends StateMachineInput {
   }
 
   void valueChanged(bool from, bool to);
+
+  @override
+  void copy(StateMachineBoolBase source) {
+    super.copy(source);
+    _value = source._value;
+  }
 }

lib/src/generated/animation/state_machine_component_base.dart

@@ -36,4 +36,9 @@ abstract class StateMachineComponentBase<T extends CoreContext>
   }
 
   void nameChanged(String from, String to);
+
+  @override
+  void copy(StateMachineComponentBase source) {
+    _name = source._name;
+  }
 }

lib/src/generated/animation/state_machine_number_base.dart

@@ -38,4 +38,10 @@ abstract class StateMachineNumberBase extends StateMachineInput {
   }
 
   void valueChanged(double from, double to);
+
+  @override
+  void copy(StateMachineNumberBase source) {
+    super.copy(source);
+    _value = source._value;
+  }
 }

lib/src/generated/animation/state_transition_base.dart

@@ -109,4 +109,13 @@ abstract class StateTransitionBase extends StateMachineLayerComponent {
   }
 
   void exitTimeChanged(int from, int to);
+
+  @override
+  void copy(StateTransitionBase source) {
+    super.copy(source);
+    _stateToId = source._stateToId;
+    _flags = source._flags;
+    _duration = source._duration;
+    _exitTime = source._exitTime;
+  }
 }

lib/src/generated/animation/transition_condition_base.dart

@@ -34,4 +34,9 @@ abstract class TransitionConditionBase<T extends CoreContext> extends Core<T> {
   }
 
   void inputIdChanged(int from, int to);
+
+  @override
+  void copy(TransitionConditionBase source) {
+    _inputId = source._inputId;
+  }
 }

lib/src/generated/animation/transition_number_condition_base.dart

@@ -38,4 +38,10 @@ abstract class TransitionNumberConditionBase extends TransitionValueCondition {
   }
 
   void valueChanged(double from, double to);
+
+  @override
+  void copy(TransitionNumberConditionBase source) {
+    super.copy(source);
+    _value = source._value;
+  }
 }

lib/src/generated/animation/transition_value_condition_base.dart

@@ -36,4 +36,10 @@ abstract class TransitionValueConditionBase extends TransitionCondition {
   }
 
   void opValueChanged(int from, int to);
+
+  @override
+  void copy(TransitionValueConditionBase source) {
+    super.copy(source);
+    _opValue = source._opValue;
+  }
 }

lib/src/generated/artboard_base.dart

@@ -159,4 +159,15 @@ abstract class ArtboardBase extends ContainerComponent {
   }
 
   void originYChanged(double from, double to);
+
+  @override
+  void copy(ArtboardBase source) {
+    super.copy(source);
+    _width = source._width;
+    _height = source._height;
+    _x = source._x;
+    _y = source._y;
+    _originX = source._originX;
+    _originY = source._originY;
+  }
 }

lib/src/generated/bones/bone_base.dart

@@ -41,4 +41,10 @@ abstract class BoneBase extends SkeletalComponent {
   }
 
   void lengthChanged(double from, double to);
+
+  @override
+  void copy(BoneBase source) {
+    super.copy(source);
+    _length = source._length;
+  }
 }

lib/src/generated/bones/cubic_weight_base.dart

@@ -100,4 +100,13 @@ abstract class CubicWeightBase extends Weight {
   }
 
   void outIndicesChanged(int from, int to);
+
+  @override
+  void copy(CubicWeightBase source) {
+    super.copy(source);
+    _inValues = source._inValues;
+    _inIndices = source._inIndices;
+    _outValues = source._outValues;
+    _outIndices = source._outIndices;
+  }
 }

lib/src/generated/bones/root_bone_base.dart

@@ -69,4 +69,11 @@ abstract class RootBoneBase extends Bone {
   }
 
   void yChanged(double from, double to);
+
+  @override
+  void copy(RootBoneBase source) {
+    super.copy(source);
+    _x = source._x;
+    _y = source._y;
+  }
 }

lib/src/generated/bones/skin_base.dart

@@ -156,4 +156,15 @@ abstract class SkinBase extends ContainerComponent {
   }
 
   void tyChanged(double from, double to);
+
+  @override
+  void copy(SkinBase source) {
+    super.copy(source);
+    _xx = source._xx;
+    _yx = source._yx;
+    _xy = source._xy;
+    _yy = source._yy;
+    _tx = source._tx;
+    _ty = source._ty;
+  }
 }

lib/src/generated/bones/tendon_base.dart

@@ -178,4 +178,16 @@ abstract class TendonBase extends Component {
   }
 
   void tyChanged(double from, double to);
+
+  @override
+  void copy(TendonBase source) {
+    super.copy(source);
+    _boneId = source._boneId;
+    _xx = source._xx;
+    _yx = source._yx;
+    _xy = source._xy;
+    _yy = source._yy;
+    _tx = source._tx;
+    _ty = source._ty;
+  }
 }

lib/src/generated/bones/weight_base.dart

@@ -54,4 +54,11 @@ abstract class WeightBase extends Component {
   }
 
   void indicesChanged(int from, int to);
+
+  @override
+  void copy(WeightBase source) {
+    super.copy(source);
+    _values = source._values;
+    _indices = source._indices;
+  }
 }

lib/src/generated/component_base.dart

@@ -58,4 +58,10 @@ abstract class ComponentBase<T extends CoreContext> extends Core<T> {
   }
 
   void parentIdChanged(int from, int to);
+
+  @override
+  void copy(ComponentBase source) {
+    _name = source._name;
+    _parentId = source._parentId;
+  }
 }

lib/src/generated/draw_rules_base.dart

@@ -40,4 +40,10 @@ abstract class DrawRulesBase extends ContainerComponent {
   }
 
   void drawTargetIdChanged(int from, int to);
+
+  @override
+  void copy(DrawRulesBase source) {
+    super.copy(source);
+    _drawTargetId = source._drawTargetId;
+  }
 }

lib/src/generated/draw_target_base.dart

@@ -59,4 +59,11 @@ abstract class DrawTargetBase extends Component {
   }
 
   void placementValueChanged(int from, int to);
+
+  @override
+  void copy(DrawTargetBase source) {
+    super.copy(source);
+    _drawableId = source._drawableId;
+    _placementValue = source._placementValue;
+  }
 }

lib/src/generated/drawable_base.dart

@@ -65,4 +65,11 @@ abstract class DrawableBase extends Node {
   }
 
   void drawableFlagsChanged(int from, int to);
+
+  @override
+  void copy(DrawableBase source) {
+    super.copy(source);
+    _blendModeValue = source._blendModeValue;
+    _drawableFlags = source._drawableFlags;
+  }
 }

lib/src/generated/node_base.dart

@@ -65,4 +65,11 @@ abstract class NodeBase extends TransformComponent {
   }
 
   void yChanged(double from, double to);
+
+  @override
+  void copy(NodeBase source) {
+    super.copy(source);
+    _x = source._x;
+    _y = source._y;
+  }
 }

lib/src/generated/shapes/clipping_shape_base.dart

@@ -81,4 +81,12 @@ abstract class ClippingShapeBase extends Component {
   }
 
   void isVisibleChanged(bool from, bool to);
+
+  @override
+  void copy(ClippingShapeBase source) {
+    super.copy(source);
+    _sourceId = source._sourceId;
+    _fillRule = source._fillRule;
+    _isVisible = source._isVisible;
+  }
 }

lib/src/generated/shapes/cubic_asymmetric_vertex_base.dart

@@ -93,4 +93,12 @@ abstract class CubicAsymmetricVertexBase extends CubicVertex {
   }
 
   void outDistanceChanged(double from, double to);
+
+  @override
+  void copy(CubicAsymmetricVertexBase source) {
+    super.copy(source);
+    _rotation = source._rotation;
+    _inDistance = source._inDistance;
+    _outDistance = source._outDistance;
+  }
 }

lib/src/generated/shapes/cubic_detached_vertex_base.dart

@@ -118,4 +118,13 @@ abstract class CubicDetachedVertexBase extends CubicVertex {
   }
 
   void outDistanceChanged(double from, double to);
+
+  @override
+  void copy(CubicDetachedVertexBase source) {
+    super.copy(source);
+    _inRotation = source._inRotation;
+    _inDistance = source._inDistance;
+    _outRotation = source._outRotation;
+    _outDistance = source._outDistance;
+  }
 }

lib/src/generated/shapes/cubic_mirrored_vertex_base.dart

@@ -68,4 +68,11 @@ abstract class CubicMirroredVertexBase extends CubicVertex {
   }
 
   void distanceChanged(double from, double to);
+
+  @override
+  void copy(CubicMirroredVertexBase source) {
+    super.copy(source);
+    _rotation = source._rotation;
+    _distance = source._distance;
+  }
 }

lib/src/generated/shapes/paint/fill_base.dart

@@ -39,4 +39,10 @@ abstract class FillBase extends ShapePaint {
   }
 
   void fillRuleChanged(int from, int to);
+
+  @override
+  void copy(FillBase source) {
+    super.copy(source);
+    _fillRule = source._fillRule;
+  }
 }

lib/src/generated/shapes/paint/gradient_stop_base.dart

@@ -55,4 +55,11 @@ abstract class GradientStopBase extends Component {
   }
 
   void positionChanged(double from, double to);
+
+  @override
+  void copy(GradientStopBase source) {
+    super.copy(source);
+    _colorValue = source._colorValue;
+    _position = source._position;
+  }
 }

lib/src/generated/shapes/paint/linear_gradient_base.dart

@@ -126,4 +126,14 @@ abstract class LinearGradientBase extends ContainerComponent {
   }
 
   void opacityChanged(double from, double to);
+
+  @override
+  void copy(LinearGradientBase source) {
+    super.copy(source);
+    _startX = source._startX;
+    _startY = source._startY;
+    _endX = source._endX;
+    _endY = source._endY;
+    _opacity = source._opacity;
+  }
 }

lib/src/generated/shapes/paint/shape_paint_base.dart

@@ -38,4 +38,10 @@ abstract class ShapePaintBase extends ContainerComponent {
   }
 
   void isVisibleChanged(bool from, bool to);
+
+  @override
+  void copy(ShapePaintBase source) {
+    super.copy(source);
+    _isVisible = source._isVisible;
+  }
 }

lib/src/generated/shapes/paint/solid_color_base.dart

@@ -33,4 +33,10 @@ abstract class SolidColorBase extends Component {
   }
 
   void colorValueChanged(int from, int to);
+
+  @override
+  void copy(SolidColorBase source) {
+    super.copy(source);
+    _colorValue = source._colorValue;
+  }
 }

lib/src/generated/shapes/paint/stroke_base.dart

@@ -107,4 +107,13 @@ abstract class StrokeBase extends ShapePaint {
   }
 
   void transformAffectsStrokeChanged(bool from, bool to);
+
+  @override
+  void copy(StrokeBase source) {
+    super.copy(source);
+    _thickness = source._thickness;
+    _cap = source._cap;
+    _join = source._join;
+    _transformAffectsStroke = source._transformAffectsStroke;
+  }
 }

lib/src/generated/shapes/paint/trim_path_base.dart

@@ -99,4 +99,13 @@ abstract class TrimPathBase extends Component {
   }
 
   void modeValueChanged(int from, int to);
+
+  @override
+  void copy(TrimPathBase source) {
+    super.copy(source);
+    _start = source._start;
+    _end = source._end;
+    _offset = source._offset;
+    _modeValue = source._modeValue;
+  }
 }

lib/src/generated/shapes/parametric_path_base.dart

@@ -118,4 +118,13 @@ abstract class ParametricPathBase extends Path {
   }
 
   void originYChanged(double from, double to);
+
+  @override
+  void copy(ParametricPathBase source) {
+    super.copy(source);
+    _width = source._width;
+    _height = source._height;
+    _originX = source._originX;
+    _originY = source._originY;
+  }
 }

lib/src/generated/shapes/path_base.dart

@@ -41,4 +41,10 @@ abstract class PathBase extends Node {
   }
 
   void pathFlagsChanged(int from, int to);
+
+  @override
+  void copy(PathBase source) {
+    super.copy(source);
+    _pathFlags = source._pathFlags;
+  }
 }

lib/src/generated/shapes/path_vertex_base.dart

@@ -63,4 +63,11 @@ abstract class PathVertexBase extends ContainerComponent {
   }
 
   void yChanged(double from, double to);
+
+  @override
+  void copy(PathVertexBase source) {
+    super.copy(source);
+    _x = source._x;
+    _y = source._y;
+  }
 }

lib/src/generated/shapes/points_path_base.dart

@@ -46,4 +46,10 @@ abstract class PointsPathBase extends Path {
   }
 
   void isClosedChanged(bool from, bool to);
+
+  @override
+  void copy(PointsPathBase source) {
+    super.copy(source);
+    _isClosed = source._isClosed;
+  }
 }

lib/src/generated/shapes/polygon_base.dart

@@ -72,4 +72,11 @@ abstract class PolygonBase extends ParametricPath {
   }
 
   void cornerRadiusChanged(double from, double to);
+
+  @override
+  void copy(PolygonBase source) {
+    super.copy(source);
+    _points = source._points;
+    _cornerRadius = source._cornerRadius;
+  }
 }

lib/src/generated/shapes/rectangle_base.dart

@@ -148,4 +148,14 @@ abstract class RectangleBase extends ParametricPath {
   }
 
   void cornerRadiusBRChanged(double from, double to);
+
+  @override
+  void copy(RectangleBase source) {
+    super.copy(source);
+    _linkCornerRadius = source._linkCornerRadius;
+    _cornerRadiusTL = source._cornerRadiusTL;
+    _cornerRadiusTR = source._cornerRadiusTR;
+    _cornerRadiusBL = source._cornerRadiusBL;
+    _cornerRadiusBR = source._cornerRadiusBR;
+  }
 }

lib/src/generated/shapes/star_base.dart

@@ -50,4 +50,10 @@ abstract class StarBase extends Polygon {
   }
 
   void innerRadiusChanged(double from, double to);
+
+  @override
+  void copy(StarBase source) {
+    super.copy(source);
+    _innerRadius = source._innerRadius;
+  }
 }

lib/src/generated/shapes/straight_vertex_base.dart

@@ -43,4 +43,10 @@ abstract class StraightVertexBase extends PathVertex<Weight> {
   }
 
   void radiusChanged(double from, double to);
+
+  @override
+  void copy(StraightVertexBase source) {
+    super.copy(source);
+    _radius = source._radius;
+  }
 }

lib/src/generated/transform_component_base.dart

@@ -104,4 +104,13 @@ abstract class TransformComponentBase extends ContainerComponent {
   }
 
   void opacityChanged(double from, double to);
+
+  @override
+  void copy(TransformComponentBase source) {
+    super.copy(source);
+    _rotation = source._rotation;
+    _scaleX = source._scaleX;
+    _scaleY = source._scaleY;
+    _opacity = source._opacity;
+  }
 }

lib/src/rive_core/artboard.dart

@@ -87,6 +87,7 @@ class Artboard extends ArtboardBase with ShapePaintContainer {
         }
         step++;
       }
+
       return true;
     }
     return didUpdate;
@@ -411,4 +412,15 @@ class Artboard extends ArtboardBase with ShapePaintContainer {
 
     _firstDrawable = lastDrawable;
   }
+
+  /// Make a copy of the this [Artboard]. This duplicates internal objects in
+  /// the hierarchy but shares animations and state machines with the original
+  /// [Artboard] it is instanced from. Instance an [Artboard] when you want to
+  /// show it muliptle times on the screen in the different states.
+  Artboard instance() {
+    /// Intentionally not implemented in the editor, must be overridden in
+    /// runtime version of the artboard.
+    throw UnsupportedError(
+        'Instancing the artboard in the editor isn\'t supported');
+  }
 }

lib/src/rive_core/shapes/polygon.dart

@@ -15,6 +15,8 @@ class Polygon extends PolygonBase {
 
   @override
   List<PathVertex<Weight>> get vertices {
+    double ox = -originX * width + width / 2;
+    double oy = -originY * height + height / 2;
     var vertexList = <PathVertex<Weight>>[];
     var halfWidth = width / 2;
     var halfHeight = height / 2;
@@ -22,8 +24,8 @@ class Polygon extends PolygonBase {
     var inc = 2 * pi / points;
     for (int i = 0; i < points; i++) {
       vertexList.add(StraightVertex.procedural()
-        ..x = cos(angle) * halfWidth
-        ..y = sin(angle) * halfHeight
+        ..x = ox + cos(angle) * halfWidth
+        ..y = oy + sin(angle) * halfHeight
         ..radius = cornerRadius);
       angle += inc;
     }

lib/src/rive_core/shapes/shape.dart

@@ -30,7 +30,9 @@ class Shape extends ShapeBase with ShapePaintContainer {
 
   bool addPath(Path path) {
     paintChanged();
-    return paths.add(path);
+    var added = paths.add(path);
+
+    return added;
   }
 
   void _markComposerDirty() {

lib/src/rive_core/shapes/star.dart

@@ -12,6 +12,9 @@ class Star extends StarBase {
 
   @override
   List<PathVertex<Weight>> get vertices {
+    double ox = -originX * width + width / 2;
+    double oy = -originY * height + height / 2;
+
     var actualPoints = points * 2;
     var vertexList = <PathVertex<Weight>>[];
     var halfWidth = width / 2;
@@ -22,13 +25,13 @@ class Star extends StarBase {
     var inc = 2 * pi / actualPoints;
     while (vertexList.length < actualPoints) {
       vertexList.add(StraightVertex.procedural()
-        ..x = cos(angle) * halfWidth
-        ..y = sin(angle) * halfHeight
+        ..x = ox + cos(angle) * halfWidth
+        ..y = oy + sin(angle) * halfHeight
         ..radius = cornerRadius);
       angle += inc;
       vertexList.add(StraightVertex.procedural()
-        ..x = cos(angle) * innerHalfWidth
-        ..y = sin(angle) * innerHalfHeight
+        ..x = ox + cos(angle) * innerHalfWidth
+        ..y = oy + sin(angle) * innerHalfHeight
         ..radius = cornerRadius);
       angle += inc;
     }

lib/src/runtime_artboard.dart

@@ -106,4 +106,32 @@ class RuntimeArtboard extends Artboard implements CoreContext {
   void markNeedsAdvance() {
     _redraw.notify();
   }
+
+  Artboard? instance() {
+    var artboard = RuntimeArtboard();
+    artboard.copy(this);
+    artboard._objects.add(artboard);
+    // First copy the objects ensuring onAddedDirty can later find them in the
+    // _objects list.
+    for (final object in _objects.skip(1)) {
+      Core? clone = object?.clone();
+      artboard._objects.add(clone);
+    }
+
+    // Then run the onAddedDirty loop.
+    for (final object in artboard.objects.skip(1)) {
+      if (object is Component &&
+          object.parentId == ComponentBase.parentIdInitialValue) {
+        object.parent = artboard;
+      }
+      object?.onAddedDirty();
+    }
+    for (final object in artboard.objects.toList(growable: false)) {
+      if (object == null) {
+        continue;
+      }
+      object.onAdded();
+    }
+    artboard.clean();
+  }
 }