Adding support for TransformConstraints.

lib/src/generated/constraints/transform_constraint_base.dart

@@ -0,0 +1,78 @@
+/// Core automatically generated
+/// lib/src/generated/constraints/transform_constraint_base.dart.
+/// Do not modify manually.
+
+import 'package:rive/src/generated/component_base.dart';
+import 'package:rive/src/generated/constraints/constraint_base.dart';
+import 'package:rive/src/generated/constraints/targeted_constraint_base.dart';
+import 'package:rive/src/rive_core/constraints/targeted_constraint.dart';
+
+abstract class TransformConstraintBase extends TargetedConstraint {
+  static const int typeKey = 83;
+  @override
+  int get coreType => TransformConstraintBase.typeKey;
+  @override
+  Set<int> get coreTypes => {
+        TransformConstraintBase.typeKey,
+        TargetedConstraintBase.typeKey,
+        ConstraintBase.typeKey,
+        ComponentBase.typeKey
+      };
+
+  /// --------------------------------------------------------------------------
+  /// SourceSpaceValue field with key 179.
+  static const int sourceSpaceValueInitialValue = 0;
+  int _sourceSpaceValue = sourceSpaceValueInitialValue;
+  static const int sourceSpaceValuePropertyKey = 179;
+
+  /// The source transform space.
+  int get sourceSpaceValue => _sourceSpaceValue;
+
+  /// Change the [_sourceSpaceValue] field value.
+  /// [sourceSpaceValueChanged] will be invoked only if the field's value has
+  /// changed.
+  set sourceSpaceValue(int value) {
+    if (_sourceSpaceValue == value) {
+      return;
+    }
+    int from = _sourceSpaceValue;
+    _sourceSpaceValue = value;
+    if (hasValidated) {
+      sourceSpaceValueChanged(from, value);
+    }
+  }
+
+  void sourceSpaceValueChanged(int from, int to);
+
+  /// --------------------------------------------------------------------------
+  /// DestSpaceValue field with key 180.
+  static const int destSpaceValueInitialValue = 0;
+  int _destSpaceValue = destSpaceValueInitialValue;
+  static const int destSpaceValuePropertyKey = 180;
+
+  /// The destination transform space.
+  int get destSpaceValue => _destSpaceValue;
+
+  /// Change the [_destSpaceValue] field value.
+  /// [destSpaceValueChanged] will be invoked only if the field's value has
+  /// changed.
+  set destSpaceValue(int value) {
+    if (_destSpaceValue == value) {
+      return;
+    }
+    int from = _destSpaceValue;
+    _destSpaceValue = value;
+    if (hasValidated) {
+      destSpaceValueChanged(from, value);
+    }
+  }
+
+  void destSpaceValueChanged(int from, int to);
+
+  @override
+  void copy(TransformConstraintBase source) {
+    super.copy(source);
+    _sourceSpaceValue = source._sourceSpaceValue;
+    _destSpaceValue = source._destSpaceValue;
+  }
+}

lib/src/generated/rive_core_context.dart

@@ -49,6 +49,7 @@ import 'package:rive/src/generated/constraints/constraint_base.dart';
 import 'package:rive/src/generated/constraints/distance_constraint_base.dart';
 import 'package:rive/src/generated/constraints/ik_constraint_base.dart';
 import 'package:rive/src/generated/constraints/targeted_constraint_base.dart';
+import 'package:rive/src/generated/constraints/transform_constraint_base.dart';
 import 'package:rive/src/generated/draw_rules_base.dart';
 import 'package:rive/src/generated/draw_target_base.dart';
 import 'package:rive/src/generated/drawable_base.dart';
@@ -113,6 +114,7 @@ import 'package:rive/src/rive_core/bones/tendon.dart';
 import 'package:rive/src/rive_core/bones/weight.dart';
 import 'package:rive/src/rive_core/constraints/distance_constraint.dart';
 import 'package:rive/src/rive_core/constraints/ik_constraint.dart';
+import 'package:rive/src/rive_core/constraints/transform_constraint.dart';
 import 'package:rive/src/rive_core/draw_rules.dart';
 import 'package:rive/src/rive_core/draw_target.dart';
 import 'package:rive/src/rive_core/node.dart';
@@ -146,6 +148,8 @@ class RiveCoreContext {
         return DistanceConstraint();
       case IKConstraintBase.typeKey:
         return IKConstraint();
+      case TransformConstraintBase.typeKey:
+        return TransformConstraint();
       case AnimationStateBase.typeKey:
         return AnimationState();
       case KeyedObjectBase.typeKey:
@@ -313,6 +317,16 @@ class RiveCoreContext {
           object.parentBoneCount = value;
         }
         break;
+      case TransformConstraintBase.sourceSpaceValuePropertyKey:
+        if (object is TransformConstraintBase && value is int) {
+          object.sourceSpaceValue = value;
+        }
+        break;
+      case TransformConstraintBase.destSpaceValuePropertyKey:
+        if (object is TransformConstraintBase && value is int) {
+          object.destSpaceValue = value;
+        }
+        break;
       case AnimationStateBase.animationIdPropertyKey:
         if (object is AnimationStateBase && value is int) {
           object.animationId = value;
@@ -933,6 +947,8 @@ class RiveCoreContext {
       case TargetedConstraintBase.targetIdPropertyKey:
       case DistanceConstraintBase.modeValuePropertyKey:
       case IKConstraintBase.parentBoneCountPropertyKey:
+      case TransformConstraintBase.sourceSpaceValuePropertyKey:
+      case TransformConstraintBase.destSpaceValuePropertyKey:
       case AnimationStateBase.animationIdPropertyKey:
       case KeyedObjectBase.objectIdPropertyKey:
       case BlendAnimationBase.animationIdPropertyKey:
@@ -1089,6 +1105,10 @@ class RiveCoreContext {
         return (object as DistanceConstraintBase).modeValue;
       case IKConstraintBase.parentBoneCountPropertyKey:
         return (object as IKConstraintBase).parentBoneCount;
+      case TransformConstraintBase.sourceSpaceValuePropertyKey:
+        return (object as TransformConstraintBase).sourceSpaceValue;
+      case TransformConstraintBase.destSpaceValuePropertyKey:
+        return (object as TransformConstraintBase).destSpaceValue;
       case AnimationStateBase.animationIdPropertyKey:
         return (object as AnimationStateBase).animationId;
       case KeyedObjectBase.objectIdPropertyKey:
@@ -1405,6 +1425,16 @@ class RiveCoreContext {
           object.parentBoneCount = value;
         }
         break;
+      case TransformConstraintBase.sourceSpaceValuePropertyKey:
+        if (object is TransformConstraintBase) {
+          object.sourceSpaceValue = value;
+        }
+        break;
+      case TransformConstraintBase.destSpaceValuePropertyKey:
+        if (object is TransformConstraintBase) {
+          object.destSpaceValue = value;
+        }
+        break;
       case AnimationStateBase.animationIdPropertyKey:
         if (object is AnimationStateBase) {
           object.animationId = value;

lib/src/rive_core/constraints/constraint.dart

@@ -1,3 +1,6 @@
+import 'package:rive/src/rive_core/artboard.dart';
+import 'package:rive/src/rive_core/component.dart';
+import 'package:rive/src/rive_core/math/mat2d.dart';
 import 'package:rive/src/generated/constraints/constraint_base.dart';
 import 'package:rive/src/rive_core/transform_component.dart';
 export 'package:rive/src/generated/constraints/constraint_base.dart';
@@ -29,4 +32,19 @@ abstract class Constraint extends ConstraintBase {
   void update(int dirt) {}
 
   void markConstraintDirty() => constrainedComponent?.markTransformDirty();
+
+  @override
+  void onDirty(int mask) => markConstraintDirty();
+}
+
+/// Get the parent's world transform. Takes into consideration when the parent
+/// is an artboard.
+Mat2D parentWorld(TransformComponent component) {
+  var parent = component.parent;
+  if (parent is Artboard) {
+    return parent.worldTransform;
+  } else if (parent is TransformComponent) {
+    return parent.worldTransform;
+  }
+  return Mat2D();
 }

lib/src/rive_core/constraints/distance_constraint.dart

@@ -3,6 +3,7 @@ import 'package:rive/src/generated/constraints/distance_constraint_base.dart';
 import 'package:rive/src/rive_core/transform_component.dart';
 export 'package:rive/src/generated/constraints/distance_constraint_base.dart';
 
+/// [DistanceConstraint]'s logical distancing method.
 enum DistanceConstraintMode { closer, further, exact }
 
 const _distanceEpsilon = 0.001;
@@ -57,7 +58,4 @@ class DistanceConstraint extends DistanceConstraintBase {
 
   DistanceConstraintMode get mode => DistanceConstraintMode.values[modeValue];
   set mode(DistanceConstraintMode value) => modeValue = value.index;
-
-  @override
-  bool validate() => super.validate() && parent is TransformComponent;
 }

lib/src/rive_core/constraints/ik_constraint.dart

@@ -1,6 +1,6 @@
 import 'dart:math';
-import 'package:rive/src/rive_core/artboard.dart';
 import 'package:rive/src/rive_core/bones/bone.dart';
+import 'package:rive/src/rive_core/constraints/constraint.dart';
 import 'package:rive/src/rive_core/math/mat2d.dart';
 import 'package:rive/src/rive_core/math/transform_components.dart';
 import 'package:rive/src/rive_core/math/vec2d.dart';
@@ -68,7 +68,6 @@ class IKConstraint extends IKConstraintBase {
     }
     // Now put them in FK order (top to bottom).
     for (final bone in bones.reversed) {
-      bone.addPeerConstraint(this);
       nextFKChain.add(_BoneChainLink(
         index: nextFKChain.length,
         bone: bone,
@@ -117,9 +116,9 @@ class IKConstraint extends IKConstraintBase {
     // Decompose the chain.
     for (final item in _fkChain) {
       var bone = item.bone;
-      Mat2D parentWorld = _parentWorld(bone);
+      Mat2D parentWorldTransform = parentWorld(bone);
 
-      Mat2D.invert(item.parentWorldInverse, parentWorld);
+      Mat2D.invert(item.parentWorldInverse, parentWorldTransform);
 
       var boneTransform = bone.transform;
       Mat2D.multiply(
@@ -145,7 +144,7 @@ class IKConstraint extends IKConstraintBase {
                 j < end;
                 j++) {
               var fk = _fkChain[j];
-              Mat2D.invert(fk.parentWorldInverse, _parentWorld(fk.bone));
+              Mat2D.invert(fk.parentWorldInverse, parentWorld(fk.bone));
             }
           }
           break;
@@ -249,7 +248,7 @@ class IKConstraint extends IKConstraintBase {
     _constrainRotation(firstChild, r2);
     if (firstChild != fk2) {
       var bone = fk2.bone;
-      Mat2D.multiply(bone.worldTransform, _parentWorld(bone), bone.transform);
+      Mat2D.multiply(bone.worldTransform, parentWorld(bone), bone.transform);
     }
 
     // Simple storage, need this for interpolation.
@@ -273,7 +272,7 @@ class _BoneChainLink {
 
 void _constrainRotation(_BoneChainLink link, double rotation) {
   var bone = link.bone;
-  Mat2D parentWorld = _parentWorld(bone);
+  Mat2D parentWorldTransform = parentWorld(bone);
   var boneTransform = bone.transform;
   if (rotation == 0) {
     Mat2D.setIdentity(boneTransform);
@@ -295,14 +294,5 @@ void _constrainRotation(_BoneChainLink link, double rotation) {
     boneTransform[2] = boneTransform[0] * skew + boneTransform[2];
     boneTransform[3] = boneTransform[1] * skew + boneTransform[3];
   }
-  Mat2D.multiply(bone.worldTransform, parentWorld, boneTransform);
-}
-
-Mat2D _parentWorld(TransformComponent component) {
-  var parent = component.parent;
-  if (parent is Artboard) {
-    return parent.worldTransform;
-  } else {
-    return (parent as TransformComponent).worldTransform;
-  }
+  Mat2D.multiply(bone.worldTransform, parentWorldTransform, boneTransform);
 }

lib/src/rive_core/constraints/transform_constraint.dart

@@ -0,0 +1,74 @@
+import 'dart:math';
+
+import 'package:rive/src/rive_core/constraints/constraint.dart';
+import 'package:rive/src/rive_core/math/mat2d.dart';
+import 'package:rive/src/rive_core/math/transform_components.dart';
+import 'package:rive/src/generated/constraints/transform_constraint_base.dart';
+import 'package:rive/src/rive_core/transform_component.dart';
+import 'package:rive/src/rive_core/transform_space.dart';
+export 'package:rive/src/generated/constraints/transform_constraint_base.dart';
+
+/// A constraint copies the transform from the target component to the
+/// constrained component in world or local space.
+class TransformConstraint extends TransformConstraintBase {
+  final TransformComponents componentsA = TransformComponents();
+  final TransformComponents componentsB = TransformComponents();
+
+  TransformSpace get destSpace => TransformSpace.values[destSpaceValue];
+  set destSpace(TransformSpace value) => destSpaceValue = value.index;
+
+  TransformSpace get sourceSpace => TransformSpace.values[sourceSpaceValue];
+  set sourceSpace(TransformSpace value) => sourceSpaceValue = value.index;
+
+  @override
+  void destSpaceValueChanged(int from, int to) => markConstraintDirty();
+
+  @override
+  void sourceSpaceValueChanged(int from, int to) => markConstraintDirty();
+
+  @override
+  void constrain(TransformComponent component) {
+    if (target == null) {
+      return;
+    }
+    var transformA = component.worldTransform;
+    var transformB = Mat2D.clone(target!.worldTransform);
+    if (sourceSpace == TransformSpace.local) {
+      var targetParentWorld = parentWorld(target!);
+
+      var inverse = Mat2D();
+      if (!Mat2D.invert(inverse, targetParentWorld)) {
+        return;
+      }
+      Mat2D.multiply(transformB, inverse, transformB);
+    }
+    if (destSpace == TransformSpace.local && component.parent != null) {
+      var targetParentWorld = parentWorld(component);
+      Mat2D.multiply(transformB, targetParentWorld, transformB);
+    }
+
+    Mat2D.decompose(transformA, componentsA);
+    Mat2D.decompose(transformB, componentsB);
+
+    var angleA = componentsA[4] % (pi * 2);
+    var angleB = componentsB[4] % (pi * 2);
+    var diff = angleB - angleA;
+    if (diff > pi) {
+      diff -= pi * 2;
+    } else if (diff < -pi) {
+      diff += pi * 2;
+    }
+
+    var t = strength;
+    var ti = 1 - t;
+
+    componentsB[4] = angleA + diff * t;
+    componentsB[0] = componentsA[0] * ti + componentsB[0] * t;
+    componentsB[1] = componentsA[1] * ti + componentsB[1] * t;
+    componentsB[2] = componentsA[2] * ti + componentsB[2] * t;
+    componentsB[3] = componentsA[3] * ti + componentsB[3] * t;
+    componentsB[5] = componentsA[5] * ti + componentsB[5] * t;
+
+    Mat2D.compose(component.worldTransform, componentsB);
+  }
+}

lib/src/rive_core/transform_component.dart

@@ -3,6 +3,7 @@ import 'package:rive/src/rive_core/component.dart';
 import 'package:rive/src/rive_core/component_dirt.dart';
 import 'package:rive/src/rive_core/constraints/constraint.dart';
 import 'package:rive/src/rive_core/constraints/ik_constraint.dart';
+import 'package:rive/src/rive_core/constraints/transform_constraint.dart';
 import 'package:rive/src/rive_core/container_component.dart';
 import 'package:rive/src/rive_core/draw_rules.dart';
 import 'package:rive/src/rive_core/drawable.dart';
@@ -165,6 +166,7 @@ abstract class TransformComponent extends TransformComponentBase {
         addDirt(ComponentDirt.clip, recurse: true);
 
         break;
+      case TransformConstraintBase.typeKey:
       case IKConstraintBase.typeKey:
       case DistanceConstraintBase.typeKey:
         _constraints.add(child as Constraint);
@@ -187,6 +189,7 @@ abstract class TransformComponent extends TransformComponentBase {
           addDirt(ComponentDirt.clip, recurse: true);
         }
         break;
+      case TransformConstraintBase.typeKey:
       case IKConstraintBase.typeKey:
       case DistanceConstraintBase.typeKey:
         _constraints.remove(child as Constraint);