[flutter] codegen now uses nullability info from spine-c ir-generator to make return and parameter types optional if necessary.

spine-flutter/codegen/package.json

@@ -3,7 +3,8 @@
   "type": "module",
   "scripts": {
     "format": "npx -y typescript-formatter -r **/*.ts",
-    "generate": "npx tsx src/index.ts"
+    "generate": "npx tsx src/index.ts",
+    "check": "npx biome check src && npx tsc --noEmit"
   },
   "dependencies": {
     "spine-c-codegen": "file:../../spine-c/codegen"

spine-flutter/codegen/src/dart-writer.ts

@@ -383,13 +383,13 @@ export class DartWriter {
 
 	private createGetter (method: CMethod, cType: CClassOrStruct, classType: 'concrete' | 'abstract' | 'interface', renamedMethod?: string): DartMember {
 		const propertyName = renamedMethod || this.extractPropertyName(method.name, cType.name);
-		const dartReturnType = this.toDartReturnType(method.returnType);
+		const dartReturnType = this.toDartReturnType(method.returnType, method.returnTypeNullable);
 
 		// Interface methods have no implementation (from spec)
 		let implementation = '';
 		if (classType !== 'interface') {
 			implementation = `final result = SpineBindings.bindings.${method.name}(_ptr);
-    ${this.generateReturnConversion(method.returnType, 'result')}`;
+    ${this.generateReturnConversion(method.returnType, 'result', method.returnTypeNullable)}`;
 		}
 
 		// Check if this is an override
@@ -446,7 +446,7 @@ export class DartWriter {
 
 	private createMethod (method: CMethod, cType: CClassOrStruct, classType: 'concrete' | 'abstract' | 'interface', renamedMethod?: string): DartMember {
 		let methodName = renamedMethod || this.toDartMethodName(method.name, cType.name);
-		const dartReturnType = this.toDartReturnType(method.returnType);
+		const dartReturnType = this.toDartReturnType(method.returnType, method.returnTypeNullable);
 
 		// Check if this is a static method
 		const isStatic = method.parameters.length === 0 ||
@@ -479,7 +479,7 @@ export class DartWriter {
 				implementation = `SpineBindings.bindings.${method.name}(${args});`;
 			} else {
 				implementation = `final result = SpineBindings.bindings.${method.name}(${args});
-    ${this.generateReturnConversion(method.returnType, 'result')}`;
+    ${this.generateReturnConversion(method.returnType, 'result', method.returnTypeNullable)}`;
 			}
 		}
 
@@ -824,11 +824,13 @@ ${declaration} {`;
 				const cClass = this.classMap.get(cElementType);
 
 				if (cClass && this.isAbstract(cClass)) {
-					// Use RTTI to determine concrete type for abstract classes
+					// Use RTTI to determine concrete type for abstract classes - handle null case
+					lines.push(`    if (buffer[index].address == 0) return null;`);
 					const rttiCode = this.generateRttiBasedInstantiation(dartElementType, 'buffer[index]', cClass);
 					lines.push(`    ${rttiCode}`);
 				} else {
-					lines.push(`    return ${dartElementType}.fromPointer(buffer[index]);`);
+					// For array elements, check if the pointer is null
+					lines.push(`    return buffer[index].address == 0 ? null : ${dartElementType}.fromPointer(buffer[index]);`);
 				}
 			}
 
@@ -846,7 +848,9 @@ ${declaration} {`;
 
 			// Convert value to C type
 			const param = setMethod.parameters[2]; // The value parameter
-			const convertedValue = this.convertDartToC('value', param);
+			// Create a copy of the parameter with nullable flag for proper conversion
+			const nullableParam = { ...param, isNullable: !this.isPrimitiveArrayType(elementType) };
+			const convertedValue = this.convertDartToC('value', nullableParam);
 			lines.push(`    SpineBindings.bindings.${setMethod.name}(nativePtr.cast(), index, ${convertedValue});`);
 			lines.push('  }');
 		}
@@ -876,7 +880,7 @@ ${declaration} {`;
 		// Handle pointer types
 		if (elementType.endsWith('*')) {
 			const baseType = elementType.slice(0, -1).trim();
-			return this.toDartTypeName(`spine_${toSnakeCase(baseType)}`);
+			return `${this.toDartTypeName(`spine_${toSnakeCase(baseType)}`)}?`;
 		}
 
 		// For primitive types, return the Dart type directly
@@ -896,8 +900,8 @@ ${declaration} {`;
 			return 'bool';
 		}
 
-		// For object types, convert to PascalCase
-		return this.toPascalCase(elementType);
+		// For object types, convert to PascalCase and make nullable since arrays can contain null pointers
+		return `${this.toPascalCase(elementType)}?`;
 	}
 
 	private isPrimitiveArrayType (elementType: string): boolean {
@@ -1120,19 +1124,22 @@ ${declaration} {`;
 		return enumValue;
 	}
 
-	private toDartReturnType (cType: string): string {
+	private toDartReturnType (cType: string, nullable?: boolean): string {
+		let baseType: string;
 		if (cType === 'void') return 'void';
-		if (cType === 'char*' || cType === 'char *' || cType === 'const char*' || cType === 'const char *') return 'String';
-		if (cType === 'float' || cType === 'double') return 'double';
-		if (cType === 'int' || cType === 'size_t' || cType === 'int32_t' || cType === 'uint32_t') return 'int';
-		if (cType === 'bool') return 'bool';
+		if (cType === 'char*' || cType === 'char *' || cType === 'const char*' || cType === 'const char *') baseType = 'String';
+		else if (cType === 'float' || cType === 'double') baseType = 'double';
+		else if (cType === 'int' || cType === 'size_t' || cType === 'int32_t' || cType === 'uint32_t') baseType = 'int';
+		else if (cType === 'bool') baseType = 'bool';
 		// Handle primitive pointer types
-		if (cType === 'void*' || cType === 'void *') return 'Pointer<Void>';
-		if (cType === 'float*' || cType === 'float *') return 'Pointer<Float>';
-		if (cType === 'uint32_t*' || cType === 'uint32_t *') return 'Pointer<Uint32>';
-		if (cType === 'uint16_t*' || cType === 'uint16_t *') return 'Pointer<Uint16>';
-		if (cType === 'int*' || cType === 'int *') return 'Pointer<Int32>';
-		return this.toDartTypeName(cType);
+		else if (cType === 'void*' || cType === 'void *') baseType = 'Pointer<Void>';
+		else if (cType === 'float*' || cType === 'float *') baseType = 'Pointer<Float>';
+		else if (cType === 'uint32_t*' || cType === 'uint32_t *') baseType = 'Pointer<Uint32>';
+		else if (cType === 'uint16_t*' || cType === 'uint16_t *') baseType = 'Pointer<Uint16>';
+		else if (cType === 'int*' || cType === 'int *') baseType = 'Pointer<Int32>';
+		else baseType = this.toDartTypeName(cType);
+		
+		return nullable ? `${baseType}?` : baseType;
 	}
 
 	private toDartParameterType (param: CParameter): string {
@@ -1143,7 +1150,7 @@ ${declaration} {`;
 		if (param.cType === 'void*' || param.cType === 'void *') {
 			return 'Pointer<Void>';
 		}
-		return this.toDartReturnType(param.cType);
+		return this.toDartReturnType(param.cType, param.isNullable);
 	}
 
 	private convertDartToC (dartValue: string, param: CParameter): string {
@@ -1152,38 +1159,62 @@ ${declaration} {`;
 		}
 
 		if (this.enumNames.has(param.cType)) {
+			if (param.isNullable) {
+				return `${dartValue}?.value ?? 0`;
+			}
 			return `${dartValue}.value`;
 		}
 
 		if (param.cType.startsWith('spine_')) {
+			if (param.isNullable) {
+				return `${dartValue}?.nativePtr.cast() ?? Pointer.fromAddress(0)`;
+			}
 			return `${dartValue}.nativePtr.cast()`;
 		}
 
 		return dartValue;
 	}
 
-	private generateReturnConversion (cReturnType: string, resultVar: string): string {
+	private generateReturnConversion (cReturnType: string, resultVar: string, nullable?: boolean): string {
 		if (cReturnType === 'char*' || cReturnType === 'char *' || cReturnType === 'const char*' || cReturnType === 'const char *') {
+			if (nullable) {
+				return `return ${resultVar}.address == 0 ? null : ${resultVar}.cast<Utf8>().toDartString();`;
+			}
 			return `return ${resultVar}.cast<Utf8>().toDartString();`;
 		}
 
 		if (this.enumNames.has(cReturnType)) {
 			const dartType = this.toDartTypeName(cReturnType);
+			if (nullable) {
+				return `return ${resultVar} == 0 ? null : ${dartType}.fromValue(${resultVar});`;
+			}
 			return `return ${dartType}.fromValue(${resultVar});`;
 		}
 
 		if (cReturnType.startsWith('spine_array_')) {
 			const dartType = this.toDartTypeName(cReturnType);
+			if (nullable) {
+				return `return ${resultVar}.address == 0 ? null : ${dartType}.fromPointer(${resultVar});`;
+			}
 			return `return ${dartType}.fromPointer(${resultVar});`;
 		}
 
 		if (cReturnType.startsWith('spine_')) {
 			const dartType = this.toDartTypeName(cReturnType);
 			const cClass = this.classMap.get(cReturnType);
-			if (cClass && this.isAbstract(cClass)) {
-				return this.generateRttiBasedInstantiation(dartType, resultVar, cClass);
+			
+			if (nullable) {
+				if (cClass && this.isAbstract(cClass)) {
+					return `if (${resultVar}.address == 0) return null;
+    ${this.generateRttiBasedInstantiation(dartType, resultVar, cClass)}`;
+				}
+				return `return ${resultVar}.address == 0 ? null : ${dartType}.fromPointer(${resultVar});`;
+			} else {
+				if (cClass && this.isAbstract(cClass)) {
+					return this.generateRttiBasedInstantiation(dartType, resultVar, cClass);
+				}
+				return `return ${dartType}.fromPointer(${resultVar});`;
 			}
-			return `return ${dartType}.fromPointer(${resultVar});`;
 		}
 
 		return `return ${resultVar};`;

spine-flutter/lib/generated/animation.dart

@@ -80,10 +80,10 @@ class Animation {
     SpineBindings.bindings.spine_animation_set_duration(_ptr, value);
   }
 
-  void apply(Skeleton skeleton, double lastTime, double time, bool loop, ArrayEvent pEvents, double alpha,
+  void apply(Skeleton skeleton, double lastTime, double time, bool loop, ArrayEvent? pEvents, double alpha,
       MixBlend blend, MixDirection direction, bool appliedPose) {
     SpineBindings.bindings.spine_animation_apply(_ptr, skeleton.nativePtr.cast(), lastTime, time, loop,
-        pEvents.nativePtr.cast(), alpha, blend.value, direction.value, appliedPose);
+        pEvents?.nativePtr.cast() ?? Pointer.fromAddress(0), alpha, blend.value, direction.value, appliedPose);
   }
 
   String get name {

spine-flutter/lib/generated/animation_state.dart

@@ -89,9 +89,9 @@ class AnimationState {
     SpineBindings.bindings.spine_animation_state_set_empty_animations(_ptr, value);
   }
 
-  TrackEntry getCurrent(int trackIndex) {
+  TrackEntry? getCurrent(int trackIndex) {
     final result = SpineBindings.bindings.spine_animation_state_get_current(_ptr, trackIndex);
-    return TrackEntry.fromPointer(result);
+    return result.address == 0 ? null : TrackEntry.fromPointer(result);
   }
 
   AnimationStateData get data {
@@ -130,11 +130,12 @@ class AnimationState {
     return result;
   }
 
-  void disposeTrackEntry(TrackEntry entry) {
-    SpineBindings.bindings.spine_animation_state_dispose_track_entry(_ptr, entry.nativePtr.cast());
+  void disposeTrackEntry(TrackEntry? entry) {
+    SpineBindings.bindings
+        .spine_animation_state_dispose_track_entry(_ptr, entry?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
-  Pointer<Void> get rendererObject {
+  Pointer<Void>? get rendererObject {
     final result = SpineBindings.bindings.spine_animation_state_get_renderer_object(_ptr);
     return result;
   }

spine-flutter/lib/generated/arrays.dart

@@ -198,7 +198,7 @@ class ArrayPropertyId extends NativeArray<int> {
 }
 
 /// ArrayAnimation wrapper
-class ArrayAnimation extends NativeArray<Animation> {
+class ArrayAnimation extends NativeArray<Animation?> {
   ArrayAnimation.fromPointer(Pointer<spine_array_animation_wrapper> super.ptr);
 
   @override
@@ -207,17 +207,17 @@ class ArrayAnimation extends NativeArray<Animation> {
   }
 
   @override
-  Animation operator [](int index) {
+  Animation? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_animation_buffer(nativePtr.cast());
-    return Animation.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : Animation.fromPointer(buffer[index]);
   }
 }
 
 /// ArrayAtlasPage wrapper
-class ArrayAtlasPage extends NativeArray<AtlasPage> {
+class ArrayAtlasPage extends NativeArray<AtlasPage?> {
   ArrayAtlasPage.fromPointer(Pointer<spine_array_atlas_page_wrapper> super.ptr);
 
   @override
@@ -226,17 +226,17 @@ class ArrayAtlasPage extends NativeArray<AtlasPage> {
   }
 
   @override
-  AtlasPage operator [](int index) {
+  AtlasPage? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_atlas_page_buffer(nativePtr.cast());
-    return AtlasPage.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : AtlasPage.fromPointer(buffer[index]);
   }
 }
 
 /// ArrayAtlasRegion wrapper
-class ArrayAtlasRegion extends NativeArray<AtlasRegion> {
+class ArrayAtlasRegion extends NativeArray<AtlasRegion?> {
   ArrayAtlasRegion.fromPointer(Pointer<spine_array_atlas_region_wrapper> super.ptr);
 
   @override
@@ -245,17 +245,17 @@ class ArrayAtlasRegion extends NativeArray<AtlasRegion> {
   }
 
   @override
-  AtlasRegion operator [](int index) {
+  AtlasRegion? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_atlas_region_buffer(nativePtr.cast());
-    return AtlasRegion.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : AtlasRegion.fromPointer(buffer[index]);
   }
 }
 
 /// ArrayAttachment wrapper
-class ArrayAttachment extends NativeArray<Attachment> {
+class ArrayAttachment extends NativeArray<Attachment?> {
   ArrayAttachment.fromPointer(Pointer<spine_array_attachment_wrapper> super.ptr);
 
   @override
@@ -264,11 +264,12 @@ class ArrayAttachment extends NativeArray<Attachment> {
   }
 
   @override
-  Attachment operator [](int index) {
+  Attachment? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_attachment_buffer(nativePtr.cast());
+    if (buffer[index].address == 0) return null;
     final rtti = SpineBindings.bindings.spine_attachment_get_rtti(buffer[index]);
     final className = SpineBindings.bindings.spine_rtti_get_class_name(rtti).cast<Utf8>().toDartString();
     switch (className) {
@@ -291,7 +292,7 @@ class ArrayAttachment extends NativeArray<Attachment> {
 }
 
 /// ArrayBone wrapper
-class ArrayBone extends NativeArray<Bone> {
+class ArrayBone extends NativeArray<Bone?> {
   ArrayBone.fromPointer(Pointer<spine_array_bone_wrapper> super.ptr);
 
   @override
@@ -300,17 +301,17 @@ class ArrayBone extends NativeArray<Bone> {
   }
 
   @override
-  Bone operator [](int index) {
+  Bone? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_bone_buffer(nativePtr.cast());
-    return Bone.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : Bone.fromPointer(buffer[index]);
   }
 }
 
 /// ArrayBoneData wrapper
-class ArrayBoneData extends NativeArray<BoneData> {
+class ArrayBoneData extends NativeArray<BoneData?> {
   ArrayBoneData.fromPointer(Pointer<spine_array_bone_data_wrapper> super.ptr);
 
   @override
@@ -319,17 +320,17 @@ class ArrayBoneData extends NativeArray<BoneData> {
   }
 
   @override
-  BoneData operator [](int index) {
+  BoneData? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_bone_data_buffer(nativePtr.cast());
-    return BoneData.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : BoneData.fromPointer(buffer[index]);
   }
 }
 
 /// ArrayBonePose wrapper
-class ArrayBonePose extends NativeArray<BonePose> {
+class ArrayBonePose extends NativeArray<BonePose?> {
   ArrayBonePose.fromPointer(Pointer<spine_array_bone_pose_wrapper> super.ptr);
 
   @override
@@ -338,17 +339,17 @@ class ArrayBonePose extends NativeArray<BonePose> {
   }
 
   @override
-  BonePose operator [](int index) {
+  BonePose? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_bone_pose_buffer(nativePtr.cast());
-    return BonePose.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : BonePose.fromPointer(buffer[index]);
   }
 }
 
 /// ArrayBoundingBoxAttachment wrapper
-class ArrayBoundingBoxAttachment extends NativeArray<BoundingBoxAttachment> {
+class ArrayBoundingBoxAttachment extends NativeArray<BoundingBoxAttachment?> {
   ArrayBoundingBoxAttachment.fromPointer(Pointer<spine_array_bounding_box_attachment_wrapper> super.ptr);
 
   @override
@@ -357,17 +358,17 @@ class ArrayBoundingBoxAttachment extends NativeArray<BoundingBoxAttachment> {
   }
 
   @override
-  BoundingBoxAttachment operator [](int index) {
+  BoundingBoxAttachment? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_bounding_box_attachment_buffer(nativePtr.cast());
-    return BoundingBoxAttachment.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : BoundingBoxAttachment.fromPointer(buffer[index]);
   }
 }
 
 /// ArrayConstraint wrapper
-class ArrayConstraint extends NativeArray<Constraint> {
+class ArrayConstraint extends NativeArray<Constraint?> {
   ArrayConstraint.fromPointer(Pointer<spine_array_constraint_wrapper> super.ptr);
 
   @override
@@ -376,11 +377,12 @@ class ArrayConstraint extends NativeArray<Constraint> {
   }
 
   @override
-  Constraint operator [](int index) {
+  Constraint? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_constraint_buffer(nativePtr.cast());
+    if (buffer[index].address == 0) return null;
     final rtti = SpineBindings.bindings.spine_constraint_get_rtti(buffer[index]);
     final className = SpineBindings.bindings.spine_rtti_get_class_name(rtti).cast<Utf8>().toDartString();
     switch (className) {
@@ -401,7 +403,7 @@ class ArrayConstraint extends NativeArray<Constraint> {
 }
 
 /// ArrayConstraintData wrapper
-class ArrayConstraintData extends NativeArray<ConstraintData> {
+class ArrayConstraintData extends NativeArray<ConstraintData?> {
   ArrayConstraintData.fromPointer(Pointer<spine_array_constraint_data_wrapper> super.ptr);
 
   @override
@@ -410,11 +412,12 @@ class ArrayConstraintData extends NativeArray<ConstraintData> {
   }
 
   @override
-  ConstraintData operator [](int index) {
+  ConstraintData? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_constraint_data_buffer(nativePtr.cast());
+    if (buffer[index].address == 0) return null;
     final rtti = SpineBindings.bindings.spine_constraint_data_get_rtti(buffer[index]);
     final className = SpineBindings.bindings.spine_rtti_get_class_name(rtti).cast<Utf8>().toDartString();
     switch (className) {
@@ -435,7 +438,7 @@ class ArrayConstraintData extends NativeArray<ConstraintData> {
 }
 
 /// ArrayEvent wrapper
-class ArrayEvent extends NativeArray<Event> {
+class ArrayEvent extends NativeArray<Event?> {
   ArrayEvent.fromPointer(Pointer<spine_array_event_wrapper> super.ptr);
 
   @override
@@ -444,17 +447,17 @@ class ArrayEvent extends NativeArray<Event> {
   }
 
   @override
-  Event operator [](int index) {
+  Event? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_event_buffer(nativePtr.cast());
-    return Event.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : Event.fromPointer(buffer[index]);
   }
 }
 
 /// ArrayEventData wrapper
-class ArrayEventData extends NativeArray<EventData> {
+class ArrayEventData extends NativeArray<EventData?> {
   ArrayEventData.fromPointer(Pointer<spine_array_event_data_wrapper> super.ptr);
 
   @override
@@ -463,17 +466,17 @@ class ArrayEventData extends NativeArray<EventData> {
   }
 
   @override
-  EventData operator [](int index) {
+  EventData? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_event_data_buffer(nativePtr.cast());
-    return EventData.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : EventData.fromPointer(buffer[index]);
   }
 }
 
 /// ArrayFromProperty wrapper
-class ArrayFromProperty extends NativeArray<FromProperty> {
+class ArrayFromProperty extends NativeArray<FromProperty?> {
   ArrayFromProperty.fromPointer(Pointer<spine_array_from_property_wrapper> super.ptr);
 
   @override
@@ -482,11 +485,12 @@ class ArrayFromProperty extends NativeArray<FromProperty> {
   }
 
   @override
-  FromProperty operator [](int index) {
+  FromProperty? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_from_property_buffer(nativePtr.cast());
+    if (buffer[index].address == 0) return null;
     final rtti = SpineBindings.bindings.spine_from_property_get_rtti(buffer[index]);
     final className = SpineBindings.bindings.spine_rtti_get_class_name(rtti).cast<Utf8>().toDartString();
     switch (className) {
@@ -509,7 +513,7 @@ class ArrayFromProperty extends NativeArray<FromProperty> {
 }
 
 /// ArrayPhysicsConstraint wrapper
-class ArrayPhysicsConstraint extends NativeArray<PhysicsConstraint> {
+class ArrayPhysicsConstraint extends NativeArray<PhysicsConstraint?> {
   ArrayPhysicsConstraint.fromPointer(Pointer<spine_array_physics_constraint_wrapper> super.ptr);
 
   @override
@@ -518,17 +522,17 @@ class ArrayPhysicsConstraint extends NativeArray<PhysicsConstraint> {
   }
 
   @override
-  PhysicsConstraint operator [](int index) {
+  PhysicsConstraint? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_physics_constraint_buffer(nativePtr.cast());
-    return PhysicsConstraint.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : PhysicsConstraint.fromPointer(buffer[index]);
   }
 }
 
 /// ArrayPolygon wrapper
-class ArrayPolygon extends NativeArray<Polygon> {
+class ArrayPolygon extends NativeArray<Polygon?> {
   ArrayPolygon.fromPointer(Pointer<spine_array_polygon_wrapper> super.ptr);
 
   @override
@@ -537,17 +541,17 @@ class ArrayPolygon extends NativeArray<Polygon> {
   }
 
   @override
-  Polygon operator [](int index) {
+  Polygon? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_polygon_buffer(nativePtr.cast());
-    return Polygon.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : Polygon.fromPointer(buffer[index]);
   }
 }
 
 /// ArraySkin wrapper
-class ArraySkin extends NativeArray<Skin> {
+class ArraySkin extends NativeArray<Skin?> {
   ArraySkin.fromPointer(Pointer<spine_array_skin_wrapper> super.ptr);
 
   @override
@@ -556,17 +560,17 @@ class ArraySkin extends NativeArray<Skin> {
   }
 
   @override
-  Skin operator [](int index) {
+  Skin? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_skin_buffer(nativePtr.cast());
-    return Skin.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : Skin.fromPointer(buffer[index]);
   }
 }
 
 /// ArraySlot wrapper
-class ArraySlot extends NativeArray<Slot> {
+class ArraySlot extends NativeArray<Slot?> {
   ArraySlot.fromPointer(Pointer<spine_array_slot_wrapper> super.ptr);
 
   @override
@@ -575,17 +579,17 @@ class ArraySlot extends NativeArray<Slot> {
   }
 
   @override
-  Slot operator [](int index) {
+  Slot? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_slot_buffer(nativePtr.cast());
-    return Slot.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : Slot.fromPointer(buffer[index]);
   }
 }
 
 /// ArraySlotData wrapper
-class ArraySlotData extends NativeArray<SlotData> {
+class ArraySlotData extends NativeArray<SlotData?> {
   ArraySlotData.fromPointer(Pointer<spine_array_slot_data_wrapper> super.ptr);
 
   @override
@@ -594,17 +598,17 @@ class ArraySlotData extends NativeArray<SlotData> {
   }
 
   @override
-  SlotData operator [](int index) {
+  SlotData? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_slot_data_buffer(nativePtr.cast());
-    return SlotData.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : SlotData.fromPointer(buffer[index]);
   }
 }
 
 /// ArrayTextureRegion wrapper
-class ArrayTextureRegion extends NativeArray<TextureRegion> {
+class ArrayTextureRegion extends NativeArray<TextureRegion?> {
   ArrayTextureRegion.fromPointer(Pointer<spine_array_texture_region_wrapper> super.ptr);
 
   @override
@@ -613,17 +617,17 @@ class ArrayTextureRegion extends NativeArray<TextureRegion> {
   }
 
   @override
-  TextureRegion operator [](int index) {
+  TextureRegion? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_texture_region_buffer(nativePtr.cast());
-    return TextureRegion.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : TextureRegion.fromPointer(buffer[index]);
   }
 }
 
 /// ArrayTimeline wrapper
-class ArrayTimeline extends NativeArray<Timeline> {
+class ArrayTimeline extends NativeArray<Timeline?> {
   ArrayTimeline.fromPointer(Pointer<spine_array_timeline_wrapper> super.ptr);
 
   @override
@@ -632,11 +636,12 @@ class ArrayTimeline extends NativeArray<Timeline> {
   }
 
   @override
-  Timeline operator [](int index) {
+  Timeline? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_timeline_buffer(nativePtr.cast());
+    if (buffer[index].address == 0) return null;
     final rtti = SpineBindings.bindings.spine_timeline_get_rtti(buffer[index]);
     final className = SpineBindings.bindings.spine_rtti_get_class_name(rtti).cast<Utf8>().toDartString();
     switch (className) {
@@ -719,7 +724,7 @@ class ArrayTimeline extends NativeArray<Timeline> {
 }
 
 /// ArrayToProperty wrapper
-class ArrayToProperty extends NativeArray<ToProperty> {
+class ArrayToProperty extends NativeArray<ToProperty?> {
   ArrayToProperty.fromPointer(Pointer<spine_array_to_property_wrapper> super.ptr);
 
   @override
@@ -728,11 +733,12 @@ class ArrayToProperty extends NativeArray<ToProperty> {
   }
 
   @override
-  ToProperty operator [](int index) {
+  ToProperty? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_to_property_buffer(nativePtr.cast());
+    if (buffer[index].address == 0) return null;
     final rtti = SpineBindings.bindings.spine_to_property_get_rtti(buffer[index]);
     final className = SpineBindings.bindings.spine_rtti_get_class_name(rtti).cast<Utf8>().toDartString();
     switch (className) {
@@ -755,7 +761,7 @@ class ArrayToProperty extends NativeArray<ToProperty> {
 }
 
 /// ArrayTrackEntry wrapper
-class ArrayTrackEntry extends NativeArray<TrackEntry> {
+class ArrayTrackEntry extends NativeArray<TrackEntry?> {
   ArrayTrackEntry.fromPointer(Pointer<spine_array_track_entry_wrapper> super.ptr);
 
   @override
@@ -764,17 +770,17 @@ class ArrayTrackEntry extends NativeArray<TrackEntry> {
   }
 
   @override
-  TrackEntry operator [](int index) {
+  TrackEntry? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_track_entry_buffer(nativePtr.cast());
-    return TrackEntry.fromPointer(buffer[index]);
+    return buffer[index].address == 0 ? null : TrackEntry.fromPointer(buffer[index]);
   }
 }
 
 /// ArrayUpdate wrapper
-class ArrayUpdate extends NativeArray<Update> {
+class ArrayUpdate extends NativeArray<Update?> {
   ArrayUpdate.fromPointer(Pointer<spine_array_update_wrapper> super.ptr);
 
   @override
@@ -783,11 +789,12 @@ class ArrayUpdate extends NativeArray<Update> {
   }
 
   @override
-  Update operator [](int index) {
+  Update? operator [](int index) {
     if (index < 0 || index >= length) {
       throw RangeError.index(index, this, 'index');
     }
     final buffer = SpineBindings.bindings.spine_array_update_buffer(nativePtr.cast());
+    if (buffer[index].address == 0) return null;
     final rtti = SpineBindings.bindings.spine_update_get_rtti(buffer[index]);
     final className = SpineBindings.bindings.spine_rtti_get_class_name(rtti).cast<Utf8>().toDartString();
     switch (className) {

spine-flutter/lib/generated/atlas.dart

@@ -53,9 +53,9 @@ class Atlas {
     SpineBindings.bindings.spine_atlas_flip_v(_ptr);
   }
 
-  AtlasRegion findRegion(String name) {
+  AtlasRegion? findRegion(String name) {
     final result = SpineBindings.bindings.spine_atlas_find_region(_ptr, name.toNativeUtf8().cast<Char>());
-    return AtlasRegion.fromPointer(result);
+    return result.address == 0 ? null : AtlasRegion.fromPointer(result);
   }
 
   ArrayAtlasPage get pages {

spine-flutter/lib/generated/atlas_attachment_loader.dart

@@ -65,54 +65,58 @@ class AtlasAttachmentLoader implements AttachmentLoader {
   }
 
   @override
-  RegionAttachment newRegionAttachment(Skin skin, String name, String path, Sequence sequence) {
+  RegionAttachment? newRegionAttachment(Skin skin, String name, String path, Sequence? sequence) {
     final result = SpineBindings.bindings.spine_atlas_attachment_loader_new_region_attachment(
         _ptr,
         skin.nativePtr.cast(),
         name.toNativeUtf8().cast<Char>(),
         path.toNativeUtf8().cast<Char>(),
-        sequence.nativePtr.cast());
-    return RegionAttachment.fromPointer(result);
+        sequence?.nativePtr.cast() ?? Pointer.fromAddress(0));
+    return result.address == 0 ? null : RegionAttachment.fromPointer(result);
   }
 
   @override
-  MeshAttachment newMeshAttachment(Skin skin, String name, String path, Sequence sequence) {
-    final result = SpineBindings.bindings.spine_atlas_attachment_loader_new_mesh_attachment(_ptr, skin.nativePtr.cast(),
-        name.toNativeUtf8().cast<Char>(), path.toNativeUtf8().cast<Char>(), sequence.nativePtr.cast());
-    return MeshAttachment.fromPointer(result);
+  MeshAttachment? newMeshAttachment(Skin skin, String name, String path, Sequence? sequence) {
+    final result = SpineBindings.bindings.spine_atlas_attachment_loader_new_mesh_attachment(
+        _ptr,
+        skin.nativePtr.cast(),
+        name.toNativeUtf8().cast<Char>(),
+        path.toNativeUtf8().cast<Char>(),
+        sequence?.nativePtr.cast() ?? Pointer.fromAddress(0));
+    return result.address == 0 ? null : MeshAttachment.fromPointer(result);
   }
 
   @override
-  BoundingBoxAttachment newBoundingBoxAttachment(Skin skin, String name) {
+  BoundingBoxAttachment? newBoundingBoxAttachment(Skin skin, String name) {
     final result = SpineBindings.bindings.spine_atlas_attachment_loader_new_bounding_box_attachment(
         _ptr, skin.nativePtr.cast(), name.toNativeUtf8().cast<Char>());
-    return BoundingBoxAttachment.fromPointer(result);
+    return result.address == 0 ? null : BoundingBoxAttachment.fromPointer(result);
   }
 
   @override
-  PathAttachment newPathAttachment(Skin skin, String name) {
+  PathAttachment? newPathAttachment(Skin skin, String name) {
     final result = SpineBindings.bindings.spine_atlas_attachment_loader_new_path_attachment(
         _ptr, skin.nativePtr.cast(), name.toNativeUtf8().cast<Char>());
-    return PathAttachment.fromPointer(result);
+    return result.address == 0 ? null : PathAttachment.fromPointer(result);
   }
 
   @override
-  PointAttachment newPointAttachment(Skin skin, String name) {
+  PointAttachment? newPointAttachment(Skin skin, String name) {
     final result = SpineBindings.bindings.spine_atlas_attachment_loader_new_point_attachment(
         _ptr, skin.nativePtr.cast(), name.toNativeUtf8().cast<Char>());
-    return PointAttachment.fromPointer(result);
+    return result.address == 0 ? null : PointAttachment.fromPointer(result);
   }
 
   @override
-  ClippingAttachment newClippingAttachment(Skin skin, String name) {
+  ClippingAttachment? newClippingAttachment(Skin skin, String name) {
     final result = SpineBindings.bindings.spine_atlas_attachment_loader_new_clipping_attachment(
         _ptr, skin.nativePtr.cast(), name.toNativeUtf8().cast<Char>());
-    return ClippingAttachment.fromPointer(result);
+    return result.address == 0 ? null : ClippingAttachment.fromPointer(result);
   }
 
-  AtlasRegion findRegion(String name) {
+  AtlasRegion? findRegion(String name) {
     final result =
         SpineBindings.bindings.spine_atlas_attachment_loader_find_region(_ptr, name.toNativeUtf8().cast<Char>());
-    return AtlasRegion.fromPointer(result);
+    return result.address == 0 ? null : AtlasRegion.fromPointer(result);
   }
 }

spine-flutter/lib/generated/atlas_page.dart

@@ -154,7 +154,7 @@ class AtlasPage {
     SpineBindings.bindings.spine_atlas_page_set_index(_ptr, value);
   }
 
-  Pointer<Void> get texture {
+  Pointer<Void>? get texture {
     final result = SpineBindings.bindings.spine_atlas_page_get_texture(_ptr);
     return result;
   }

spine-flutter/lib/generated/atlas_region.dart

@@ -57,9 +57,9 @@ class AtlasRegion extends TextureRegion {
     SpineBindings.bindings.spine_atlas_region_dispose(_ptr);
   }
 
-  AtlasPage get page {
+  AtlasPage? get page {
     final result = SpineBindings.bindings.spine_atlas_region_get_page(_ptr);
-    return AtlasPage.fromPointer(result);
+    return result.address == 0 ? null : AtlasPage.fromPointer(result);
   }
 
   String get name {
@@ -137,8 +137,8 @@ class AtlasRegion extends TextureRegion {
     return ArrayFloat.fromPointer(result);
   }
 
-  set page(AtlasPage value) {
-    SpineBindings.bindings.spine_atlas_region_set_page(_ptr, value.nativePtr.cast());
+  set page(AtlasPage? value) {
+    SpineBindings.bindings.spine_atlas_region_set_page(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
   set name(String value) {

spine-flutter/lib/generated/attachment_loader.dart

@@ -42,10 +42,10 @@ import 'skin.dart';
 /// AttachmentLoader wrapper
 abstract class AttachmentLoader {
   Pointer get nativePtr;
-  RegionAttachment newRegionAttachment(Skin skin, String name, String path, Sequence sequence);
-  MeshAttachment newMeshAttachment(Skin skin, String name, String path, Sequence sequence);
-  BoundingBoxAttachment newBoundingBoxAttachment(Skin skin, String name);
-  PathAttachment newPathAttachment(Skin skin, String name);
-  PointAttachment newPointAttachment(Skin skin, String name);
-  ClippingAttachment newClippingAttachment(Skin skin, String name);
+  RegionAttachment? newRegionAttachment(Skin skin, String name, String path, Sequence? sequence);
+  MeshAttachment? newMeshAttachment(Skin skin, String name, String path, Sequence? sequence);
+  BoundingBoxAttachment? newBoundingBoxAttachment(Skin skin, String name);
+  PathAttachment? newPathAttachment(Skin skin, String name);
+  PointAttachment? newPointAttachment(Skin skin, String name);
+  ClippingAttachment? newClippingAttachment(Skin skin, String name);
 }

spine-flutter/lib/generated/bone.dart

@@ -53,13 +53,15 @@ class Bone extends PosedActive implements Posed, Update {
   @override
   Pointer get nativePtr => _ptr;
 
-  factory Bone(BoneData data, Bone parent) {
-    final ptr = SpineBindings.bindings.spine_bone_create(data.nativePtr.cast(), parent.nativePtr.cast());
+  factory Bone(BoneData data, Bone? parent) {
+    final ptr = SpineBindings.bindings
+        .spine_bone_create(data.nativePtr.cast(), parent?.nativePtr.cast() ?? Pointer.fromAddress(0));
     return Bone.fromPointer(ptr);
   }
 
-  factory Bone.from(Bone bone, Bone parent) {
-    final ptr = SpineBindings.bindings.spine_bone_create2(bone.nativePtr.cast(), parent.nativePtr.cast());
+  factory Bone.from(Bone bone, Bone? parent) {
+    final ptr = SpineBindings.bindings
+        .spine_bone_create2(bone.nativePtr.cast(), parent?.nativePtr.cast() ?? Pointer.fromAddress(0));
     return Bone.fromPointer(ptr);
   }
 
@@ -74,9 +76,9 @@ class Bone extends PosedActive implements Posed, Update {
     return Rtti.fromPointer(result);
   }
 
-  Bone get parent {
+  Bone? get parent {
     final result = SpineBindings.bindings.spine_bone_get_parent(_ptr);
-    return Bone.fromPointer(result);
+    return result.address == 0 ? null : Bone.fromPointer(result);
   }
 
   ArrayBone get children {

spine-flutter/lib/generated/bone_data.dart

@@ -47,9 +47,9 @@ class BoneData extends PosedData {
   @override
   Pointer get nativePtr => _ptr;
 
-  factory BoneData(int index, String name, BoneData parent) {
-    final ptr =
-        SpineBindings.bindings.spine_bone_data_create(index, name.toNativeUtf8().cast<Char>(), parent.nativePtr.cast());
+  factory BoneData(int index, String name, BoneData? parent) {
+    final ptr = SpineBindings.bindings.spine_bone_data_create(
+        index, name.toNativeUtf8().cast<Char>(), parent?.nativePtr.cast() ?? Pointer.fromAddress(0));
     return BoneData.fromPointer(ptr);
   }
 
@@ -63,9 +63,9 @@ class BoneData extends PosedData {
     return result;
   }
 
-  BoneData get parent {
+  BoneData? get parent {
     final result = SpineBindings.bindings.spine_bone_data_get_parent(_ptr);
-    return BoneData.fromPointer(result);
+    return result.address == 0 ? null : BoneData.fromPointer(result);
   }
 
   double get length {

spine-flutter/lib/generated/clipping_attachment.dart

@@ -56,13 +56,14 @@ class ClippingAttachment extends VertexAttachment {
     SpineBindings.bindings.spine_clipping_attachment_dispose(_ptr);
   }
 
-  SlotData get endSlot {
+  SlotData? get endSlot {
     final result = SpineBindings.bindings.spine_clipping_attachment_get_end_slot(_ptr);
-    return SlotData.fromPointer(result);
+    return result.address == 0 ? null : SlotData.fromPointer(result);
   }
 
-  set endSlot(SlotData value) {
-    SpineBindings.bindings.spine_clipping_attachment_set_end_slot(_ptr, value.nativePtr.cast());
+  set endSlot(SlotData? value) {
+    SpineBindings.bindings
+        .spine_clipping_attachment_set_end_slot(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
   Color get color {

spine-flutter/lib/generated/draw_order_timeline.dart

@@ -54,7 +54,8 @@ class DrawOrderTimeline extends Timeline {
     SpineBindings.bindings.spine_draw_order_timeline_dispose(_ptr);
   }
 
-  void setFrame(int frame, double time, ArrayInt drawOrder) {
-    SpineBindings.bindings.spine_draw_order_timeline_set_frame(_ptr, frame, time, drawOrder.nativePtr.cast());
+  void setFrame(int frame, double time, ArrayInt? drawOrder) {
+    SpineBindings.bindings
+        .spine_draw_order_timeline_set_frame(_ptr, frame, time, drawOrder?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 }

spine-flutter/lib/generated/event_queue_entry.dart

@@ -45,9 +45,9 @@ class EventQueueEntry {
   /// Get the native pointer for FFI calls
   Pointer get nativePtr => _ptr;
 
-  factory EventQueueEntry(EventType eventType, TrackEntry trackEntry, Event event) {
-    final ptr = SpineBindings.bindings
-        .spine_event_queue_entry_create(eventType.value, trackEntry.nativePtr.cast(), event.nativePtr.cast());
+  factory EventQueueEntry(EventType eventType, TrackEntry? trackEntry, Event? event) {
+    final ptr = SpineBindings.bindings.spine_event_queue_entry_create(eventType.value,
+        trackEntry?.nativePtr.cast() ?? Pointer.fromAddress(0), event?.nativePtr.cast() ?? Pointer.fromAddress(0));
     return EventQueueEntry.fromPointer(ptr);
   }
 
@@ -64,21 +64,21 @@ class EventQueueEntry {
     SpineBindings.bindings.spine_event_queue_entry_set__type(_ptr, value.value);
   }
 
-  TrackEntry get entry {
+  TrackEntry? get entry {
     final result = SpineBindings.bindings.spine_event_queue_entry_get__entry(_ptr);
-    return TrackEntry.fromPointer(result);
+    return result.address == 0 ? null : TrackEntry.fromPointer(result);
   }
 
-  set entry(TrackEntry value) {
-    SpineBindings.bindings.spine_event_queue_entry_set__entry(_ptr, value.nativePtr.cast());
+  set entry(TrackEntry? value) {
+    SpineBindings.bindings.spine_event_queue_entry_set__entry(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
-  Event get event {
+  Event? get event {
     final result = SpineBindings.bindings.spine_event_queue_entry_get__event(_ptr);
-    return Event.fromPointer(result);
+    return result.address == 0 ? null : Event.fromPointer(result);
   }
 
-  set event(Event value) {
-    SpineBindings.bindings.spine_event_queue_entry_set__event(_ptr, value.nativePtr.cast());
+  set event(Event? value) {
+    SpineBindings.bindings.spine_event_queue_entry_set__event(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 }

spine-flutter/lib/generated/from_property.dart

@@ -63,12 +63,12 @@ abstract class FromProperty {
     SpineBindings.bindings.spine_from_property_set__offset(_ptr, value);
   }
 
-  ArrayToProperty get to {
+  ArrayToProperty? get to {
     final result = SpineBindings.bindings.spine_from_property_get__to(_ptr);
-    return ArrayToProperty.fromPointer(result);
+    return result.address == 0 ? null : ArrayToProperty.fromPointer(result);
   }
 
-  set to(ArrayToProperty value) {
-    SpineBindings.bindings.spine_from_property_set__to(_ptr, value.nativePtr.cast());
+  set to(ArrayToProperty? value) {
+    SpineBindings.bindings.spine_from_property_set__to(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 }

spine-flutter/lib/generated/mesh_attachment.dart

@@ -108,31 +108,32 @@ class MeshAttachment extends VertexAttachment {
     SpineBindings.bindings.spine_mesh_attachment_set_path(_ptr, value.toNativeUtf8().cast<Char>());
   }
 
-  TextureRegion get region {
+  TextureRegion? get region {
     final result = SpineBindings.bindings.spine_mesh_attachment_get_region(_ptr);
-    return TextureRegion.fromPointer(result);
+    return result.address == 0 ? null : TextureRegion.fromPointer(result);
   }
 
-  set region(TextureRegion value) {
-    SpineBindings.bindings.spine_mesh_attachment_set_region(_ptr, value.nativePtr.cast());
+  set region(TextureRegion? value) {
+    SpineBindings.bindings.spine_mesh_attachment_set_region(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
-  Sequence get sequence {
+  Sequence? get sequence {
     final result = SpineBindings.bindings.spine_mesh_attachment_get_sequence(_ptr);
-    return Sequence.fromPointer(result);
+    return result.address == 0 ? null : Sequence.fromPointer(result);
   }
 
-  set sequence(Sequence value) {
-    SpineBindings.bindings.spine_mesh_attachment_set_sequence(_ptr, value.nativePtr.cast());
+  set sequence(Sequence? value) {
+    SpineBindings.bindings.spine_mesh_attachment_set_sequence(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
-  MeshAttachment get parentMesh {
+  MeshAttachment? get parentMesh {
     final result = SpineBindings.bindings.spine_mesh_attachment_get_parent_mesh(_ptr);
-    return MeshAttachment.fromPointer(result);
+    return result.address == 0 ? null : MeshAttachment.fromPointer(result);
   }
 
-  set parentMesh(MeshAttachment value) {
-    SpineBindings.bindings.spine_mesh_attachment_set_parent_mesh(_ptr, value.nativePtr.cast());
+  set parentMesh(MeshAttachment? value) {
+    SpineBindings.bindings
+        .spine_mesh_attachment_set_parent_mesh(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
   ArrayUnsignedShort get edges {

spine-flutter/lib/generated/region_attachment.dart

@@ -140,22 +140,23 @@ class RegionAttachment extends Attachment {
     SpineBindings.bindings.spine_region_attachment_set_path(_ptr, value.toNativeUtf8().cast<Char>());
   }
 
-  TextureRegion get region {
+  TextureRegion? get region {
     final result = SpineBindings.bindings.spine_region_attachment_get_region(_ptr);
-    return TextureRegion.fromPointer(result);
+    return result.address == 0 ? null : TextureRegion.fromPointer(result);
   }
 
-  set region(TextureRegion value) {
-    SpineBindings.bindings.spine_region_attachment_set_region(_ptr, value.nativePtr.cast());
+  set region(TextureRegion? value) {
+    SpineBindings.bindings.spine_region_attachment_set_region(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
-  Sequence get sequence {
+  Sequence? get sequence {
     final result = SpineBindings.bindings.spine_region_attachment_get_sequence(_ptr);
-    return Sequence.fromPointer(result);
+    return result.address == 0 ? null : Sequence.fromPointer(result);
   }
 
-  set sequence(Sequence value) {
-    SpineBindings.bindings.spine_region_attachment_set_sequence(_ptr, value.nativePtr.cast());
+  set sequence(Sequence? value) {
+    SpineBindings.bindings
+        .spine_region_attachment_set_sequence(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
   ArrayFloat get offset {

spine-flutter/lib/generated/render_command.dart

@@ -47,22 +47,22 @@ class RenderCommand {
     SpineBindings.bindings.spine_render_command_dispose(_ptr);
   }
 
-  Pointer<Float> get positions {
+  Pointer<Float>? get positions {
     final result = SpineBindings.bindings.spine_render_command_get_positions(_ptr);
     return result;
   }
 
-  Pointer<Float> get uvs {
+  Pointer<Float>? get uvs {
     final result = SpineBindings.bindings.spine_render_command_get_uvs(_ptr);
     return result;
   }
 
-  Pointer<Uint32> get colors {
+  Pointer<Uint32>? get colors {
     final result = SpineBindings.bindings.spine_render_command_get_colors(_ptr);
     return result;
   }
 
-  Pointer<Uint32> get darkColors {
+  Pointer<Uint32>? get darkColors {
     final result = SpineBindings.bindings.spine_render_command_get_dark_colors(_ptr);
     return result;
   }
@@ -72,7 +72,7 @@ class RenderCommand {
     return result;
   }
 
-  Pointer<Uint16> get indices {
+  Pointer<Uint16>? get indices {
     final result = SpineBindings.bindings.spine_render_command_get_indices(_ptr);
     return result;
   }
@@ -87,13 +87,13 @@ class RenderCommand {
     return BlendMode.fromValue(result);
   }
 
-  Pointer<Void> get texture {
+  Pointer<Void>? get texture {
     final result = SpineBindings.bindings.spine_render_command_get_texture(_ptr);
     return result;
   }
 
-  RenderCommand get next {
+  RenderCommand? get next {
     final result = SpineBindings.bindings.spine_render_command_get_next(_ptr);
-    return RenderCommand.fromPointer(result);
+    return result.address == 0 ? null : RenderCommand.fromPointer(result);
   }
 }

spine-flutter/lib/generated/rtti.dart

@@ -47,9 +47,9 @@ class Rtti {
     SpineBindings.bindings.spine_rtti_dispose(_ptr);
   }
 
-  String get className {
+  String? get className {
     final result = SpineBindings.bindings.spine_rtti_get_class_name(_ptr);
-    return result.cast<Utf8>().toDartString();
+    return result.address == 0 ? null : result.cast<Utf8>().toDartString();
   }
 
   bool isExactly(Rtti rtti) {

spine-flutter/lib/generated/sequence.dart

@@ -60,8 +60,9 @@ class Sequence {
     return Sequence.fromPointer(result);
   }
 
-  void apply(SlotPose slot, Attachment attachment) {
-    SpineBindings.bindings.spine_sequence_apply(_ptr, slot.nativePtr.cast(), attachment.nativePtr.cast());
+  void apply(SlotPose? slot, Attachment? attachment) {
+    SpineBindings.bindings.spine_sequence_apply(
+        _ptr, slot?.nativePtr.cast() ?? Pointer.fromAddress(0), attachment?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
   String getPath(String basePath, int index) {

spine-flutter/lib/generated/skeleton.dart

@@ -79,8 +79,8 @@ class Skeleton {
     SpineBindings.bindings.spine_skeleton_constrained(_ptr, object.nativePtr.cast());
   }
 
-  void sortBone(Bone bone) {
-    SpineBindings.bindings.spine_skeleton_sort_bone(_ptr, bone.nativePtr.cast());
+  void sortBone(Bone? bone) {
+    SpineBindings.bindings.spine_skeleton_sort_bone(_ptr, bone?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
   static void sortReset(ArrayBone bones) {
@@ -118,14 +118,14 @@ class Skeleton {
     return ArrayUpdate.fromPointer(result);
   }
 
-  Bone get rootBone {
+  Bone? get rootBone {
     final result = SpineBindings.bindings.spine_skeleton_get_root_bone(_ptr);
-    return Bone.fromPointer(result);
+    return result.address == 0 ? null : Bone.fromPointer(result);
   }
 
-  Bone findBone(String boneName) {
+  Bone? findBone(String boneName) {
     final result = SpineBindings.bindings.spine_skeleton_find_bone(_ptr, boneName.toNativeUtf8().cast<Char>());
-    return Bone.fromPointer(result);
+    return result.address == 0 ? null : Bone.fromPointer(result);
   }
 
   ArraySlot get slots {
@@ -133,9 +133,9 @@ class Skeleton {
     return ArraySlot.fromPointer(result);
   }
 
-  Slot findSlot(String slotName) {
+  Slot? findSlot(String slotName) {
     final result = SpineBindings.bindings.spine_skeleton_find_slot(_ptr, slotName.toNativeUtf8().cast<Char>());
-    return Slot.fromPointer(result);
+    return result.address == 0 ? null : Slot.fromPointer(result);
   }
 
   ArraySlot get drawOrder {
@@ -143,9 +143,9 @@ class Skeleton {
     return ArraySlot.fromPointer(result);
   }
 
-  Skin get skin {
+  Skin? get skin {
     final result = SpineBindings.bindings.spine_skeleton_get_skin(_ptr);
-    return Skin.fromPointer(result);
+    return result.address == 0 ? null : Skin.fromPointer(result);
   }
 
   void setAttachment(String slotName, String attachmentName) {
@@ -273,13 +273,14 @@ class Skeleton {
     SpineBindings.bindings.spine_skeleton_set_skin_1(_ptr, skinName.toNativeUtf8().cast<Char>());
   }
 
-  void setSkin2(Skin newSkin) {
-    SpineBindings.bindings.spine_skeleton_set_skin_2(_ptr, newSkin.nativePtr.cast());
+  void setSkin2(Skin? newSkin) {
+    SpineBindings.bindings.spine_skeleton_set_skin_2(_ptr, newSkin?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
-  Attachment getAttachment(String slotName, String attachmentName) {
+  Attachment? getAttachment(String slotName, String attachmentName) {
     final result = SpineBindings.bindings.spine_skeleton_get_attachment_1(
         _ptr, slotName.toNativeUtf8().cast<Char>(), attachmentName.toNativeUtf8().cast<Char>());
+    if (result.address == 0) return null;
     final rtti = SpineBindings.bindings.spine_attachment_get_rtti(result);
     final className = SpineBindings.bindings.spine_rtti_get_class_name(rtti).cast<Utf8>().toDartString();
     switch (className) {
@@ -300,9 +301,10 @@ class Skeleton {
     }
   }
 
-  Attachment getAttachment2(int slotIndex, String attachmentName) {
+  Attachment? getAttachment2(int slotIndex, String attachmentName) {
     final result = SpineBindings.bindings
         .spine_skeleton_get_attachment_2(_ptr, slotIndex, attachmentName.toNativeUtf8().cast<Char>());
+    if (result.address == 0) return null;
     final rtti = SpineBindings.bindings.spine_attachment_get_rtti(result);
     final className = SpineBindings.bindings.spine_rtti_get_class_name(rtti).cast<Utf8>().toDartString();
     switch (className) {

spine-flutter/lib/generated/skeleton_binary.dart

@@ -60,10 +60,10 @@ class SkeletonBinary {
     SpineBindings.bindings.spine_skeleton_binary_dispose(_ptr);
   }
 
-  SkeletonData readSkeletonDataFile(String path) {
+  SkeletonData? readSkeletonDataFile(String path) {
     final result =
         SpineBindings.bindings.spine_skeleton_binary_read_skeleton_data_file(_ptr, path.toNativeUtf8().cast<Char>());
-    return SkeletonData.fromPointer(result);
+    return result.address == 0 ? null : SkeletonData.fromPointer(result);
   }
 
   set scale(double value) {

spine-flutter/lib/generated/skeleton_bounds.dart

@@ -74,14 +74,16 @@ class SkeletonBounds {
     return result;
   }
 
-  Polygon getPolygon(BoundingBoxAttachment attachment) {
-    final result = SpineBindings.bindings.spine_skeleton_bounds_get_polygon(_ptr, attachment.nativePtr.cast());
-    return Polygon.fromPointer(result);
+  Polygon? getPolygon(BoundingBoxAttachment? attachment) {
+    final result = SpineBindings.bindings
+        .spine_skeleton_bounds_get_polygon(_ptr, attachment?.nativePtr.cast() ?? Pointer.fromAddress(0));
+    return result.address == 0 ? null : Polygon.fromPointer(result);
   }
 
-  BoundingBoxAttachment getBoundingBox(Polygon polygon) {
-    final result = SpineBindings.bindings.spine_skeleton_bounds_get_bounding_box(_ptr, polygon.nativePtr.cast());
-    return BoundingBoxAttachment.fromPointer(result);
+  BoundingBoxAttachment? getBoundingBox(Polygon? polygon) {
+    final result = SpineBindings.bindings
+        .spine_skeleton_bounds_get_bounding_box(_ptr, polygon?.nativePtr.cast() ?? Pointer.fromAddress(0));
+    return result.address == 0 ? null : BoundingBoxAttachment.fromPointer(result);
   }
 
   ArrayPolygon get polygons {
@@ -129,14 +131,14 @@ class SkeletonBounds {
     return result;
   }
 
-  BoundingBoxAttachment containsPoint2(double x, double y) {
+  BoundingBoxAttachment? containsPoint2(double x, double y) {
     final result = SpineBindings.bindings.spine_skeleton_bounds_contains_point_2(_ptr, x, y);
-    return BoundingBoxAttachment.fromPointer(result);
+    return result.address == 0 ? null : BoundingBoxAttachment.fromPointer(result);
   }
 
-  BoundingBoxAttachment intersectsSegment(double x1, double y1, double x2, double y2) {
+  BoundingBoxAttachment? intersectsSegment(double x1, double y1, double x2, double y2) {
     final result = SpineBindings.bindings.spine_skeleton_bounds_intersects_segment_1(_ptr, x1, y1, x2, y2);
-    return BoundingBoxAttachment.fromPointer(result);
+    return result.address == 0 ? null : BoundingBoxAttachment.fromPointer(result);
   }
 
   bool intersectsSegment2(Polygon polygon, double x1, double y1, double x2, double y2) {

spine-flutter/lib/generated/skeleton_clipping.dart

@@ -55,9 +55,9 @@ class SkeletonClipping {
     SpineBindings.bindings.spine_skeleton_clipping_dispose(_ptr);
   }
 
-  int clipStart(Skeleton skeleton, Slot slot, ClippingAttachment clip) {
+  int clipStart(Skeleton skeleton, Slot slot, ClippingAttachment? clip) {
     final result = SpineBindings.bindings.spine_skeleton_clipping_clip_start(
-        _ptr, skeleton.nativePtr.cast(), slot.nativePtr.cast(), clip.nativePtr.cast());
+        _ptr, skeleton.nativePtr.cast(), slot.nativePtr.cast(), clip?.nativePtr.cast() ?? Pointer.fromAddress(0));
     return result;
   }
 

spine-flutter/lib/generated/skeleton_data.dart

@@ -58,31 +58,31 @@ class SkeletonData {
     SpineBindings.bindings.spine_skeleton_data_dispose(_ptr);
   }
 
-  BoneData findBone(String boneName) {
+  BoneData? findBone(String boneName) {
     final result = SpineBindings.bindings.spine_skeleton_data_find_bone(_ptr, boneName.toNativeUtf8().cast<Char>());
-    return BoneData.fromPointer(result);
+    return result.address == 0 ? null : BoneData.fromPointer(result);
   }
 
-  SlotData findSlot(String slotName) {
+  SlotData? findSlot(String slotName) {
     final result = SpineBindings.bindings.spine_skeleton_data_find_slot(_ptr, slotName.toNativeUtf8().cast<Char>());
-    return SlotData.fromPointer(result);
+    return result.address == 0 ? null : SlotData.fromPointer(result);
   }
 
-  Skin findSkin(String skinName) {
+  Skin? findSkin(String skinName) {
     final result = SpineBindings.bindings.spine_skeleton_data_find_skin(_ptr, skinName.toNativeUtf8().cast<Char>());
-    return Skin.fromPointer(result);
+    return result.address == 0 ? null : Skin.fromPointer(result);
   }
 
-  EventData findEvent(String eventDataName) {
+  EventData? findEvent(String eventDataName) {
     final result =
         SpineBindings.bindings.spine_skeleton_data_find_event(_ptr, eventDataName.toNativeUtf8().cast<Char>());
-    return EventData.fromPointer(result);
+    return result.address == 0 ? null : EventData.fromPointer(result);
   }
 
-  Animation findAnimation(String animationName) {
+  Animation? findAnimation(String animationName) {
     final result =
         SpineBindings.bindings.spine_skeleton_data_find_animation(_ptr, animationName.toNativeUtf8().cast<Char>());
-    return Animation.fromPointer(result);
+    return result.address == 0 ? null : Animation.fromPointer(result);
   }
 
   String get name {
@@ -109,13 +109,14 @@ class SkeletonData {
     return ArraySkin.fromPointer(result);
   }
 
-  Skin get defaultSkin {
+  Skin? get defaultSkin {
     final result = SpineBindings.bindings.spine_skeleton_data_get_default_skin(_ptr);
-    return Skin.fromPointer(result);
+    return result.address == 0 ? null : Skin.fromPointer(result);
   }
 
-  set defaultSkin(Skin value) {
-    SpineBindings.bindings.spine_skeleton_data_set_default_skin(_ptr, value.nativePtr.cast());
+  set defaultSkin(Skin? value) {
+    SpineBindings.bindings
+        .spine_skeleton_data_set_default_skin(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
   ArrayEventData get events {

spine-flutter/lib/generated/skeleton_json.dart

@@ -60,16 +60,16 @@ class SkeletonJson {
     SpineBindings.bindings.spine_skeleton_json_dispose(_ptr);
   }
 
-  SkeletonData readSkeletonDataFile(String path) {
+  SkeletonData? readSkeletonDataFile(String path) {
     final result =
         SpineBindings.bindings.spine_skeleton_json_read_skeleton_data_file(_ptr, path.toNativeUtf8().cast<Char>());
-    return SkeletonData.fromPointer(result);
+    return result.address == 0 ? null : SkeletonData.fromPointer(result);
   }
 
-  SkeletonData readSkeletonData(String json) {
+  SkeletonData? readSkeletonData(String json) {
     final result =
         SpineBindings.bindings.spine_skeleton_json_read_skeleton_data(_ptr, json.toNativeUtf8().cast<Char>());
-    return SkeletonData.fromPointer(result);
+    return result.address == 0 ? null : SkeletonData.fromPointer(result);
   }
 
   set scale(double value) {

spine-flutter/lib/generated/skeleton_renderer.dart

@@ -53,8 +53,8 @@ class SkeletonRenderer {
     SpineBindings.bindings.spine_skeleton_renderer_dispose(_ptr);
   }
 
-  RenderCommand render(Skeleton skeleton) {
+  RenderCommand? render(Skeleton skeleton) {
     final result = SpineBindings.bindings.spine_skeleton_renderer_render(_ptr, skeleton.nativePtr.cast());
-    return RenderCommand.fromPointer(result);
+    return result.address == 0 ? null : RenderCommand.fromPointer(result);
   }
 }

spine-flutter/lib/generated/skin.dart

@@ -66,8 +66,9 @@ class Skin {
         .spine_skin_set_attachment(_ptr, slotIndex, name.toNativeUtf8().cast<Char>(), attachment.nativePtr.cast());
   }
 
-  Attachment getAttachment(int slotIndex, String name) {
+  Attachment? getAttachment(int slotIndex, String name) {
     final result = SpineBindings.bindings.spine_skin_get_attachment(_ptr, slotIndex, name.toNativeUtf8().cast<Char>());
+    if (result.address == 0) return null;
     final rtti = SpineBindings.bindings.spine_attachment_get_rtti(result);
     final className = SpineBindings.bindings.spine_rtti_get_class_name(rtti).cast<Utf8>().toDartString();
     switch (className) {

spine-flutter/lib/generated/slider_data.dart

@@ -128,17 +128,18 @@ class SliderData extends PosedData implements ConstraintData {
     SpineBindings.bindings.spine_slider_data_set_loop(_ptr, value);
   }
 
-  BoneData get bone {
+  BoneData? get bone {
     final result = SpineBindings.bindings.spine_slider_data_get_bone(_ptr);
-    return BoneData.fromPointer(result);
+    return result.address == 0 ? null : BoneData.fromPointer(result);
   }
 
-  set bone(BoneData value) {
-    SpineBindings.bindings.spine_slider_data_set_bone(_ptr, value.nativePtr.cast());
+  set bone(BoneData? value) {
+    SpineBindings.bindings.spine_slider_data_set_bone(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
-  FromProperty get property {
+  FromProperty? get property {
     final result = SpineBindings.bindings.spine_slider_data_get_property(_ptr);
+    if (result.address == 0) return null;
     final rtti = SpineBindings.bindings.spine_from_property_get_rtti(result);
     final className = SpineBindings.bindings.spine_rtti_get_class_name(rtti).cast<Utf8>().toDartString();
     switch (className) {
@@ -159,8 +160,8 @@ class SliderData extends PosedData implements ConstraintData {
     }
   }
 
-  set property(FromProperty value) {
-    SpineBindings.bindings.spine_slider_data_set_property(_ptr, value.nativePtr.cast());
+  set property(FromProperty? value) {
+    SpineBindings.bindings.spine_slider_data_set_property(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
   double get scale {

spine-flutter/lib/generated/slot_pose.dart

@@ -84,8 +84,9 @@ class SlotPose {
     SpineBindings.bindings.spine_slot_pose_set_has_dark_color(_ptr, value);
   }
 
-  Attachment get attachment {
+  Attachment? get attachment {
     final result = SpineBindings.bindings.spine_slot_pose_get_attachment(_ptr);
+    if (result.address == 0) return null;
     final rtti = SpineBindings.bindings.spine_attachment_get_rtti(result);
     final className = SpineBindings.bindings.spine_rtti_get_class_name(rtti).cast<Utf8>().toDartString();
     switch (className) {
@@ -106,8 +107,8 @@ class SlotPose {
     }
   }
 
-  set attachment(Attachment value) {
-    SpineBindings.bindings.spine_slot_pose_set_attachment(_ptr, value.nativePtr.cast());
+  set attachment(Attachment? value) {
+    SpineBindings.bindings.spine_slot_pose_set_attachment(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
   int get sequenceIndex {

spine-flutter/lib/generated/timeline.dart

@@ -52,10 +52,10 @@ abstract class Timeline {
     return Rtti.fromPointer(result);
   }
 
-  void apply(Skeleton skeleton, double lastTime, double time, ArrayEvent pEvents, double alpha, MixBlend blend,
+  void apply(Skeleton skeleton, double lastTime, double time, ArrayEvent? pEvents, double alpha, MixBlend blend,
       MixDirection direction, bool appliedPose) {
     SpineBindings.bindings.spine_timeline_apply(_ptr, skeleton.nativePtr.cast(), lastTime, time,
-        pEvents.nativePtr.cast(), alpha, blend.value, direction.value, appliedPose);
+        pEvents?.nativePtr.cast() ?? Pointer.fromAddress(0), alpha, blend.value, direction.value, appliedPose);
   }
 
   int get frameEntries {

spine-flutter/lib/generated/track_entry.dart

@@ -67,9 +67,9 @@ class TrackEntry {
     SpineBindings.bindings.spine_track_entry_set_animation(_ptr, value.nativePtr.cast());
   }
 
-  TrackEntry get previous {
+  TrackEntry? get previous {
     final result = SpineBindings.bindings.spine_track_entry_get_previous(_ptr);
-    return TrackEntry.fromPointer(result);
+    return result.address == 0 ? null : TrackEntry.fromPointer(result);
   }
 
   bool get loop {
@@ -221,9 +221,9 @@ class TrackEntry {
     SpineBindings.bindings.spine_track_entry_set_mix_draw_order_threshold(_ptr, value);
   }
 
-  TrackEntry get next {
+  TrackEntry? get next {
     final result = SpineBindings.bindings.spine_track_entry_get_next(_ptr);
-    return TrackEntry.fromPointer(result);
+    return result.address == 0 ? null : TrackEntry.fromPointer(result);
   }
 
   bool get isComplete {
@@ -254,14 +254,14 @@ class TrackEntry {
     SpineBindings.bindings.spine_track_entry_set_mix_blend(_ptr, value.value);
   }
 
-  TrackEntry get mixingFrom {
+  TrackEntry? get mixingFrom {
     final result = SpineBindings.bindings.spine_track_entry_get_mixing_from(_ptr);
-    return TrackEntry.fromPointer(result);
+    return result.address == 0 ? null : TrackEntry.fromPointer(result);
   }
 
-  TrackEntry get mixingTo {
+  TrackEntry? get mixingTo {
     final result = SpineBindings.bindings.spine_track_entry_get_mixing_to(_ptr);
-    return TrackEntry.fromPointer(result);
+    return result.address == 0 ? null : TrackEntry.fromPointer(result);
   }
 
   void resetRotationDirections() {
@@ -288,7 +288,7 @@ class TrackEntry {
     return result;
   }
 
-  Pointer<Void> get rendererObject {
+  Pointer<Void>? get rendererObject {
     final result = SpineBindings.bindings.spine_track_entry_get_renderer_object(_ptr);
     return result;
   }

spine-flutter/lib/generated/vertex_attachment.dart

@@ -86,8 +86,9 @@ abstract class VertexAttachment extends Attachment {
     SpineBindings.bindings.spine_vertex_attachment_set_world_vertices_length(_ptr, value);
   }
 
-  Attachment get timelineAttachment {
+  Attachment? get timelineAttachment {
     final result = SpineBindings.bindings.spine_vertex_attachment_get_timeline_attachment(_ptr);
+    if (result.address == 0) return null;
     final rtti = SpineBindings.bindings.spine_attachment_get_rtti(result);
     final className = SpineBindings.bindings.spine_rtti_get_class_name(rtti).cast<Utf8>().toDartString();
     switch (className) {
@@ -108,8 +109,9 @@ abstract class VertexAttachment extends Attachment {
     }
   }
 
-  set timelineAttachment(Attachment value) {
-    SpineBindings.bindings.spine_vertex_attachment_set_timeline_attachment(_ptr, value.nativePtr.cast());
+  set timelineAttachment(Attachment? value) {
+    SpineBindings.bindings
+        .spine_vertex_attachment_set_timeline_attachment(_ptr, value?.nativePtr.cast() ?? Pointer.fromAddress(0));
   }
 
   void copyTo(VertexAttachment other) {