[cpp] Add pose architecture foundation for 4.3-beta

- Replace Updatable interface with Update interface
- Add Pose<P> template interface for pose management
- Add PosedData<P> abstract base class for setup data
- Add Posed<D,P,A> base class linking data, pose, and applied states
- Add PosedActive<D,P,A> extending Posed with active state management
- Update spine.h to include new pose system headers

This implements the foundational pose architecture required for the 4.3-beta
constraint system overhaul. The new pose-based system provides better separation
of concerns and enables more flexible constraint management.

.gitignore

@@ -222,3 +222,7 @@ spine-godot/vc140.pdb
 spine-godot/example-v4-extension/bin
 spine-godot/example-v4-extension/MoltenVK.xcframework
 spine-flutter/example/android/app/.cxx
+CLAUDE.md
+.claude
+port-plan.md
+port-todo.md

spine-cpp/spine-cpp/include/spine/Pose.h

@@ -27,28 +27,17 @@
  * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *****************************************************************************/
 
-#ifndef Spine_Updatable_h
-#define Spine_Updatable_h
-
-#include <spine/RTTI.h>
-#include <spine/SpineObject.h>
-#include <spine/Physics.h>
+#ifndef Spine_Pose_h
+#define Spine_Pose_h
 
 namespace spine {
-	class SP_API Updatable : public SpineObject {
-	RTTI_DECL
-
+	template<typename P>
+	class Pose {
 	public:
-		Updatable();
+		virtual ~Pose() {}
 
-		virtual ~Updatable();
-
-		virtual void update(Physics physics) = 0;
-
-		virtual bool isActive() = 0;
-
-		virtual void setActive(bool inValue) = 0;
+		virtual void set(const P& pose) = 0;
 	};
 }
 
-#endif /* Spine_Updatable_h */
+#endif /* Spine_Pose_h */

spine-cpp/spine-cpp/include/spine/Posed.h

@@ -0,0 +1,83 @@
+/******************************************************************************
+ * Spine Runtimes License Agreement
+ * Last updated April 5, 2025. Replaces all prior versions.
+ *
+ * Copyright (c) 2013-2025, Esoteric Software LLC
+ *
+ * Integration of the Spine Runtimes into software or otherwise creating
+ * derivative works of the Spine Runtimes is permitted under the terms and
+ * conditions of Section 2 of the Spine Editor License Agreement:
+ * http://esotericsoftware.com/spine-editor-license
+ *
+ * Otherwise, it is permitted to integrate the Spine Runtimes into software
+ * or otherwise create derivative works of the Spine Runtimes (collectively,
+ * "Products"), provided that each user of the Products must obtain their own
+ * Spine Editor license and redistribution of the Products in any form must
+ * include this license and copyright notice.
+ *
+ * THE SPINE RUNTIMES ARE PROVIDED BY ESOTERIC SOFTWARE LLC "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL ESOTERIC SOFTWARE LLC BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES,
+ * BUSINESS INTERRUPTION, OR LOSS OF USE, DATA, OR PROFITS) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************/
+
+#ifndef Spine_Posed_h
+#define Spine_Posed_h
+
+#include <spine/SpineObject.h>
+#include <spine/PosedData.h>
+#include <spine/Pose.h>
+
+namespace spine {
+	template<typename D, typename P, typename A>
+	class Posed : public SpineObject {
+	public:
+		Posed(D& data, P& pose, A& constrained) : _data(data), _pose(pose), _constrained(constrained), _applied(&pose) {
+		}
+
+		virtual ~Posed() {}
+
+		void setupPose() {
+			_pose.set(_data.getSetupPose());
+		}
+
+		/// The constraint's setup pose data.
+		D& getData() {
+			return _data;
+		}
+
+		const D& getData() const {
+			return _data;
+		}
+
+		P& getPose() {
+			return _pose;
+		}
+
+		const P& getPose() const {
+			return _pose;
+		}
+
+		A& getAppliedPose() {
+			return *_applied;
+		}
+
+		const A& getAppliedPose() const {
+			return *_applied;
+		}
+
+	protected:
+		D& _data;
+		P& _pose;
+		A& _constrained;
+		A* _applied;
+	};
+}
+
+#endif /* Spine_Posed_h */

spine-cpp/spine-cpp/include/spine/PosedActive.h

@@ -0,0 +1,61 @@
+/******************************************************************************
+ * Spine Runtimes License Agreement
+ * Last updated April 5, 2025. Replaces all prior versions.
+ *
+ * Copyright (c) 2013-2025, Esoteric Software LLC
+ *
+ * Integration of the Spine Runtimes into software or otherwise creating
+ * derivative works of the Spine Runtimes is permitted under the terms and
+ * conditions of Section 2 of the Spine Editor License Agreement:
+ * http://esotericsoftware.com/spine-editor-license
+ *
+ * Otherwise, it is permitted to integrate the Spine Runtimes into software
+ * or otherwise create derivative works of the Spine Runtimes (collectively,
+ * "Products"), provided that each user of the Products must obtain their own
+ * Spine Editor license and redistribution of the Products in any form must
+ * include this license and copyright notice.
+ *
+ * THE SPINE RUNTIMES ARE PROVIDED BY ESOTERIC SOFTWARE LLC "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL ESOTERIC SOFTWARE LLC BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES,
+ * BUSINESS INTERRUPTION, OR LOSS OF USE, DATA, OR PROFITS) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************/
+
+#ifndef Spine_PosedActive_h
+#define Spine_PosedActive_h
+
+#include <spine/Posed.h>
+
+namespace spine {
+	template<typename D, typename P, typename A>
+	class PosedActive : public Posed<D, P, A> {
+	public:
+		PosedActive(D& data, P& pose, A& constrained) : Posed<D, P, A>(data, pose, constrained), _active(false) {
+			this->setupPose();
+		}
+
+		virtual ~PosedActive() {}
+
+		/// Returns false when this constraint won't be updated by
+		/// Skeleton::updateWorldTransform(Physics) because a skin is required and the
+		/// active skin does not contain this item.
+		/// @see Skin::getBones()
+		/// @see Skin::getConstraints()
+		/// @see PosedData::getSkinRequired()
+		/// @see Skeleton::updateCache()
+		bool isActive() const {
+			return _active;
+		}
+
+	protected:
+		bool _active;
+	};
+}
+
+#endif /* Spine_PosedActive_h */

spine-cpp/spine-cpp/include/spine/PosedData.h

@@ -0,0 +1,79 @@
+/******************************************************************************
+ * Spine Runtimes License Agreement
+ * Last updated April 5, 2025. Replaces all prior versions.
+ *
+ * Copyright (c) 2013-2025, Esoteric Software LLC
+ *
+ * Integration of the Spine Runtimes into software or otherwise creating
+ * derivative works of the Spine Runtimes is permitted under the terms and
+ * conditions of Section 2 of the Spine Editor License Agreement:
+ * http://esotericsoftware.com/spine-editor-license
+ *
+ * Otherwise, it is permitted to integrate the Spine Runtimes into software
+ * or otherwise create derivative works of the Spine Runtimes (collectively,
+ * "Products"), provided that each user of the Products must obtain their own
+ * Spine Editor license and redistribution of the Products in any form must
+ * include this license and copyright notice.
+ *
+ * THE SPINE RUNTIMES ARE PROVIDED BY ESOTERIC SOFTWARE LLC "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL ESOTERIC SOFTWARE LLC BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES,
+ * BUSINESS INTERRUPTION, OR LOSS OF USE, DATA, OR PROFITS) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************/
+
+#ifndef Spine_PosedData_h
+#define Spine_PosedData_h
+
+#include <spine/SpineObject.h>
+#include <spine/SpineString.h>
+#include <spine/Pose.h>
+
+namespace spine {
+	/// The base class for all constrained datas.
+	template<typename P>
+	class PosedData : public SpineObject {
+	public:
+		PosedData(const String& name, P& setup) : _name(name), _setup(setup), _skinRequired(false) {
+		}
+
+		virtual ~PosedData() {}
+
+		/// The constraint's name, which is unique across all constraints in the skeleton of the same type.
+		const String& getName() const {
+			return _name;
+		}
+
+		P& getSetupPose() {
+			return _setup;
+		}
+
+		const P& getSetupPose() const {
+			return _setup;
+		}
+
+		/// When true, Skeleton::updateWorldTransform(Physics) only updates this constraint if the Skeleton::getSkin()
+		/// contains this constraint.
+		/// 
+		/// See Skin::getConstraints().
+		bool getSkinRequired() const {
+			return _skinRequired;
+		}
+
+		void setSkinRequired(bool skinRequired) {
+			_skinRequired = skinRequired;
+		}
+
+	protected:
+		const String _name;
+		P& _setup;
+		bool _skinRequired;
+	};
+}
+
+#endif /* Spine_PosedData_h */

spine-cpp/spine-cpp/include/spine/Update.h

@@ -0,0 +1,55 @@
+/******************************************************************************
+ * Spine Runtimes License Agreement
+ * Last updated April 5, 2025. Replaces all prior versions.
+ *
+ * Copyright (c) 2013-2025, Esoteric Software LLC
+ *
+ * Integration of the Spine Runtimes into software or otherwise creating
+ * derivative works of the Spine Runtimes is permitted under the terms and
+ * conditions of Section 2 of the Spine Editor License Agreement:
+ * http://esotericsoftware.com/spine-editor-license
+ *
+ * Otherwise, it is permitted to integrate the Spine Runtimes into software
+ * or otherwise create derivative works of the Spine Runtimes (collectively,
+ * "Products"), provided that each user of the Products must obtain their own
+ * Spine Editor license and redistribution of the Products in any form must
+ * include this license and copyright notice.
+ *
+ * THE SPINE RUNTIMES ARE PROVIDED BY ESOTERIC SOFTWARE LLC "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL ESOTERIC SOFTWARE LLC BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES,
+ * BUSINESS INTERRUPTION, OR LOSS OF USE, DATA, OR PROFITS) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************/
+
+#ifndef Spine_Update_h
+#define Spine_Update_h
+
+#include <spine/RTTI.h>
+#include <spine/SpineObject.h>
+#include <spine/Physics.h>
+
+namespace spine {
+	class Skeleton;
+
+	/// The interface for items updated by Skeleton::updateWorldTransform(Physics).
+	class SP_API Update : public SpineObject {
+	RTTI_DECL
+
+	public:
+		Update();
+
+		virtual ~Update();
+
+		/// @param skeleton The skeleton being updated.
+		/// @param physics Determines how physics and other non-deterministic updates are applied.
+		virtual void update(Skeleton& skeleton, Physics physics) = 0;
+	};
+}
+
+#endif /* Spine_Update_h */

spine-cpp/spine-cpp/include/spine/spine.h

@@ -107,7 +107,11 @@
 #include <spine/TransformConstraintTimeline.h>
 #include <spine/TranslateTimeline.h>
 #include <spine/Triangulator.h>
-#include <spine/Updatable.h>
+#include <spine/Update.h>
+#include <spine/Pose.h>
+#include <spine/PosedData.h>
+#include <spine/Posed.h>
+#include <spine/PosedActive.h>
 #include <spine/Vector.h>
 #include <spine/VertexAttachment.h>
 #include <spine/Vertices.h>

spine-cpp/spine-cpp/src/spine/Update.cpp

@@ -27,14 +27,14 @@
  * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *****************************************************************************/
 
-#include <spine/Updatable.h>
+#include <spine/Update.h>
 
 using namespace spine;
 
-RTTI_IMPL_NOPARENT(Updatable)
+RTTI_IMPL_NOPARENT(Update)
 
-Updatable::Updatable() {
+Update::Update() {
 }
 
-Updatable::~Updatable() {
-}
+Update::~Update() {
+}