Working on state for location

src/items/InteractiveObject.cpp

@@ -230,4 +230,31 @@ namespace ZL {
         renderer.RenderUniform1f("uAlpha", 1.0f);
     }
 
+    void InteractiveObjectState::save(nlohmann::json& out) const
+    {
+        out["positionX"] = position.x();
+        out["positionY"] = position.y();
+        out["positionZ"] = position.z();
+        out["rotationY"] = rotationY;
+        out["scale"]     = scale;
+        out["alpha"]     = alpha;
+        out["isActive"]  = isActive;
+        // isAnimating and animTask are not saved: animations snap to their end
+        // state on load (the final position/scale/alpha is already in the fields above).
+    }
+
+    void InteractiveObjectState::load(const nlohmann::json& in)
+    {
+        position.x() = in.value("positionX", position.x());
+        position.y() = in.value("positionY", position.y());
+        position.z() = in.value("positionZ", position.z());
+        rotationY    = in.value("rotationY", rotationY);
+        scale        = in.value("scale",     scale);
+        alpha        = in.value("alpha",     alpha);
+        isActive     = in.value("isActive",  isActive);
+        // Cancel any in-flight animation; state was restored to final values above.
+        isAnimating = false;
+        animTask.reset();
+    }
+
 } // namespace ZL

src/items/InteractiveObjectState.h

@@ -4,6 +4,7 @@
 #include <functional>
 #include <Eigen/Core>
 #include <Eigen/Geometry>
+#include "external/nlohmann/json.hpp"
 
 namespace ZL {
 
@@ -63,6 +64,10 @@ public:
     bool  isActive   = true;
     bool  isAnimating = false;
     std::optional<AnimTask> animTask;
+
+    // --- Serialisation (runtime mutable fields only) ---
+    void save(nlohmann::json& out) const;
+    void load(const nlohmann::json& in);
 };
 
 } // namespace ZL