redeclare implicitly undeclared parameters

src/CameraNode.cpp

@@ -581,6 +581,9 @@ CameraNode::process(libcamera::Request *const request)
       RCLCPP_ERROR_STREAM(get_logger(), "request '" << request->toString() << "' cancelled");
     }
 
+    // redeclare implicitly undeclared parameters
+    parameter_handler.redeclare();
+
     // queue the request again for the next frame
     request->reuse(libcamera::Request::ReuseBuffers);
 

src/ParameterHandler.cpp

@@ -111,6 +111,9 @@ ParameterHandler::declare(const libcamera::ControlInfoMap &controls)
       "}..{" + info.max().toString() + "}" +
       (info.def().isNone() ? std::string {} : " (default: {" + info.def().toString() + "})");
 
+    // store descriptor for later re-declaration
+    parameter_descriptors[id->name()] = descriptor;
+
     // Camera controls can have arrays for minimum and maximum values, but the parameter descriptor
     // only supports scalar bounds. Get smallest bounds for minimum and maximum set and warn user.
     if (info.min().isArray() || info.max().isArray()) {
@@ -199,6 +202,16 @@ ParameterHandler::move_control_values(libcamera::ControlList &controls)
   controls = std::move(control_values);
 }
 
+void
+ParameterHandler::redeclare()
+{
+  for (const auto &[name, _] : camera_controls) {
+    if (!node->has_parameter(name)) {
+      node->declare_parameter(name, rclcpp::ParameterValue {}, parameter_descriptors.at(name), true);
+    }
+  }
+}
+
 void
 ParameterHandler::PreSetResolve(std::vector<rclcpp::Parameter> &parameters)
 {

src/ParameterHandler.hpp

@@ -30,6 +30,9 @@ class ParameterHandler
   void
   move_control_values(libcamera::ControlList &controls);
 
+  void
+  redeclare();
+
 private:
   struct control_info_t
   {
@@ -51,6 +54,8 @@ class ParameterHandler
   libcamera::ControlList control_values;
   std::mutex control_values_lock;
 
+  std::unordered_map<std::string, rcl_interfaces::msg::ParameterDescriptor> parameter_descriptors;
+
   void
   PreSetResolve(std::vector<rclcpp::Parameter> &parameters);