Add episode info message

Docs/python_api.md

@@ -15,6 +15,8 @@
 
 ## `carla.World`
 
+- `id`
+- `map_name`
 - `get_blueprint_library()`
 - `get_spectator()`
 - `get_weather()`

LibCarla/source/carla/client/World.cpp

@@ -16,6 +16,14 @@
 namespace carla {
 namespace client {
 
+  uint32_t World::GetId() const {
+    return _episode->GetCurrentEpisodeId();
+  }
+
+  const std::string &World::GetMapName() const {
+    return _episode->GetCurrentMapName();
+  }
+
   SharedPtr<BlueprintLibrary> World::GetBlueprintLibrary() const {
     return _episode->GetBlueprintLibrary();
   }

LibCarla/source/carla/client/World.h

@@ -29,6 +29,10 @@ namespace client {
     World &operator=(const World &) = default;
     World &operator=(World &&) = default;
 
+    uint32_t GetId() const;
+
+    const std::string &GetMapName() const;
+
     SharedPtr<BlueprintLibrary> GetBlueprintLibrary() const;
 
     SharedPtr<Actor> GetSpectator() const;

LibCarla/source/carla/client/detail/Client.cpp

@@ -65,10 +65,18 @@ namespace detail {
     _pimpl->rpc_client.set_timeout(timeout.milliseconds());
   }
 
+  std::string Client::GetClientVersion() {
+    return ::carla::version();
+  }
+
   std::string Client::GetServerVersion() {
     return _pimpl->CallAndWait<std::string>("version");
   }
 
+  rpc::EpisodeInfo Client::GetEpisodeInfo() {
+    return _pimpl->CallAndWait<rpc::EpisodeInfo>("get_episode_info");
+  }
+
   std::vector<rpc::ActorDefinition> Client::GetActorDefinitions() {
     return _pimpl->CallAndWait<std::vector<rpc::ActorDefinition>>("get_actor_definitions");
   }

LibCarla/source/carla/client/detail/Client.h

@@ -12,6 +12,7 @@
 #include "carla/geom/Transform.h"
 #include "carla/rpc/Actor.h"
 #include "carla/rpc/ActorDefinition.h"
+#include "carla/rpc/EpisodeInfo.h"
 #include "carla/rpc/WeatherParameters.h"
 
 #include <functional>
@@ -49,8 +50,12 @@ namespace detail {
 
     void SetTimeout(time_duration timeout);
 
+    std::string GetClientVersion();
+
     std::string GetServerVersion();
 
+    rpc::EpisodeInfo GetEpisodeInfo();
+
     std::vector<rpc::ActorDefinition> GetActorDefinitions();
 
     rpc::Actor GetSpectator();

LibCarla/source/carla/client/detail/EpisodeState.h

@@ -17,8 +17,6 @@ namespace detail {
   class EpisodeState : private MovableNonCopyable {
   public:
 
-    EpisodeState() = default; /// @todo
-
     EpisodeState(rpc::EpisodeInfo description)
       : _description(std::move(description)) {}
 

LibCarla/source/carla/client/detail/Simulator.cpp

@@ -19,6 +19,18 @@ namespace carla {
 namespace client {
 namespace detail {
 
+  static void ValidateVersions(Client &client) {
+    const auto vc = client.GetClientVersion();
+    const auto vs = client.GetServerVersion();
+    if (vc != vs) {
+      log_warning(
+          "Version mismatch detected: You are trying to connect to a simulator",
+          "that might be incompatible with this API");
+      log_warning("Client API version:    =", vc);
+      log_warning("Simulator API version  =", vs);
+    }
+  }
+
   // ===========================================================================
   // -- Constructor ------------------------------------------------------------
   // ===========================================================================
@@ -30,10 +42,21 @@ namespace detail {
       const bool enable_garbage_collection)
     : LIBCARLA_INITIALIZE_LIFETIME_PROFILER("SimulatorClient("s + host + ":" + std::to_string(port) + ")"),
       _client(host, port, worker_threads),
-      _episode(), /// @todo
       _gc_policy(enable_garbage_collection ?
         GarbageCollectionPolicy::Enabled : GarbageCollectionPolicy::Disabled) {}
 
+  // ===========================================================================
+  // -- Access to current episode ----------------------------------------------
+  // ===========================================================================
+
+  EpisodeProxy Simulator::GetCurrentEpisode() {
+    if (_episode == nullptr) {
+      ValidateVersions(_client);
+      _episode = std::make_unique<EpisodeState>(_client.GetEpisodeInfo());
+    }
+    return EpisodeProxy{shared_from_this()};
+  }
+
   // ===========================================================================
   // -- Access to global objects in the episode --------------------------------
   // ===========================================================================

LibCarla/source/carla/client/detail/Simulator.h

@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include "carla/Debug.h"
 #include "carla/Memory.h"
 #include "carla/NonCopyable.h"
 #include "carla/Version.h"
@@ -54,13 +55,17 @@ namespace detail {
     /// @{
 
     auto GetCurrentEpisodeId() const {
-      return _episode.GetId();
+      DEBUG_ASSERT(_episode != nullptr);
+      return _episode->GetId();
     }
 
-    EpisodeProxy GetCurrentEpisode() {
-      return EpisodeProxy{shared_from_this()};
+    const std::string &GetCurrentMapName() const {
+      DEBUG_ASSERT(_episode != nullptr);
+      return _episode->GetMapName();
     }
 
+    EpisodeProxy GetCurrentEpisode();
+
     /// @}
     // =========================================================================
     /// @name Garbage collection policy
@@ -82,7 +87,7 @@ namespace detail {
     }
 
     std::string GetClientVersion() {
-      return ::carla::version();
+      return _client.GetClientVersion();
     }
 
     std::string GetServerVersion() {
@@ -165,7 +170,7 @@ namespace detail {
 
     Client _client;
 
-    EpisodeState _episode;
+    std::unique_ptr<EpisodeState> _episode;
 
     GarbageCollectionPolicy _gc_policy;
   };

PythonAPI/source/libcarla/World.cpp

@@ -24,6 +24,8 @@ void export_world() {
     (arg("blueprint"), arg("transform"), arg("attach_to")=carla::SharedPtr<cc::Actor>())
 
   class_<cc::World>("World", no_init)
+    .add_property("id", &cc::World::GetId)
+    .add_property("map_name", CALL_RETURNING_COPY(cc::World, GetMapName))
     .def("get_blueprint_library", CONST_CALL_WITHOUT_GIL(cc::World, GetBlueprintLibrary))
     .def("get_spectator", CONST_CALL_WITHOUT_GIL(cc::World, GetSpectator))
     .def("get_weather", CONST_CALL_WITHOUT_GIL(cc::World, GetWeather))

Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Game/CarlaEpisode.cpp

@@ -10,6 +10,13 @@
 #include "EngineUtils.h"
 #include "GameFramework/SpectatorPawn.h"
 
+UCarlaEpisode::UCarlaEpisode(const FObjectInitializer &ObjectInitializer)
+  : Super(ObjectInitializer),
+    Id([]() {
+      static uint32 COUNTER = 0u;
+      return ++COUNTER;
+    }()) {}
+
 void UCarlaEpisode::InitializeAtBeginPlay()
 {
   auto World = GetWorld();

Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Game/CarlaEpisode.h

@@ -21,6 +21,13 @@ class CARLA_API UCarlaEpisode : public UObject
 
 public:
 
+  UCarlaEpisode(const FObjectInitializer &ObjectInitializer);
+
+  auto GetId() const
+  {
+    return Id;
+  }
+
   UFUNCTION(BlueprintCallable)
   const FString &GetMapName() const
   {
@@ -97,6 +104,8 @@ private:
     ActorDispatcher.Bind(ActorFactory);
   }
 
+  const uint32 Id = 0u;
+
   UPROPERTY(VisibleAnywhere)
   FString MapName;
 

Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Server/TheNewCarlaServer.cpp

@@ -16,6 +16,7 @@
 #include <carla/rpc/Actor.h>
 #include <carla/rpc/ActorDefinition.h>
 #include <carla/rpc/ActorDescription.h>
+#include <carla/rpc/EpisodeInfo.h>
 #include <carla/rpc/Server.h>
 #include <carla/rpc/Transform.h>
 #include <carla/rpc/VehicleControl.h>
@@ -133,7 +134,12 @@ void FTheNewCarlaServer::FPimpl::BindActions()
 
   Server.BindAsync("ping", []() { return true; });
 
-  Server.BindAsync("version", []() { return std::string(carla::version()); });
+  Server.BindAsync("version", []() -> std::string { return carla::version(); });
+
+  Server.BindSync("get_episode_info", [this]() -> cr::EpisodeInfo {
+    RequireEpisode();
+    return {Episode->GetId(), cr::FromFString(Episode->GetMapName())};
+  });
 
   Server.BindSync("get_actor_definitions", [this]() {
     RequireEpisode();