Add C++ client example

CHANGELOG.md

@@ -4,7 +4,8 @@
  - Added optional parameter to show more details about a recorder file (related to `show_recorder_file_info.py`)
  - Added playback speed (slow/fast motion) for the replayer
  - We can use an absolute path for the recorded files (to choose where to 'write to' or 'read from')
-* Fixed Lidar effectiveness bug in manual_control.py
+ * Fixed Lidar effectiveness bug in manual_control.py
+ * Added C++ client example using LibCarla
 
 ## CARLA 0.9.5
 

Examples/CppClient/.gitignore

@@ -0,0 +1,5 @@
+/ToolChain.cmake
+/bin
+/build
+/libcarla-install
+_*

Examples/CppClient/Makefile

@@ -0,0 +1,60 @@
+CARLADIR=$(CURDIR)/../..
+BUILDDIR=$(CURDIR)/build
+BINDIR=$(CURDIR)/bin
+INSTALLDIR=$(CURDIR)/libcarla-install
+TOOLCHAIN=$(CURDIR)/ToolChain.cmake
+
+CC=/usr/bin/clang-6.0
+CXX=/usr/bin/clang++-6.0
+CXXFLAGS=-std=c++14 -pthread -fPIC -O3 -DNDEBUG -Werror -Wall -Wextra
+
+define log
+ @echo "\033[1;35m$(1)\033[0m"
+endef
+
+default: build
+
+clean:
+ @rm -rf $(BUILDDIR) $(INSTALLDIR)
+ @rm -f ToolChain.cmake
+
+run: build
+ $(call log,Running C++ Client...)
+ @$(BINDIR)/cpp_client
+
+build: $(BINDIR)/cpp_client
+
+$(BINDIR)/cpp_client: build_libcarla
+ $(call log,Compiling C++ Client...)
+ @mkdir -p $(BINDIR)
+ @$(CXX) $(CXXFLAGS) -I$(INSTALLDIR)/include -L$(INSTALLDIR)/lib \
+ -o $(BINDIR)/cpp_client main.cpp \
+ -Wl,-Bstatic -lcarla_client -lrpc -lboost_filesystem -Wl,-Bdynamic \
+ -lpng -ltiff -ljpeg
+
+build_libcarla: $(TOOLCHAIN)
+ @cd $(CARLADIR); make setup
+ @mkdir -p $(BUILDDIR)
+ $(call log,Compiling LibCarla.client...)
+ @{ \
+ cd $(BUILDDIR); \
+ if [ ! -f "build.ninja" ]; then \
+ cmake \
+ -G "Ninja" \
+ -DCMAKE_BUILD_TYPE=Client \
+ -DLIBCARLA_BUILD_RELEASE=ON \
+ -DLIBCARLA_BUILD_DEBUG=OFF \
+ -DLIBCARLA_BUILD_TEST=OFF \
+ -DCMAKE_TOOLCHAIN_FILE=$(TOOLCHAIN) \
+ -DCMAKE_INSTALL_PREFIX=$(INSTALLDIR) \
+ -DCMAKE_EXPORT_COMPILE_COMMANDS=1 \
+ $(CARLADIR); \
+ fi; \
+ ninja; \
+ ninja install | grep -v "Up-to-date:"; \
+ }
+
+$(TOOLCHAIN):
+ @echo "set(CMAKE_C_COMPILER $(CC))" > $(TOOLCHAIN)
+ @echo "set(CMAKE_CXX_COMPILER $(CXX))" >> $(TOOLCHAIN)
+ @echo "set(CMAKE_CXX_FLAGS \"\$${CMAKE_CXX_FLAGS} $(CXXFLAGS)\" CACHE STRING \"\" FORCE)" >> $(TOOLCHAIN)

Examples/CppClient/README.md

@@ -0,0 +1,75 @@
+C++ Client Example
+==================
+
+This example creates an application using CARLA's C++ API to connect and control
+the simulator from C++.
+
+Compile and run
+---------------
+
+Use the Makefile provided (Linux only), to compile and run the example. Note
+that it expects to have a simulator running at port 2000.
+
+```
+make run
+```
+
+How it works
+------------
+
+In order to link our application against LibCarla, we need to compile LibCarla
+with the same compiler and configuration we are using with our application. To
+do so, we generate a CMake tool-chain file specifying the compiler and flags we
+want
+
+```cmake
+# Example ToolChain.cmake
+set(CMAKE_C_COMPILER /usr/bin/clang-6.0)
+set(CMAKE_CXX_COMPILER /usr/bin/clang++-6.0)
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -std=c++14 -O3 -DNDEBUG" CACHE STRING "" FORCE)
+```
+
+We pass this file to CMake when compiling LibCarla.client
+
+```sh
+cd /path/to/carla-root-folder
+
+make setup
+
+cd /path/to/build-folder
+
+cmake \
+ -G "Ninja" \
+ -DCMAKE_BUILD_TYPE=Client \
+ -DLIBCARLA_BUILD_RELEASE=ON \
+ -DLIBCARLA_BUILD_DEBUG=OFF \
+ -DLIBCARLA_BUILD_TEST=OFF \
+ -DCMAKE_TOOLCHAIN_FILE=/path/to/ToolChain.cmake \
+ -DCMAKE_INSTALL_PREFIX=/path/to/install-folder \
+ /path/to/carla-root-folder
+
+ninja
+ninja install
+```
+
+This will generate the following structure at the provided install path
+
+```
+libcarla-install/
+├── include/
+│ ├── carla/
+│ ├── boost/
+│ ├── rpc/
+│ └── ...
+└── lib/
+ ├── libcarla_client.a
+ ├── librpc.a
+ ├── libboost_filesystem.a
+ └── ...
+```
+
+Our application needs to be linked at minimum against `libcarla_client.a` and
+`librpc.a`. If we make use of IO functionality and/or image processing we would
+need to link against `boost_filesystem`, `png`, `tiff`, and/or `jpeg`.
+
+For more details take a look at the Makefile provided.

Examples/CppClient/main.cpp

@@ -0,0 +1,133 @@
+#include <iostream>
+#include <random>
+#include <sstream>
+#include <stdexcept>
+#include <thread>
+
+#include <carla/client/ActorBlueprint.h>
+#include <carla/client/BlueprintLibrary.h>
+#include <carla/client/Client.h>
+#include <carla/client/Map.h>
+#include <carla/client/Sensor.h>
+#include <carla/client/TimeoutException.h>
+#include <carla/client/World.h>
+#include <carla/geom/Transform.h>
+#include <carla/image/ImageIO.h>
+#include <carla/image/ImageView.h>
+#include <carla/sensor/data/Image.h>
+
+namespace cc = carla::client;
+namespace cg = carla::geom;
+namespace csd = carla::sensor::data;
+
+using namespace std::chrono_literals;
+using namespace std::string_literals;
+
+#define EXPECT_TRUE(pred) if (!(pred)) { throw std::runtime_error(#pred); }
+
+/// Pick a random element from @a range.
+template <typename RangeT, typename RNG>
+static auto &RandomChoice(const RangeT &range, RNG &&generator) {
+ EXPECT_TRUE(range.size() > 0u);
+ std::uniform_int_distribution<size_t> dist{0u, range.size() - 1u};
+ return range[dist(std::forward<RNG>(generator))];
+}
+
+/// Save a semantic segmentation image to disk converting to CityScapes palette.
+static void SaveSemSegImageToDisk(const csd::Image &image) {
+ using namespace carla::image;
+
+ char buffer[9u];
+ std::snprintf(buffer, sizeof(buffer), "%08zu", image.GetFrameNumber());
+ auto filename = "_images/"s + buffer + ".png";
+
+ auto view = ImageView::MakeColorConvertedView(
+ ImageView::MakeView(image),
+ ColorConverter::CityScapesPalette());
+ ImageIO::WriteView(filename, view);
+}
+
+int main() {
+ try {
+
+ std::mt19937_64 rng((std::random_device())());
+
+ auto client = cc::Client("localhost", 2000);
+ client.SetTimeout(10s);
+
+ std::cout << "Client API version : " << client.GetClientVersion() << '\n';
+ std::cout << "Server API version : " << client.GetServerVersion() << '\n';
+
+ // Load a random town.
+ auto town_name = RandomChoice(client.GetAvailableMaps(), rng);
+ std::cout << "Loading world: " << town_name << std::endl;
+ auto world = client.LoadWorld(town_name);
+
+ // Get a random vehicle blueprint.
+ auto blueprint_library = world.GetBlueprintLibrary();
+ auto vehicles = blueprint_library->Filter("vehicle");
+ auto blueprint = RandomChoice(*vehicles, rng);
+
+ // Randomize the blueprint.
+ if (blueprint.ContainsAttribute("color")) {
+ auto &attribute = blueprint.GetAttribute("color");
+ blueprint.SetAttribute(
+ "color",
+ RandomChoice(attribute.GetRecommendedValues(), rng));
+ }
+
+ // Find a valid spawn point.
+ auto map = world.GetMap();
+ auto transform = RandomChoice(map->GetRecommendedSpawnPoints(), rng);
+
+ // Spawn the vehicle.
+ auto actor = world.SpawnActor(blueprint, transform);
+ std::cout << "Spawned " << actor->GetDisplayId() << '\n';
+ auto vehicle = boost::static_pointer_cast<cc::Vehicle>(actor);
+
+ // Apply control to vehicle.
+ cc::Vehicle::Control control;
+ control.throttle = 1.0f;
+ vehicle->ApplyControl(control);
+
+ // Move spectator so we can see the vehicle from the simulator window.
+ auto spectator = world.GetSpectator();
+ transform.location += 32.0f * transform.GetForwardVector();
+ transform.location.z += 2.0f;
+ transform.rotation.yaw += 180.0f;
+ transform.rotation.pitch = -15.0f;
+ spectator->SetTransform(transform);
+
+ // Find a camera blueprint.
+ auto camera_bp = blueprint_library->Find("sensor.camera.semantic_segmentation");
+ EXPECT_TRUE(camera_bp != nullptr);
+
+ // Spawn a camera attached to the vehicle.
+ auto camera_transform = cg::Transform{
+ cg::Location{-5.5f, 0.0f, 2.8f}, // x, y, z.
+ cg::Rotation{-15.0f, 0.0f, 0.0f}}; // pitch, yaw, roll.
+ auto cam_actor = world.SpawnActor(*camera_bp, camera_transform, actor.get());
+ auto camera = boost::static_pointer_cast<cc::Sensor>(cam_actor);
+
+ // Register a callback to save images to disk.
+ camera->Listen([](auto data) {
+ auto image = boost::static_pointer_cast<csd::Image>(data);
+ EXPECT_TRUE(image != nullptr);
+ SaveSemSegImageToDisk(*image);
+ });
+
+ std::this_thread::sleep_for(10s);
+
+ // Remove actors from the simulation.
+ camera->Destroy();
+ vehicle->Destroy();
+ std::cout << "Actors destroyed." << std::endl;
+
+ } catch (const cc::TimeoutException &e) {
+ std::cout << '\n' << e.what() << std::endl;
+ return 1;
+ } catch (const std::exception &e) {
+ std::cout << "\nException: " << e.what() << std::endl;
+ return 2;
+ }
+}

LibCarla/cmake/client/CMakeLists.txt

@@ -194,6 +194,9 @@ if (LIBCARLA_BUILD_RELEASE)
  if (WIN32) # @todo Fix PythonAPI build on Windows.
  set_target_properties(carla_client PROPERTIES COMPILE_FLAGS ${CMAKE_CXX_FLAGS_RELEASE})
  else ()
+ if (NOT DEFINED CMAKE_CXX_FLAGS_RELEASE_CLIENT)
+ set(CMAKE_CXX_FLAGS_RELEASE_CLIENT ${CMAKE_CXX_FLAGS_RELEASE})
+ endif()
  set_target_properties(carla_client PROPERTIES COMPILE_FLAGS ${CMAKE_CXX_FLAGS_RELEASE_CLIENT})
  endif (WIN32)