Update build system for Linux

README.md

@@ -1,9 +1,41 @@
 CARLA UE4 Plugin
 ================
 
-To build within a project [CarlaServer](Source/CarlaServer/README.md) needs to
-be built first.
+Plugin for Unreal Engine 4.
 
-See [carla-ue4](https://bitbucket.org/carla-cvc/carla-ue4).
+Compiling a UE4 project with CARLA plugin
+-----------------------------------------
 
+Clone or copy the files of this repository under the folder
+`<project-root>/Plugins/Carla`.
 
+Build CarlaServer located at `<project-root>/Plugins/Carla/Source/CarlaServer`,
+follow the instructions [here](Source/CarlaServer/README.md) to build all the
+necessary dependencies too.
+
+Now compile the Unreal project.
+
+#### Linux
+
+Opening the .uproject file with UE4Editor usually triggers a recompile. If not
+you can follow the next steps to do it manually.
+
+Generate project files
+
+    $ <unreal-installation-path>/GenerateProjectFiles.sh -project="<full-path-to-the-project-root-folder>/<project-name>.uproject" -game -engine
+
+Build project in the in-editor configuration
+
+    $ cd <project-root-folder>
+    $ make <project-name>Editor
+
+Now you can launch the editor.
+
+#### Windows
+
+Usually double-clicking the .uproject file triggers a recompile.
+
+To build from Visual Studio, right-click the project file and select "Generate
+Visual Studio Files". Open the generated solution (.sln) and compile. You can
+change the build configuration to development/debug both in-editor and
+standalone game.

Source/Carla/Carla.Build.cs

@@ -127,7 +127,12 @@ public class Carla : ModuleRules
   {
     if (Target.Platform == UnrealTargetPlatform.Linux)
     {
-      PublicAdditionalLibraries.Add("turbojpeg");
+      string TurboJPEGLibPath = System.Environment.GetEnvironmentVariable("TURBOJPEG_LIB_PATH");
+      if (string.IsNullOrEmpty(TurboJPEGLibPath) || !System.IO.Directory.Exists(TurboJPEGLibPath))
+      {
+        throw new System.Exception("TURBOJPEG_LIB_PATH is not defined, or points to a non-existant directory, please set this environment variable.");
+      }
+      PublicAdditionalLibraries.Add(Path.Combine(TurboJPEGLibPath, "libturbojpeg.a"));
     }
   }
 

Source/CarlaServer/CMakeLists.txt

@@ -90,8 +90,12 @@ endif (UNIX)
 
 if (UNIX)
 
-  set(TurboJPEG_LIBRARIES ${TurboJPEG_LIBRARIES} turbojpeg)
-  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DWITH_TURBOJPEG")
+  if (EXISTS $ENV{TURBOJPEG_LIB_PATH})
+    set(TurboJPEG_LIBRARIES ${TurboJPEG_LIBRARIES} $ENV{TURBOJPEG_LIB_PATH}/libturbojpeg.a)
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DWITH_TURBOJPEG")
+  else (EXISTS $ENV{TURBOJPEG_LIB_PATH})
+    message(FATAL_ERROR "TURBOJPEG_LIB_PATH is not defined, or points to a non-existant directory, please set this environment variable.")
+  endif (EXISTS $ENV{TURBOJPEG_LIB_PATH})
 
 elseif (WIN32)
 

Source/CarlaServer/README.md

@@ -12,19 +12,27 @@ Install boost, protobuf, cmake and ninja.
 
     $ sudo apt-get install libprotobuf-dev protobuf-compiler libboost-all-dev cmake ninja-build
 
-Run make
-
-    $ make
-
 Requires to manually compile
 [TurboJPEG](https://github.com/libjpeg-turbo/libjpeg-turbo).
 Follow the instructions
-[here](https://github.com/libjpeg-turbo/libjpeg-turbo/blob/master/BUILDING.md).
-At the configure step add PIC compile option
+[here](https://github.com/libjpeg-turbo/libjpeg-turbo/blob/master/BUILDING.md),
+but at the configure step make sure to use the compile option -fPIC otherwise
+Unreal is not able to link
 
     $ {source_directory}/configure CFLAGS='-fPIC'
     $ make
 
+Most probably libraries are generated under `.lib` folder.
+
+Set the environment variable `TURBOJPEG_LIB_PATH` to a folder containing the
+generated `libturbojpeg.a` (e.g., add
+`export TURBOJPEG_LIB_PATH=<path-to-the-folder>` to your `~/.bashrc`). This way
+we can find the right version of the library from Unreal Build Tool.
+
+Back to CarlaServer folder, run make
+
+    $ make
+
 #### Windows
 
 Note: JPEG compression is not implemented on Windows, the server won't send any