Vizor Infraworld Cornerstone

Cornerstone is a fast and robust converter utility, used to generate UE4-friendly code to provide gRPC functionality into your game. The generated code can be used for both C++ and Blueprints, and thus should be placed into your project's Source or Plugin's source folder to be able to be compiled and executed. You shouldn't modify the generated code (at least within normal, not debug conditions). Instead if you want some behavior change - you should look into the Options section.

It has to be used with the Infraworld Runtime plugin for Unreal Engine 4.

Building

You need a JDK 8+ installation (we recommend Java SE Development Kit 8u172, but it was tested to be built and ran alongside with Java9 or Java10 as well).

Being written 100% in Java 8, Cornerstone can be built using Maven (See how to intstall Maven for Windows, but I definitely recommend you to use chocolatey for package management).

To build the converter executable and run it's tests, just run:

mvn package

Then you can find built jar as target/cornerstone.jar. Since it is compiled as an executable jar, you may run it by just using:

java -jar target/cornerstone.jar

Usage

Since Cornerstone is a quite complex program, it uses command line arguments and/or configuration YML files to decide what to do. Cornerstone has to be built with it's base configuration file to define some base options.

Two possible ways to re-define options are:

• To copy the base configuration file and place at it the same level as compiled jar. Then feel free to modify any option as you want. This saves you from providing every single option as command line option each time you run the converter.
• To use command line arguments (run the jar with --help option to see the list of all available options). Note that command line options are 'prime' options and they can override options, taken from the config. One more time:

Command line option > Override config option > Base config option

List of available options:

• src_path A path, where *.proto source files are.
• dst_public_path A path, where public generated C++ files containing structures for messages and classes for RPC clients should be placed.
• dst_private_path A path, where private generated C++ files should be placed, containing implementations of RPC clients and helpers for ProtoCasts.
• module_name Name of the module (Required to compute an API, like MYMODULE_API for MyModule module name). Left it blank if you don't want to use API. If not left blank, it mustn't contain any spaces, this is checked in run-time.
• precompiled_header An Unreal Header Tool requires each *.cpp file to include a precompiled header or PCH, here you may define, which header is had to be used. In case you're using precompiled headers - provide a valid relative or absolute path to the precompiled header.
• wrappers_path Name of the folder, where files generated by proto compiler (protoc) should reside.
• company_name Company name will be used to declare category, where RPC methods will be placed.
• log_level Override log level if you want to. May be ignored, then log4j2.xml will be used.
• no_fork Set to true to force the converter to work in the single thread. False by default.

Additional options (only available from CLI):

• --help Prints help message and lists all available commands
• --credits Outputs the creators of Cornerstone

Limitations

Despite the fact, that both proto2 and proto3 syntaxes are supported, there's several limitations applied to your code:

• oneof fields are supported, but generated UE4 equivalent TVariant is not supported by blueprints.
• No support for group statement yet.
• No support for nested containers, e.g. you can't delcare a map<map<int32, string>, string>, because it isn't supported in UE4, note that you can use bytes (which is actually a container type) for map's key and/or value type, bytes field can be repeated.

Debugging

Since Cornerstone is an open source software, you may want to debug it or add some extra functionality. Since it is distributed as Maven project, you can import it as a Maven solution for Eclipse, Intellij IDEA or any of your favorite Java IDE.

Contribution

Please feel free to report known bugs, propose new features and improve tests using Github's pull request system. Thank you very much for contributing into free software.