RmlSolLua

Generate bindings for RmlUi using sol3.

RmlUi's built-in Lua plugin only supports Lua 5.2 and up. This project leverages the sol3 library to generate bindings that are compatible with Lua versions 5.1+ (and LuaJIT 2.1+ and MoonJIT). RmlSolLua also extends the base Lua implementation with many new bindings.

This project requires C++17.

Usage

#include <RmlUi/RmlUi.h>
#include <sol/sol.hpp>
#include <RmlSolLua/RmlSolLua.h>

int main()
{
  // Open the sol3 Lua state.
  sol::state lua;
  lua.open_libraries(sol::lib::base, sol::lib::string, sol::lib::table, sol::lib::math);

  // Initialize RmlUi.
  Backend::Initialize(...);
  Rml::Initialise();

  // Initialize RmlSolLua.
  Rml::SolLua::Initialise(&lua);

  // Do stuff.
  {
    // ...
  }

  // Collect garbage before shutdown.
  // This is needed in RmlUi 5.0 and below to prevent a crash.
  // Alternatively, make sure initialize the RmlSolLua plugin LAST.
  lua.collect_garbage();

  // Shutdown RmlUi.
  // This will also close RmlSolLua.
  Rml::Shutdown();
  Backend::Shutdown();

  return 0;
}

Note

RmlSolLua does not manage your sol3 sol::state. You must ensure it stays in scope until after the call to Rml::Shutdown.

RmlUi 5.0 has a use-after-free bug with plugin shutdown that involves plugins that monitor Rml::Element creation and deletion (like the Debugger plugin). To avoid a crash, you must either initialize RmlSolLua LAST (after Debugger), or call the collect_garbage function on your Lua state right before you shut down RmlUi.

Coverage

RmlSolLua contains all the RmlUi 5.0 Lua bindings EXCEPT:

• custom element instancing
• datagrid sources and formatters

RmlSolLua contains many extra Lua bindings not covered by RmlUi 5.0. There are too many to list, but they can be found in the bindings under src/bind/*.cpp below any //-- comments. Any binding not covered by RmlUi's base Lua bindings are kept separate to be easily identified.

License

RmlSolLua is published under the MIT license.