Provide a Lua Function

Demonstrates implementation of a plugin function that can be registered in the script environment.

Registration

Native plugins can register functions to be called from Lua. Currently these can only be registered in the global table, and cannot replace existing functions of the same name.

This is done using VRFFIRegister.

static HFFIVar multiply(int argc, HFFIVar* argv, void*) {
  return VRFFIMakeDouble(VRFFIGetDouble(argv[0]) * VRFFIGetDouble(argv[1]));
}

PLUGIN_ENTRY_POINT int VRTREE_APIENTRY VRPInit()
{
  VRPLUGIN_LOADVRTREE;

  VRFFIRegister("SpecialMultiply", &multiply, 2, nullptr);

  return 0;
}

print(SpecialMultiply(5, 5)) -- prints 25