LuaScript

class rlogic::LuaScript : public rlogic::LogicNode

The LuaScript class is the cornerstone of RAMSES Logic as it encapsulates a Lua script and the associated with it Lua environment. LuaScript instances are created by the rlogic::LogicEngine class.

A LuaScript can be created from Lua source code which must fulfill following requirements:

  • valid Lua 5.1 syntax

  • contains two global functions - interface() and run() with no parameters and no return values

  • declares its inputs and outputs in the interface() function, and its logic in the run() function

  • the interface() function declares zero or more inputs and outputs to the IN and OUT global symbols

  • inputs and outputs are declared like this: 

    function interface()
    IN.input_name = TYPE
    OUT.output_name = TYPE
end

  • TYPE is one of [INT|FLOAT|BOOL|STRING|VEC2F|VEC3F|VEC4F|VEC2I|VEC3I|VEC4I], or…

  • TYPE can be also a Lua table with nested properties, obeying the same rules as above, or…

  • TYPE can be an array declaration of the form ARRAY(n, T) where:

    • n is a positive integer

    • T obeys the same rules as TYPE, except T can not be an ARRAY itself

    • T can be a struct, i.e. arrays of structs are supported

  • Each property must have a name (string) - other types like number, bool etc. are not supported as keys

  • TYPE can also be defined in a module, see rlogic::LuaModule for details

  • the run() function only accesses the IN and OUT global symbols and the properties defined by it

Violating any of these requirements will result in errors, which can be obtained by calling rlogic::LogicEngine::getErrors(). The LuaScript object encapsulates a Lua environment (see official Lua docs) which strips all global table entries after the script is loaded to the Lua state, and leaves only the run() function. Note that none of the TYPE labels should be used in user code (outside of run() at least) for other than interface definition purposes, see rlogic::LuaModule for details.

See also the full documentation at https://ramses-logic.readthedocs.io/en/latest/api.html for more details on Lua and its interaction with C++.

Public Functions

void overrideLuaPrint(LuaPrintFunction luaPrintFunction)

Overrides the lua print function with a custom function. Each time “print” is used inside a lua script, the function will be called. Because the lua “print” function allows an arbitrary amount of parameters, the function is called for each provided parameter.

Parameters

  • luaPrintFunction: to use for printing

LuaScript(std::unique_ptr<internal::LuaScriptImpl> impl) noexcept

Constructor of LuaScript. User is not supposed to call this - script are created by other factory classes

Parameters

  • impl: implementation details of the script

~LuaScript() noexcept override

Destructor of LuaScript

LuaScript(const LuaScript &other) = delete

Copy Constructor of LuaScript is deleted because scripts are not supposed to be copied

Parameters

  • other: script to copy from

LuaScript(LuaScript &&other) = delete

Move Constructor of LuaScript is deleted because scripts are not supposed to be moved

Parameters

  • other: script to move from

LuaScript &operator=(const LuaScript &other) = delete

Assignment operator of LuaScript is deleted because scripts are not supposed to be copied

Parameters

  • other: script to assign from

LuaScript &operator=(LuaScript &&other) = delete

Move assignment operator of LuaScript is deleted because scripts are not supposed to be moved

Parameters

  • other: script to move from

Public Members

internal::LuaScriptImpl &m_script

Implementation detail of LuaScript