LuaScriptEngine.cpp

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#include "LuaScriptEngine.hpp"
 
#include "LuaScript.hpp"
#include "LuaScriptQueue.hpp"
#include "LuaContextManager.hpp"
#include "LuaFunctions.hpp"
 
#include "Logger.hpp"
 
namespace BARE2D {
 
    LuaScriptEngine::LuaScriptEngine()
    {
    }
 
    LuaScriptEngine::~LuaScriptEngine()
    {
        // Lua automatically garbage collects.
    }
 
    void LuaScriptEngine::init(std::string luaModulesPath)
    {
        // Create the master state
        m_masterState = luaL_newstate();
        
        // now load all the standard Lua libraries for the master state
        luaL_openlibs(m_masterState);
        
        // Set the package.path variable for Lua so that extra user-created modules can be loaded in.
        // Put the global variable's name on the stack
        lua_getglobal(m_masterState, "package");
        // Push the path identifier for any and all modules
        lua_pushstring(m_masterState, std::string(luaModulesPath + "/?.lua").c_str());
        // Now set package**.path** instead of just package (combines items on the stack, popping the value - the path in this case)
        lua_setfield(m_masterState, -2, "path");
        // Clean up, popping the whole item.
        lua_pop(m_masterState, 1);
        
        // register the delay() function.
        registerCFunction(LuaFunctions::delay, "delay");
        // register the print() function
        registerCFunction(LuaFunctions::print, "print");
    }
 
    void LuaScriptEngine::registerModule(std::string filename)
    {
        throwError(BAREError::UNINITIALIZED_FUNCTION, "LuaScriptEngine::registerModule");
    }
 
    void LuaScriptEngine::registerCFunction(lua_CFunction function, std::string name)
    {
        // Needs to add a C-function to the masterState
        // Push the function to the stack with no closure variables (this is equivalent to lua_pushcclosure(L, func, 0) as stated in the docs
        lua_pushcfunction(m_masterState, function);
        // Pop the function from the stack and create a global with name `name`
        lua_setglobal(m_masterState, name.c_str());
    }
    
    // addValueToRegistry is defined in the LuaScriptEngine_impl.tcc template file.
 
    void LuaScriptEngine::update()
    {
        // First, update all the contexts which are already running
        LuaContextManager::getInstance()->update();
        
        // Second, convert all new LuaScripts on the queue to LuaContextWrappers
        // Use a for each loop because we're fancy like that
        for(std::pair<unsigned int, LuaScript*> e : LuaScriptQueue::getInstance()->getQueue()) {
            // Create the new context wrapper jazz for a new script to run in
            LuaScriptContextWrapper* context = createLuaContext(e.second);
            
            // Activate it
            context->start();
            
            // Throw it on into the context manager with the ID given before (that's the e.first part.)
            LuaContextManager::getInstance()->addContext(e.first, context);
        }
        // Clear the queue - we've activated all the scripts
        LuaScriptQueue::getInstance()->clearQueue();
    }
 
    LuaScriptContextWrapper* LuaScriptEngine::createLuaContext(LuaScript* script)
    {
        // Allocate the memory for a new one
        LuaScriptContextWrapper* context = new LuaScriptContextWrapper();
        // Actually initialize it.
        context->init(m_masterState, script);
        
        return context;
    }
    
    lua_State* LuaScriptEngine::getMasterState() {
        return m_masterState;
    }
 
}