lol/doc/tutorial/14_lol_lua.cpp

//
//  Lol Engine — Lua tutorial
//
//  Copyright © 2014—2015 Benjamin “Touky” Huet <huet.benjamin@gmail.com>
//
//  Lol Engine is free software. It comes without any warranty, to
//  the extent permitted by applicable law. You can redistribute it
//  and/or modify it under the terms of the Do What the Fuck You Want
//  to Public License, Version 2, as published by the WTFPL Task Force.
//  See http://www.wtfpl.net/ for more details.
//

#if HAVE_CONFIG_H
#   include "config.h"
#endif

#include <lol/engine.h>
#include "loldebug.h"
#include <cstdio>

using namespace lol;

//-----------------------------------------------------------------------------
class DemoObject : public LuaObject
{
    typedef Lolua::VarPtr<DemoObject> LuaDemoObjectPtr;
public:
    DemoObject() : LuaObject() {}
    virtual ~DemoObject() {}
    static DemoObject* New(LuaState* l, int arg_nb)
    {
        UNUSED(l);
        UNUSED(arg_nb);
        return new DemoObject();
    }

    //-------------------------------------------------------------------------
    static int AddFive(LuaState* l)
    {
        LuaInt32 i; i.Get(l, 1);
        i += 5;
        return i.Return(l);
    }
    static int AddTenInstance(LuaState* l)
    {
        LuaStack stack(l);
        LuaDemoObjectPtr obj;
        LuaFloat f;
        stack >> obj >> f;
        f = obj->AddTenMethod(f);
        return f.Return(l);
    }
    float AddTenMethod(float f)
    {
        return (f + 10);
    }

    static int GetX(LuaState* l)
    {
        LuaStack stack(l);
        LuaDemoObjectPtr obj;
        LuaInt32 i;
        stack >> obj;
        i = obj->m_x;
        return stack << i;
    }
    static int SetX(LuaState* l)
    {
        LuaStack stack(l);
        LuaDemoObjectPtr obj;
        LuaInt32 i;
        stack >> obj >> i;
        obj->m_x = i;
        return 0;
    }

    //-------------------------------------------------------------------------
    static const LuaObjectLib* GetLib()
    {
        static const LuaObjectLib lib = LuaObjectLib(
            "LoluaDemo",
            { { "AddFive", &DemoObject::AddFive } },
            { { "AddTenInstance", &DemoObject::AddTenInstance } },
            { { "X", &DemoObject::GetX, &DemoObject::SetX } });
        return &lib;
    }

    int m_x = 0;
};

//-----------------------------------------------------------------------------
static int GlobalAddString(LuaState* l)
{
    LuaString s; s.Get(l, 1);
    s() += "_added";
    return s.Return(l);
}

//-----------------------------------------------------------------------------
class LoluaDemoLoader : public LuaLoader
{
public:
    LoluaDemoLoader() : LuaLoader()
    {
        LuaState* l = GetLuaState();

        //Registering demo object
        LuaObjectDef::Register<DemoObject>(l);

        //Registering function
        LuaFunction add_string(l, "GlobalAddString", &GlobalAddString);
    }
    virtual ~LoluaDemoLoader()
    {

    }
    void TestStuff()
    {
        LuaState* l = GetLuaState();

        /*
        //create property
        lua_pushnumber(l, 5.0);
        lua_setfield(l, -2, "x");

        lua_getglobal(l, "vector");
        int table = lua_istable(l, -1);
        lua_getfield(l, -1, "x");
        Lolua::Var<float> var(l, -1);
        lua_pop(l, 2);
        vec3 t;
        */

        //table = lua_isuserdata(l, -1);
        //Var<T> var(m_lua_state, -1);
        //lua_pop(m_lua_state, 1);
        //lua_getfield (lua_State *L, int index, const char *k);
        //return var.V();
    }
};

//-----------------------------------------------------------------------------
class LoluaDemo : public WorldEntity
{
public:
    LoluaDemo()
    {
    }

    virtual void TickGame(float seconds)
    {
        WorldEntity::TickGame(seconds);

        LoluaDemoLoader* demo_loader = new LoluaDemoLoader();

        //Execute script
        demo_loader->ExecLuaFile("14_lol_lua.lua");
        demo_loader->TestStuff();

        //Grab global test values
        float testvalue_num = demo_loader->GetVar<float>("testvalue_num");
        int32_t testvalue_int = demo_loader->GetVar<int32_t>("testvalue_int");
        uint32_t testvalue_uint = demo_loader->GetVar<uint32_t>("testvalue_uint");
        String testvalue_str = demo_loader->GetVar<String>("testvalue_str");

        //Grab string modified with function
        String function_return = demo_loader->GetVar<String>("function_return");

        //Grab global values modified with DemoObject
        int32_t loluademo_return = demo_loader->GetVar<int32_t>("loluademo_return");
        int32_t loluademo_getx = demo_loader->GetVar<int32_t>("loluademo_getx");
        float loluademo_inst_return = demo_loader->GetVar<float>("loluademo_inst_return");
        DemoObject* loluademo_inst = demo_loader->GetPtr<DemoObject>("loluademo_inst");

        msg::info("Lua Vars: \
            testvalue_num: %.2f, testvalue_int: %i, testvalue_uint: %i, testvalue_str: %s.\n",
            testvalue_num, testvalue_int, testvalue_uint, testvalue_str.C());
        msg::info("Lua Vars: \
            function_return: %s, loluademo_return: %i, loluademo_inst_return: %.f, loluademo_getx: %i, loluademo_inst->m_x: %i.\n",
            function_return.C(), loluademo_return, loluademo_inst_return, loluademo_getx, loluademo_inst->m_x);

        delete demo_loader;

        Ticker::Shutdown();
    }

    virtual void TickDraw(float seconds, Scene &scene)
    {
        WorldEntity::TickDraw(seconds, scene);
    }
};

//-----------------------------------------------------------------------------
int main(int argc, char **argv)
{
    System::Init(argc, argv);

    Application app("Tutorial 14: Lolua Demo", ivec2(800, 600), 60.0f);

    new LoluaDemo();

    app.Run();
    return EXIT_SUCCESS;
}