转让lua性能executeGlobalFunction

没有其他的，搞搞cocos2dx的lua文字，话lua这件事情在几年前学过一段时间。还曾对自己c++介面，我已经做了一些小东西。只是时间的流逝，模糊记忆。

拿起点功夫和成本。下面是我的一些经验。





cocos2dx运用tolua++来制作的lua接口，tolua++文档不多，网上的一些文章也是答非所问，所以自己看代码是最佳学习途径。

cocos2dx操作lua的类是CCLuaEngine，当中实现了载入与实行lua脚本。以及操作lua stack。

LuaCocos2d.cpp非常主要，文件的开头凝视也说明其是由tolua++自己主动生成的，我们想在lua中操作自定义的类就是通过改动此文件实现的，两个重要函数是void tolua_reg_types (lua_State* tolua_S)与int tolua_Cocos2d_open (lua_State* tolua_S)，前者是注冊自定义类型，后者是定义其接口，调用关系是tolua_Cocos2d_open调用tolua_reg_types，而tolua_Cocos2d_open是在CCLuaEngine的init中调用的。

如果我要向lua注冊新类。那么首先我要在tolua_reg_types中加入一行注冊代码，然后在tolua_Cocos2d_open加入其接口说明。我将这两个步骤定义成两个函数，单独在一个文件里实现。文件名称为cwLuaReg.cpp，内容为：

#include "cwLuaReg.h"





#include "cwGameObject.h"

#include "cwCollisionObject.h"

#include "cwGravityObject.h"





#ifdef __cplusplus





static int tolua_collect_cwGameObject(lua_State* tolua_S)

{

    cwGameObject* self = (cwGameObject*) tolua_tousertype(tolua_S,1,0);

    delete self;

    return 0;

}





static int tolua_collect_cwGravityObject(lua_State* tolua_S)

{

    cwGravityObject* self = (cwGravityObject*) tolua_tousertype(tolua_S,1,0);

    delete self;

    return 0;

}





#ifndef TOLUA_DISABLE_tolua_cw_GameObject_create00

static int tolua_cw_GameObject_create00(lua_State* tolua_S)

{

    tolua_Error tolua_err;

    if(!tolua_isusertable(tolua_S,1,"cwGameObject",0,&tolua_err) ||

        !tolua_isnoobj(tolua_S,2,&tolua_err))

        goto tolua_lerror;

    else

    {

        {

            cwGameObject* tolua_ret = (cwGameObject*)  cwGameObject::create();

            int nID = (tolua_ret) ? (int)tolua_ret->m_uID : -1;

            int* pLuaID = (tolua_ret) ?

&tolua_ret->m_nLuaID : NULL;

            toluafix_pushusertype_ccobject(tolua_S, nID, pLuaID, (void*)tolua_ret,"cwGameObject");

        }

    }

    return 1;

tolua_lerror:

    return 0;

}

#endif //#ifndef TOLUA_DISABLE





#ifndef TOLUA_DISABLE_tolua_cw_GameObject_getSpeed00

static int tolua_cw_GameObject_getSpeed00(lua_State* tolua_S)

{

#ifndef TOLUA_RELEASE

    tolua_Error tolua_err;

    if (!tolua_isusertype(tolua_S,1,"cwGameObject",0,&tolua_err) ||

        !tolua_isnoobj(tolua_S,2,&tolua_err))

        goto tolua_lerror;

    else

#endif

    {

        cwGameObject* self = (cwGameObject*)  tolua_tousertype(tolua_S,1,0);

#ifndef TOLUA_RELEASE

        if (!self) tolua_error(tolua_S,"invalid 'self' in function 'speed'", NULL);

#endif

        {

            float tolua_ret = (float)  self->speed();

            tolua_pushnumber(tolua_S,(lua_Number)tolua_ret);

        }

    }

    return 1;

#ifndef TOLUA_RELEASE

    tolua_lerror:

    tolua_error(tolua_S,"#ferror in function 'speed'.",&tolua_err);

    return 0;

#endif

}

#endif





#ifndef TOLUA_DISABLE_tolua_cw_GameObject_setSpeed00

static int tolua_cw_GameObject_setSpeed00(lua_State* tolua_S)

{

#ifndef TOLUA_RELEASE

    tolua_Error tolua_err;

    if (!tolua_isusertype(tolua_S,1,"cwGameObject",0,&tolua_err) ||

        !tolua_isnumber(tolua_S,2,0,&tolua_err) ||

        !tolua_isnoobj(tolua_S,3,&tolua_err))

        goto tolua_lerror;

    else

#endif

    {

        cwGameObject* self = (cwGameObject*)  tolua_tousertype(tolua_S,1,0);

        float speed = ((float)  tolua_tonumber(tolua_S,2,0));

#ifndef TOLUA_RELEASE

        if (!self) tolua_error(tolua_S,"invalid 'self' in function 'setSpeed'", NULL);

#endif

        {

            self->setSpeed(speed);

        }

    }

    return 0;

#ifndef TOLUA_RELEASE

    tolua_lerror:

    tolua_error(tolua_S,"#ferror in function 'setSpeed'.",&tolua_err);

    return 0;

#endif

}

#endif





#ifndef TOLUA_DISABLE_tolua_cw_GameObject_getMoveDir00

static int tolua_cw_GameObject_getMoveDir00(lua_State* tolua_S)

{

#ifndef TOLUA_RELEASE

    tolua_Error tolua_err;

    if (!tolua_isusertype(tolua_S,1,"cwGameObject",0,&tolua_err) ||

        !tolua_isnoobj(tolua_S,2,&tolua_err))

        goto tolua_lerror;

    else

#endif

    {

        cwGameObject* self = (cwGameObject*)  tolua_tousertype(tolua_S,1,0);

#ifndef TOLUA_RELEASE

        if (!self) tolua_error(tolua_S,"invalid 'self' in function 'getMoveDir'", NULL);

#endif

        cwVector2D& dir = self->moveDir();

        tolua_pushnumber(tolua_S,(lua_Number)dir.x);

        tolua_pushnumber(tolua_S,(lua_Number)dir.y);

    }

    return 2;

#ifndef TOLUA_RELEASE

    tolua_lerror:

    tolua_error(tolua_S,"#ferror in function 'getMoveDir'.",&tolua_err);

    return 0;

#endif

}

#endif





#ifndef TOLUA_DISABLE_tolua_cw_GameObject_setMoveDir00

static int tolua_cw_GameObject_setMoveDir00(lua_State* tolua_S)

{

#ifndef TOLUA_RELEASE

    tolua_Error tolua_err;

    if (!tolua_isusertype(tolua_S,1,"cwGameObject",0,&tolua_err) ||

        !tolua_isnumber(tolua_S,2,0,&tolua_err) ||

        !tolua_isnumber(tolua_S,3,0,&tolua_err) ||

        !tolua_isnoobj(tolua_S,4,&tolua_err))

        goto tolua_lerror;

    else

#endif

    {

        cwGameObject* self = (cwGameObject*)  tolua_tousertype(tolua_S,1,0);

        float dirX = ((float)  tolua_tonumber(tolua_S,2,0));

        float dirY = ((float)  tolua_tonumber(tolua_S,3,0));

#ifndef TOLUA_RELEASE

        if (!self) tolua_error(tolua_S,"invalid 'self' in function 'setMoveDir'", NULL);

#endif

        self->setMoveDir(dirX, dirY);

    }

    return 0;

#ifndef TOLUA_RELEASE

    tolua_lerror:

    tolua_error(tolua_S,"#ferror in function 'getMoveDir'.",&tolua_err);

    return 0;

#endif

}

#endif





#endif





TOLUA_API int tolua_cwLua_reg_types(lua_State* tolua_S)

{

    //add by sunny

    tolua_usertype(tolua_S,"cwGameObject");

    tolua_usertype(tolua_S,"cwGravityObject");

    //end sunny





    return 1;

}





TOLUA_API int tolua_cwLua_reg(lua_State* tolua_S)

{

#ifdef __cplusplus

    tolua_cclass(tolua_S,"cwGameObject","cwGameObject","CCSprite",tolua_collect_cwGameObject);

#else

    tolua_cclass(tolua_S,"cwGameObject","cwGameObject","CCSprite",NULL);

#endif





    tolua_beginmodule(tolua_S,"cwGameObject");

    tolua_function(tolua_S,"create",tolua_cw_GameObject_create00);

    tolua_function(tolua_S,"speed",tolua_cw_GameObject_getSpeed00);

    tolua_function(tolua_S,"setSpeed",tolua_cw_GameObject_setSpeed00);

    tolua_function(tolua_S,"moveDir",tolua_cw_GameObject_getMoveDir00);

    tolua_function(tolua_S,"setMoveDir",tolua_cw_GameObject_setMoveDir00);

    tolua_endmodule(tolua_S);





#ifdef __cplusplus

    tolua_cclass(tolua_S,"cwGravityObject","cwGravityObject","cwGameObject",tolua_collect_cwGravityObject);

#else

    tolua_cclass(tolua_S,"cwGravityObject","cwGravityObject","cwGameObject",NULL);

#endif





    tolua_beginmodule(tolua_S,"cwGravityObject");

    tolua_endmodule(tolua_S);





    return 1;

}





将tolua_cwLua_reg_types和tolua_cwLua_reg分别加到LuaCocos2d.cpp相应函数末尾。这样两个类cwGameObject与cwGravityObject就能够在lua中使用了。

做到这还不能达到我的期望，原因是cocos2d的luaproject里。在AppDelegate::applicationDidFinishLaunching函数中仅仅是载入并运行了hello.lua脚本文件。然后一切就都交给lua了，而我仅仅是想使用lua实现一些AI方面的功能，即cwGameObject在须要运行AI时。调用lua中的一个函数。所以我须要的是一个能够调用lua函数的功能，查看了一下CCLuaEngine类。貌似没有我想要的。仅仅能自己添了个函数：

virtual int executeGlobalFunction(const char* functionName, float dt, CCObject* pObject, const char* typeName);

functionName：被调lua函数名；dt：帧时间间隔。pObject：调用lua的对象；typeName：pObject对象类型

实现例如以下：

int CCLuaEngine::executeGlobalFunction(const char* functionName, float dt, CCObject* pObject, const char* typeName)

{

    lua_getglobal(m_state, functionName);      





    if (!lua_isfunction(m_state, -1))

    {

        CCLOG("[LUA ERROR] name '%s' does not represent a Lua function", functionName);

        lua_pop(m_state, 1);

        return 0;

    }





    pushFloat(dt);

    pushCCObject(pObject, typeName);





    int error = lua_pcall(m_state, 2, 1, 0);            





    if (error)

    {

        CCLOG("[LUA ERROR] %s", lua_tostring(m_state, - 1));

        lua_pop(m_state, 1); // clean error message

        return 0;

    }





    // get return value

    if (!lua_isnumber(m_state, -1))

    {

        lua_pop(m_state, 1);

        return 0;

    }





    int ret = lua_tointeger(m_state, -1);

    lua_pop(m_state, 1);                                               

    return ret;

}

基本上是照着其它函数扒下来的，不同之处就是加了两个push。

函数写的比較死。能够写一个接受可变參数的函数，做的通用些。





如果我要在cwGameObject的upadte函数中调用“do_obj_update”lua函数，写法例如以下：

void cwGameObject::update(float dt)

{

    CCLuaEngine::defaultEngine()->executeGlobalFunction("do_obj_update", dt, this,"cwGameObject");

}

这样在创建cwGameObject时scheduleUpdate一下就能够了。





lua脚本：

-- for CCLuaEngine traceback

function __G__TRACKBACK__(msg)

    print("----------------------------------------")

    print("LUA ERROR: " .. tostring(msg) .. "\n")

    print(debug.traceback())

    print("----------------------------------------")

end





winSize = CCDirector:sharedDirector():getWinSize()





-- avoid memory leak

collectgarbage("setpause", 100)

collectgarbage("setstepmul", 5000)





function do_obj_update(dt, obj)

    local x, y = obj:getPosition()

    local vx, vy = obj:moveDir()





    x = x + vx*dt*obj:speed()

    y = y + vy*dt*obj:speed()





    if x < 0 then

        x = 0

        obj:setMoveDir(-vx, vy)

    end





    if x > winSize.width then

        x = winSize.width

        obj:setMoveDir(-vx, vy)

    end

   

    if y < 0 then

        y = 0

        obj:setMoveDir(vx, -vy)

    end





    if y > winSize.height then

        y = winSize.height

        obj:setMoveDir(vx, -vy)

    end





    obj:setPosition(x, y)

end





print("test.lua loaded.")





脚本非常easy，do_obj_update函数仅仅是做了一些边框推断。

别忘了改动AppDelegate::applicationDidFinishLaunching加载脚本文件名～～

cocos2dx版本号：cocos2d-2.0-x-2.0.3

http://blog.csdn.net/honghaier/article/details/8700574