cocos2dx——lua自动和手动绑定

【自动绑定】

参考：http://my.oschina.net/skyhacker2/blog/298397

主要是通过引擎自带的tools/tolua，主要步骤如下：

1.编写好要导出的c++类，如果是libcocos2d里添加，需要添加导出标记：class CC_DLL Test

2.到tolua目录根据README.mdown配置好环境：

* Make sure that you have installed `android-ndk-r9b`.
* Download python2.7.3 (32bit) from (http://www.python.org/ftp/python/2.7.3/python-2.7.3.msi).
* Add the installed path of python (e.g. C:\Python27) to windows environment variable named 'PATH'.
* Download pyyaml from http://pyyaml.org/download/pyyaml/PyYAML-3.10.win32-py2.7.exe and install it.
* Download pyCheetah from https://raw.github.com/dumganhar/my_old_cocos2d-x_backup/download/downloads/Cheetah.zip,unzip it to "C:\Python27\Lib\site-packages"
* Set environment variables (`NDK_ROOT`)
* Go to "cocos2d-x/tools/tolua" folder,and run "genbindings.py". The generated codes will be under "cocos\scripting\auto-generated\js-bindings".

3.创建一个ini文件，比如 cocos2dx_custom.ini，参照其他的ini自己做一些修改：

# the prefix to be added to the generated functions. You might or might not use this in your own
# templates
prefix = cocos2dx_custom

# create a target namespace (in javascript,this would create some code like the equiv. to `ns = ns || {}`)
# all classes will be embedded in that namespace
target_namespace = cc

# what headers to parse
headers = %(cocosdir)s/cocos/for_lua/Test.h

# what classes to produce code for. You can use regular expressions here. When testing the regular
# expression,it will be enclosed in "^$",like this: "^Menu*$".
classes = Test.*

skip = 

# classes for which there will be no "parent" lookup
classes_have_no_parents = Test

abstract_classes =

4.拷贝一份genbindings_custom.py，修改cmd_args：

cmd_args = {'cocos2dx_custom.ini' : ('cocos2dx_custom','lua_cocos2dx_custom_auto'),\
                    }

5.运行 genbindings_custom.py会生成xx_auto.h/cpp到cocos\scripting\lua-bindings\auto目录，然后你添加到引擎的libluacocos2d工程去

6.要在lua中使用，还在启动时注册。现在3.7的版本里AppDelegate::applicationDidFinishLaunching会调用lua_module_register，所以：

#include "lua_cocos2dx_custom_auto.hpp"
#include "fun.h"

int lua_module_register(lua_State* L)
{
    register_cocosdenshion_module(L);
	register_all_cocos2dx_custom(L);

	register_foo(L);

    return 1;
}

7.然后你就可以在lua里使用了：

-- test custom
 local msg = cc.Test:helloMsg()
 print(msg)

【手动绑定】

参考：http://www.tairan.com/archives/5493

1.创建c++类（fun.h)：

#pragma once

#include <iostream>
#include <sstream>

extern "C"
{
#include <lua.h>
#include <lauxlib.h>
#include <lualib.h>
}

class Foo
{
public:
	Foo(const std::string & name) : name(name)
	{
		std::cout << "Foo is born" << std::endl;
	}

	std::string Add(int a,int b)
	{
		std::stringstream ss;
		ss << name << ": " << a << " + " << b << " = " << (a + b);
		return ss.str();
	}

	~Foo()
	{
		std::cout << "Foo is gone" << std::endl;
	}

private:
	std::string name;
};

void register_foo(lua_State *L);

2.导出到lua(fun.cpp)：

#include "fun.h"

int l_Foo_constructor(lua_State *L) {
	const char *name = luaL_checkstring(L,1);
	Foo **udata = (Foo**)lua_newuserdata(L,sizeof(Foo*));
	*udata = new Foo(name);

	luaL_getmetatable(L,"luaL_Foo");
	// stack:
	// -1	metatable "luaL_Foo"
	// -2	userdata
	// -3	string param
	lua_setmetatable(L,-2);

	return 1;
}

Foo* l_CheckFoo(lua_State *L,int n) {
	return *(Foo**)luaL_checkudata(L,n,"luaL_Foo");
}

int l_Foo_Add(lua_State *L) {
	Foo *foo = l_CheckFoo(L,1);
	int a = luaL_checknumber(L,2);
	int b = luaL_checknumber(L,3);

	std::string s = foo->Add(a,b);
	lua_pushstring(L,s.c_str());

	// stack:
	// -1 result string
	// -2 metatable "luaL_Foo"
	// -3 userdata
	// -4 string param

	return 1;
}

int l_Foo_destructor(lua_State *L) {
	Foo *foo = l_CheckFoo(L,1);
	delete foo;

	return 0;
}

void register_foo(lua_State *L) {
	luaL_Reg sFooRefs[] = {
		{ "new",l_Foo_constructor },{ "add",l_Foo_Add },{ "__gc",l_Foo_destructor },{ NULL,NULL }
	};

	luaL_newmetatable(L,"luaL_Foo");
	luaL_register(L,NULL,sFooRefs);
	lua_pushvalue(L,-1);

	// stack:
	// -1: metatable "luaL_Foo"
	// -2: metatable "luaL_Foo"

	// this pops the stack
	lua_setfield(L,-1,"__index");

	lua_setglobal(L,"Foo");
}

3.启动时注册

4.在lua中使用：

 function Foo:speak()
	print("hello,i am a Foo")
 end

 local foo = Foo.new("adfan")
 local m = foo:add(3,4)
 print(m)

 foo:speak()
 
 Foo.add_ = Foo.add
 function Foo:add(a,b)
	return "magic: " .. self:add_(a,b)
 end

 m = foo:add(9,8)
 print(m)

说明：手动绑定的话，参照引擎导出的那些manual.cpp即可，用tolua的那些接口很方便，用上面的这种方式主要是展示这个流程