备注:
1 作者对于Lua的使用较少,纯粹从使用出发,对它的理解较浅,可能有错误,还请路过的各位大牛多多指正。
2 本笔记代码部分参考cocos2dx2.2.3代码,代码版权归原作者所有。
3 由于作者时间,经验,能力有限,笔记可能不完整,以后随用随补充吧。@H_502_10@
CCLuaStack代码较多,里面实现了大部分Lua与C++代码的交互细节,这里一点点的笔记吧。@H_502_10@
lua_print:
打印栈中的所有的内容。参考网址如下:【 http://cstriker1407.info/blog/lua-basic-notes-stack/】@H_502_10@
namespace { |
int lua_print(lua_State * luastate) |
{ |
int nargs = lua_gettop(luastate); |
std::string t; |
for ( int i=1; i <= nargs; i++) |
{ |
if (lua_istable(luastate,i)) |
t += "table" ; |
else if (lua_isnone(luastate,i)) |
t += "none" ; |
else if (lua_isnil(luastate,i)) |
t += "nil" ; |
else if (lua_isboolean(luastate,i)) |
{ |
if (lua_toboolean(luastate,i) != 0) |
t += "true" ; |
else |
t += "false" ; |
} |
else if (lua_isfunction(luastate,i)) |
t += "function" ; |
else if (lua_islightuserdata(luastate,i)) |
t += "lightuserdata" ; |
else if (lua_isthread(luastate,i)) |
t += "thread" ; |
else |
{ |
const char * str = lua_tostring(luastate,i); |
if (str) |
t += lua_tostring(luastate,i); |
else |
t += lua_typename(luastate,lua_type(luastate,i)); |
} |
if (i!=nargs) |
t += "\t" ; |
} |
CCLOG( "[LUA-print] %s" ,t.c_str()); |
return 0; |
} |
} // namespace { |
创建与初始化:
代码虽然很简短,但是函数调用很多。这里先笔记下最上层的函数调用,底层的函数实现分别笔记。@H_502_10@
//创建一个新的lua运行环境 |
CCLuaStack *CCLuaStack::create( void ) |
{ |
CCLuaStack *stack = new CCLuaStack(); |
stack->init(); |
stack->autorelease(); |
return stack; |
} |
//将一个已有的lua运行环境附到一个新的LuaStacck上。 |
CCLuaStack *CCLuaStack::attach(lua_State *L) |
{ |
CCLuaStack *stack = new CCLuaStack(); |
stack->initWithLuaState(L); |
stack->autorelease(); |
return stack; |
} |
//初始化一个新的lua运行环境 |
bool CCLuaStack::init( void ) |
{ |
m_state = lua_open(); //新建一个lua环境 |
luaL_openlibs(m_state); //将lua标准库注册到lua环境中 |
toluafix_open(m_state); |
// Register our version of the global "print" function |
const luaL_reg global_functions [] = { |
{ "print" ,lua_print}, |
{NULL,NULL} |
}; |
#if (CC_TARGET_PLATFORM == CC_PLATFORM_IOS || CC_TARGET_PLATFORM == CC_PLATFORM_MAC) |
CCLuaObjcBridge::luaopen_luaoc(m_state); |
#endif |
register_all_cocos2dx_manual(m_state); |
register_all_cocos2dx_extension_manual(m_state); |
register_all_cocos2dx_studio_manual(m_state); |
// add cocos2dx loader |
addLuaLoader(cocos2dx_lua_loader); |
return true ; |
} |
//将一个已有的lua运行环境附到本LuaStack上,直接赋值即可。 |
bool CCLuaStack::initWithLuaState(lua_State *L) |
{ |
m_state = L; |
return true ; |
} |
修改变量package[“path”]:
将新的lua文件路径添加到Lua保存的路径中。参考网址如下:【http://cstriker1407.info/blog/lua-basic-notes-stack-variable-exchange/】@H_502_10@
void CCLuaStack::addSearchPath( const char * path) |
{ |
lua_getglobal(m_state, "package" ); /* L: package */ |
lua_getfield(m_state,-1, "path" ); /* get package.path,L: package path */ |
const char * cur_path = lua_tostring(m_state,-1); |
lua_pushfstring(m_state, "%s;%s/?.lua" ,cur_path,path); /* L: package path newpath */ |
lua_setfield(m_state,-3, "path" ); /* package.path = newpath,L: package path */ |
lua_pop(m_state,2); /* L: - */ |
} |
addLuaLoader:
将自定义的loader方法添加到Lua环境中。@H_502_10@
void CCLuaStack::addLuaLoader(lua_CFunction func) |
{ |
if (!func) return ; |
|
// stack content after the invoking of the function |
// get loader table |
lua_getglobal(m_state, "loaders" ); /* L: package,loaders */ |
|
// insert loader into index 2 |
lua_pushcfunction(m_state,func); /* L: package,loaders,func */ |
for ( int i = lua_objlen(m_state,-2) + 1; i > 2; --i) |
{ |
lua_rawgeti(m_state,-2,i - 1); /* L: package,func,function */ |
// we call lua_rawgeti,so the loader table now is at -3 |
lua_rawseti(m_state,i); /* L: package,func */ |
} |
lua_rawseti(m_state,2); /* L: package,loaders */ |
|
// set loaders into package |
lua_setfield(m_state, "loaders" ); /* L: package */ |
|
lua_pop(m_state,1); |
} |
在Lua中删掉与某个Object有关的注册信息:
void CCLuaStack::removeScriptObjectByCCObject(CCObject* pObj) |
{ |
toluafix_remove_ccobject_by_refid(m_state,pObj->m_nLuaID); |
} |
void CCLuaStack::removeScriptHandler( int nHandler) |
{ |
toluafix_remove_function_by_refid(m_state,nHandler); |
} |
在C中调用Lua脚本:
参考网址如下:【 http://cstriker1407.info/blog/lua-basic-notes-c-call-lua/】@H_502_10@
//执行Lua脚本字符串 |
int CCLuaStack::executeString( const char *codes) |
{ |
//首先把字符串载入到Lua环境中 |
luaL_loadstring(m_state,codes); |
return executeFunction(0); //以0个入参执行该脚本。 |
} |
//执行Lua脚本文件 |
int CCLuaStack::executeScriptFile( const char * filename) |
{ |
#if (CC_TARGET_PLATFORM == CC_PLATFORM_ANDROID) |
std::string code( "require \"" ); |
code.append(filename); |
code.append( "\"" ); |
return executeString(code.c_str()); |
#else |
std::string fullPath = CCFileUtils::sharedFileUtils()->fullPathForFilename(filename); |
++m_callFromLua; |
//执行该文件 |
int nRet = luaL_dofile(m_state,fullPath.c_str()); |
--m_callFromLua; |
//通过对m_callFromLua的判断,来确认lua脚本是正常执行完毕的。 |
CC_ASSERT(m_callFromLua >= 0); |
// lua_gc(m_state,LUA_GCCOLLECT,0); |
|
if (nRet != 0) |
CCLOG( "[LUA ERROR] %s" ,lua_tostring(m_state,-1)); |
lua_pop(m_state,1); //弹出栈顶的错误信息,保证栈恢复到以前。 |
return nRet; |
} |
//执行成功,忽略掉脚本返回值,直接返回0 |
return 0; |
#endif |
} |
int CCLuaStack::executeGlobalFunction( const char * functionName) |
{ |
lua_getglobal(m_state,functionName); /* query function by name,stack: function */ |
if (!lua_isfunction(m_state,-1)) |
{ //如果栈顶不是函数,说明没有找到,直接日志,清理栈,返回。 |
CCLOG( "[LUA ERROR] name '%s' does not represent a Lua function" ,functionName); |
lua_pop(m_state,1); |
return 0; |
} |
//找到了,执行 |
return executeFunction(0); |
} |
//numArgs表示入参的数量 |
int CCLuaStack::executeFunction( int numArgs) |
{ |
int functionIndex = -(numArgs + 1); |
if (!lua_isfunction(m_state,functionIndex)) //检查该位置是否是函数 |
{ |
//不是,直接返回,并且清理栈 |
CCLOG( "value at stack [%d] is not function" ,functionIndex); |
lua_pop(m_state,numArgs + 1); // remove function and arguments |
return 0; |
} |
//在Lua环境中找到函数__G__TRACKBACK__ |
int traceback = 0; |
lua_getglobal(m_state, "__G__TRACKBACK__" ); /* L: ... func arg1 arg2 ... G */ |
if (!lua_isfunction(m_state,-1)) |
{ //如果没有找到__G__TRACKBACK__,那么就把栈顶清理掉 |
lua_pop(m_state,1); /* L: ... func arg1 arg2 ... */ |
} |
else |
{ //找到了,就把__G__TRACKBACK__向后放,放到func后面 |
lua_insert(m_state,functionIndex - 1); /* L: ... G func arg1 arg2 ... */ |
traceback = functionIndex - 1; |
} |
|
int error = 0; |
++m_callFromLua; |
error = lua_pcall(m_state,numArgs,1,traceback); /* L: ... [G] ret */ |
--m_callFromLua; |
if (error) |
{ |
if (traceback == 0) |
{ |
CCLOG( "[LUA ERROR] %s" ,- 1)); /* L: ... error */ |
lua_pop(m_state,1); // remove error message from stack |
} |
else /* L: ... G error */ |
{ |
lua_pop(m_state,2); // remove __G__TRACKBACK__ and error message from stack |
} |
return 0; |
} |
//没有错误,就处理返回值 |
// get return value |
int ret = 0; |
if (lua_isnumber(m_state,-1)) |
{ |
ret = lua_tointeger(m_state,-1); |
} |
else if (lua_isboolean(m_state,-1)) |
{ |
ret = lua_toboolean(m_state,-1); |
} |
// remove return value from stack |
lua_pop(m_state,1); /* L: ... [G] */ |
|
if (traceback) |
{ |
lua_pop(m_state,1); // remove __G__TRACKBACK__ from stack /* L: ... */ |
} |
//返回 函数的返回值 |
return ret; |
} |
int CCLuaStack::executeFunctionByHandler( int nHandler, int numArgs) |
{ |
int ret = 0; |
//首先在Lua环境中找到这个函数 |
if (pushFunctionByHandler(nHandler)) /* L: ... arg1 arg2 ... func */ |
{ |
if (numArgs > 0) |
{ |
lua_insert(m_state,-(numArgs + 1)); /* L: ... func arg1 arg2 ... */ |
} |
//执行函数 |
ret = executeFunction(numArgs); |
} |
//清理栈,并返回结果 |
lua_settop(m_state,0); |
return ret; |
} |
//人工产生一个错误信息 |
bool CCLuaStack::handleAssert( const char *msg) |
{ |
if (m_callFromLua == 0) return false ; |
//将错误信息放到栈顶 |
lua_pushfstring(m_state, "ASSERT Failed ON LUA EXECUTE: %s" ,msg ? msg : "unknown" ); |
//人工产生一个Lua错误。 |
lua_error(m_state); |
return true ; |
} |
int CCLuaStack::reallocateScriptHandler( int nHandler) |
{ |
LUA_FUNCTION nNewHandle = -1; |
|
if (pushFunctionByHandler(nHandler)) |
{ |
nNewHandle = toluafix_ref_function(m_state,lua_gettop(m_state),0); |
} |
/* |
toluafix_get_function_by_refid(m_state,nNewHandle); |
if (!lua_isfunction(m_state,-1)) |
{ |
CCLOG("Error!"); |
} |
lua_settop(m_state,0); |
*/ |
return nNewHandle; |
} |
//和executeFunction类似,不过这里的Lua函数会返回多个值。这里用pResultArray来保存返回值。 |
int CCLuaStack::executeFunctionReturnArray( int nHandler, int nNumArgs, int nNummResults,CCArray* pResultArray) |
{ |
if (NULL == pResultArray) |
return 0; |
//首先在Lua环境中找到这个函数 |
if (pushFunctionByHandler(nHandler)) /* L: ... arg1 arg2 ... func */ |
{ |
if (nNumArgs > 0) |
{ |
//调整栈的顺序,以符合Lua的调用规则 |
lua_insert(m_state,-(nNumArgs + 1)); /* L: ... func arg1 arg2 ... */ |
int functionIndex = -(nNumArgs + 1); |
if (!lua_isfunction(m_state,functionIndex)) |
{ |
CCLOG( "value at stack [%d] is not function" ,functionIndex); |
lua_pop(m_state,nNumArgs + 1); // remove function and arguments |
return 0; |
} |
|
int traceback = 0; |
lua_getglobal(m_state, "__G__TRACKBACK__" ); /* L: ... func arg1 arg2 ... G */ |
if (!lua_isfunction(m_state,-1)) |
{ |
lua_pop(m_state,1); /* L: ... func arg1 arg2 ... */ |
} |
else |
{ |
lua_insert(m_state,functionIndex - 1); /* L: ... G func arg1 arg2 ... */ |
traceback = functionIndex - 1; |
} |
|
int error = 0; |
++m_callFromLua; |
error = lua_pcall(m_state,nNumArgs,nNummResults,traceback); /* L: ... [G] ret1 ret2 ... retResults*/ |
--m_callFromLua; |
if (error) |
{ |
if (traceback == 0) |
{ |
CCLOG( "[LUA ERROR] %s" ,- 1)); /* L: ... error */ |
lua_pop(m_state,1); // remove error message from stack |
} |
else /* L: ... G error */ |
{ |
lua_pop(m_state,2); // remove __G__TRACKBACK__ and error message from stack |
} |
return 0; |
} |
|
// get return value,don't pass LUA_MULTRET to numResults, |
for ( int i = 0 ; i < nNummResults; i++) { if (lua_type(m_state,-1) == LUA_TBOOLEAN) { bool value = lua_toboolean(m_state,-1); pResultArray->addObject(CCBool::create(value)) ; |
|
} else if (lua_type(m_state,-1) == LUA_TNUMBER) { |
|
double value = lua_tonumber(m_state,-1); |
pResultArray->addObject(CCDouble::create(value)); |
|
} else if (lua_type(m_state,-1) == LUA_TSTRING) { |
|
const char * value = lua_tostring(m_state,-1); |
pResultArray->addObject(CCString::create(value)); |
|
} else { |
|
pResultArray->addObject( static_cast <ccobject*>(tolua_tousertype(m_state,NULL))); |
} |
// remove return value from stack |
lua_pop(m_state,1); /* L: ... [G] ret1 ret2 ... ret*/ |
} |
/* L: ... [G]*/ |
|
if (traceback) |
{ |
lua_pop(m_state,1); // remove __G__TRACKBACK__ from stack /* L: ... */ |
} |
} |
} |
|
lua_settop(m_state,0); |
|
return 1; |
} |
</ccobject*> |
其中,关于【 __G__TRACKBACK__】,可以查看一下HelloLua工程中的hello.lua文件,有部分内容如下:@H_502_10@
- - for CCLuaEngine traceback |
function __G__TRACKBACK__(msg) |
cclog( "----------------------------------------" ) |
cclog( "LUA ERROR: " .. tostring(msg) .. "\n" ) |
cclog(debug.traceback()) |
cclog( "----------------------------------------" ) |
end |
基本类型压栈的处理:
//清空栈 |
void CCLuaStack::clean( void ) |
{ |
lua_settop(m_state,0); |
} |
//以下为各种压栈 |
void CCLuaStack::pushInt( int intValue) |
{ |
lua_pushinteger(m_state,intValue); |
} |
void CCLuaStack::pushFloat( float floatValue) |
{ |
lua_pushnumber(m_state,floatValue); |
} |
void CCLuaStack::pushBoolean( bool boolValue) |
{ |
lua_pushboolean(m_state,boolValue); |
} |
void CCLuaStack::pushString( const char * stringValue) |
{ |
lua_pushstring(m_state,stringValue); |
} |
void CCLuaStack::pushString( const char * stringValue, int length) |
{ |
lua_pushlstring(m_state,stringValue,length); |
} |
void CCLuaStack::pushNil( void ) |
{ |
lua_pushnil(m_state); |
} |
复杂类型压栈的处理:
//把ccobject压入堆栈 |
void CCLuaStack::pushCCObject(CCObject* objectValue, const char * typeName) |
{ |
toluafix_pushusertype_ccobject(m_state,objectValue->m_uID,&objectValue->m_nLuaID,objectValue,typeName); |
} |
//吧CCLuaValue压入堆栈,这里根据value的类型进行不同的操作。 |
void CCLuaStack::pushCCLuaValue( const CCLuaValue& value) |
{ |
const CCLuaValueType type = value.getType(); |
if (type == CCLuaValueTypeInt) |
{ |
return pushInt(value.intValue()); |
} |
else if (type == CCLuaValueTypeFloat) |
{ |
return pushFloat(value.floatValue()); |
} |
else if (type == CCLuaValueTypeBoolean) |
{ |
return pushBoolean(value.booleanValue()); |
} |
else if (type == CCLuaValueTypeString) |
{ |
return pushString(value.stringValue().c_str()); |
} |
else if (type == CCLuaValueTypeDict) |
{ |
pushCCLuaValueDict(value.dictValue()); |
} |
else if (type == CCLuaValueTypeArray) |
{ |
pushCCLuaValueArray(value.arrayValue()); |
} |
else if (type == CCLuaValueTypeCCObject) |
{ |
pushCCObject(value.ccobjectValue(),value.getCCObjectTypename().c_str()); |
} |
} |
//把一个字典压入堆栈。 |
void CCLuaStack::pushCCLuaValueDict( const CCLuaValueDict& dict) |
{ |
lua_newtable(m_state); /* L: table */ |
for (CCLuaValueDictIterator it = dict.begin(); it != dict.end(); ++it) |
{ |
lua_pushstring(m_state,it->first.c_str()); /* L: table key */ |
pushCCLuaValue(it->second); /* L: table key value */ |
lua_rawset(m_state,-3); /* table.key = value,L: table */ |
} |
} |
//把一个数组压入堆栈 |
void CCLuaStack::pushCCLuaValueArray( const CCLuaValueArray& array) |
{ |
lua_newtable(m_state); /* L: table */ |
int index = 1; |
for (CCLuaValueArrayIterator it = array.begin(); it != array.end(); ++it) |
{ |
pushCCLuaValue(*it); /* L: table value */ |
lua_rawseti(m_state,index); /* table[index] = value,L: table */ |
++index; |
} |
} |
bool CCLuaStack::pushFunctionByHandler( int nHandler) |
{ |
toluafix_get_function_by_refid(m_state,nHandler); /* L: ... func */ |
if (!lua_isfunction(m_state,-1)) |
{ |
CCLOG( "[LUA ERROR] function refid '%d' does not reference a Lua function" ,nHandler); |
lua_pop(m_state,1); |
return false ; |
} |
return true ; |
} |