【cocos2d-x從c++到js】14：註冊函數

前面的文章中講過，在遊戲啓動時，會調用大量的addRegisterCallback函數，向SpiderMonkey註冊Cocos2d-x引擎的函數。

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ScriptingCore* sc = ScriptingCore::getInstance(); sc->addRegisterCallback(register_all_cocos2dx); sc->addRegisterCallback(register_all_cocos2dx_extension); sc->addRegisterCallback(register_cocos2dx_js_extensions); sc->addRegisterCallback(register_all_cocos2dx_extension_manual); sc->addRegisterCallback(jsb_register_chipmunk); sc->addRegisterCallback(JSB_register_opengl); sc->addRegisterCallback(jsb_register_system); sc->addRegisterCallback(MinXmlHttpRequest::_js_register); sc->addRegisterCallback(register_jsb_websocket); sc->addRegisterCallback(register_all_cocos2dx_builder); sc->addRegisterCallback(register_CCBuilderReader); sc->addRegisterCallback(register_all_cocos2dx_gui); sc->addRegisterCallback(register_all_cocos2dx_gui_manual); sc->addRegisterCallback(register_all_cocos2dx_studio); sc->addRegisterCallback(register_all_cocos2dx_studio_manual); sc->addRegisterCallback(register_all_cocos2dx_spine); sc->start();

以register_all_cocos2dx註冊函數爲例，跳轉到實現代碼：

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void register_all_cocos2dx(JSContext* cx, JSObject* obj) {     // first, try to get the ns     JS::RootedValue nsval(cx);     JSObject *ns;     JS_GetProperty(cx, obj, "cc", &nsval);     if (nsval == JSVAL_VOID) {         ns = JS_NewObject(cx, NULL, NULL, NULL);         nsval = OBJECT_TO_JSVAL(ns);         JS_SetProperty(cx, obj, "cc", nsval);     } else {         JS_ValueToObject(cx, nsval, &ns);     }     obj = ns;     js_register_cocos2dx_Action(cx, obj);     js_register_cocos2dx_FiniteTimeAction(cx, obj);     js_register_cocos2dx_ActionInstant(cx, obj);     js_register_cocos2dx_Hide(cx, obj);     js_register_cocos2dx_Node(cx, obj);     js_register_cocos2dx_Scene(cx, obj);     js_register_cocos2dx_TransitionScene(cx, obj);     js_register_cocos2dx_TransitionEaseScene(cx, obj);     js_register_cocos2dx_TransitionMoveInL(cx, obj);     js_register_cocos2dx_TransitionMoveInB(cx, obj);     js_register_cocos2dx_Layer(cx, obj);     js_register_cocos2dx___LayerRGBA(cx, obj);     js_register_cocos2dx_AtlasNode(cx, obj);     js_register_cocos2dx_TileMapAtlas(cx, obj);     js_register_cocos2dx_TransitionMoveInT(cx, obj);     js_register_cocos2dx_TransitionMoveInR(cx, obj);     js_register_cocos2dx_ParticleSystem(cx, obj);     js_register_cocos2dx_ParticleSystemQuad(cx, obj);     js_register_cocos2dx_ParticleSnow(cx, obj);     js_register_cocos2dx_ActionInterval(cx, obj);     js_register_cocos2dx_ActionCamera(cx, obj);     js_register_cocos2dx_ProgressFromTo(cx, obj);     js_register_cocos2dx_MoveBy(cx, obj);     js_register_cocos2dx_MoveTo(cx, obj);     js_register_cocos2dx_JumpBy(cx, obj);     js_register_cocos2dx_ActionEase(cx, obj);     js_register_cocos2dx_EaseBounce(cx, obj);     js_register_cocos2dx_EaseBounceIn(cx, obj);     js_register_cocos2dx_TransitionRotoZoom(cx, obj);     js_register_cocos2dx_Director(cx, obj);     js_register_cocos2dx_Texture2D(cx, obj);     js_register_cocos2dx_EaseElastic(cx, obj);     js_register_cocos2dx_EaseElasticOut(cx, obj);     js_register_cocos2dx_EaseBackOut(cx, obj);     js_register_cocos2dx_TransitionSceneOriented(cx, obj);     js_register_cocos2dx_TransitionFlipX(cx, obj);     js_register_cocos2dx_Spawn(cx, obj);     js_register_cocos2dx_SimpleAudioEngine(cx, obj);     js_register_cocos2dx_SkewTo(cx, obj);     js_register_cocos2dx_SkewBy(cx, obj);     js_register_cocos2dx_TransitionProgress(cx, obj);     js_register_cocos2dx_TransitionProgressVertical(cx, obj);     js_register_cocos2dx_TMXTiledMap(cx, obj);     js_register_cocos2dx_GridAction(cx, obj);     js_register_cocos2dx_Grid3DAction(cx, obj);     js_register_cocos2dx_FadeIn(cx, obj);     js_register_cocos2dx_AnimationCache(cx, obj);     js_register_cocos2dx_FlipX3D(cx, obj);     js_register_cocos2dx_FlipY3D(cx, obj);     js_register_cocos2dx_EaseSineInOut(cx, obj);     js_register_cocos2dx_TransitionFlipAngular(cx, obj);     js_register_cocos2dx_EGLViewProtocol(cx, obj);     js_register_cocos2dx_EGLView(cx, obj);     js_register_cocos2dx_EaseElasticInOut(cx, obj);     js_register_cocos2dx_Show(cx, obj);     js_register_cocos2dx_FadeOut(cx, obj);     js_register_cocos2dx_CallFunc(cx, obj);     js_register_cocos2dx_Waves3D(cx, obj);     js_register_cocos2dx_ParticleFireworks(cx, obj);     js_register_cocos2dx_MenuItem(cx, obj);     js_register_cocos2dx_MenuItemSprite(cx, obj);     js_register_cocos2dx_MenuItemImage(cx, obj);     js_register_cocos2dx_ParticleFire(cx, obj);     js_register_cocos2dx_TransitionZoomFlipAngular(cx, obj);     js_register_cocos2dx_EaseRateAction(cx, obj);     js_register_cocos2dx_EaseIn(cx, obj);     js_register_cocos2dx_EaseExponentialInOut(cx, obj);     js_register_cocos2dx_EaseBackInOut(cx, obj);     js_register_cocos2dx_EaseExponentialOut(cx, obj);     js_register_cocos2dx_SpriteBatchNode(cx, obj);     js_register_cocos2dx_Label(cx, obj);     js_register_cocos2dx_Application(cx, obj);     js_register_cocos2dx_DelayTime(cx, obj);     js_register_cocos2dx_LabelAtlas(cx, obj);     js_register_cocos2dx_LabelBMFont(cx, obj);     js_register_cocos2dx_TransitionFadeTR(cx, obj);     js_register_cocos2dx_TransitionFadeBL(cx, obj);     js_register_cocos2dx_EaseElasticIn(cx, obj);     js_register_cocos2dx_ParticleSpiral(cx, obj);     js_register_cocos2dx_TiledGrid3DAction(cx, obj);     js_register_cocos2dx_FadeOutTRTiles(cx, obj);     js_register_cocos2dx_FadeOutUpTiles(cx, obj);     js_register_cocos2dx_FadeOutDownTiles(cx, obj);     js_register_cocos2dx_TextureCache(cx, obj);     js_register_cocos2dx_ActionTween(cx, obj);     js_register_cocos2dx_TransitionFadeDown(cx, obj);     js_register_cocos2dx_ParticleSun(cx, obj);     js_register_cocos2dx_TransitionProgressHorizontal(cx, obj);     js_register_cocos2dx_TMXObjectGroup(cx, obj);     js_register_cocos2dx_TMXLayer(cx, obj);     js_register_cocos2dx_FlipX(cx, obj);     js_register_cocos2dx_FlipY(cx, obj);     js_register_cocos2dx_TransitionSplitCols(cx, obj);     js_register_cocos2dx_Timer(cx, obj);     js_register_cocos2dx_FadeTo(cx, obj);     js_register_cocos2dx_Repeat(cx, obj);     js_register_cocos2dx_Place(cx, obj);     js_register_cocos2dx_GLProgram(cx, obj);     js_register_cocos2dx_EaseBounceOut(cx, obj);     js_register_cocos2dx_RenderTexture(cx, obj);     js_register_cocos2dx_TintBy(cx, obj);     js_register_cocos2dx_TransitionShrinkGrow(cx, obj);     js_register_cocos2dx_Sprite(cx, obj);     js_register_cocos2dx_LabelTTF(cx, obj);     js_register_cocos2dx_ClippingNode(cx, obj);     js_register_cocos2dx_ParticleFlower(cx, obj);     js_register_cocos2dx_ParticleSmoke(cx, obj);     js_register_cocos2dx_LayerMultiplex(cx, obj);     js_register_cocos2dx_Blink(cx, obj);     js_register_cocos2dx_ShaderCache(cx, obj);     js_register_cocos2dx_JumpTo(cx, obj);     js_register_cocos2dx_ParticleExplosion(cx, obj);     js_register_cocos2dx_TransitionJumpZoom(cx, obj);     js_register_cocos2dx_Touch(cx, obj);     js_register_cocos2dx_AnimationFrame(cx, obj);     js_register_cocos2dx_NodeGrid(cx, obj);     js_register_cocos2dx_TMXLayerInfo(cx, obj);     js_register_cocos2dx_TMXTilesetInfo(cx, obj);     js_register_cocos2dx_GridBase(cx, obj);     js_register_cocos2dx_TiledGrid3D(cx, obj);     js_register_cocos2dx_ParticleGalaxy(cx, obj);     js_register_cocos2dx_Twirl(cx, obj);     js_register_cocos2dx_MenuItemLabel(cx, obj);     js_register_cocos2dx_LayerColor(cx, obj);     js_register_cocos2dx_FadeOutBLTiles(cx, obj);     js_register_cocos2dx_LayerGradient(cx, obj);     js_register_cocos2dx_TargetedAction(cx, obj);     js_register_cocos2dx_RepeatForever(cx, obj);     js_register_cocos2dx_CardinalSplineTo(cx, obj);     js_register_cocos2dx_CardinalSplineBy(cx, obj);     js_register_cocos2dx_TransitionFlipY(cx, obj);     js_register_cocos2dx_TurnOffTiles(cx, obj);     js_register_cocos2dx_TintTo(cx, obj);     js_register_cocos2dx_CatmullRomTo(cx, obj);     js_register_cocos2dx_ToggleVisibility(cx, obj);     js_register_cocos2dx_DrawNode(cx, obj);     js_register_cocos2dx_TransitionTurnOffTiles(cx, obj);     js_register_cocos2dx_RotateTo(cx, obj);     js_register_cocos2dx_TransitionSplitRows(cx, obj);     js_register_cocos2dx_TransitionProgressRadialCCW(cx, obj);     js_register_cocos2dx_ScaleTo(cx, obj);     js_register_cocos2dx_TransitionPageTurn(cx, obj);     js_register_cocos2dx_BezierBy(cx, obj);     js_register_cocos2dx_BezierTo(cx, obj);     js_register_cocos2dx_Menu(cx, obj);     js_register_cocos2dx_SpriteFrame(cx, obj);     js_register_cocos2dx_ActionManager(cx, obj);     js_register_cocos2dx_TransitionFade(cx, obj);     js_register_cocos2dx_TransitionZoomFlipX(cx, obj);     js_register_cocos2dx_SpriteFrameCache(cx, obj);     js_register_cocos2dx_TransitionCrossFade(cx, obj);     js_register_cocos2dx_Ripple3D(cx, obj);     js_register_cocos2dx_TransitionSlideInL(cx, obj);     js_register_cocos2dx_TransitionSlideInT(cx, obj);     js_register_cocos2dx_StopGrid(cx, obj);     js_register_cocos2dx_ShakyTiles3D(cx, obj);     js_register_cocos2dx_PageTurn3D(cx, obj);     js_register_cocos2dx_Grid3D(cx, obj);     js_register_cocos2dx_TransitionProgressInOut(cx, obj);     js_register_cocos2dx_EaseBackIn(cx, obj);     js_register_cocos2dx_SplitRows(cx, obj);     js_register_cocos2dx_Follow(cx, obj);     js_register_cocos2dx_Animate(cx, obj);     js_register_cocos2dx_ShuffleTiles(cx, obj);     js_register_cocos2dx_ProgressTimer(cx, obj);     js_register_cocos2dx_ParticleMeteor(cx, obj);     js_register_cocos2dx_EaseInOut(cx, obj);     js_register_cocos2dx_TransitionZoomFlipY(cx, obj);     js_register_cocos2dx_ScaleBy(cx, obj);     js_register_cocos2dx_Lens3D(cx, obj);     js_register_cocos2dx_Animation(cx, obj);     js_register_cocos2dx_TMXMapInfo(cx, obj);     js_register_cocos2dx_EaseExponentialIn(cx, obj);     js_register_cocos2dx_ReuseGrid(cx, obj);     js_register_cocos2dx_MenuItemAtlasFont(cx, obj);     js_register_cocos2dx_Liquid(cx, obj);     js_register_cocos2dx_OrbitCamera(cx, obj);     js_register_cocos2dx_ParticleBatchNode(cx, obj);     js_register_cocos2dx_Component(cx, obj);     js_register_cocos2dx_TextFieldTTF(cx, obj);     js_register_cocos2dx_ParticleRain(cx, obj);     js_register_cocos2dx_Waves(cx, obj);     js_register_cocos2dx_EaseOut(cx, obj);     js_register_cocos2dx_MenuItemFont(cx, obj);     js_register_cocos2dx_TransitionFadeUp(cx, obj);     js_register_cocos2dx_EaseSineOut(cx, obj);     js_register_cocos2dx_JumpTiles3D(cx, obj);     js_register_cocos2dx_MenuItemToggle(cx, obj);     js_register_cocos2dx_RemoveSelf(cx, obj);     js_register_cocos2dx_SplitCols(cx, obj);     js_register_cocos2dx_MotionStreak(cx, obj);     js_register_cocos2dx_RotateBy(cx, obj);     js_register_cocos2dx_FileUtils(cx, obj);     js_register_cocos2dx_ProgressTo(cx, obj);     js_register_cocos2dx_TransitionProgressOutIn(cx, obj);     js_register_cocos2dx_CatmullRomBy(cx, obj);     js_register_cocos2dx_Sequence(cx, obj);     js_register_cocos2dx_Shaky3D(cx, obj);     js_register_cocos2dx_TransitionProgressRadialCW(cx, obj);     js_register_cocos2dx_EaseBounceInOut(cx, obj);     js_register_cocos2dx_TransitionSlideInR(cx, obj);     js_register_cocos2dx___NodeRGBA(cx, obj);     js_register_cocos2dx_ParallaxNode(cx, obj);     js_register_cocos2dx_Scheduler(cx, obj);     js_register_cocos2dx_EaseSineIn(cx, obj);     js_register_cocos2dx_WavesTiles3D(cx, obj);     js_register_cocos2dx_TransitionSlideInB(cx, obj);     js_register_cocos2dx_Speed(cx, obj);     js_register_cocos2dx_ShatteredTiles3D(cx, obj); }

首先看到的是從根對象中獲取一個“cc”屬性（如果獲取不到，就新建一個），因爲JS中沒有名字空間的概念，所以我們使用一個cc對象來表示類似的功能。所有的類型和函數都是這個cc對象下面的屬性。在Cocos2d-x 3.0中，C++層面，類名去掉了CC的前綴，和js保持一致。

然後就是一大堆子函數，每個函數都負責註冊一個對應的類。打開js_register_cocos2dx_Sprite，這個函數負責註冊Sprite類。

打開js_register_cocos2dx_Sprite的實現代碼

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void js_register_cocos2dx_Sprite(JSContext *cx, JSObject *global) {     jsb_cocos2d_Sprite_class = (JSClass *)calloc(1, sizeof(JSClass));     jsb_cocos2d_Sprite_class->name = "Sprite";     jsb_cocos2d_Sprite_class->addProperty = JS_PropertyStub;     jsb_cocos2d_Sprite_class->delProperty = JS_DeletePropertyStub;     jsb_cocos2d_Sprite_class->getProperty = JS_PropertyStub;     jsb_cocos2d_Sprite_class->setProperty = JS_StrictPropertyStub;     jsb_cocos2d_Sprite_class->enumerate = JS_EnumerateStub;     jsb_cocos2d_Sprite_class->resolve = JS_ResolveStub;     jsb_cocos2d_Sprite_class->convert = JS_ConvertStub;     jsb_cocos2d_Sprite_class->finalize = js_cocos2d_Sprite_finalize;     jsb_cocos2d_Sprite_class->flags = JSCLASS_HAS_RESERVED_SLOTS(2);     static JSPropertySpec properties[] = {         {0, 0, 0, JSOP_NULLWRAPPER, JSOP_NULLWRAPPER}     };     static JSFunctionSpec funcs[] = {         JS_FN("setSpriteFrame", js_cocos2dx_Sprite_setSpriteFrame, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("setTexture", js_cocos2dx_Sprite_setTexture, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("getTexture", js_cocos2dx_Sprite_getTexture, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("setFlippedY", js_cocos2dx_Sprite_setFlippedY, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("setFlippedX", js_cocos2dx_Sprite_setFlippedX, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("getBatchNode", js_cocos2dx_Sprite_getBatchNode, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("getOffsetPosition", js_cocos2dx_Sprite_getOffsetPosition, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("removeAllChildrenWithCleanup", js_cocos2dx_Sprite_removeAllChildrenWithCleanup, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("updateQuadVertices", js_cocos2dx_Sprite_updateQuadVertices, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("updateTransform", js_cocos2dx_Sprite_updateTransform, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("setTextureRect", js_cocos2dx_Sprite_setTextureRect, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("isFrameDisplayed", js_cocos2dx_Sprite_isFrameDisplayed, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("getAtlasIndex", js_cocos2dx_Sprite_getAtlasIndex, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("setBatchNode", js_cocos2dx_Sprite_setBatchNode, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("setDisplayFrameWithAnimationName", js_cocos2dx_Sprite_setDisplayFrameWithAnimationName, 2, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("setTextureAtlas", js_cocos2dx_Sprite_setTextureAtlas, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("getSpriteFrame", js_cocos2dx_Sprite_getSpriteFrame, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("isDirty", js_cocos2dx_Sprite_isDirty, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("setAtlasIndex", js_cocos2dx_Sprite_setAtlasIndex, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("setDirty", js_cocos2dx_Sprite_setDirty, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("isTextureRectRotated", js_cocos2dx_Sprite_isTextureRectRotated, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("getTextureRect", js_cocos2dx_Sprite_getTextureRect, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("getTextureAtlas", js_cocos2dx_Sprite_getTextureAtlas, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("isFlippedX", js_cocos2dx_Sprite_isFlippedX, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("isFlippedY", js_cocos2dx_Sprite_isFlippedY, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("setVertexRect", js_cocos2dx_Sprite_setVertexRect, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("ctor", js_cocos2d_Sprite_ctor, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FS_END     };     static JSFunctionSpec st_funcs[] = {         JS_FN("create", js_cocos2dx_Sprite_create, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("createWithTexture", js_cocos2dx_Sprite_createWithTexture, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("createWithSpriteFrameName", js_cocos2dx_Sprite_createWithSpriteFrameName, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FN("createWithSpriteFrame", js_cocos2dx_Sprite_createWithSpriteFrame, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),         JS_FS_END     };     jsb_cocos2d_Sprite_prototype = JS_InitClass(         cx, global,         jsb_cocos2d_Node_prototype,         jsb_cocos2d_Sprite_class,         dummy_constructor<cocos2d::Sprite>, 0, // no constructor         properties,         funcs,         NULL, // no static properties         st_funcs);     // make the class enumerable in the registered namespace     JSBool found;     JS_SetPropertyAttributes(cx, global, "Sprite", JSPROP_ENUMERATE | JSPROP_READONLY, &found);     // add the proto and JSClass to the type->js info hash table     TypeTest<cocos2d::Sprite> t;     js_type_class_t *p;     std::string typeName = t.s_name();     if (_js_global_type_map.find(typeName) == _js_global_type_map.end())     {         p = (js_type_class_t *)malloc(sizeof(js_type_class_t));         p->jsclass = jsb_cocos2d_Sprite_class;         p->proto = jsb_cocos2d_Sprite_prototype;         p->parentProto = jsb_cocos2d_Node_prototype;         _js_global_type_map.insert(std::make_pair(typeName, p));     } }

看起來比較長，其實很簡單，我們一段一段分析。

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jsb_cocos2d_Sprite_class = (JSClass *)calloc(1, sizeof(JSClass)); jsb_cocos2d_Sprite_class->name = "Sprite"; jsb_cocos2d_Sprite_class->addProperty = JS_PropertyStub; jsb_cocos2d_Sprite_class->delProperty = JS_DeletePropertyStub; jsb_cocos2d_Sprite_class->getProperty = JS_PropertyStub; jsb_cocos2d_Sprite_class->setProperty = JS_StrictPropertyStub; jsb_cocos2d_Sprite_class->enumerate = JS_EnumerateStub; jsb_cocos2d_Sprite_class->resolve = JS_ResolveStub; jsb_cocos2d_Sprite_class->convert = JS_ConvertStub; jsb_cocos2d_Sprite_class->finalize = js_cocos2d_Sprite_finalize; jsb_cocos2d_Sprite_class->flags = JSCLASS_HAS_RESERVED_SLOTS(2);

首先，我們構造了一個JSClass對象，這個對象保存了一部分Sprite類的相關信息（注意，只是一部分而已）。其中包括類名，還有大量函數的佔位符JS_XXXStub，這些函數是在一定情況下被調用的，如：添加刪除屬性，查看修改屬性等等。這塊其實不用特別關注，因爲使用的都是SpiderMonkey自帶的缺省實現。Cocos2d-x引擎只是在最後把finalize函數替換成自己的函數了。最後那個參數表示這個類，有幾個Reserved Slots槽，這東西我們在之前講回調函數的時候見過。

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static JSPropertySpec properties[] = {     {0, 0, 0, JSOP_NULLWRAPPER, JSOP_NULLWRAPPER} }; static JSFunctionSpec funcs[] = {     JS_FN("setSpriteFrame", js_cocos2dx_Sprite_setSpriteFrame, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("setTexture", js_cocos2dx_Sprite_setTexture, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("getTexture", js_cocos2dx_Sprite_getTexture, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("setFlippedY", js_cocos2dx_Sprite_setFlippedY, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("setFlippedX", js_cocos2dx_Sprite_setFlippedX, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("getBatchNode", js_cocos2dx_Sprite_getBatchNode, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("getOffsetPosition", js_cocos2dx_Sprite_getOffsetPosition, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("removeAllChildrenWithCleanup", js_cocos2dx_Sprite_removeAllChildrenWithCleanup, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("updateQuadVertices", js_cocos2dx_Sprite_updateQuadVertices, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("updateTransform", js_cocos2dx_Sprite_updateTransform, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("setTextureRect", js_cocos2dx_Sprite_setTextureRect, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("isFrameDisplayed", js_cocos2dx_Sprite_isFrameDisplayed, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("getAtlasIndex", js_cocos2dx_Sprite_getAtlasIndex, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("setBatchNode", js_cocos2dx_Sprite_setBatchNode, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("setDisplayFrameWithAnimationName", js_cocos2dx_Sprite_setDisplayFrameWithAnimationName, 2, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("setTextureAtlas", js_cocos2dx_Sprite_setTextureAtlas, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("getSpriteFrame", js_cocos2dx_Sprite_getSpriteFrame, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("isDirty", js_cocos2dx_Sprite_isDirty, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("setAtlasIndex", js_cocos2dx_Sprite_setAtlasIndex, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("setDirty", js_cocos2dx_Sprite_setDirty, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("isTextureRectRotated", js_cocos2dx_Sprite_isTextureRectRotated, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("getTextureRect", js_cocos2dx_Sprite_getTextureRect, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("getTextureAtlas", js_cocos2dx_Sprite_getTextureAtlas, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("isFlippedX", js_cocos2dx_Sprite_isFlippedX, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("isFlippedY", js_cocos2dx_Sprite_isFlippedY, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("setVertexRect", js_cocos2dx_Sprite_setVertexRect, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("ctor", js_cocos2d_Sprite_ctor, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FS_END }; static JSFunctionSpec st_funcs[] = {     JS_FN("create", js_cocos2dx_Sprite_create, 0, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("createWithTexture", js_cocos2dx_Sprite_createWithTexture, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("createWithSpriteFrameName", js_cocos2dx_Sprite_createWithSpriteFrameName, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FN("createWithSpriteFrame", js_cocos2dx_Sprite_createWithSpriteFrame, 1, JSPROP_PERMANENT | JSPROP_ENUMERATE),     JS_FS_END };

然後是填寫大量的參數，包括屬性，靜態屬性，函數，靜態函數。注意，因爲Cocos2d-x的類完全使用Setter和Getter，所以一般是沒有屬性和靜態屬性的。比較重要的是靜態函數和普通函數。我們看一下宏函數JS_FN。他的第一個參數是函數名，這個和C++層的函數命名是一致的，第二個參數在SpiderMonkey調用JS層對應的C++函數時的回調函數，這個函數我們之前的文章中分析過。第三個參數是函數調用時的參數個數。最後一個參數，是一些訪問特性，JSPROP_PERMANENT表示不可刪除，JSPROP_ENUMERATE表示在枚舉時可見（JS的for遍歷）。

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jsb_cocos2d_Sprite_prototype = JS_InitClass(     cx, global,     jsb_cocos2d_Node_prototype,     jsb_cocos2d_Sprite_class,     dummy_constructor<cocos2d::Sprite>, 0, // no constructor     properties,     funcs,     NULL, // no static properties     st_funcs); // make the class enumerable in the registered namespace JSBool found; JS_SetPropertyAttributes(cx, global, "Sprite", JSPROP_ENUMERATE | JSPROP_READONLY, &found);

因爲JS使用的是原型繼承，那麼我們需要構造一個原型，需要的參數也很多，都是我們上面配置好的，上下文，父對象，原型，JSClass對象，各種屬性和函數。然後，會自動把這個原型設置爲global（就是之前的cc對象）的一個屬性。最後，設置好訪問特性。

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TypeTest<cocos2d::Sprite> t;     js_type_class_t *p;     std::string typeName = t.s_name();     if (_js_global_type_map.find(typeName) == _js_global_type_map.end())     {         p = (js_type_class_t *)malloc(sizeof(js_type_class_t));         p->jsclass = jsb_cocos2d_Sprite_class;         p->proto = jsb_cocos2d_Sprite_prototype;         p->parentProto = jsb_cocos2d_Node_prototype;         _js_global_type_map.insert(std::make_pair(typeName, p));     }

最後這段代碼是Cocos2d-x引擎自己做的一個設計，把類型信息存到一個map裏，這個設計以後會經常見到。可以用來查詢，另外在JS虛擬機清空時，也用來遍歷刪除對應的類型信息。做法是先放到一個map裏，然後cleanup時遍歷這個map即可。就不贅述了。

本文出自 “做遊戲的老G” 博客，請務必保留此出處http://goldlion.blog.51cto.com/4127613/1357617