待学习 异步加载 纹理 addImageAsync

--------------------------------------------------------------------
--
-- TextureAsync
--
--------------------------------------------------------------------

local function TextureAsync()
    local ret = createTestLayer("Texture Async Load",
                                "Textures should load while an animation is being run")
    local m_nImageOffset = 0

    local size =cc.Director:getInstance():getWinSize()

    local label = cc.Label:createWithTTF("Loading...", s_markerFeltFontPath, 32)
    label:setAnchorPoint(cc.p(0.5, 0.5))
    label:setPosition(cc.p( size.width/2, size.height/2))
    ret:addChild(label, 10)

    local  scale = cc.ScaleBy:create(0.3, 2)
    local  scale_back = scale:reverse()
    local  seq = cc.Sequence:create(scale, scale_back)
    label:runAction(cc.RepeatForever:create(seq))

    local function imageLoaded(texture)
        local director = cc.Director:getInstance()

        local sprite = cc.Sprite:createWithTexture(texture)
        sprite:setAnchorPoint(cc.p(0,0))
        ret:addChild(sprite, -1)

        local size = director:getWinSize()
        local i = m_nImageOffset * 32
        sprite:setPosition(cc.p( i % size.width, math.floor((i / size.width)) * 32 ))

        m_nImageOffset = m_nImageOffset + 1
        cclog("Image loaded:...")-- %p", tex)
    end

    local function loadImages(dt)
        local i = 0
        local j = 0
        for i=0, 7 do
            for j=0, 7 do
                local szSpriteName = string.format(
                    "Images/sprites_test/sprite-%d-%d.png", i, j)
                cc.Director:getInstance():getTextureCache():addImageAsync(
                    szSpriteName, imageLoaded)
            end
        end

        cc.Director:getInstance():getTextureCache():addImageAsync("Images/background1.jpg", imageLoaded)
        cc.Director:getInstance():getTextureCache():addImageAsync("Images/background2.jpg", imageLoaded)
        cc.Director:getInstance():getTextureCache():addImageAsync("Images/background.png", imageLoaded)
        cc.Director:getInstance():getTextureCache():addImageAsync("Images/atlastest.png", imageLoaded)
        cc.Director:getInstance():getTextureCache():addImageAsync("Images/grossini_dance_atlas.png",imageLoaded)

        ret:unscheduleUpdate()
    end

    local function onNodeEvent(event)
        if event == "enter" then
            ret:scheduleUpdateWithPriorityLua(loadImages,0)
        elseif event == "exit" then
            ret:unscheduleUpdate()
            cc.Director:getInstance():getTextureCache():removeAllTextures()
        end
    end

    ret:registerScriptHandler(onNodeEvent)
    return ret
end