Cocos2d-x 3.2 Lua示例CocosDenshionTest（音频测试）

本篇博客介绍Cocos2d-x 3.2中Lua示例的音频测试，Cocos2d-x使用SimpleAudioEngine这个类来实现音频的控制，比如播放、暂停、停止等操作。

Lua代码中，使用的是AudioEngine，具体实现可以参考AudioEngine.lua文件，只是把SimpleAudioEngin进行了封装。

示例代码：

--[[
CocosDenshionTest.lua
Cocos2d-x 音频支持
]]--
require "AudioEngine"
local EFFECT_FILE = "effect1.wav"

local MUSIC_FILE = nil
-- 获取目标平台
local targetPlatform = cc.Application:getInstance():getTargetPlatform()
-- iphone或者ipad
if (cc.PLATFORM_OS_IPHONE == targetPlatform) or (cc.PLATFORM_OS_IPAD == targetPlatform) then
  MUSIC_FILE = "background.caf" -- caf格式
else
  MUSIC_FILE = "background.mp3" -- mp3格式
end

local LINE_SPACE = 40

local function CocosDenshionTest()
  local ret = cc.Layer:create()
  local m_pItmeMenu = nil
  local m_tBeginPos = cc.p(0, 0)
  local m_nSoundId = 0

  -- 测试菜单项
  local testItems = {
    "play background music",
    "stop background music",
    "pause background music",
    "resume background music",
    "rewind background music",
    "is background music playing",
    "play effect",
    "play effect repeatly",
    "stop effect",
    "unload effect",
    "add background music volume",
    "sub background music volume",
    "add effects volume",
    "sub effects volume",
    "pause effect",
    "resume effect",
    "pause all effects",
    "resume all effects",
    "stop all effects"
  }

  -- 菜单回调方法
  local function menuCallback(tag, pMenuItem)
    local nIdx = pMenuItem:getLocalZOrder() - 10000
    -- play background music
    if nIdx ==  0 then
      AudioEngine.playMusic(MUSIC_FILE, true) -- 播放音乐
    elseif nIdx == 1 then
      -- stop background music
      AudioEngine.stopMusic()  -- 停止背景音乐
    elseif nIdx == 2 then
      -- pause background music
      AudioEngine.pauseMusic() -- 暂停音乐
    elseif nIdx == 3 then
      -- resume background music
      AudioEngine.resumeMusic() -- 继续播放音乐
      -- rewind background music
    elseif nIdx == 4 then
      AudioEngine.rewindMusic()  -- 循环播放
    elseif nIdx == 5 then
      -- is background music playing
      if AudioEngine.isMusicPlaying () then -- 音乐正在播放
        cclog("background music is playing")
      else
        cclog("background music is not playing")
      end
    elseif nIdx == 6 then
      -- play effect
      m_nSoundId = AudioEngine.playEffect(EFFECT_FILE)   -- 播放音效
    elseif nIdx == 7 then
      -- play effect
      m_nSoundId = AudioEngine.playEffect(EFFECT_FILE, true) -- 播放音效，第二个参数表示是否循环，true表示循环
    elseif nIdx == 8 then
      -- stop effect
      AudioEngine.stopEffect(m_nSoundId) -- 停止音效
    elseif nIdx == 9 then
      -- unload effect
      AudioEngine.unloadEffect(EFFECT_FILE)  -- 不加载音效
    elseif nIdx == 10 then
      -- add bakcground music volume
      AudioEngine.setMusicVolume(AudioEngine.getMusicVolume() + 0.1) -- 增加音量
    elseif nIdx == 11 then
      -- sub backgroud music volume
      AudioEngine.setMusicVolume(AudioEngine.getMusicVolume() - 0.1) -- 减小音量
    elseif nIdx == 12 then
      -- add effects volume
      AudioEngine.setEffectsVolume(AudioEngine.getEffectsVolume() + 0.1) -- 增加音效音量
    elseif nIdx == 13 then
      -- sub effects volume
      AudioEngine.setEffectsVolume(AudioEngine.getEffectsVolume() - 0.1) -- 减少音效音量
    elseif nIdx == 14 then
      AudioEngine.pauseEffect(m_nSoundId)  -- 暂停音效
    elseif nIdx == 15 then
      AudioEngine.resumeEffect(m_nSoundId) -- 恢复音效
    elseif nIdx == 16 then
      AudioEngine.pauseAllEffects() -- 暂停所有音效
    elseif nIdx == 17 then
      AudioEngine.resumeAllEffects() -- 恢复所有音效
    elseif nIdx == 18 then
      AudioEngine.stopAllEffects() -- 停止所有音效
    end
  end
  -- add menu items for tests
  m_pItmeMenu = cc.Menu:create() -- 创建菜单

  m_nTestCount = table.getn(testItems)
  local i = 1
  for  i = 1, m_nTestCount do
    local  label = cc.Label:createWithTTF(testItems[i], s_arialPath, 24)
    label:setAnchorPoint(cc.p(0.5, 0.5))
    local  pMenuItem = cc.MenuItemLabel:create(label) -- 菜单标签
    pMenuItem:registerScriptTapHandler(menuCallback) -- 注册菜单回调方法
    m_pItmeMenu:addChild(pMenuItem, i + 10000 -1)
    pMenuItem:setPosition( cc.p( VisibleRect:center().x, (VisibleRect:top().y - i * LINE_SPACE) ))
  end

  -- 设置菜单内容大小
  m_pItmeMenu:setContentSize(cc.size(VisibleRect:getVisibleRect().width, (m_nTestCount + 1) * LINE_SPACE))
  m_pItmeMenu:setPosition(cc.p(0, 0))
  ret:addChild(m_pItmeMenu)

  -- preload background music and effect
  AudioEngine.preloadMusic( MUSIC_FILE ) -- 预加载音乐
  AudioEngine.preloadEffect( EFFECT_FILE ) -- 预加载音效

  -- set default volume
  AudioEngine.setEffectsVolume(0.5) -- 设置音效音量
  AudioEngine.setMusicVolume(0.5) -- 设置音乐音量

  local function onNodeEvent(event)
    if event == "enter" then -- 进来时

    elseif event == "exit" then --  退出时
      AudioEngine.destroyInstance() -- 销毁对象
    end
  end

  -- 注册层的结点事件
  ret:registerScriptHandler(onNodeEvent)

  local prev = {x = 0, y = 0}
  local function onTouchEvent(eventType, x, y)
    if eventType == "began" then -- 开始点击
      prev.x = x
      prev.y = y
      m_tBeginPos = cc.p(x, y) -- 开始点击位置
      return true
    elseif  eventType == "moved" then -- 移动事件
      local touchLocation = cc.p(x, y) -- 获取触摸的位置
      local nMoveY = touchLocation.y - m_tBeginPos.y -- 触摸位置减去开始位置等于移动的距离
      local curPosX, curPosY = m_pItmeMenu:getPosition() -- 获取当前菜单的位置
      local curPos = cc.p(curPosX, curPosY) --  当前位置
      local nextPos = cc.p(curPos.x, curPos.y + nMoveY) -- 下一个位置

      if nextPos.y < 0.0 then
        m_pItmeMenu:setPosition(cc.p(0, 0))
      end

      if nextPos.y > ((m_nTestCount + 1)* LINE_SPACE - VisibleRect:getVisibleRect().height) then
        m_pItmeMenu:setPosition(cc.p(0, ((m_nTestCount + 1)* LINE_SPACE - VisibleRect:getVisibleRect().height)))
      end

      m_pItmeMenu:setPosition(nextPos)
      m_tBeginPos.x = touchLocation.x  -- 重新记录开始位置
      m_tBeginPos.y = touchLocation.y

      prev.x = x
      prev.y = y
    end
  end

  -- 触摸开始回调方法
  local function onTouchBegan(touch, event)
    local location = touch:getLocation()
    prev.x = location.x
    prev.y = location.y
    m_tBeginPos = location
    return true
  end

  -- 触摸移动的回调方法
  local function onTouchMoved(touch, event)
    local location = touch:getLocation()
    local touchLocation = location
    local nMoveY = touchLocation.y - m_tBeginPos.y
    local curPosX, curPosY = m_pItmeMenu:getPosition()
    local curPos = cc.p(curPosX, curPosY)
    local nextPos = cc.p(curPos.x, curPos.y + nMoveY)

    if nextPos.y < 0.0 then
      m_pItmeMenu:setPosition(cc.p(0, 0))
    end

    if nextPos.y > ((m_nTestCount + 1)* LINE_SPACE - VisibleRect:getVisibleRect().height) then
      m_pItmeMenu:setPosition(cc.p(0, ((m_nTestCount + 1)* LINE_SPACE - VisibleRect:getVisibleRect().height)))
    end

    m_pItmeMenu:setPosition(nextPos)
    m_tBeginPos.x = touchLocation.x
    m_tBeginPos.y = touchLocation.y

    prev.x = location.x
    prev.y = location.y
  end

  -- 单点触摸
  local listener = cc.EventListenerTouchOneByOne:create()
  listener:setSwallowTouches(true)
  -- 注册脚本监听事件
  listener:registerScriptHandler(onTouchBegan,cc.Handler.EVENT_TOUCH_BEGAN )
  listener:registerScriptHandler(onTouchMoved,cc.Handler.EVENT_TOUCH_MOVED )
  local eventDispatcher = ret:getEventDispatcher()
  eventDispatcher:addEventListenerWithSceneGraphPriority(listener, ret)

  return ret
end

function CocosDenshionTestMain()
  cclog("CocosDenshionTestMain")
  local scene = cc.Scene:create()
  scene:addChild(CocosDenshionTest())
  scene:addChild(CreateBackMenuItem())
  return scene
end