如何使用 Corona SDK 检测第一个碰撞物体

Question

函数scene:create（事件） -- 包括 Corona 的 "physics" 库当地物理 = 需要 "physics" physics.start() -- Seed 数字的随机性 math.randomseed(os.time())

-- Called when the scene's view does not exist.
-- 
-- INSERT code here to initialize the scene
-- e.g. add display objects to 'sceneGroup', add touch listeners, etc.
local sound = audio.loadStream("pudi.mp3")
audio.play(sound, { channel=1, loops=-1, fadein=3000})

local sceneGroup = self.view
-- create a grey rectangle as the backdrop
local background = display.newImageRect("background.jpg", screenW, screenH )
background.anchorX = 0
background.anchorY = 0

local finishline = display.newRect( 0, 450, 750, 5 )
physics.addBody(finishline,"static",{friction=2.0,bounce=0.3})
finishline.myName = "finishline"

local blueTurtle = display.newImageRect("blueturtle.png",33,42)
physics.addBody(blueTurtle,"dynamic",{friction=2.0,bounce=0})
blueTurtle.myName = "Blue Turtle"

local redTurtle = display.newImageRect("redturtle.png",33,42)
physics.addBody(redTurtle,"dynamic",{friction=2.0,bounce=0})
redTurtle.myName = "Red Turtle"

local greenTurtle = display.newImageRect("turtlegreen.png",33,42)
physics.addBody(greenTurtle,"dynamic",{friction=2.0,bounce=0})
greenTurtle.myName = "Green Turtle"


blueTurtle.x = 50
blueTurtle.y = 25

redTurtle.x = 150
redTurtle.y = 25

greenTurtle.x = 250
greenTurtle.y = 25

local function numberGenerator1()
    local myRandomNumber = math.random(80000, 180000)   
    timer.performWithDelay( 1000, numberGenerator)
   return myRandomNumber
end

local function numberGenerator2()
    local myRandomNumber = math.random(80000, 180000)   
    timer.performWithDelay( 1000, numberGenerator)
   return myRandomNumber
end

local function numberGenerator3()
    local myRandomNumber = math.random(80000, 180000)   
    timer.performWithDelay( 1000, numberGenerator)
   return myRandomNumber
end

time1 = numberGenerator1()
time2 = numberGenerator2()
time3 = numberGenerator3()


transition.to(blueTurtle,{x=50,y=350,time=time1})
transition.to(redTurtle,{x=150,y=350,time=time2})
transition.to(greenTurtle,{x=250,y=350,time=time3})

local function onCollision(event)
    if (event.phase == "began") then
        if(event.object2.myName == 'Blue Turtle') then
             print("Blue Turtle Wins")
             event.object2 = nil
             composer.gotoScene( "instruction", "fade", 500 )    

        elseif(event.object2.myName == 'Red Turtle') then
             print("Red Turtle Wins")
             event.object2 = nil
             composer.gotoScene( "instruction", "fade", 500 )    

        elseif(event.object2.myName == 'Green Turtle') then               
             print("Green Turtle Wins")      
             event.object2 = nil
             composer.gotoScene( "instruction", "fade", 500 )    


        end 
    end 


end

Runtime:addEventListener("collision",onCollision)

结束

我喜欢让第一只到达终点线的乌龟然后显示乌龟获胜的 GUI。

Answer 1

首先，gotoScene() 确实在 if 语句中起作用.. 要在此处解决您的问题，您需要执行以下操作：

1- 将所有显示对象插入到场景组中，这样当您转到其他场景时，所有对象都会从屏幕上移除。

sceneGroup:insert(background)
sceneGroup:insert(finishline)
sceneGroup:insert(redTurtle)
sceneGroup:insert(blueTurtle)
sceneGroup:insert(greenTurtle)

2- 在离开场景之前，你需要停止音频，删除 eventListeners，取消定时器，以及你正在使用的转换。我注意到你在定时器功能中有一些错误，我会修改您的代码为：

-您需要为需要计时器的目的调用相同的函数，而不是使用 numberGenerator。

 local function numberGenerator1()
        local myRandomNumber = math.random(80000, 180000)
        timer1 = timer.performWithDelay( 1000, numberGenerator1)
       return myRandomNumber
    end

 local function numberGenerator2()
        local myRandomNumber = math.random(80000, 180000)
        timer2 = timer.performWithDelay( 1000, numberGenerator2)
       return myRandomNumber
    end

 local function numberGenerator3()
        local myRandomNumber = math.random(80000, 180000)
        timer3 = timer.performWithDelay( 1000, numberGenerator3)
       return myRandomNumber
    end

time1 = numberGenerator1()
time2 = numberGenerator2()
time3 = numberGenerator3()


blueTrans = transition.to(blueTurtle,{x=50,y=350,time=time1})
redTrans = transition.to(redTurtle,{x=150,y=350,time=time2})
greenTrans = transition.to(greenTurtle,{x=250,y=350,time=time3})

然后你清理你的场景.. 所以在 scene:hide()

Runtime:removeEventListener("collision",onCollision)
transition.cancel ( blueTrans )
transition.cancel ( redTrans )
transition.cancel ( greenTrans )
timer.cancel(timer1)
timer.cancel(timer2)
timer.cancel(timer3)

3 - 对于 gotoScene() 你可以传递一个参数来确定哪只乌龟赢了，所以我在 If 语句中修改了它：

composer.gotoScene( "instruction", {effect = "fade",time = 500, params = { winningTurtle = "Blue" }}) 

composer.gotoScene( "instruction", {effect = "fade",time = 500, params = { winningTurtle = "Red" }})

composer.gotoScene( "instruction", {effect = "fade",time = 500, params = { winningTurtle = "Green" }} )

4- 最后.. 在 instruction.lua .. 在 scene:show()

里面

local prevScene = composer.getSceneName( "previous" )
composer.removeScene(prevScene)

以及访问上一个文件发送的参数

local params = event.params
print("The Winning Turtle is :" .. params.winningTurtle)

如何使用 Corona SDK 检测第一个碰撞物体

How To Detect The First Collided Object Using Corona SDK

lua

collision-detection

coronasdk