Restarting game

Solar2D Composer
#1

Hello,

I am new to Corona SDK.  I am trying to restart a game using storyboard.gotoScene on another lua file then use storyboard.removeScene() then storyboard.gotoScene.  I always received “attempt to call method ‘applyLinearImpulse’ (a nil value)” error.  It watch the tutorial about this technique but it does not seem to work for me.  Can someone tell me what’s wrong with my codes.

Thanks,

Quincy

require “CiderDebugger”;

–
– game.lua

–requires

local storyboard = require(“storyboard”)
local scene = storyboard.newScene()

local physics = require “physics”
physics.start()

local rocket

function propel(self, event)
   rocket:play()
   rocket:applyLinearImpulse(0, -10, rocket.x, rocket.y)
end

local function restartGame(event)
    if (“ended” == event.phase) then
        storyboard.gotoScene(“restart”, {time=250, effect=“crossFade”})
    end
end

local function checkLocation(event)
    if rocket.y < 50 then
        --print (rocket.y)
       
        storyboard.gotoScene(“complete”, {time=250, effect=“crossFade”})
    end
    
end

function scene:createScene(event)
    local screenGroup = self.view
    local nightSky = display.newImage(“nightsky.png”, display.contentCenterX, display.contentCenterY)
    nightSky:addEventListener(“touch”, propel)
    screenGroup:insert(nightSky)
    
    local ground = display.newImage(“moon.png”)
    ground.x = display.contentCenterX
    ground.y = 0
    physics.addBody(ground, “static”)
    screenGroup:insert(ground)
    
    local top = display.newImage(“moon.png”)
    top.x = display.contentCenterX
    top.y = 1024
    physics.addBody(top, “static”)
    screenGroup:insert(top)
    
    --rocket = display.newImage(“rocket.png”, display.contentCenterX, 1024-200)
    
    local rocketOptions = {
        width = 36,
        height = 64,
        numFrames = 3,
        sheetContentWidth = 108,
        sheetContentHeight = 64
    }
    local rocketSpriteSheet = graphics.newImageSheet(“rocket_launch.png”, rocketOptions)
    
    local sequenceData = {
        start = 1,
        count = 3,
        time = 1800,
        loopCount =1,
        loopDirection = “forward”
    }
    
    rocket = display.newSprite(rocketSpriteSheet , sequenceData)
    rocket.x = display.contentCenterX
    rocket.y = display.contentHeight/2
    rocket:play()
    
    physics.addBody(rocket, “dynamic”, {density= 1.05, bounce=0.1, friction=0.1, radius=23})
    
    screenGroup:insert(rocket)
    
    local btnRestart = display.newImage(“restart.png”, 48, 48)
    btnRestart:addEventListener(“touch”, restartGame)
    screenGroup:insert(btnRestart)
    
end

function scene:enterScene(event)
    local screenGroup = self.view
    rocket.enterFrame = checkLocation
    Runtime:addEventListener(“enterFrame”, checkLocation)
    
end

function scene:exitScene(event)
    Runtime:removeEventListener(“touch”, propel)
    physics.stop()
    
end

function scene:destroyScene(event)
    local screenGroup = self.view

end

– “createScene” event is dispatched if scene’s view does not exist
scene:addEventListener( “createScene”, scene )

– “enterScene” event is dispatched whenever scene transition has finished
scene:addEventListener( “enterScene”, scene )

– “exitScene” event is dispatched before next scene’s transition begins
scene:addEventListener( “exitScene”, scene )

– “destroyScene” event is dispatched before view is unloaded, which can be
– automatically unloaded in low memory situations, or explicitly via a call to
– storyboard.purgeScene() or storyboard.removeScene().
scene:addEventListener( “destroyScene”, scene )

return scene
 

–

–
– restart.lua

–requires

local storyboard = require(“storyboard”)

local scene = storyboard.newScene()

function scene:createScene(event)
    local screenGroup = self.view
 
    --Background
    local sky = display.newImage(“nightsky.png”)
    sky.x = display.contentCenterX
    sky.y = display.contentCenterY
    screenGroup:insert(sky)

end

function scene:enterScene(event)
    local screenGroup = self.view
    storyboard.removeScene(“game”)
    storyboard.gotoScene(“game”, {time=250, effect=“crossFade”})
end

function scene:exitScene(event)
   local screenGroup = self.view
end

function scene:destroyScene(event)
    local screenGroup = self.view
end

– “createScene” event is dispatched if scene’s view does not exist
scene:addEventListener( “createScene”, scene )

– “enterScene” event is dispatched whenever scene transition has finished
scene:addEventListener( “enterScene”, scene )

– “exitScene” event is dispatched before next scene’s transition begins
scene:addEventListener( “exitScene”, scene )

– “destroyScene” event is dispatched before view is unloaded, which can be
– automatically unloaded in low memory situations, or explicitly via a call to
– storyboard.purgeScene() or storyboard.removeScene().
scene:addEventListener( “destroyScene”, scene )

return scene

 

#2

I think I found the problem: I remove the event listener and stop the physics. I have see other examples that doing some sort of clean up in exitScene.  What should I include there?

function scene:exitScene(event)
–    Runtime:removeEventListener(“touch”, propel)
–    physics.stop()
    local screenGroup = self.view
   
end

#3

I think I found the problem: I remove the event listener and stop the physics. I have see other examples that doing some sort of clean up in exitScene.  What should I include there?

function scene:exitScene(event)
–    Runtime:removeEventListener(“touch”, propel)
–    physics.stop()
    local screenGroup = self.view
   
end