I'm trying to make a game in Corona SDK where a player runs and survives through obstacles by either jumping over them or killing them using bullets. The problem is that the game ends even if the player fires the bullet. But it should be over only if the player collides with the obstacles.
This is my code till now!!
--local screen_adjustment = 1
local physics = require "physics"
physics.start()
local storyboard = require ("storyboard")
local scene = storyboard.newScene()
function scene:createScene( event )
local screenGroup=self.view
background=display.newImage("rsz_islands1-background-animation.png")
background:setReferencePoint(display.BottomLeftReferencePoint)
background.x=-50
background.y=330
background.speed=math.random(2,6)
screenGroup:insert(background)
background1=display.newImage("rsz_islands1-background-animation.png")
background1:setReferencePoint(display.BottomLeftReferencePoint)
background1.x=500
background1.y=330
background1.speed=math.random(2,6)
screenGroup:insert(background1)
rightArrow=display.newImageRect("right_arrow.png",50,100)
rightArrow:setReferencePoint(display.BottomLeftReferencePoint)
rightArrow.x=370
rightArrow.y=290
screenGroup:insert(rightArrow)
upArrow=display.newImageRect("up_Arrow.png",100,50)
upArrow:setReferencePoint(display.BottomLeftReferencePoint)
upArrow.x=250
upArrow.y=240
screenGroup:insert(upArrow)
stone=display.newImageRect("stone.png",100,50)
stone:setReferencePoint(display.BottomLeftReferencePoint)
stone.x=math.random(500,1500)
stone.y=280
stone.speed=math.random(2,6)
physics.addBody(stone,"static",{bounce=0,friction=0,})
screenGroup:insert(stone)
base = display.newRect(0,0,450,3)
base.x=-50
base.y=282
base:setReferencePoint(display.BottomLeftReferencePoint)
base:setFillColor(255,255,255)
--physics.addBody(base,"static",{bounce=0.1,friction=0.1})
physics.addBody(base,"static",{bounce=0,friction=1.0,density=1.0})
screenGroup:insert(base)
base.myName="base1"
local sheetData = {
width=65,
height=75,
numFrames=4,
sheetContentWidth=130,
sheetContentHeight=150
}
local mySprite = graphics.newImageSheet("imageSheet.png",sheetData)
local sequenceData = {
name="normalRun",
frames={1,2,3,4},
time=500,
loopcount=0
}
animation = display.newSprite(mySprite,sequenceData)
if(animation.x<50) then
animation.x=50
end
animation.y=245
physics.addBody(animation,{bounce=0.3,friction=1.0,density=1.0,radius=35})
animation:play()
screenGroup:insert(animation)
animation.myName="animation1"
local sheetTigerData = {
width=100,
height=57,
numFrames=8,
sheetContentWidth=400,
sheetContentHeight=120
}
local myTigerSprite
graphics.newImageSheet("tigerImageSheet.png",sheetTigerData)
local sequenceTigerData = {
name="normalRun",
frames={1,2,3,4,5,6,7,8},
time=500,
loopcount=0
}
tigeranimation = display.newSprite(myTigerSprite,sequenceTigerData)
--tigeranimation.x=700
tigeranimation.x=math.random(500,1500)
tigeranimation.y=255
tigeranimation.speed=math.random(2,6)
physics.addBody(tigeranimation,"static",{bounce=0,friction=.2})
tigeranimation:play()
screenGroup:insert(tigeranimation)
local sheetBirdData = {
width=60,
height=40,
numFrames=6,
sheetContentWidth=180,
sheetContentHeight=80
}
local myBirdSprite =
graphics.newImageSheet("birdimagesheet.png",sheetBirdData)
local sequenceBirdData = {
name="normalRun",
frames={1,2,3,4,5,6},
time=500,
loopcount=0
}
birdanimation = display.newSprite(myBirdSprite,sequenceBirdData)
birdanimation.x=math.random(500,2500)
birdanimation.y=math.random(100,200)
birdanimation.speed=2
birdanimation.initY=birdanimation.y
birdanimation.amp=50
birdanimation.angle=math.random(1,360)
physics.addBody(birdanimation,"static",{friction=.2,bounce=0})
birdanimation:play()
screenGroup:insert(birdanimation)
local sheetCatData = {
width=100,
height=48,
numFrames=8,
sheetContentWidth=200,
sheetContentHeight=200
}
local myCatSprite =
graphics.newImageSheet("rsz_runningcat.png",sheetCatData)
local sequenceCatData = {
name="normalRun",
frames={2,1,4,3,6,5,8,7},
time=500,
loopcount=0
}
catanimation = display.newSprite(myCatSprite,sequenceCatData)
catanimation.x=tigeranimation.x+math.random(110,1500)
catanimation.y=255
catanimation.speed=math.random(2,6)
physics.addBody(catanimation,"static",{bounce=0,friction=.2})
catanimation:play()
screenGroup:insert(catanimation)
gameSound=audio.loadStream("gamesound.mp3")
audio.play(gameSound)
gunshot=audio.loadStream("gunshot3.mp3")
end
function scrollBack( self,event )
if self.x<-590 then
self.x=500
audio.play(gameSound)
else
self.x=self.x-3
audio.play(gameSound)
end
end
function moveTiger( self,event )
if self.x<-100 then
self.x=math.random(1500,4000)
self.y=255
self.speed=math.random(3,6)
audio.play(gameSound)
else
self.x=self.x-self.speed
audio.play(gameSound)
end
end
function moveCat( self,event )
if self.x<-100 then
self.x=tigeranimation.x+math.random(800,2000)
self.y=255
self.speed=math.random(3,6)
else
self.x=self.x-self.speed
end
end
function moveStone( self,event )
if self.x<-100 then
self.x=math.random(1000,5000)
self.y=280
self.speed=math.random(3,6)
else
self.x=self.x-self.speed
end
end
function moveBird( self,event )
if self.x<-100 then
self.x=math.random(500,2500)
--self.x=300
self.y=math.random(100,200)
self.speed=2
self.amp=math.random(25,75)
self.angle=math.random(1,360)
--self.y=280
--self.speed=math.random(3,6)
else
self.x=self.x-self.speed
self.angle=self.angle+.1
self.y=self.amp*math.sin(self.angle)+self.initY
end
end
function fireLasers()
blaster = display.newImageRect( "bullet.png", 40, 15 )
physics.addBody(blaster,"dynamic")
blaster.x = animation.x+50
blaster.y = animation.y-10
--blaster.collided=false
if(animation.x<50) then
animation.x=50
end
transition.to( blaster, { time=1000, x=500} )
audio.play(gunshot)
end
function handleFireButton( event )
if ( event.phase == "began" ) then
-- Fire the weapon
fireLasers()
elseif ( event.phase == "ended" ) then
-- Stop firing the weapon
fireLasers()
end
return true
end
positionInAir = false
function jump(event)
if(event.phase == "began" and positionInAir==false) then
--playerInAir = true
--animation:setLinearVelocity( 0, 1 )
animation:applyForce(0,-1000,animation.x,animation.y)
positionInAir=true
--physics.addBody(animation,"dynamic")
--print("touch")
end
return true
end
function onCollision( event )
if(event.object1.myName == "base1" and event.object2.myName == "animation1")
then
positionInAir = false;
-- base:removeSelf()
end
end
local function onManCollide(event)
if ( event.phase == "began" ) then
storyboard.gotoScene("restart","fade",400)
audio.stop()
end
end
function scene:enterScene( event )
background.enterFrame=scrollBack
Runtime:addEventListener("enterFrame",background)
background1.enterFrame=scrollBack
Runtime:addEventListener("enterFrame",background1)
stone.enterFrame=moveStone
Runtime:addEventListener("enterFrame",stone)
tigeranimation.enterFrame=moveTiger
Runtime:addEventListener("enterFrame",tigeranimation)
birdanimation.enterFrame=moveBird
Runtime:addEventListener("enterFrame",birdanimation)
catanimation.enterFrame=moveCat
Runtime:addEventListener("enterFrame",catanimation)
animation.collision=onManCollide
animation:addEventListener("collision",onManCollide)
rightArrow:addEventListener( "touch", handleFireButton )
--Runtime:addEventListener( "touch", handleFireButton )
--Runtime:addEventListener( "enterFrame", handleFireButton )
--upArrow:addEventListener("touch", jump)
--Runtime:addEventListener( "collision", onCollision )
--Runtime:addEventListener( "touch", onScreenTouch )
--rightArrow:addEventListener( "touch", handleFireButton )
end
function scene:exitScene( event )
Runtime:removeEventListener("enterFrame",background)
Runtime:removeEventListener("enterFrame",background1)
Runtime:removeEventListener("enterFrame",stone)
Runtime:removeEventListener("enterFrame",tigeranimation)
Runtime:removeEventListener("enterFrame",birdanimation)
Runtime:removeEventListener("enterFrame",catanimation)
Runtime:removeEventListener("enterFrame",onManCollide)
rightArrow:removeEventListener( "touch", handleFireButton )
upArrow:removeEventListener("touch", jump)
Runtime:removeEventListener( "collision", onCollision )
end
function scene:destroyScene( event )
end
--local myGroup=display.newGroup()
--physics.addBody(background,"static",{bounce=0.1,friction=0.9})
--physics.addBody(background1,"static",{ bounce=0.1,friction=0.9})
scene:addEventListener("createScene",scene)
scene:addEventListener("enterScene",scene)
scene:addEventListener("exitScene",scene)
scene:addEventListener("destroyScene",scene)
return scene
You need to ask a specific question, what you have said is quite vague. Does the game end each time the player fires the bullet? Also you should consider migrating from storyboard to composer.
i see allways that people write in the collusion function (example):
local onCollision = function(event)
if event.phase == "began" then
event.object2:removeSelf();
event.object2 = nil;
end
end
Runtime:addEventListener("collision",onCollision);
why you dont just write:
local onCollision = function(event)
event.object2:removeSelf();
event.object2 = nil;
end
Runtime:addEventListener("collision",onCollision);
I dont understand what is the point?
consider this example,
local object = display.newImage( "ball.png" )
function object:touch( event )
if event.phase == "began" then
display.getCurrentStage():setFocus( self )
self.isFocus = true
elseif event.phase == "moved" then
print( "moved phase" )
elseif event.phase == "ended" or event.phase == "cancelled" then
display.getCurrentStage():setFocus( nil )
self.isFocus = false
end
end
return true
end
object:addEventListener( "touch", object )
If you doesn't add the phase your touch will be detected in all the three phase,
thus it executes all the statements with in function three times.
To avoid this we are using the phase.
In your case ,
local onCollision = function(event)
event.object2:removeSelf();
event.object2 = nil;
end
Runtime:addEventListener("collision",onCollision);
The code inside this will be called three times, this results in error. Since in began phase itself your object will be removed, when it comes to moved phase it will give you error, since object is already removed.
Please refer this, http://docs.coronalabs.com/api/event/touch/phase.html
I'm a beginner in Corona developping and i've to problem to identify the collision between 3 objects. In fact, this is my code :
The first object is my player :
player = display.newImageRect("ballon.png", 150,170 )
player.anchorX = 0.5
player.anchorY = 0.5
player.x = display.contentCenterX - 450
player.y = display.contentCenterY+250
physics.addBody(player, "static", {density=0.1, bounce=0.1, friction=0.1,})
player.myName="player"
screenGroup:insert(player)
The second object is created within a function :
function addWindSlow(self,event)
height = math.random(display.contentCenterY - 200, display.contentCenterY + 200)
windslow = display.newImage( "wind-neg.png")
windslow.x = display.contentWidth
windslow.y = height
windslow.speed = 4
windslow.myName="windslow"
physics.addBody(windslow, "static", {density = 0.1, bounce = 0, isSensor = false})
elements:insert(windslow) end
function addWindFast(self,event)
height = math.random(display.contentCenterY - 200, display.contentCenterY + 200)
windfast = display.newImage( "wind-pos.png")
windfast.x = display.contentWidth
windfast.y = height
windfast.speed = 4
windfast.myName="windfast"
physics.addBody(windfast, "static", {density = 0.1, bounce = 0, isSensor = false})
elements:insert(windfast) end
And finally, the thirth object is the same but called "addWindFast() with a different image"
So i would like to know once my player is on collision with the windslow, i need to do an action... and if it's the object windfast, another action. That's my code :
function onCollision( event )
if ( event.phase == "began" ) then
if event.other.windslow and event.other.isVisible==true then
print("windslow has been touch !")
end
end
end
I found something about the pre-collision, I'll use it once i got the information how to "identify" the object...I'll need to prevent the collision and avoid it if the player is going to touch the windfast or windslow.
We thank you for all dude !
It looks like windslow and windfast are defined outside of onCollision event handler so you should compare to those:
function onCollision( event )
if ( event.phase == "began" ) then
if event.other == windslow and event.other.isVisible==true then
print("windslow has been touch !")
end
if event.other == windfast and event.other.isVisible==true then
print("windfast has been touch !")
end
end
end -- (missing from your post but probably in your code)
The above assumes that you have registered for collision events on your player. You could also register a different collision handler on each wind:
windslow:addEventListener("collision", onCollisionSlow)
windfast:addEventListener("collision", onCollisionFast)
In that case the two collision handlers could just check if event.other == player. The advantage of that is you are separating the code for each one. You could of course do the same with your player handler:
function onCollisionSlow(other)
print('collided with slow')
end
function onCollisionFast(other)
print('collided with fast')
end
collisionHandlers = {
[windslow] = onCollisionSlow,
[windfast] = onCollisionFast,
}
function onCollision( event )
if ( event.phase == "began" ) then
collisionFunc = collisionHandlers[event.other]
if collisionFunc ~= nil and event.other.isVisible then
collisionFunc(event.other)
end
end
end
You could identify the other object with the myName property you've specified.
For example:
function onCollision( event )
if ( event.phase == "began" ) then
if (event.other.myName == "windslow" and event.other.isVisible==true) then
print("windslow has been touched!")
elseif (event.other.myName = "windfast" and event.other.isVisible==true) then
print("windfast has been touched!")
end
end
I have a listener for loading remote images, but I need to be able to pass an ID number to that listener, and I'm not really sure how to do it. My code to retrieve the remote image is:
display.loadRemoteImage("http://www.newyorker.com/online/blogs/photobooth/NASAEarth-01.jpg", "GET", networkListener, "banner.png",system.TemporaryDirectory, (globalData.contentX * rows2) + globalData.contentX/2, 20 + (i - 1) % 6 * 140
And the listener I have is:
local function networkListener( event )
if ( event.isError ) then
print ( "Network error - download failed" )
else
local target = event.target
target.alpha = 0
transition.to( target, { alpha = 1.0 } )
target.width = 590
target.height = 110
target:addEventListener( "touch", target )
scrollView:insert(target)
function target:touch(event)
if event.phase == "began" then
display.getCurrentStage():setFocus( self )
self.isFocus = true
elseif self.isFocus then
if event.phase == "moved" then
numMoved = numMoved + 1
if(numMoved > 10) then
display.getCurrentStage():setFocus( nil )
self.isFocus = false
scrollView:takeFocus( event )
end
elseif event.phase == "ended" or event.phase == "cancelled" then
globalData.selectedLocationID = target.id --This needs to be the ID that I pass to this listener
if(globalData.approvedToggle == 1) then
storyboard.gotoScene("businessScene")
else
storyboard.gotoScene("locationScene")
end
display.getCurrentStage():setFocus( nil )
self.isFocus = false
end
end
return true
end
end
Any help in this matter would be greatly appreciated, thanks!
I did this a while back on an Ecommerence app I was making. I'm not to familer with storyboard, but I do remember using this API. If I remember correctly, you need to use event.target as the event listener and pass everything through there. I also remember that you can embed a function inside of the display.loadRemoteImage API like this:
itemImage = display.loadRemoteImage(itemData.imageURL, "GET",
function(event)
event.target.xScale = 0.4
event.target.yScale = 0.4
function openSite(event)
if event.phase == "ended" then
system.openURL( itemData.itemURL )
end
end
event.target:addEventListener( "tap", openSite )
end)
My advice is remove all the story board stuff, and try making the API work in a different document. I think that you need to simplify it so you aren't confused.
Hopefully this helps.
When I tried to execute the following piece of code it gives me this error:
Attempt to index field 'other' (a nil value)
but I don't know why.
The code:
function onCollision(event)
if event.phase == "began" then
if event.other.star == "star" then
score = score + 1
elseif event.other.mine1 == "mine1" then
if jet.collided == false then
timer.cancel(tmr)
jet.collided = true
jet.bodyType = "static"
explode()
end
end
end
end
Thanks in advance :)
As #lhf and #RBerteig said the problem is event.other is nil, so trying to access the star member fails attempting to index a nil value.
Assuming event.other can indeed be nil, the idiomatic way to solve your problem would be to add a nil check to the previous if if event.phase == "began" and event.other then, since both if and else conditions depend on event.other to be set.
function onCollision(event)
if event.phase == "began" and event.other then
if event.other.star == "star" then
score = score + 1
elseif event.other.mine1 == "mine1" then
if jet.collided == false then
timer.cancel(tmr)
jet.collided = true
jet.bodyType = "static"
explode()
end
end
end
end
In case you're wondering about the message of 'attempt to index field' you can also read more about lua index metamethod here