what happens to my sprite/body when it leaves the world bounds?

Games
#1

Hi,

say I have a floor in my world, so that my balls can bounce off it and off my stage (out of the side)

what happens to my sprite/body?

at the moment i have a BallActor class and this contains my sprite. the sprite also has a reference back to the actor so that i can access it during collisions

eg

[lua]obj = new BallActor()
print(obj.sprite) – will return a table reference to the sprite created in the BallActor class
obj.sprite.actor = obj – set reference back to actor
physics.addBody(obj.sprite)

local function onCollision( event )

local obj1 = event.object – ie my sprite
local actor = obj1.actor
…
end[/lua]

depending what Corona does with my sprite/body when it leaves the stage will affect what I can do with my actor (eg does my sprite reference still exist or has Corona removed it when it left the stage bounds etc)

thanks
j
[import]uid: 6645 topic_id: 3453 reply_id: 303453[/import]

#2

presumably corona isn’t going to just remove the body outside the screen, since otherwise i could never have a game world bigger than my screen!.. but what I was wondering also is if my floor is a rectangular sprite the width of the screen, presumably my ball (for instance) can bounce off the floor, out of the screen and then drop below. Do I need to manage it’s existence based on the y position in that case? Does it just keep falling otherwise? Does the Corona engine enforce any limits itself? [import]uid: 6645 topic_id: 3453 reply_id: 10363[/import]

#3

my guess is that it keeps falling. Just do a test with an object and print out its coordinates. [import]uid: 5712 topic_id: 3453 reply_id: 10373[/import]

#4

just checked and yes it did.

i’ll check if its x is outside the screen in this instance and remove/recycle it

my other question is how to best remove it from it’s actor efficiently

if i remove the sprite, i cant reference the actor directly so is what i did above the best way to do it?

[lua]local obj1 = event.object – ie my sprite
local actor = obj1.actor – the class that created the sprite
obj1:removeSelf()
actor=nil – wont this just delete my local reference to my actor, rather than removing the actor itself[/lua]

would i be better keeping a allActors array (local to my main application) and removing it from there?

[lua]local function onCollision( event )

local obj1 = event.object – ie my sprite
local actor = obj1.actor
…
local actorToRemove = splice(onScreenActors[instanceOf(onScreenActors, obj1.actor)],1)
push(actorsToRemove, actorToRemove)

end

local function removeDeadItems()

for i = #actorsToRemove,1,-1 do
local actor = actorsToRemove[i]

actor.sprite:removeSelf()

– not needed?
– actorsToRemove[i]=nil
– actor=nil

end

actorsToRemove={}

end[/lua]

(note splice, push etc are my own functions, not native)

thanks
j [import]uid: 6645 topic_id: 3453 reply_id: 10391[/import]

#5

Your actor is stored inside the display object. Any displayobject that will be removed and has custom properties (your actor for an example) turn into a simple table that has to be removed then by assigning nil to it.

[lua]local obj1 = event.object – ie my sprite
local actor = obj1.actor – the class that created the sprite
obj1:removeSelf()
obj1=nil[/lua]

my other question is how to best remove it from it's actor efficiently

Actually you have the actor attached to the object, not opposite. [import]uid: 5712 topic_id: 3453 reply_id: 10417[/import]

#6

Actually it’s a circular reference I think. My main app creates an instance of my Actor class which creates sprite. Then in my main app I am setting actor.sprite.actor = actor . I don’t know if this is a bad idea but it allows me to reference my actor from the event object. I just don’t know how to remove everything properly. Maybe I would be better not doing this and having an allActors(sprite) lookup instead? [import]uid: 6645 topic_id: 3453 reply_id: 10425[/import]