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Moving an alien to bottom of the screen?
Posted: Wed Dec 17, 2014 1:09 pm
by ConallChloride
Hi all, I have code to move the enemy ship in my game, however I cannot get it to move from the top of the card to the bottom. Spawning of the enemy works, but movement down does not.
Code: Select all
on moveAlien
if moveEnemy = FALSE then
movealien
end if
set the top of image "alienEnemy" to (the top of image"alienEnemy" + 5)
if the top of image "alienEnemy" >= 400 then
delete image"alienEnemy"
put false into moveEnemy
//put (lives - 1) into lives
put false into alienEnemy
put false into moveEnemy
end if
end moveAlien
This is what I have so far. Any help is appreciated!
Many thanks, Conall
Re: Moving an alien to bottom of the screen?
Posted: Wed Dec 17, 2014 1:27 pm
by ConallChloride
Update: Movement now works due to adding in the line "send "moveAlien" to me in 5 milliseconds", however when the enemy is shot I get an error with the first line in this sub-rutine "set the top of image "alienEnemy" to (the top of image"alienEnemy" + 5)". Can anyone help?
Thanks, Conall
Re: Moving an alien to bottom of the screen?
Posted: Wed Dec 17, 2014 2:04 pm
by Klaus
Hi Canall,
sorry, don't get this?
WHAT condition in your handler refers to the fact that an ALIEN might be "dead"?
And WHAT error do you get?
We surely need a tad more info!
Best
Klaus
Re: Moving an alien to bottom of the screen?
Posted: Thu Dec 18, 2014 9:59 am
by ConallChloride
Hi Klaus
So basically, when my bullet intersects with the alien the image is deleted. This can happen up to four times before I'm taken into my code due to a problem with the line "set the top of image "alienEnemy" to (the top of image"alienEnemy" + 5)"
I'm not too sure on how I can fix this.
The whole block is
Code: Select all
on moveAlien
if moveEnemy = FALSE then
return false
end if
if game = false then
return false
end if
set the top of image "alienEnemy" to (the top of image"alienEnemy" + 5)
if the top of image "alienEnemy" >= 590 then
delete image"alienEnemy"
put false into moveEnemy
put (lives - 1) into lives
put false into alienEnemy
send gameloop to me
end if
send moveAlien to me in 5 millisecs
end moveAlien
Re: Moving an alien to bottom of the screen?
Posted: Thu Dec 18, 2014 1:23 pm
by Klaus
Hi Conall,
hm, still not sure I get it
Maybe addind another if then clause will do the trick?
Code: Select all
on moveAlien
if there is NOT an img "alienEnemy" then
exit moveAlien
end if
...
?
Best
Klaus
Re: Moving an alien to bottom of the screen?
Posted: Fri Dec 19, 2014 4:44 am
by Newbie4
Even after you delete the alienEnemy, you still send the message "moveAlien". Could it be that message that gets you the next time you go in that code and try to move an alienenemy that has been deleted?
Try this
Code: Select all
set the top of image "alienEnemy" to (the top of image"alienEnemy" + 5)
if the top of image "alienEnemy" >= 590 then
delete image"alienEnemy"
put false into moveEnemy
put (lives - 1) into lives
put false into alienEnemy
send gameloop to me
else
send moveAlien to me in 5 millisecs
end if