Lua Programming Help Thread

[shadow-evillink]

@shadow-evillink:
Is this your complete code?

testing---------------
 
 black=Color.new(0,0,0)
 
 background=Image.load("background.png")
 
 
 screen:blit(0,0,backgroun d,false)
 screen.waitVblankStart()
 screen.flip()
 end
 
 screenrint(200,130,"It worked Finally",black)
 screen:flip()
 while true do
 screen.waitVblankStart()
 end
 end

if so then it should be:

 black=Color.new(0,0,0)
 background=Image.load("background.png")
 screen:blit(0,0,background,false)
 screenrint(200,130,"It worked Finally",black)

 while true do
 screen.waitVblankStart()
 screen:flip()
 end

The thing you did wrong was that you put in an "end" while there wasn't any if/while/for/etc. command in fornt of it. Also you have a lot of waitVblankstart's and screenflips, but that should still work, i think.[/QUOTE]

Thanks, I'm just now learning lua. I will test it out and thanks again.

[Altair]

No prob!

@KKDDKK
You should put a "then" after each "elseif" aswell.

[soadnation]

k im working on hetting the inmages on the screen. i thought it would be easy but i keeo getting this error.

PlayerStand = Image.load(layerstand.png")...]:6 '=' expected near 'screen'

this is from ttlde

and this is my code

PlayerStand = Image.load("playerstand.png")
PlayerJump = Image.load("playerjump.png")
Obj = Image.load("obj.png")
green = Color.new(0, 255, 0)
-Start Code

screen:blit(100, 90, PlayerStand)
screen.flip()
screen.waitVblankStart()

ive been over my code abouty 20 times and i cant fiogure out what is wrong with it.

[c5cha7]

k im working on hetting the inmages on the screen. i thought it would be easy but i keeo getting this error.

PlayerStand = Image.load(layerstand.png")...]:6 '=' expected near 'screen'

this is from ttlde

and this is my code

PlayerStand = Image.load("playerstand.png")
PlayerJump = Image.load("playerjump.png")
Obj = Image.load("obj.png")
green = Color.new(0, 255, 0)
-Start Code

screen:blit(100, 90, PlayerStand)
screen.flip()
screen.waitVblankStart()

ive been over my code abouty 20 times and i cant fiogure out what is wrong with it.

Fixed version, I have just fixed a error but
your code end's because it doesnt loop [0 second's so it end's].

 
PlayerStand = Image.load("Playerstand.png")
PlayerJump = Image.load("Playerjump.png")
Obj = Image.load("Obj.png")
green = Color.new(0, 255, 0)

screen:blit(100, 90, PlayerStand)
screen.waitVblankStart()
screen.flip()

Fully working Version (To loop the image)

 
PlayerStand = Image.load("Playerstand.png")
PlayerJump = Image.load("Playerjump.png")
Obj = Image.load("Obj.png")
green = Color.new(0, 255, 0)

while true do
screen:blit(100, 90, PlayerStand)
screen.waitVblankStart()
screen.flip()
end

[soadnation]

k thanks. completly forgot about the lopp that goes around the waitVblanks

[Altair]

@KKDDKK
here is a full working (tested myself) code:

Default 
Code:
stage =1
black=Color.new(0,0,0)
background1=Image.load("1.jpg")
 background2=Image.load("2.jpg")
 background3=Image.load("3.jpg")
 background4=Image.load("4.jpg")
 background5=Image.load("5.jpg")
 sound=Sound.load("sound.wav")
while true do
screen:clear(black)
sound:play()
if stage==1 then
screen:blit(0,0,background1)
stage=2
elseif stage==2 then
screen:blit(0,0,background2)
stage=3
elseif stage==3 then
screen:blit(0,0,background3)
 stage=4
elseif stage==4 then
screen:blit(0,0,background4)
 stage=5
elseif stage==5 then
screen:blit(0,0,background5)
 stage=6
elseif stage==6 then
screen:blit(0,0,background2)
 stage=1
end
screen.waitVblankStart(90)
screen.flip()
end

[Altair]

Hey soadnation, what is it you're making?

[soadnation]

its a 2-d version of a mini game in an early xboxd title

now im working on adding simeple movement but it gives me a runtime error on line 11(if pad left) "Attemt to index global 'pad' (a function value)"

PlayerStand = Image.load("Playerstand.png")
PlayerJump = Image.load("Playerjump.png")
Obj = Image.load("Obj.png")
green = Color.new(0, 255, 0)
XAxis = 100

while true do
screen:clear()
pad = Controls.read

if pad:left() then
	XAxis = XAxis-1
end

if pad:right() then
	XAxis = XAxis+1
end

screen:blit(X, 90, PlayerStand)
screen.waitVblankStart()
screen.flip()
end

i usualy wouldnt post this right away and try to work it out myself a little but before i post it here but im going to bed and i was hoping to get the left/right movement down by tomorow.

nevermind. saw that i was missing the "()" after pad = control read right as it posted. but when it starts the picture doesnt move when i hit left and right

[Altair]

well that's because your image blits at (X, 90) while you don't state the X, because you use "XAxis" above!

[soadnation]

yea. figured that out when i got on this morning. thanks anyways.

now i got a question. can i make a collision funtion for an object and then duplicate the object multiple times?

[c5cha7]

yea. figured that out when i got on this morning. thanks anyways.

now i got a question. can i make a collision funtion for an object and then duplicate the object multiple times?

This is where i am stuck
Collisions aint going so well
If anyone could help then thank's

[Altair]

well i know you can do that with tiles, eventhough i don't understand it. (I don't get the assigning of the letters to each part of a piture. Can someone maybe explain?). But i don't know if you can just copy it, because then the variables will mixup, or not? Hmmmm.... i'll think about it.

[Altair]

i think you can use a function and the then you give it as arguments the coordinats of each object. So say you have x1,y1,x2,y2,etc. and you have a function collision(x,y).
Then you can say

if xcoordinate==x1 and ycoordinate ==y1 then
collision(x1,y1)
end

etc.

I dont know if thats the best/shortest way of doing it though.

[soadnation]

the thing im trying to make will have pipes(some on the ground some in the air) that all move the same way. they are all gona be the same picture just at different heights. thats why i was wondering if i could just have collision for one of them and then just copy it.

[PSPMillionaire]

Here's a tile engine I was messing around with. I ported this from Darkbasic language into lua, and changed some things around a bit as well. It has working collision based on images stored in an array. if the index to the image is less than 50 then you wont collide with the tile. Above 50 you will. This is messy since i was just tinkering around with the code. But you can look at it, for fun if anything. Not sure which images i used so i may have included a few more than needed.
Oh, and this scrolls the screen in all directions as well, like an RPG.

[Altair]

thanks, i looked at the lua tut again aswell and now i get the tilestuff. BTW PSPMillionaire, what are all the "61"'s in "map[1] "? I don't see any picture 61.

[soadnation]

how do i add get rid of the white background on my pictures? i tried the alpha equals true command but it doesnt work. if it helps i used photoshop for them.

[PSPMillionaire]

thanks, i looked at the lua tut again aswell and now i get the tilestuff. BTW PSPMillionaire, what are all the "61"'s in "map[1] "? I don't see any picture 61.

Images[61] = Image.load("Brick.png")

That is the image associated with it :)

[Altair]

Wow that was stupid! I just read over it. Next time ill read better. thx though!

@soadnation
You have to make the white background transparent. If you use photoshop then it's easy. Just use magic eraser, one click and its done.

[soadnation]

stupid me. i ment paint. never thought i would get THOSE two mixed up.

one problem. in my menu script i told it to do file index.lua in the data folder but it never does.

i have this in my menu script

dofile("./jumpdata/index.lua")

this is my file structure

-Jump folder
-Index.lua
--JumpData folder
-index.lua
-picture files

once this is done and i get the duck done and some new obj ill probly release an early version(without collision)

[Altair]

i think you aren't supposed to put the filename in "s (dont know what they're called in english). So it becomes:

dofile(./jumpdata/index.lua)

[soadnation]

i need the quotes i know that. i dont need the ( though. still doesnt work now. now its

dofile "jumpdata/Index.lua

also what is wrong with thise line of code?

if math:random(0, 1)==0 then

when i try running it it says
wrong number of arguments

[Altair]

its

if math.random(0, 1)==0 then

I think that should work

hmm in the wiki it says:
dofile([filename])
If that doesn't work then i dont know because i havent used that before. But Ill try it if i have the time.

[soadnation]

still doesnt work. right now im not even that worried with the dofuile. its the mathrandom part. without it i cant go any further.

this is the code its in

if np<6 and rc==1 and math:random(0,1)==0 then screenLblit(x1, y1, Obj) else end

[Altair]

I told you it's with a point, not a colon.
So it's:
if np<6 and rc==1 and math.random(0,1)==0 then screenLblit(x1, y1, Obj) else end
and not
if np<6 and rc==1 and math:random(0,1)==0 then screenLblit(x1, y1, Obj) else end

[Altair]

Ok i figured the dofile() out:

it's just
dofile("index.lua")
if it's in the same directory

If its not, then you can do this:
dofile("map/map/index.lua")

or you can put this in front of it:
System.currentDirectory("map/map")

Instead of "map/map" you type the directory its in (duh).

Both methods work.

So for you its:

dofile("jumpdata/index.lua")

or

System.currentDirectory("jumpdata")
dofile("index.lua")

Hope that helped

[soadnation]

see i thought it was with a : because in ttlde it has a lua funtion dictiopnsary type thing wherte u select it and it shows up on screen. it had showed up with a : not a .

[Altair]

well i used a . instead of a : and with me it works

[Altair]

and if it still doesnt work. Try storing the math.random(0,1) in a variable first and compare the variable in the if statement.

[soadnation]

it works. i just now need to think of whats the best way to go about this.
also i just did the dofile and it works perfectly. thatnks alot.