Lua Programming Help Thread

[Urameshi]

Ok i tried that table.remove and it didnt work, and now im stuck again

[yumCOOKIEZZ]

How would I make an image stay.
if pad:triangle() then
screen:blit(0, 236, start, true)
screen.flip()
end

That will work while I hold it down, but I want it to stay once its pressed once.

[youresam]

Ok i tried that table.remove and it didnt work, and now im stuck again

table.remove is so simple..
-= Double Post =-

How would I make an image stay.
if pad:triangle() then
screen:blit(0, 236, start, true)
screen.flip()
end

That will work while I hold it down, but I want it to stay once its pressed once.

Use a bool variable.

[TacticalPenguin]

aka if pad:triangle() then showtheimage = true end
if showtheimage then screen:blit(x,y,theimage) end

[yumCOOKIEZZ]

Thanks ;D

(I'm gonna try to cut down on questions -.-)
-= Double Post =-
When I did that it gives the same effect. The image is loading a lot of times and giving problemness.

[youresam]

..
in the begining
showstart = false

..main..

showstart = pad:triangle() or showstart
...
if showstart then screen:blit(0, 236, start, true) end

[SG57]

Yonathan - Wouldn't 'showstart = pad:triangle()' do the same as his first method (where it shows only when held), as if tirnagle isn't being pressed, than return false, making showstart false, making it not blit hte image...

[youresam]

Yonathan - Wouldn't 'showstart = pad:triangle()' do the same as his first method (where it shows only when held), as if tirnagle isn't being pressed, than return false, making showstart false, making it not blit hte image...

Read the whole thing..
showstart = pad:triangle() or showstart

btw this is youresam :P

[TacticalPenguin]

And since it's an or statement, only one part must be true to make it true. So if showstart is already true it will remain true.

[k0ud]

HIYA im back to the scene:)...

can anyone tell me how to make a menu selector go to right and left instead of up and down? coz my app will make too many menu...;)

[youresam]

HIYA im back to the scene:)...

can anyone tell me how to make a menu selector go to right and left instead of up and down? coz my app will make too many menu...;)

*sigh*
Change the coordinates.

[yumCOOKIEZZ]

I got what I wanted to work. When you scroll over the image, it will change. When you scroll off, it changes back. One problem is when ON the image itself theres a bit of lag and the cursor moves slowly. Is there any way to prevent this?

I can still work around it but it would be helpful to fix.

[k0ud]

*sigh*
Change the coordinates.

if i change coords i still need to use the up and down not right and left button right?>.<

[youresam]

I got what I wanted to work. When you scroll over the image, it will change. When you scroll off, it changes back. One problem is when ON the image itself theres a bit of lag and the cursor moves slowly. Is there any way to prevent this?

I can still work around it but it would be helpful to fix.

Err...what?
-= Double Post =-

if i change coords i still need to use the up and down not right and left button right?>.<

...how are the buttons a problem??

[k0ud]

hmm my menu selection is a lil big.... so i want an up and down,left and right selection..

[youresam]

oh, and, thats a bit more complicated

[k0ud]

yeah lol thats y i asked.. if its just the coords i wont ask lol

[yumCOOKIEZZ]

Err...what?
-= Double Post =-

...how are the buttons a problem??

Uhg...How do I explain it...

There are 2 images. Exactly the same in size, shape, ect. Just some differing in colors. One will display no matter what. One will display when I scroll over to it. When the cursor (what I use to move with the analog) is over the image, the second image is written on top of the first.

Why am I explaining?...Heres the code.
showstart = false
if x > 0 and x < 50 and y >236 and y < 272 then showstart = true end
if x > 50 and y < 236 then showstart = false
if showstart then
starton = Image.load ("images/Start-Over.png")
screen:blit (0, 236, starton, true)

else
screen:blit(0, 236, start, true)
end

[SG57]

tuhm... Simply change all 'down()' to 'left()' and all 'up()' to 'right()'. If you structure each menu option from left to right, you wont need to redo the entire menu code.

Guy above me - its cause you continually load your Start-Over.png once on it. Simply move it out of the infinite loop, not in your if statement.

[k0ud]

ok thx sg ill try after i buy a battery

[xmex]

Id like to take this opporuntity to draw back to my problem

function MedCol()
for y=1,en_2 do
for u=1,no_bull do
if asteroidmed[y].x+24>bullet[u].x and asteroidmed[y].x<bullet[u].x+6 and asteroidmed[y].y+24>bullet[u].y and asteroidmed[y].y<bullet[u].y+6 then
score=score+20
asteroidsm[en_3+1]={x=asteroidmed[y].x, y=asteroidmed[y].y, width=32, height=32, vspeed=(math.random(0,1))-(math.random(0,2)), hspeed=(math.random(0,1))-(math.random(0,2))}
en_3=en_3+1
asteroidmed[y].x=489346983
bullet[u].x=-99999999999
end
end
end
end

I get an error that in the collision if "attempt to index field "?" null value". There is a asteroidmed array, en_2 is equal to 1, there are several bullets, no_bull is the amount of bullets, there is an asteroidmed[1] and it has x and y coordinates, same as the bullet. However i see no difference with this code and my other one:

function Collision()
for f=1,en_1 do
for g=1, no_bull do
if asteroid[f].x+32>bullet[g].x and asteroid[f].x<bullet[g].x+6 and asteroid[f].y+32>bullet[g].y and asteroid[f].y<bullet[g].y+6 then
score=score+20
asteroid[en_2+1]={x=asteroid[f].x, y=asteroid[f].y, width=32, height=32, vspeed=(math.random(0,1))-(math.random(0,2)), hspeed=(math.random(0,1))-(math.random(0,2))}
en_2=en_2+1
asteroid[f].x=489346983
bullet[g].x=-99999999999
end
end
end
end

Apart from the names. any help?!

I have tried a lot of things. What does the error mean? Uncalled table/variable?
-= Double Post =-
Never mind, I fixed that error (finally)

[myschoo]

ok thx sg ill try after i buy a battery

you can make menu with tables...

so you will have only for example 5 lines on the screen which could be changed with left right

[psp phd]

Could someone please explain how to make looping Backgrounds on a menu. Say 3 bgs' showing for 3 seconds a piece. If thats possible...

Thanks for the help guys :)

[KleptoOne]

forget the fact that its a menu and ask yourself, how would I make a 3 frame animation? Theres craploads of tutorials out there that will help you with this, or look into the animlib.

[xmex]

Is there a way to draw an image at an angle?

[psp phd]

forget the fact that its a menu and ask yourself, how would I make a 3 frame animation? Theres craploads of tutorials out there that will help you with this, or look into the animlib.

Damn... In the time it took you to write that you could have just copy/pasted the code snippet for me...

But I'll google animlib, to see what I can find out about it. Thanks for the heads up on that. :)

[KleptoOne]

Not really, unless you texture the image to triangles using the GU, then you can scale and rotate all you want. The only way I know of to do it without the GU is to copy the image pixel by pixel, running it through an algorithm that will angle it, but this process is so slow that you would have to buffer the created images into some type of array and it would eat up your memory quick depending on the size of the image.
-= Double Post =-

Damn... In the time it took you to write that you could have just copy/pasted the code snippet for me...

But I'll google animlib, to see what I can find out about it. Thanks for the heads up on that. :)

The reason I said that was because a lot of the newer programmers are getting lazy. When I was learning I would read everything I could get my hands on to figure something out, and if I needed help on something I always asked regarding the concept and not the code, because its the concepts that will allow you to jump into pretty much any language and be productive.
Chances are you already realize this and you're just being lazy, which I understand, but I personally can't promote.

[psp phd]

The reason I said that was because a lot of the newer programmers are getting lazy. When I was learning I would read everything I could get my hands on to figure something out, and if I needed help on something I always asked regarding the concept and not the code, because its the concepts that will allow you to jump into pretty much any language and be productive.
Chances are you already realize this and you're just being lazy, which I understand, but I personally can't promote.

Actually, I have wrote a simple project in LUA and have since decided to pick up C instead. (I just needed something to get my feet wet with all this)
But - I thought it would be nice to do a 10 min. spiff up the lua project.

Lua was good to get comfortable with the basic concepts of programming. But I don't want to stuff my brain up with a bunch of info I'm never going to use again. LOL. C is much different from Lua. And the rules of C are what I have begin studying. Why confuse myself with more Lua stuff? I just wanted a quick code snippet to polish up & end my lua project. Then I dont plan on using Lua anymore...


EDIT: And I'm far from lazy bud... This is a hobby for me. I work 40+ hrs a week.

[ahrimanes]

hii there people, im makings some test, and i im in a way to make more eficient process i have.... ok i have a value in a variable and i want another variable.. to be a poiter of the last one...soo..if:
var1 = 10
var2 = pointer of var1... then
when i do var1 = 20.. var2 automatically takes the var1 value... how can i do that ?
also i want to do this:
var1 ={x=1,y=1}
var2 ={x=2,y=2}
var3 = {{pointer of var1},{pointer of var2}}
soo when i change the values of var1.x the var3[1].x actomatically takes the value... how to do this in lua ? the point is that i wont redefine the var3 each time the others change his value.

[KleptoOne]

Actually, I have wrote a simple project in LUA and have since decided to pick up C instead. (I just needed something to get my feet wet with all this)
But - I thought it would be nice to do a 10 min. spiff up the lua project.

Lua was good to get comfortable with the basic concepts of programming. But I don't want to stuff my brain up with a bunch of info I'm never going to use again. LOL. C is much different from Lua. And the rules of C are what I have begin studying. Why confuse myself with more Lua stuff? I just wanted a quick code snippet to polish up & end my lua project. Then I dont plan on using Lua anymore...


EDIT: And I'm far from lazy bud... This is a hobby for me. I work 40+ hrs a week.

A simple animation is the same regardless of the language that you use. You find a way to judge time and cycle through the images based on that. Also, none of us are being paid to do this, so given that its a hobby why would you want to cheat yourself of the learning process and ask for ready made code? I guarentee you that if you learned how to animate in lua, it would help you in C.