Lua Programming Help Thread

[Grimfate126]

Sorry, i have to be honest. I wasn't thinking properly....just typing while i was doing my math homework (or was I.....?). Honestly, i do use "else if" in my menu code in C.

if you say so. But your excuse seems a little shabby. bah.

[SG57]

I just didn't like how he said " "if" is less code then "elseif" "
That just seems like something a nub would say.

BTW, Doesn't this look nice?

if x == 2 then
	blah
		end
			elseif x == 3 then
	blah	
		end
			elseif x == 4 then
	blah
end

Why in the world did i say that?
Because i think super should learn how to indent.

Uhm, i hope you realize you have like 5 indeitations for the if statement, than 2 for the code to execure, then 1 for hte end... That is quite random (to me) and will be unreadable in any semi-large project.

Personally, my indentations are 2-5 spaces.

int main() {
   for(;;) {
      if(condtion is true) { 
         break;
      }
   }
   return 0;
}

[SuperBatXS]

Uhm, i hope you realize you have like 5 indeitations for the if statement, than 2 for the code to execure, then 1 for hte end... That is quite random (to me) and will be unreadable in any semi-large project.

Personally, my indentations are 2-5 spaces.

int main() {
   for(;;) {
      if(condtion is true) { 
         break;
      }
   }
   return 0;
}

Yea, the code that you just posted ( for(;;) { ) is exactly what i am using for the G-Pack's credit loading screens. It works very very well, and i greatly thank psp-programming for that. Lol, i didn't know they had that in lua because i never actually coded in lua well enough to use it.

[blotus21]

Hi... I am a noob at LUA and just beginning to learn it...

Could someone tell me how to make a program wait for a certain amount of time?

[SuperBatXS]

Hi... I am a noob at LUA and just beginning to learn it...

Could someone tell me how to make a program wait for a certain amount of time?

Either make your own timer or use this:

screen.waitVblankStart(60)

I put 60 there, which is a second. Every 60 is a second. For example, if i use 300 instead, it would be 5 seconds.

Use this to learn lua in an easy way:

http://www.psp-programming.com/tutor...a/lesson02.htm

[blotus21]

ah, thanks very much... I'll try to do it that way ^_^

[Anti-QuickJay]

Uhm, i hope you realize you have like 5 indeitations for the if statement, than 2 for the code to execure, then 1 for hte end... That is quite random (to me) and will be unreadable in any semi-large project.

Personally, my indentations are 2-5 spaces.

int main() {
   for(;;) {
      if(condtion is true) { 
         break;
      }
   }
   return 0;
}

To ME its real easy to read, When i have alot of lines of code, Its still easy for ME, I guess people just shave different preferences.

[yaustar]

if x == 2 then
	blah
		end
			elseif x == 3 then
	blah	
		end
			elseif x == 4 then
	blah
end

That is definitely non-standard.

if x == 2 then
	blah
elseif x == 3 then
	blah	
elseif x == 4 then
	blah
end

This is more common place.

http://astyle.sourceforge.net/

[andyauff]

How would I rotate an image? For example, to be able to turn an image (or twist, I guess) in order to shoot different things all around you? Thanks.

[Grimfate126]

How would I rotate an image? For example, to be able to turn an image (or twist, I guess) in order to shoot different things all around you? Thanks.

use the GU.

[andyauff]

How would i do that? I thought it was for 3d. Sorry if I'm wrong, just trying to figure things out.

[GuitarGod1134]

Either make your own timer or use this:

screen.waitVblankStart(60)

I put 60 there, which is a second. Every 60 is a second. For example, if i use 300 instead, it would be 5 seconds.

Use this to learn lua in an easy way:

http://www.psp-programming.com/tutor...a/lesson02.htm

I thought it was a millasecond timer. and arent thier 100 milliseconds in a second?

EDIT_____!!!!
NVM its vblanks and there are 60 vblanks in a second. so ur right.

[Grimfate126]

How would i do that? I thought it was for 3d. Sorry if I'm wrong, just trying to figure things out.

everything software wise is based on the GU. (on the PSP) tactical penguin wrote a tutorial here:

http://forums.qj.net/f-psp-developme...ive-89527.html

[Ba11in13]

how do you add a thing so if you are at the main menu and you press credits it goes to credits what is the code for that and i would like it to be x that selects it

[youresam]

if pad:cross() then

btw, pspdude10594 = pspdude 10/5/94 = pspdude October 5th, 1994?

[Xylem]

if pad:cross() then

btw, pspdude10594 = pspdude 10/5/94 = pspdude October 5th, 1994?

Haha.......lol. Youresam, you are my hero....:ROFL:

[Ba11in13]

if pad:cross() then

btw, pspdude10594 = pspdude 10/5/94 = pspdude October 5th, 1994?

sure whatever you want to think

[youresam]

sure whatever you want to think

Uh, ok? Im assuming it was just random pounding on the keyboard. Nevermind then.

[ClearTranquil]

How come os.exit( ) freezes my PSP when I use it? I used the same method as the tutorial. It was something along the lines of this:

I'm looking to return to the XMB from an EBOOT compiled in Game Maker.

if pressing X then
     do nothing
elseif pressing O then
     os.exit( )
end

[Merick]

The command is slightly different in different versions of the player. Try using System.Quit() and see if that works

[myschoo]

yeah System.Quit() works in Cools mod

[Tinowyn]

when I use this piece of code:

for line in songindex:lines() do

song[songlineread] = line
songlineread = songlineread + 1

end

It always adds a weird character (i'm assuming its a line end) to the end of each line, any way of removing it or stopping it from happening?

Thanks

[Bob Hoil]

Hey guys i am learning lua right now and i did some tutorials. Now i am trying to combine some to make a simple game like AOTM. Can you tell me why my guy won't shoot. It encounters an error everytime u try to shoot.

green=Color.new(0,255,0)
grass=Image.load("grass.png")
player=Image.load("player.png")
tree=Image.load("tree.png")
bullet = Image.createEmpty(4,4)
bullet:clear(green)

screenwidth=480-player:width()
screenheight=272-player:width()

Player={}
Player[1]={x=200, y=50}

oldpad = Controls.read()
currentBullet = 0
direction = "right"

BulletInfo = {}
for a = 1,800 do
	BulletInfo[a] = { pic = bullet , firing = false, direction = "right", x = Player[1].x + 32, 
	y = Player[1].y + 16 }
end

function bulletSetup()
	if currentBullet < 800 then
		currentBullet = currentBullet + 1
	else
		currentBullet = 1
	end
if direction == "left" then 
BulletInfo[currentBullet].x = Player[1].x 
BulletInfo[currentBullet].y = Player[1].y + 16
end
if direction == "right" then 
BulletInfo[currentBullet].x = Player[1].x + 32 
BulletInfo[currentBullet].y = Player[1].y + 16 
end
if direction == "up" then 
BulletInfo[currentBullet].x = Player[1].x + 16 
BulletInfo[currentBullet].y = Player[1].y 
end
if direction == "down" then 
BulletInfo[currentBullet].x = Player[1].x + 16
BulletInfo[currentBullet].y = Player[1].y + 32 
end
BulletInfo[currentBullet].direction = direction
BulletInfo[currentBullet].firing = false
end
function bulletFire()
	for i = 1,800 do
		if BulletInfo[i].firing == true then
			screen:blit(BulletInfo[i].x,BulletInfo[i].y,BulletInfo[i].pic)
		end
		if BulletInfo[i].x < 0 or BulletInfo[i].x > 480 or BulletInfo[i].y < 0 or BulletInfo[i].y > 272 then 
			BulletInfo[i].firing = false 
		end
	end
end

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

	bulletSetup()

	for a=0, 14 do
		for b=0, 8 do
			screen:blit(32 * a, 32 * b, grass)
		end
	end

	screen:blit(100,100,tree)
	screen:blit(300,220,tree)
	screen:blit(87,46,tree)
	screen:blit(400,150,tree)
	screen:blit(Player[1].x,Player[1].y,player)

	if pad:left() and Player[1].x>0 then
		Player[1].x=Player[1].x-3
	end

	if pad:right() and Player[1].x<screenwidth then
		Player[1].x=Player[1].x+3
	end

	if pad:up() and Player[1].y>0 then
		Player[1].y=Player[1].y-3
	end

	if pad:down() and Player[1].y<screenheight then 
		Player[1].y=Player[1].y+3
	end

	if pad:triangle() then
		if BulletInfo[i].direction == "up" then 
			BulletInfo[i].y = BulletInfo[i].y - 10 
		end
	end
	if pad:circle() then
		if BulletInfo[i].direction == "right" then 
			BulletInfo[i].x = BulletInfo[i].x + 10 
		end
	end
	if pad:cross() then
		if BulletInfo[i].direction == "down" then 
			BulletInfo[i].y = BulletInfo[i].y + 10 
		end
	end
	if pad:square() then
		if BulletInfo[i].direction == "left" then 
			BulletInfo[i].x = BulletInfo[i].x - 10 
		end
	end

	bulletFire()

	screen.waitVblankStart()
	screen.flip()
end

[slicer4ever]

post your error please

[Bob Hoil]

GAME.LUA:105:attempt to index field '?' (a nil value)

There you go. Not sure what is wrong.
Thanks

[Urameshi]

screenwidth=480-player:width()
screenheight=272-player:width()

shouldn't it be:
screenwidth=480-Player:width()
screenheight=272-Player:width()

[Bob Hoil]

Not sure but the error is in line 105
-= Double Post =-
It has to do with something when i hit the button to shoot it encounters that error. I need this because next i am going to add enemies and collision hopefully.

Thanks to anyone that helps me out.

[Urameshi]

well in

BulletInfo = {}
for a = 1,800 do
	BulletInfo[a] = { pic = bullet , firing = false, direction = "right", x = Player[1].x + 32, 
	y = Player[1].y + 16 }
end

you stated direction="right" but right above that line you stated direction="right"

maybe that has something to do with it, also dont blame me when i say this cause im new at Lua also, but where did "right" come from?

[Bob Hoil]

Well i just started so to start i am combing tutorials to make my first game then will write my next game from my head. In the bullet one it said to shoot right.

[Urameshi]

so tha character moves right? not right in the direction i mean right is in right