Lua Programming Help Thread

[EminentJonFrost]

yea i know...*sighs* and i already made lots of changes to the code to make it smaller, but there hasnt been any actual speed changes. it sucks going back to look over what you did to see whats wrong, cause while making it you think itll all work fine, so how is it youll find whats wrong? you know? thats the point where i'm at. everything works, just not as fast as i'd hoped. not without the cpu getting a little juice.

[Grimfate126]

yea i know...*sighs* and i already made lots of changes to the code to make it smaller, but there hasnt been any actual speed changes. it sucks going back to look over what you did to see whats wrong, cause while making it you think itll all work fine, so how is it youll find whats wrong? you know? thats the point where i'm at. everything works, just not as fast as i'd hoped. not without the cpu getting a little juice.

if you trust me enough, PM me with your code. there is simply no way a lua game should go below 50 FPS. you can use the cpu boost as well, but it would also be good if you could improve your code a bit too.

[TacticalPenguin]

Yea if youd like Ill help you look over your code and if youve got an IM ill show you things to remember to make your code more efficient.

[emericaska8r]

is there any way on of you two could do the same for me? I am coding a Super Mario Bros. game (it still isn't done and has bugs of course), and it seems to run okay on the computer, but on my PSP parts are really slow.

i really need to know more efficient ways of doing things becuase i can always seem to be able to make a program do something, yet it usually isn't the best way to do it.

any help would be greatly appreciated

[TacticalPenguin]

Sure, if you've got MSN or AIM add me and send me an IM and Ill be glad to help you out.

[Nicko01]

Heres the download to the game i was working on: http://www.megaupload.com/?d=O8IQGJHF

its not that great...
It's my first lua game though.

[Dark_Merlin]

I was wondering how to set up some code to kill an enemy when you shoot them or something, example

function collisionCheckbullets(object)
if (bullet.x + bulletWidth > object.x) and (bullet.x < object.x + object.width) and (bullet.y + bulletHeight > object.y) and (bullet.y < object.y + object.height) then
*Insert Make Enemy Dissapear/Die Script Here*
end
end

[TacticalPenguin]

Well, add a variable called alive to your enemy table and set it to true.

enemy = {alive = true, x = blah, y = blah, img = blah, blah, blah}

And then only do stuff related to the enemy when alive is true.

if enemy.alive then
--AI related stuff for enemy
screen:blit(enemy.x,enemy .y,enemy.img)
end

And then make it so that enemy.alive becomes false when he is shot:

if collision(enemy,bullet) then enemy.alive = false end

[GuitarGod1134]

Why is this unstickied. And why is no one posting here anymore? tisk tisk. Ok ill spark it up with a question that doesnt really need to be answered now but I have to ask it sometime.

How would I make it check for text files? If if one is not found then print an error? I could look this up but I know someone here has the answer on the tip of thier tongue so you can save me some time lol.

[BlackShark]

good idea, I wouldn't mind being able to do that aswell!

[Dark_Merlin]

Well, add a variable called alive to your enemy table and set it to true.

enemy = {alive = true, x = blah, y = blah, img = blah, blah, blah}

And then only do stuff related to the enemy when alive is true.

if enemy.alive then
--AI related stuff for enemy
screen:blit(enemy.x,enemy .y,enemy.img)
end

And then make it so that enemy.alive becomes false when he is shot:

if collision(enemy,bullet) then enemy.alive = false end

Thanks alot

[BlackShark]

Why is this unstickied. And why is no one posting here anymore? tisk tisk. Ok ill spark it up with a question that doesnt really need to be answered now but I have to ask it sometime.

How would I make it check for text files? If if one is not found then print an error? I could look this up but I know someone here has the answer on the tip of thier tongue so you can save me some time lol.

any body have any idea how to do this?

[Anti-QuickJay]

Sticked. :)

[GuitarGod1134]

Good job pspgamer81

[TacticalPenguin]

Checking for a text file:

if io.open("nameoffile.txt", "r") then
--File exists
else
--File doesn't exist
end

[SG57]

Correction, checking for ANY file... Just not a directory.

[TacticalPenguin]

But if you're checking for a non text file then you have to change its extension.

But yes that can be used for checking for any file.

[Dark_Merlin]

Hmm, Does anyone know whats wrong with my game,

It's very...basic so far but it is so sluggish! I even put in an FPS counter and it just shows 'NaN' and every now and then for a split second 1000fps o_O

It runs fine on the pc so I'm not sure whats wrong =\

[Grimfate126]

Hmm, Does anyone know whats wrong with my game,

It's very...basic so far but it is so sluggish! I even put in an FPS counter and it just shows 'NaN' and every now and then for a split second 1000fps o_O

It runs fine on the pc so I'm not sure whats wrong =\

post your code. 1000 means your FPS counter is wrong.the FPS shouldnt go over 60, because of the screen.waitVblankStart() function, which limits it to 60.

[Dark_Merlin]

EDIT: New code with the Animation Lib FPS counter... now displaying just 0 EDIT2: Tabbed my code to make it easier to understand

Spoiler for Code:

System.usbDiskModeActivat e()
dofile ("requireC.lua")
requireC ("FPSCounter.lua")
requireC ("colors.lua")

--Load Images
player = Image.load("player.jpg")
enemy = Image.load("enemy.jpg")
bullet = Image.load("bullet.png")

--Variables
playerHeight = 32
playerWidth = 32
bulletHeight = 4
bulletWidth = 4
direction = "right"
movespeed = 2
ammo = 10
math.randomseed(os.time() )

--Arrays
Player = { x = 30, y = 100 }

Enemy = {}
Enemy[1] = { x = 100, y = 80, height = enemy:height(), width = enemy:width() }
Enemy[2] = { x = 330, y = 10, height = enemy:height(), width = enemy:width() }
Enemy[3] = { x = 450, y = 58, height = enemy:height(), width = enemy:width() }

BulletInfo = {}
for a = 1,100 do
BulletInfo[a] = { pic = bullet , firing = false, direction = "right", x = Player.x + 32, y = Player.y + 16 }
end

--Functions

function enemyOOB( )
for a = 1,3 do
if Enemy[a].x > 480 - 32 then
Enemy[a].x = Enemy[a].x - 2
end
if Enemy[a].x < 32 then
Enemy[a].x = Enemy[a].x + 2
end
if Enemy[a].y > 272 - 32 then
Enemy[a].y = Enemy[a].y - 2
end
if Enemy[a].y < 0 then
Enemy[a].y = Enemy[a].y + 2
end
end
end

function playerOOB( )
if Player.x > 480 - 32 then
Player.x = Player.x - 2
end
if Player.x < 0 then
Player.x = Player.x + 2
end
if Player.y > 272 - 32 then
Player.y = Player.y - 2
end
if Player.y < 0 then
Player.y = Player.y + 2
end
end

function enemyTooClose( )
stallclose = math.random(3)
if stallclose == 1 then
for a = 1,3 do
if Enemy[1].x > Enemy[2].x and Enemy[3].x then
Enemy[1].x = Enemy[1].x +2
elseif Enemy[1].y < Enemy[2].y and Enemy[3].y then
Enemy[1].y = Enemy[1].y -2
end
end
stallclose2 = math.random(3)
if stallclose2 == 1 then
if Enemy[2].x > Enemy[1].x and Enemy[3].x then
Enemy[2].x = Enemy[2].x +2
elseif Enemy[2].y < Enemy[1].y and Enemy[3].y then
Enemy[2].y = Enemy[2].y -2
end
end
stallclose3 = math.random(3)
if stallclose3 == 1 then
if Enemy[3].x > Enemy[2].x and Enemy[1].x then
Enemy[3].x = Enemy[3].x +2
elseif Enemy[3].y < Enemy[2].y and Enemy[1].y then
Enemy[3].y = Enemy[3].y -2
end
end
end
end

function chasePlayer()
for a = 1,3 do
stallchase = math.random(2)
if stallchase == 1 then
if Enemy[a].x > Player.x then
Enemy[a].x = Enemy[a].x - 2
elseif Enemy[a].x < Player.x then
Enemy[a].x = Enemy[a].x + 2
end
end
stallchase = math.random(2)
if stallchase == 1 then
if Enemy[a].y > Player.y then
Enemy[a].y = Enemy[a].y - 2
elseif Enemy[a].y < Player.y then
Enemy[a].y = Enemy[a].y + 2
end
end
end
end --///end the function///

function bulletSetup()
ammo = ammo - 1
if direction == "downleft" then
BulletInfo[currentBullet].x = Player.x
BulletInfo[currentBullet].y = Player.y + 32
end
if direction == "upleft" then
BulletInfo[currentBullet].x = Player.x
BulletInfo[currentBullet].y = Player.y
end
if direction == "upright" then
BulletInfo[currentBullet].x = Player.x + 32
BulletInfo[currentBullet].y = Player.y
end
if direction == "downright" then
BulletInfo[currentBullet].x = Player.x +32
BulletInfo[currentBullet].y = Player.y + 32
end
if direction == "left" then
BulletInfo[currentBullet].x = Player.x
BulletInfo[currentBullet].y = Player.y + 16
end
if direction == "right" then
BulletInfo[currentBullet].x = Player.x + 32
BulletInfo[currentBullet].y = Player.y + 16
end
if direction == "up" then
BulletInfo[currentBullet].x = Player.x + 16
BulletInfo[currentBullet].y = Player.y
end
if direction == "down" then
BulletInfo[currentBullet].x = Player.x + 16
BulletInfo[currentBullet].y = Player.y + 32
end
BulletInfo[currentBullet].direction = direction
BulletInfo[currentBullet].firing = true
end

function bulletFire()
for i = 1,100 do
if BulletInfo[i].firing == true then
if BulletInfo[i].direction == "right" then BulletInfo[i].x = BulletInfo[i].x + 10 end
if BulletInfo[i].direction == "left" then BulletInfo[i].x = BulletInfo[i].x - 10 end
if BulletInfo[i].direction == "up" then BulletInfo[i].y = BulletInfo[i].y - 10 end
if BulletInfo[i].direction == "down" then BulletInfo[i].y = BulletInfo[i].y + 10 end
if BulletInfo[i].direction == "downleft" then BulletInfo[i].y = BulletInfo[i].y + 10 BulletInfo[i].x = BulletInfo[i].x - 10 end
if BulletInfo[i].direction == "upleft" then BulletInfo[i].y = BulletInfo[i].y - 10 BulletInfo[i].x = BulletInfo[i].x - 10 end
if BulletInfo[i].direction == "upright" then BulletInfo[i].y = BulletInfo[i].y - 10 BulletInfo[i].x = BulletInfo[i].x + 10 end
if BulletInfo[i].direction == "downright" then BulletInfo[i].y = BulletInfo[i].y + 10 BulletInfo[i].x = BulletInfo[i].x + 10 end
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

function movePlayer()
pad = Controls.read()
pad2 = Controls.read( )
if pad:left() then
Player.x = Player.x - movespeed
direction = "left"
end
if pad:right() then
Player.x = Player.x + movespeed
direction = "right"
end
if pad:up() then
Player.y = Player.y - movespeed
direction = "up"
end
if pad:down() then
Player.y = Player.y + movespeed
direction = "down"
end
if pad:left( ) and pad2:down( ) then
direction = "downleft"
end
if pad:left() and pad2:up( ) then
direction = "upleft"
end
if pad:right() and pad2:up( ) then
direction = "upright"
end
if pad:right() and pad2:down( ) then
direction = "downright"
end
end

function FPS( )
local counter = FPSCounter.new()
screen:print(2,2,"FPS: " .. counter:update(),white)
end

--Main Loop
while true do
pad = Controls.read( )
pad2 = Controls.read( )
oldx = Player.x
oldy = Player.y
currentBullet = ammo
screen:clear( )

screen:blit(Player.x,Play er.y,player)

for a = 1,3 do
screen:blit(Enemy[a].x,Enemy[a].y,enemy)
end

if pad:cross() and oldpad:cross() ~= pad:cross() and ammo > 0 then
bulletSetup()
end

movePlayer( )
bulletFire( )
chasePlayer( )
enemyTooClose( )
enemyOOB( )
playerOOB( )
FPS( )

screen:print (0,50, ammo, green)

screen.waitVblankStart()
screen.flip()
oldpad = pad
end

[Cheez Pirate]

How do I keep an image from disapearing when I release the button the blitted it to the screen?

[Dark_Merlin]

Here you go

image = Image.load("image")

while true do
   pad = Controls.read()
   oldpad = pad
   if pad:cross() or oldpad:cross() then
      screen:blit(0,0, image) 
   end
screen.waitVblankStart()
screen.flip()
end

[Cheez Pirate]

Now it doesn't load the script at all. Can you explain to me the "end" after the blitting of the image, and the oldpad stuff?

[TacticalPenguin]

image = Image.load("image")

while true do
pad = Controls.read()
oldpad = pad
if pad:cross() or oldpad:cross() then
screen:blit(0,0, image) 
end
screen.waitVblankStart()
screen.flip()
end

Umm, 1. That's only going to blit the image for 1 frame.

2. You messed up oldpad very badly.

Anyways something like this:
oldpad = Controls.read()
while true do
pad = Controls.read()
if viewingimage then screen:blit(0,0,image) end
if pad:cross() and not oldpad:cross() and not viewingimage then viewingimage = true end
if pad:cross() and not oldpad:cross() and viewingimage then viewingimage = false end
screen.waitVblankStart()
screen.flip()
oldpad = pad
end

Thatll make x toggle between showing the image and not showing it.

[Dark_Merlin]

Ok with the fps is wrong thing, i replaced that fps counter with the one out of alatnet's Animated Sprite Lib and now it just shows up as 0 on the comp, im going to test it on the psp now...

EDIT: Ok the psp shows the same thing.

and what I posted for him was a full program, sorry and yeah I did oldpad wrong, sorry

[Cheez Pirate]

So confuzed.

index.lua

white = Color.new(255,255,255)
menustatus = 1
menu = Image.load("images/menu.png")
cursor = Image.load("images/cursor.png")
multiplayer = Image.load("images/multiplayer.png")
singleplayer = Image.load("images/singleplayer.png")
singleplayer2 = Image.load("images/singleplayer2.png")
oldpad = Controls.read()
while true do
pad = Controls.read()
dofile("menu.lua")
screen.waitVblankStart()
screen.flip()
oldpad = pad
end

menu.lua

screen:clear(white)
screen:blit(0,0,menu)
if menustatus == 1 then
screen:blit(280,172,cursor)
end
if menustatus == 2 then
screen:blit(280,196,cursor)
end
if pad:down() and oldpad:down() ~= pad:down() then
menustatus = menustatus + 1
end
if pad:up() and oldpad:up() ~= pad:up() then
menustatus = menustatus - 1
end
if menustatus == 0 then
menustatus = 1
end
if menustatus == 3 then
menustatus = 2
end
if pad:circle() and menustatus == 1 then
dofile("singleplayer.lua")
end
if pad:circle() and menustatus == 2 then
dofile("multiplayer.lua")
end

singleplayer.lua

screen:clear(white)
screen:blit(0,0,singleplayer)
if pad:r() and pad:l() and pad:circle() then
screen:clear(white)
screen:blit(0,0,singleplayer2)
menustatus = menustatus - 1

Maybe that will help you determine why when I load an image it won't loop.

[Dark_Merlin]

Are you trying to make it so the l + r + circle blit and keep the singleplayer2?

Wait are you saying your menu images arent staying blitted?

[Grimfate126]

So confuzed.

index.lua

white = Color.new(255,255,255)
menustatus = 1
menu = Image.load("images/menu.png")
cursor = Image.load("images/cursor.png")
multiplayer = Image.load("images/multiplayer.png")
singleplayer = Image.load("images/singleplayer.png")
singleplayer2 = Image.load("images/singleplayer2.png")
oldpad = Controls.read()
while true do
pad = Controls.read()
dofile("menu.lua")
screen.waitVblankStart()
screen.flip()
oldpad = pad
end

menu.lua

screen:clear(white)
screen:blit(0,0,menu)
if menustatus == 1 then
screen:blit(280,172,cursor)
end
if menustatus == 2 then
screen:blit(280,196,cursor)
end
if pad:down() and oldpad:down() ~= pad:down() then
menustatus = menustatus + 1
end
if pad:up() and oldpad:up() ~= pad:up() then
menustatus = menustatus - 1
end
if menustatus == 0 then
menustatus = 1
end
if menustatus == 3 then
menustatus = 2
end
if pad:circle() and menustatus == 1 then
dofile("singleplayer.lua")
end
if pad:circle() and menustatus == 2 then
dofile("multiplayer.lua")
end

singleplayer.lua

screen:clear(white)
screen:blit(0,0,singleplayer)
if pad:r() and pad:l() and pad:circle() then
screen:clear(white)
screen:blit(0,0,singleplayer2)
menustatus = menustatus - 1

Maybe that will help you determine why when I load an image it won't loop.

ok, im not even gonna TRY to read that. you need to start spacing and indenting. it will make your problems much easier to identify and solve.

[Dark_Merlin]

I think he needs to put in some loops in the other files right?

From what i see he only has one loop in the index.lua and none in the others, that would be where his only blitting for one frame problems are coming from right?

If im wrong sorry, I havnt worked with calling other files of your code in before.

[Cheez Pirate]

My main menu image ("menu") stays blitted but the other 2 only last until you let go of the button. and l + r + o are supposed to load the next singleplayer menu. I'll true putting loops in other files though.