Lua Programming Help Thread

[KINGOFNOOBS]

have u tried this on a PSP yet because it doesnt work on the Lua Player for Windows

[montrob]

worked on my psp

make sure you save it as index.lua if your using LUA player with a lowser

and did you take out the spaces that the forum makes? like between numbers and stuff?

[KINGOFNOOBS]

spaces? which ones

[montrob]

yellow = Color.new(255, 255, 0)
blue = Color.new(0, 0, 255)
orange = Color.new(223, 88, 6)
grey = Color.new(94, 97, 111)
black = Color.new(0, 0, 0)
MAKE SURE THERES NO SPACES IN THE COLOR VALUE NUMBERS 
background = Image.load("background.png")

screen:blit(0, 0, background, false)
screen.flip()
screen.waitVblankStart(12  0)AND IN PLACES LIKE HERE IN BETWEEN TEH 12 AND 0

screen:blit(0, 0, background, false)
screen:print(150, 130, "Welcome To pspBaller Beta!", blue)
screen.flip()
screen.waitVblankStart(18  0) HERE 


screen:blit(0, 0, background, false)
screen:print(40, 150, "Thank you for waiting, now Press X for Tutorial", blue)
screen.flip()
screen.waitVblankStart(12  0) HERE 

pad = Controls.read()

if pad:cross() then
screen:blit(0, 0, background, false)
screen:print(40, 150, "Welcome to the Tutorial For pspBaller", blue)
screen.flip()
screen.waitVblankStart(40  0) HERE 
end

 AND CHECK FOR RANY OTHER SPACES YOU MIGHT SEE  

[montrob]

anyone know what might be wrong with this code?
its supposed to be a tic-tac-toe program with different features.
one problem is that it doesnt start, and I dont know where yall get those errors, whenever a program doesnt run on my psp it just doesnt do anything.

help please

background = Image.load("background.png")
white = Image.load("white.png")
black = Image.load("black.png")
cursor = Image.load("cursor.png")

cursorx = 247
cursory = 123

screen:blit(0, 0, background, false)
screen:blit(247, 123, cursor)
screen.flip()
while true do
screen.waitVblankStart()

function white1()
screen:blit(305, 31, white)
screen.flip()
screen.waitVblankStart()
end

function white2()
screen:blit(305, 120, white)
screen.flip()
screen.waitVblankStart()
end

function white3()
screen:blit(305, 211, white)
screen.flip()
screen.waitVblankStart()
end

function white4()
screen:blit(217, 32, white)
screen.flip()
screen.waitVblankStart()
end

function white5()
screen:blit(217, 117, white)
screen.flip()
screen.waitVblankStart()
end

function white6()
screen:blit(217, 203, white)
screen.flip()
screen.waitVblankStart()
end

function white7()
screen:blit(134, 31, white)
screen.flip()
screen.waitVblankStart()
emd

function white8()
screen:blit(134, 117, white)
screen.flip()
screen.waitVblankStart()
end

function white9()
screen:blit(134, 208, white)
screen.flip()
screen.waitVblankStart()

function black1()
screen:blit(305, 31, black)
screen.flip()
screen.waitVblankStart()
end

function black2()
screen:blit(305, 120, black)
screen.flip()
screen.waitVblankStart()
end

function black3()
screen:blit(305, 211, black)
screen.flip()
screen.waitVblankStart()
end

function black4()
screen:blit(217, 32, black)
screen.flip()
screen.waitVblankStart()
end

function black5()
screen:blit(217, 117, black)
screen.flip()
screen.waitVblankStart()
end

function black6()
screen:blit(217, 203, black)
screen.flip()
screen.waitVblankStart()
end

function black7()
screen:blit(134, 31, black)
screen.flip()
screen.waitVblankStart()
emd

function black8()
screen:blit(134, 117, black)
screen.flip()
screen.waitVblankStart()
end

function black9()
screen:blit(134, 208, black)
screen.flip()
screen.waitVblankStart()

pad = Controls.read()

if pad:left() then
cursorx = cursorx - 85
end

if pad:right() then
cursorx = cursorx + 85
end

if pad:up() then
cursory = cursory + 76
end

if pad:down() then
cursory = cursory - 76
end

if pad:square() then
cursorx = cursorx - 85
end

if pad:circle() then
cursorx = cursorx + 85
end

if pad:triangle() then
cursory = cursory + 76
end

if pad:cross() then
cursory = cursory - 76
end

if cursorx > 296 then
if cursorx < 361 then
if cursory > 12 then
if cursory < 81 then
if pad:l() then
white1()
end

if cursorx > 296 then
if cursorx < 361 then
if cursory > 92 then
if cursory < 175 then
if pad:l() then
white2()
end

if cursorx > 296 then
if cursorx < 361 then
if cursory > 185 then
if cursory < 259 then
if pad:l() then
white3()
end

if cursorx > 205 then
if cursorx < 284 then
if cursory > 12 then
if cursory < 81 then
if pad:l() then
white4()
end

if cursorx > 205 then
if cursorx < 284 then
if cursory > 92 then
if cursory < 175 then
if pad:l() then
white5()
end

if cursorx > 205 then
if cursorx < 284 then
if cursory > 186 then
if cursory < 258 then
if pad:l() then
white6()
end

if cursorx > 128 then
if cursorx < 193 then
if cursory > 12 then
if cursory < 81 then
if pad:l() then
white7()
end

if cursorx > 128 then
if cursorx < 193 then
if cursory > 92 then
if cursory < 175 then
if pad:l() then
white8()
end

if cursorx > 128 then
if cursorx < 193 then
if cursory > 186 then
if cursory < 258 then
if pad:l() then
white9()
end

if cursorx > 296 then
if cursorx < 361 then
if cursory > 12 then
if cursory < 81 then
if pad:r() then
black1()
end

if cursorx > 296 then
if cursorx < 361 then
if cursory > 92 then
if cursory < 175 then
if pad:r() then
black2()
end

if cursorx > 296 then
if cursorx < 361 then
if cursory > 185 then
if cursory < 259 then
if pad:r() then
black3()
end

if cursorx > 205 then
if cursorx < 284 then
if cursory > 12 then
if cursory < 81 then
if pad:r() then
black4()
end

if cursorx > 205 then
if cursorx < 284 then
if cursory > 92 then
if cursory < 175 then
if pad:r() then
black5()
end

if cursorx > 205 then
if cursorx < 284 then
if cursory > 186 then
if cursory < 258 then
if pad:r() then
black6()
end

if cursorx > 128 then
if cursorx < 193 then
if cursory > 12 then
if cursory < 81 then
if pad:r() then
black7()
end

if cursorx > 128 then
if cursorx < 193 then
if cursory > 92 then
if cursory < 175 then
if pad:r() then
black8()
end

if cursorx > 128 then
if cursorx < 193 then
if cursory > 186 then
if cursory < 258 then
if pad:r() then
black9()
end

[monster356]

what's the code supposed to do?

[soadnation]

I have two questions. I want to start programing in lua so I decided to start on a simple program. How exactly do I make a menu and how do I tell the program to do a math problem?

[KINGOFNOOBS]

if pad:select() then screen:save("screenshot.tga") end

if pad:start() then
break
end

end

hmm im gettinga Weird Error when i try to Use Lua for Windows to Run pspBaller when i ran some code, it says "error: script.lua:52: no loop near 'end" here is the code by end

[joreofiorio35]

if pad:select() then screen:save("screenshot.tga") end
 
if pad:start() then
break
end
 
end

hmm im gettinga Weird Error when i try to Use Lua for Windows to Run pspBaller when i ran some code, it says "error: script.lua:52: no loop near 'end" here is the code by end

You have an extra end at the end of it. If it is ending a loop, then thats a different story. If you intend to loop it, then make sure there is a loop to start it off.

[KINGOFNOOBS]

hmm how would u make it to make it so when u press lets say, Right on the PSP Pad it moves a Object, and how would u make it so u could control how much it moves, and also how would it know what object move?

[Neodudeman]

For control the thing, the code Would be,

x=10
y=10
dude = Image.load("dude.png")

while true do
  screen:clear()
  pad = Controls.read()
  screen:blit(x,y,dude)
  if pad:up()
  y = y-1
  end
  if pad:down()
  y = y+1
  end
  if pad:left()
  x = x-1
  end
  if pad:right()
  x = x+1
  end
  if pad:start()
  break
  end
  screen.flip()
  screen.waitVblankStart()
end

The first X=10 and y=10 shows the starting x+y coordinates, which tells us where the image will be

dude = Image.load("dude.png") loads the image to be used. note that you can change the variable dude to anything you want, but remember to load the right png.

the While true makes it so that all the code within the while and the end are run.

the screen:clear() clears the screen

the pad = Controls.read() gets the input buttons from the PSP. This is needed to use Any of the controls

screen.blit(x,y,dude) displays the dude in all his glory. The blit uses the variable name from before, and not the file name

the If statements say what happens IF certain buttons are pressed.
though you may notice that when you press Up, the Y is subtracted. That goes against all logic! But on a PSP screen, and on many computers, the coordinates are 0,0 at the Top Left corner, which is why you subtract to go up.

the If pad:start() is Definetly useful because it stops the program so you dont have to keep hittin home to quit.
and the screen:flip/Vblank thing display the image

thus concludes simple controlling of an image.

That's how to control an image with the D-Pad

the analog stick is a different story Entirely. Its function isnt as linear and simple as the D-Pad's.

the analog stick ranges in intensity from -128 to 128, but can produce values lower than 32 even when it's centered, making it unreliable without the proper code.

pad = Controls.read()
ax = pad:analogX()
ay = pad:analogY()
if math.abs(ax) > 32 then
  x = x + ax / 50
end
if math.abs(ay) > 32 then
  y = y + ay / 50
end

Ok. this one Looks tricky, but is actually pretty simple.
First, the pad = Controls finds the inputs and what not.
Here, ax and ay look for the analog's movement along the X and Y axis, indetified as analogX() and analogY()
Now, the If statement.
If math.abs(ax) > 32 then
remember how i said that the analog can produce values below 32 even when centered? well this statement helps buffer that.
the math.abs(ax) just means the ABSolute value of the ax number. Absolute value changes negative numbers into positive, so that if we get a -32, it'll change it to positive 32. the > 32 makes sure that the absolute value is greater than 32, which is Really what the buffer is.
after all that is tried and set, the x = x + ax / 50 is the adding of that X intensity of the analog to the actual variable x. the /50 is to dull the intensity of the analog. Without it, the x coordinate would be going through some Crazy numbers FAST. So, to lower the addition, we just divide.

See?
Any questions?

That's controlling with the Analog!

Hope that helps!

[KINGOFNOOBS]

so for my game, pspBaller ( i think u have seen it ) which way would better?

[Neodudeman]

pspBaller? Err... lol, i haven't seen it. Though i'm willing to look

[Neodudeman]

Thoughhhhhhhh... not now... I need sleep now.. lol... it's 4 am here good night!

ACTUALLY

That game is lookin pretty sweet! I would recommend using the Analog stick, just because it feels nicer.. Though it depends on your engine. If it's REALLY linear, like, if 1+1=2 then you'd have to go with D-Pad, because the Analog outputs stuff like 89.23 and what not. BUT If it's a kinda Speeded Engine, like, If D-Pad, x=x+d-pad:left Then I would Totally recommend putting in analog stick to the addition, though the math would be harder.

[KINGOFNOOBS]

http://forums.qj.net/psp-development-forum/

and also another question, how would u set a collision of a object?

like if i wanted it to be like if the ball hits something it just simply bouces back up?

[Neodudeman]

lol... and Suddenly Things Went Bad....

Collision is Not my forte. lol. If i knew collision, I would be Out there in the Ether man... But what i Can tell you is that you're going to be needing some angle algorithms if you want to do some bouncing off walls.

Possibly you can assign certain areas of the screen as "walls" ? Maybe like, when the ball Touches a wall, reverse the x, or y, depending on the wall. Like if it was a Top or Bottom wall, reverse the Y, so that it would still travel the X coordinate, but would "bounce" off the Y. See? and it if was a vertical wall, reverse the X.

Sorry, but i Seriously have to sleep now.. lol. I wish i could help more, but i'm about to keel over with sleep deprevation. Good Night!

[lingon]

to make borders do like this :

--set these limits for your character to be kept onscreen
--x and y are your characters cordinates

leftlimit = 10
rightlimit = 460
uplimit = 20
downlimit = 260

--if statement added during control init (enforcing limits)
if x<=leftlimit then x=leftlimit
	elseif x>=rightlimit then x=rightlimit end
	if y<=uplimit then y=uplimit
	elseif y>=downlimit then y=downlimit end

Also, I wonder if it is possible to have pics in an array or if they only hold numbers and how do I call an array?

[monster356]

i have some questions about the math.random() function and music files

1. How would i make an enemy appear on the x axis in spaces like this(not exactly like that, but you get it):
-------|---------------|----|----------|----------|
|, representing my enemy

2. with wav files, what does the config on them got to be? or is there a program i can use to make xm's or mod files?

[KINGOFNOOBS]

ahh another question, how exactly would i make a tile set? like u want to play more then one object in more then one place, would u just simply do:

tile
x=1
y=1

tile
x=2
y=2

or would u keep using the Screen:Blit Command?

[lingon]

a tile set? you mean like a map or such?

[KINGOFNOOBS]

yea exactly what i mean, but i mean like how would u have it to make it each object on the map have diffrent properties

[lingon]

Well I aint sure on this but I guess something like this would work

System.usbDiskModeActivate()
 
tiles = Image.load("tiles.png")
 
map = {
	"mmmmmmmmmmmmmmmmmmmmmmmmmmmmmm",
	"mmmmmmmmmmmmmmmmmmmmmmmmmmmmmm",
	"mmeaaaaaaaaaaaaaaaaaaaaaaaafmm",
	"mmdpnnnnnnnnnnnnnnnnnnnnnnpbmm",
	"mmdokcccccclnkccccccccccclnbmm",
	"mmdojaaaaafdnbmmmmmmmmmmmdnbmm",
	"mmdooooooobdnbmmmmmmmmmmmdnbmm",
	"mmdokccclobdnbmmmmmmmmmmmdnbmm",
	"mmdobmmmdobdnbmmmmmmmmmmmdnbmm",
	"mmdobmmmdobdnjaaaaaaaaaafdnbmm",
	"mmdobmmmdpbdnnnnnnnnnnnnbdnbmm",
	"mmdobmmmhcghcccccccccclnbdnbmm",
	"mmdojaaaaaaaaaaaaaaaaainjinbmm",
	"mmdpnnnnnnnnnnnnnnnnnnnnnnpbmm",
	"mmhccccccccccccccccccccccccgmm",
	"mmmmmmmmmmmmmmmmmmmmmmmmmmmmmm",
	"mmmmmmmmmmmmmmmmmmmmmmmmmmmmmm"
}
 
function drawTile(tile, x, y)
	local tileX = math.mod(tile, 4)
	local tileY = math.floor(tile / 4)
	screen:blit(16 * x, 16 * y, tiles, 17 * tileX + 1, 17 * tileY + 1, 16, 16, false)
end	
 
while true do
	pad = Controls.read()
	if pad:start() then break end
	screen:clear()
	for y = 1, 17 do
		line = map[y]
		for x = 1, 30 do
			tile = string.byte(line, x) - string.byte("a")
			drawTile(tile, x - 1, y - 1)
		end
	end
	screen.waitVblankStart()
	screen:flip()
end

[monster356]

i have some questions about the math.random() function and music files

1. How would i make an enemy appear on the x axis in spaces like this(not exactly like that, but you get it):
-------|---------------|----|----------|----------|
|, representing my enemy

2. with wav files, what does the config on them got to be? or is there a program i can use to make xm's or mod files?

can someone give me a hand here

this was my post from before(in the quote...DUH)

[Testsuo]

Originally Posted by monster356
i have some questions about the math.random() function and music files

1. How would i make an enemy appear on the x axis in spaces like this(not exactly like that, but you get it):
-------|---------------|----|----------|----------|
|, representing my enemy

can someone give me a hand here

this was my post from before(in the quote...DUH)

Try using something like this within your main loop:

if math.random(1,300) == 150 then
addEnemy(math.random(100, 400))

replace the math.random values with your own to define how frequently enemies will appear, replace the 100,400 values with your own x,y values to give the area spread your enemy will appear in, and define your enemy image as "Enemy".... I think... dont hold me to that. :)

[monster3560]

hey it's monster356, i got banned, for like no reason....no one pmed me with a warning, and no one told me i was going to get banned......


so, the addEnemy is a blit?

[deepdorp]

hey all,
i've finally decided on a game to make with lua, but am quite new to it. I understand basic programming (mostly in BASIC and Fortran, a little C++, from engineering school), but not so much for gaming programs. The game is relatively simple, but there are a few hurdles I need to overcome to make it happen.

Anyway.... the game I have in mind is known as "SameGame" for PC or "Macigame" for MAC as well as many other versions/clones. Essentially, the game is a grid of tiles that when 2 or more tiles touch they can be selected and removed from the grid, whereupon the grid then "collapses" depending on what is removed. Clearing the grid fully and/or highscore is the object of the game.

Some of my initial problems include: (again, I am new to game or graphics-based programming so I don't even know how problematic they may be)
1. Creating a known-sized grid built from randomly selected tiles. i.e. I can build a pre-arranged grid from a tileset(similar to the pacman style gameboards) but am unsure how to make it randomly generated.
2. Use of a cursor to select blocks of touching tiles, where when the cursor is placed over a suitable group this group would become highlighted, or selectable to be removed.

Any help or pointing me in the right direction is greatly appreciated.
Thanks...

[Ace Hih]

hey I'm kinda a newbie at this but here's my question. I'm making a fighter and I made it so that the character can move to each side of the screen and not go past but I want to make it so that the image changes so that it faces the direction it's going. can someone help me?

[Master Inuyasha]

hey I'm kinda a newbie at this but here's my question. I'm making a fighter and I made it so that the character can move to each side of the screen and not go past but I want to make it so that the image changes so that it faces the direction it's going. can someone help me?

if facing==1 then
screen:blit(X,Y,Pic facing left)
end

if facing==2 then
screen:blit(X,Y,pic facing right)
end

if pad:left() then
facing = 1
imagex = imagex - 3
end

if pad:right() then
facing = 2
imagex = imagex +3
end

[Ace Hih]

Thank you so much. This thread is great!

[Ace Hih]

I hate to be annoying but for some reason it won't work.It worked before I added the code with the comments. here's my code:

System.usbDiskModeActivat e ()

field = Image.load("Naruto forestc.PNG")
block3 = Image.load("player.PNG")
player = Image.load(player2.PNG")

blockposX = 152
blockposY = 195

while true do
screen:blit(0, 0, field)
screen:blit(blockposX, blockposY, block3)

if blockposX <= 2 then
blockposX = 1
end

if blockposX >= 447 then
blockposX = 448
end

if facing==1 then --------This section
screen:blit(blockposX, blockposY, player)
end

if facing==2 then --------This section
screen:blit(blockposX, blockposY, block3)
end

pad = Controls.read()

if pad:left() then
facing = 1 ---------This Line
blockposX = blockposX - 5
end

if pad:right() then
facing = 2 ---------This Line
blockposX = blockposX + 5
end

screen.waitVblankStart()
screen.flip()


if pad:start() then
break
end
end

What did I do wrong?


Oh yeah and I ripped part of the code from someones example on this page for learning purposes. So props to them