Lua Programming Help Thread

[EminentJonFrost]

can any help me with making text return once is hit the edge off the screen? so it doesnt run if the end of the screen? thanks

I think this should do it.
What I didnt put is how 'x' changes its value. That, is up to you. :icon_wink

white = Color.new(255, 255, 255)

x = 100
y = 100

function add_to_x()
blah blah
end

function subtract_from_x()
blah blah
end

while true do

screen:clear()

if x <= 0 then 
add_to_x() -- [reverse whatever code you have manipulating 'x's value]
end

if x >= 480 then 
subtract_from_x() -- [go back to original manipulating code]
end

screen:print(x, y, "Text", white)

[Bronx]

I think this should do it.
What I didnt put is how 'x' changes its value. That, is up to you. :icon_wink

white = Color.new(255, 255, 255)

x = 100
y = 100

function add_to_x()
blah blah
end

function subtract_from_x()
blah blah
end

while true do

screen:clear()

if x <= 0 then 
add_to_x() -- [reverse whatever code you have manipulating 'x's value]
end

if x >= 480 then 
subtract_from_x() -- [go back to original manipulating code]
end

screen:print(x, y, "Text", white)

what would go in the "blah, blah"?

[natan333]

I have a question:
How can i make a picture disapear when i press a button like cross ?

[Bronx]

probably somwthing like this

if pad:cross() then
screen:clear()
end

[PSPduh]

I think this should do it.
What I didnt put is how 'x' changes its value. That, is up to you. :icon_wink

white = Color.new(255, 255, 255)

x = 100
y = 100

function add_to_x()
blah blah
end

function subtract_from_x()
blah blah
end

while true do

screen:clear()

if x <= 0 then 
add_to_x() -- [reverse whatever code you have manipulating 'x's value]
end

if x >= 480 then 
subtract_from_x() -- [go back to original manipulating code]
end

screen:print(x, y, "Text", white)

what would go in the "blah, blah"?

How x changes value.

[qwerty]

ok my new game is going to be a car game. i want to know how you would make it so if you hit the top, bottom, or sides of the other car your health is decreased. how would i do that?

[natan333]

probably somwthing like this

if pad:cross() then
screen:clear()
end

kinda helpfull but what about if there is 3 pictures, and i want to disable 1 when cross is pressed?


also

if pad:up() then
screen:blit(x0, y0, up2)
screen:flip()
screen.waitVblankStart(10)
screen:clear(black)
screen:blit(x0, y0, up1)
screen:flip()
screen.waitVblankStart(10)
screen:clear(black)
y0 = y0 - 5.1
end

this code will make the 2 pictures to keep changing but the problem is that it effect when they move too.
Can you help me making the both picture keep changing while pressing up and not make them to keep skipping to move up ?

[Bronx]

if you want to clear one imahe hen use this

if pad:cross() then
screen:clear(--your image--)
end

[Grimfate126]

hi all, i need help. i want to load many images with one command.i tried this:

ct = {}

for a = 1, 300 do

ct[a] = Image.load("ct..a...png")

end

the images are: ct1.png, ct2.png... all the way to 300. BUT when i start it, luaplayer says it had an error loading this image.

pls help me!

[Altair]

It has to be this:

ct = {}

for a = 1, 300 do

ct[a] = Image.load("ct"..a..".png")

end

You forgot two quotations

[EminentJonFrost]

hi all, i need help. i want to load many images with one command.i tried this:

ct = {}

for a = 1, 300 do

ct[a] = Image.load("ct..a...png")

end

the images are: ct1.png, ct2.png... all the way to 300. BUT when i start it, luaplayer says it had an error loading this image.

pls help me!

how about taking out two of the periods.
like:

ct[a] = Image.load("ct..a.png")

...unless the names of your images have two periods after the numbers, then I dont know.

[Altair]

no you need two periods to concatenate.

[Grimfate126]

how about taking out two of the periods.
like:

ct[a] = Image.load("ct..a.png")

...unless the names of your images have two periods after the numbers, then I dont know.

nope, ur and altairs method dont work. i think there was another guy who asked this, and pspmillionaire side you had to use a "tostring" function to get it to work. i cant find that page tho.

[Altair]

ct = {}

for a = 1, 300 do

ct[a] = Image.load("ct"..a..".png")

end

doesn't work? Do you have the pics in the same folder as the lua file?

[Grimfate126]

ct = {}

for a = 1, 300 do

ct[a] = Image.load("ct"..a..".png")

end

doesn't work? Do you have the pics in the same folder as the lua file?

wow, now that works.. weird. thx!

[Altair]

not weird at all. And no prob! What was it? the quotations or the place of the pics? If you want i can explain it.

[Grimfate126]

not weird at all. And no prob! What was it? the quotations or the place of the pics? If you want i can explain it.

i havent the sligest idea. first it didnt work i copied your code. and bam, it worked. YOUR MAGIC. :Jump: :Jump:

[Altair]

abracadabra!
hehe, nice to hear

[EminentJonFrost]

oh...i get it now.
i didnt know that worked with images too...
Does it pretty much work wherever qoutation marks are used?

[Mast3r_Shak3]

Okay this is getting on my last nerve.... ive tried a MILLION things and it wont do what i want it to do... i need to have it so when I press triangle it plays it back. But currently i have to hold it. also whenever i playback once it wont work again, ill have to restart the app to make it playback again... oh and it only plays 3 frames not 6

System.usbDiskModeActivate()

oldpad = Controls.read()

red = Color.new(255,0,0)
black = Color.new(0,0,0)
white = Color.new(255,255,255)

f = {}
f[1] = Image.load("frame#1.png")
f[2] = Image.load("frame#2.png")
f[3] = Image.load("frame#3.png")
f[4] = Image.load("frame#4.png")
f[5] = Image.load("frame#5.png")
f[6] = Image.load("frame#6.png")

canvas = Image.createEmpty(480, 272)
canvas:clear(white)
 
x0 = 200
y0 = 200
x1 = 100
y1 = 100

frame = 0
speed = 1
counter = 0

function playback()
counter = counter + speed
 if counter == 1 then
   screen:blit(0,0, f[1])
   screen.flip() 
   screen.waitVblankStart(5)
 elseif counter == 2 then
   screen:blit(0,0,f[2])
   screen.flip() 
   screen.waitVblankStart(5)
 elseif counter == 3 then
   screen:blit(0,0, f[3])
   screen.flip() 
   screen.waitVblankStart(5)
 elseif counter == 4 then
   screen:blit(0,0,f[4])
   screen.flip() 
   screen.waitVblankStart(5)
 elseif counter == 5 then
   screen:blit(0,0, f[5])
   screen.flip() 
   screen.waitVblankStart(5)
 elseif counter == 6 then
   screen:blit(0,0, f[6])
   screen.flip() 
   screen.waitVblankStart(5)
 end
end

while true do  --MAIN LOOP

canvas:print(2, 20, "Frame: " .. frame, black)

pad = Controls.read()
dx = pad:analogX()

if math.abs(dx) > 32 then
  x0 = x0 + dx / 64
end

dy = pad:analogY()

if math.abs(dy) > 32 then
  y0 = y0 + dy / 64
end

if pad:cross() then
  canvas:drawLine(x0, y0, x1, y1, black)
end

if pad:r() and oldpad:r() ~= pad:r() then 
  frame = frame + 1
  screen:save("frame#" .. frame.. ".png")
  canvas:clear(white)
end

if pad:triangle() then
  playback()
end

if pad:square() then
  canvas:clear(white)
end

if pad:start() then
  break
end
  
  x1 = x0
  y1 = y0
  screen:blit(0, 0, canvas, 0, 0, canvas:width(), canvas:height(), false)
  screen:drawLine(x1 - 5, y1, x1 + 5, y1, red)
  screen:drawLine(x1, y1 - 5, x1, y1 + 5, red)
  screen.waitVblankStart()
  screen.flip()
  oldpad = pad
end

[Altair]

oh...i get it now.
i didnt know that worked with images too...
Does it pretty much work wherever qoutation marks are used?

yep, exactly. But also if you want to put multiple vars after eachother.

[natan333]

if pad:up() then
screen:blit(x0, y0, up2)
screen:flip()
screen.waitVblankStart(10  )
screen:clear(black)
screen:blit(x0, y0, up1)
screen:flip()
screen.waitVblankStart(10  )
screen:clear(black)
y0 = y0 - 5.1
end

I posted 1 page bellow but i dont think someone will understand it.

The thing i want to do is:
make picture up1 and up2 to keep changing after like 1 second (nonstop) if i hold up pad and while i m holding up pad, both pictures move up with out messing up other pictures and the moves.

the thing i dint like the "screen.waitVblankStart(1 0)" is that it will also skip some areas when its going up and it effects other pictures that is placed in the screen.
can someone help?

[EminentJonFrost]

Okay this is getting on my last nerve.... ive tried a MILLION things and it wont do what i want it to do... i need to have it so when I press triangle it plays it back. But currently i have to hold it. also whenever i playback once it wont work again, ill have to restart the app to make it playback again... oh and it only plays 3 frames not 6

System.usbDiskModeActivate()

oldpad = Controls.read()

red = Color.new(255,0,0)
black = Color.new(0,0,0)
white = Color.new(255,255,255)

f = {}
f[1] = Image.load("frame#1.png")
f[2] = Image.load("frame#2.png")
f[3] = Image.load("frame#3.png")
f[4] = Image.load("frame#4.png")
f[5] = Image.load("frame#5.png")
f[6] = Image.load("frame#6.png")

canvas = Image.createEmpty(480, 272)
canvas:clear(white)
 
x0 = 200
y0 = 200
x1 = 100
y1 = 100

frame = 0
speed = 1
counter = 0

function playback()
counter = counter + speed
 if counter == 1 then
   screen:blit(0,0, f[1])
   screen.flip() 
   screen.waitVblankStart(5)
 elseif counter == 2 then
   screen:blit(0,0,f[2])
   screen.flip() 
   screen.waitVblankStart(5)
 elseif counter == 3 then
   screen:blit(0,0, f[3])
   screen.flip() 
   screen.waitVblankStart(5)
 elseif counter == 4 then
   screen:blit(0,0,f[4])
   screen.flip() 
   screen.waitVblankStart(5)
 elseif counter == 5 then
   screen:blit(0,0, f[5])
   screen.flip() 
   screen.waitVblankStart(5)
 elseif counter == 6 then
   screen:blit(0,0, f[6])
   screen.flip() 
   screen.waitVblankStart(5)
 end
end

while true do  --MAIN LOOP

canvas:print(2, 20, "Frame: " .. frame, black)

pad = Controls.read()
dx = pad:analogX()

if math.abs(dx) > 32 then
  x0 = x0 + dx / 64
end

dy = pad:analogY()

if math.abs(dy) > 32 then
  y0 = y0 + dy / 64
end

if pad:cross() then
  canvas:drawLine(x0, y0, x1, y1, black)
end

if pad:r() and oldpad:r() ~= pad:r() then 
  frame = frame + 1
  screen:save("frame#" .. frame.. ".png")
  canvas:clear(white)
end

play_back = false

if play_back == true then
playback()
end

if pad:triangle() then
  if play_back == false then
    play_back = true
  elseif play_back == true then
    play_back = false
  end
screen.waitVblankStart(10) -- this is so you wont accidently make it keep switching back between true and false just by holding the button down.
end

if pad:square() then
  canvas:clear(white)
end

if pad:start() then
  break
end
  
  x1 = x0
  y1 = y0
  screen:blit(0, 0, canvas, 0, 0, canvas:width(), canvas:height(), false)
  screen:drawLine(x1 - 5, y1, x1 + 5, y1, red)
  screen:drawLine(x1, y1 - 5, x1, y1 + 5, red)
  screen.waitVblankStart()
  screen.flip()
  oldpad = pad
end

try that.

[EminentJonFrost]

if pad:up() then
screen:blit(x0, y0, up2)
screen:flip()
screen.waitVblankStart(10  )
screen:clear(up2)
screen:blit(x0, y0, up2)
screen:flip()
screen.waitVblankStart(10  )
screen:clear(up1)
y0 = y0 - 5.1
end

I saw somewhere in an earlier post that that can make it clear just what is specified.

[Mast3r_Shak3]

try that.

doesnt work... it plays a frame real quick n ya...

[EminentJonFrost]

doesnt work... it plays a frame real quick n ya...

oh yea, make the "play_back = false" outside the "while true do" loop.
sorry about that.

[Mast3r_Shak3]

it works! but playback only works once :Argh: :Argh: like i can still draw frames etc. but if i hit triangle after it plays back once it wont work! this is the main problem ive been having!

[natan333]

if you want to clear one imahe hen use this

if pad:cross() then
screen:clear(--your image--)
end

screen:blit(x0, y0, player1)
screen:blit(300, 100, player2)


if pad:up() then
screen:clear(player2)
end

the clear gave me a red screen, and dint made the picture away

[Bronx]

sry, then i dont know

[natan333]

sry, then i dont know

i did something 2 times but forgot instant :icon_mad: :Cry: that false made the picture to dissapear.
when i try to put like
"player1 = false" , it gives me error