Lua Programming Help Thread

[SG57]

BlackShark - And you did such an awesome job on it too... Honestly, anyone in their right mind thinking a custom firmware had been written in Lua, let alone written by a novice (shown in your sig by homebrew releases), is NOT in their right mind... And quit being so conceited, you didnt even answer his question... (hopefully you can for htat matter)

xtreme - Your looking to use a timer... In this code below, itll do as you say, and add a '.' every 1 second, after 3 periods have been added, itll reset:

timer = Timer.new()
timer:start()

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

while true do
     screen:clear()

     screen:print(208,131,"Bricking",red)

     if timer:time() >= 1000 and timer:time() < 2000 then
       screen:print(272,131,".",red)
     elseif timer:time() >= 2000 and timer:time() < 3000 then
       screen:print(272,131,"..",red)
     elseif timer:time() >= 3000 and timer:time() < 4000 then
       screen:print(272,131,"...",red)
     elseif timer:time() >= 4000 then
       timer:reset()
       timer:start()
     end
     screen.waitVblankStart()
     screen.flip()
end

[emericaska8r]

yeah, but i just want to code simple text for now. i have

blue = Color.new(0, 0, 255)

screenrint(200, 130, "Bricking", blue)
screen.flip()

while true do
screen.waitVblankStart(60 )

screenrint(200, 130, "Bricking.", blue)
screen.flip()

while true do
screen.waitVblankStart(60 )

screenrint(200, 130, "Bricking..", blue)
screen.flip()

while true do
screen.waitVblankStart(60 )

screenrint(200, 130, "Bricking...", blue)
screen.flip()

end

but it doesnt work, any advice?

just remove all the while true do's, since your are not looping.

actually, since you wanted it to repeat you could just do one big 'while true do' loop around all the code, with and 'end' at the end.

[eyece]

blue = Color.new(0, 0, 255)
dots = {".","..","..."}
i=1
while true do
if i <= 3 then
screen:print(200,130,"bricking" .. dots[i], blue)
i=i+1
screen.flip()
screen.waitVblankStart(60)
else
--' code to run after message
end
end

edit: damn this forum RTE sucks.

[xtreme0915]

thx, where do you guys learn all this stuff? ive seen the two tuts but other than that nothing

[BlackShark]

BlackShark - And you did such an awesome job on it too... Honestly, anyone in their right mind thinking a custom firmware had been written in Lua, let alone written by a novice (shown in your sig by homebrew releases), is NOT in their right mind... And quit being so conceited, you didn't even answer his question... (hopefully you can for that matter)

Golly G wiz!

release one prank bricker and the world is out to get you! :/, Plus it wasn't for QJ readers, it was to be USED by qj readers on a friend or something :/, I wasn't being conceited was I?

Well Xtreme, SG answered your Question pretty well, so give it a try,
good luck

[yaustar]

looks like i need to get learning. Links ? i thought gu was only for 3d ?

Stick a texture on a quad and volia, we have a sprite.

Links: http://wiki.ps2dev.org/psp:lua_playe...#3d_gu_mapping
Look at the GDI tutorial which will help you get going but not understand what you are actually doing or calling.

Also look at other source code such as yoursam's Wedge Racer.

If you really want to start getting serious in programming, I recommend looking at learning vector and matrix math which you really start to use for various tasks.

[PSPhakkor]

How would I access a file in "ms0:/seplugins/"?

[SG57]

yourFile = io.open("ms0:/seplugins/whateverFile.extension","r")

You have read-only permission, meaning you cant write to a file through this file stream.

eyece - I would have done it that way, but it's inefficient to use for loops when you can easily unwrap yourself.... Plus, it's a tad unneeded to store incremental '.'s in an array.. Just use the 'i' var to determine how many periodsyou want, no need to make an array for them...

[BlackShark]

System.listDirectory("ms0 :/seplugins/")

give that a try no guarrenties but this should work.
NVM, SG beat me to the punch!

[PSPhakkor]

if I use "w" as the second arguement will I be able to write?

and on another note, what's up with people capitalizing words in their function and variable names? Just an extra keystroke to me

[Anti-QuickJay]

LUA Player is case-sensitive
Yes, You will be able to write

[PSPhakkor]

another question: can someone explain to me how to use

table System.listDirectory( [path] )

because I
m clueless how a "table of tables" works. The ps2dev wiki doesnt say how to access each element, like if I wanted the name of the first file in the directory, how would I get that? the example they gave didn;t work wit the error "attempt to call a table value"

[eyece]

I would have done it that way, but it's inefficient to use for loops when you can easily unwrap yourself.... Plus, it's a tad unneeded to store incremental '.'s in an array.. Just use the 'i' var to determine how many periodsyou want, no need to make an array for them...

as far as i know there is no way to repeat a string based on the value of a variable.
, unless you make your own function.

[xtreme0915]

ok, thx you guys, one more thing, how can i make one timer end and lead into another

[SG57]

PSPhackor -

files = System.listDirectory("ms0:/")
			
for i=1, table.getn(files) do
	screen:print(0,i*20,files[i].name,Color.new(255,255,255))
	screen:print(300,i*20, "Size: " .. files[i].size,Color.new(255,0,126))
	if files[i].directory then screen:print(200,i*20, "Directory",Color.new(0,255,0)) else screen:print(200,i*20, "File",Color.new(255,255,255)) end
end

screen.flip()

while true do
	screen.waitVblankStart()
end

That should print out whatever is on the root of your PSP, its size, and whether or not its a directory.

xtreme - Im not sure waht you mean... But..

timer = {Timer.new(),Timer.new()}

timer[1].start()

while true do
     if timer[1]:time() >=1000 then
          timer[2]:reset(timer[1]:time())
          timer[2]:start()
          timer[1]:stop()
     end
end

eyece - This is what i meant, but having only 3 values to check doesnt really have one single way to do something

green = Color.new(0, 255, 0)
i=0
while true do
	screen:print(208,131,"Bricking" , green)
	if i>=1 then screen:print(272,131,".",green) end
	if i>=2 then screen:print(282,131,".",green) end
	if i>=3 then screen:print(292,131,".",green) end
	screen.flip()
	screen.waitVblankStart(60)
	if i<=3 then i = i + 1 else break end
end
while true do end -- code to run after message

[xtreme0915]

how can i make

timer = Timer.new()
timer:start()

while true do
screen:clear()

screenrint(153,131,"Preparing flash0",red)

if timer:time() >= 1000 and timer:time() < 2000 then
screenrint(280,131,".",red)
elseif timer:time() >= 2000 and timer:time() < 3000 then
screenrint(280,131,"..",red)
elseif timer:time() >= 3000 and timer:time() < 4000 then
screenrint(280,131,"...",red)
elseif timer:time() >= 4000 then
end
screen.waitVblankStart()
screen.flip()

lead into a new timer

[PSPhakkor]

sg57, thank you very much. That cleared things up.
xtreme, what you need is probably to use the same timer but change

timer:time() < 2000

to math.floor(timer:time()/1000)==2

and change the others accordingly.

Maybe you should give that a try but if it doesn't work, then get someone who actually knows what they're doing (I'm a pretty new coder)

[SG57]

PSPhakkor - yup.

xtreme - If you want to use seconds, rather than miliseconds, divide timer:time() by 1000, and round up (ceiling) or down (floor). For the example i posted, i compared in miliseconds, to compare in seconds, youd do:

timer = Timer.new()
timer:start()

while true do
screen:clear()

screenrint(153,131,"Pre paring flash0",red)

if math.floor(timer:time()/1000) >= 1 and math.floor(timer:time()/1000) < 2 then
screenrint(280,131,".", red)
elseif math.floor(timer:time()/1000) >= 2 and math.floor(timer:time()/1000) < 3 then
screenrint(280,131,".." ,red)
elseif math.floor(timer:time()/1000) >= 3 and math.floor(timer:time()/1000) < 4 then
screenrint(280,131,"... ",red)
elseif math.floor(timer:time()/1000) >= 4 then
end
screen.waitVblankStart()
screen.flip()

[xtreme0915]

ok, after a few hours of learning and work here is what ii have tp produce

http://files.filefront.com//;6644819;;/

i still have a few alignment issues but im gonna work on it, what you think for my first time?

[Anti-QuickJay]

LOLz, Good code!
But instead of doing this

screen:clear()
screen:print(150,131,"Preparing flash0",blue)
screen:flip()

screen.waitVblankStart(60)
  
screen:clear()
screen:print(150,131,"Preparing flash0.",blue)
screen:flip()

screen.waitVblankStart(60)


screen:clear()
screen:print(150,131,"Preparing flash0..",blue)
screen:flip()

screen.waitVblankStart(60)


screen:clear()
screen:print(150,131,"Preparing flash0...",blue)
screen:flip()

Why not use a timer?

[xtreme0915]

because i just started today and timers confuse the sh17 out of me lol

[SG57]

xtreme - I posted an example that uses a timer, and does just waht you want. Timers arent confusing either, just think logically...

blah = Timer.new()

now... blah is a timer, and is not running right now. I want it to run... so...

blah:start()

Now... my timer is running.... I want to display the time in seconds, and if[] is pressed, stop it, if X is pressed, resume it, and finally, if O is pressed, reset it back to 0 and continue running

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

blah = Timer.new()
blah:start()

while true do
     screen:clear(white)
     pad = Controls.read()
     if pad:cross() then blah:start() end
     if pad:square() then blah:stop() end
     if pad:circle() then
          blah:reset() -- 0 by default
          blah:start() -- doesnt continue running once reset, so this is needed
     end

     screen:print(0,0,blah:time())
     screen.waitVblankStart()
     screen.flip()
end

-= Double Post =-
Hey guys... I need a guiene (sorry spelling) pig. Ive made a particle demo in LUA, and i need someone to test it for me.

Rather than sending you the file, jsut someone copy and paste this into a file, save itas a lua script and run it...

MAX_PARTICLES = 199 -- # of particles

particle = {} -- Particle Array (Room For Particle Info)
for i=0,MAX_PARTICLES do
    particle[i] = {
		life,				-- Particle Life
		fade,				-- Fade Speed
		x,					-- X Position
		y,					-- Y Position
		z,					-- Z Position
		xi,					-- X Direction
		yi,					-- Y Direction
		zi					-- Z Direction
    }
end

V, Angle = 0, 0

function Init()		-- All Setup Goes Here
    for loop=0,MAX_PARTICLES do			-- Initializes All Particles
      particle[loop].life=255 -- Give All The Particles Full Life
      particle[loop].fade=255/(math.random(0,100)/1000+0.05) -- Random Fade Speed

      V = math.random(0,25)  -- Speed of the particle
      Angle = math.random(0,360)  -- Angle of the particle

      particle[loop].x = 240   -- Set X position
      particle[loop].y = 136   -- Set Y position
      particle[loop].z = 0   -- Set Z position

      particle[loop].xi = math.sin(Angle) * V   -- Set X velocity
      particle[loop].yi = math.cos(Angle) * V   -- Set Y velocity
      particle[loop].zi = ((math.random(0,10)-5)/10) * V   -- Set Z velocity
    end
end

   
function DrawScene()	-- Here's Where We Do All The Drawing
  screen:clear()
  for loop=0,MAX_PARTICLES do -- Loop Through All The Particles
    x=particle[loop].x  -- Grab Our Particle X Position
    y=particle[loop].y  -- Grab Our Particle Y Position
    z=particle[loop].z  -- Grab Our Particle Z Position

    x = 480 / 2 + x * z
    y = 272 / 2 + y * z

    -- Draw The Particle Using Our RGB Values, Fade The Particle Based On It's Life
    screen:fillRect(x,y,4,4,Color.new(126,126,255,particle[loop].life))

    particle[loop].x=particle[loop].x+particle[loop].xi   -- Move On The X Axis By X Speed
    particle[loop].y=particle[loop].y+particle[loop].yi   -- Move On The Y Axis By Y Speed
    particle[loop].z=particle[loop].z+particle[loop].zi   -- Move On The Z Axis By Z Speed

    -- Slow down the particles
    particle[loop].xi=particle[loop].xi*2
    particle[loop].yi=particle[loop].yi*2
    particle[loop].zi=particle[loop].zi*2

    particle[loop].life=particle[loop].life-particle[loop].fade  -- Reduce Particles Life By 'Fade'

    if (particle[loop].life<255/0.05) then -- If Particle Is Burned Out
      particle[loop].life=255  -- Give It New Life
      particle[loop].fade=255/((math.random(100))/10000 + 0.005)  -- Random Fade Value
      particle[loop].x= 240  -- Center On X Axis
      particle[loop].y= 136  -- Center On Y Axis
      particle[loop].z= 0  -- Center On Z Axis
      V = (math.random(9)+1)
      Angle = math.random(360)

      particle[loop].xi = math.sin(Angle) * V
      particle[loop].yi = math.cos(Angle) * V
      particle[loop].zi = (math.random(10)-5)
    end
  end
  screen.waitVblankStart()
  screen.flip()
end

Init()

while true do DrawScene() end

Tell me what happens - please and thank you.

[eyece]

it just displayed allot of 4x4 rectangles at 240x136, but after i changed

    x=particle[loop].x  -- Grab Our Particle X Position
    y=particle[loop].y  -- Grab Our Particle Y Position
    z=particle[loop].z  -- Grab Our Particle Z Position

to

    x=particle[loop].xi  -- Grab Our Particle X Position
    y=particle[loop].yi  -- Grab Our Particle Y Position
    z=particle[loop].zi  -- Grab Our Particle Z Position

it made a mess in the middle of my screen:
http://img408.imageshack.us/img408/3...mation1dh3.gif

[yaustar]

SG57, Lua arrays start from 1 not 0.

for i=0,MAX_PARTICLES do

[eyece]

SG57, Lua arrays start from 1 not 0.

shouldnt matter becuase he created the table in the same way (0-199), but true.

[yaustar]

How are you slowing down the particles?

-- Slow down the particles
    particle[loop].xi=particle[loop].xi*2
    particle[loop].yi=particle[loop].yi*2
    particle[loop].zi=particle[loop].zi*2

This doubles the speed, not slow it down.

particle[loop].fade=255/(math.random(0,100)/1000+0.05) -- Random Fade Speed

Why something so complicated, just have fade a random number between 50 and 150 and you will still get the ssame effect.

if (particle[loop].life<255/0.05) then -- If Particle Is Burned Out

Just check if life is below 0.

if ( particle[loop].life < 0 ) then

[SG57]

yaustar - I ported this from it's original OpenGL C++ form, and since the OpenGL API uses colors from 0.0 - 1.0, I needed the same % of intensity, in a 255-base form. So, 255/original_color would result in the smae effect. Now that I think about it, it SHOULD be multiply 255 by the original color... hmm... As for the comments, totally disregard them. I know it speeds it up, 2x actually, and since my PC runs the original particle demo flawlessly at 50% of the x,y, and z vector speeds (times them by .5), I could only assume the PSP would have a slower framerate. So, just to start it out, I doubled the vector speeds. The comments dont mean to much now, as Ive had to adopt quite alot of changes for this to work wthout a 3D API... And yes, I know Lua, on default, sets the first element of an array as the '1' element. So I worked around it, as eyece pointed out...

eyece - The squares should have of faded out as they moved outward. Did they just seem to move from inside to the out?

Here - change all '255/' to '255/*' and it should fade out properly... Ill work on it more after school.

[yaustar]

My question is whether particle[0] exists. I don't understand why you are making the the life part of the particle so complicated. Start at 255 (full colour) and count down by a fixed amount each frame by the .fade (which is a random number between 15 and 50). Once life is below 0 (ie can't be seen), then reset the particle.

[EminentJonFrost]

thx, where do you guys learn all this stuff? ive seen the two tuts but other than that nothing

like anything else my friend, we watch others (look at scripts), and practice. i've been at this...for as long as i've been a member here, (well, its a hobby really) and i have a long ways to go. at least, in my defense, i have had no prior programming history.

[myschoo]

x = 255

timer = Timer.new(0)
timer:stop()

function colorText()

pad = Controls.read()

if pad:cross() then
timer:start()
screen:print(100,100, "text meni farbu!", Color.new(x,x,x))
end
if timer:time() > 0 < 1000 then
x = x - 1
end
if timer:time() > 1000 < 2000 then
x = x - 1
end
if timer:time() > 2000 < 3000 then
x = x - 1
end
if timer:time() > 3000 < 4000 then
x = x - 1
end
if timer:time() > 4000 < 5000 then
x = x - 1
end
end

while true do

screen:clear()

colorText()

screen.waitVblankStart()
screen.flip()
end

whats wrong with this? it should change colours...

error:15: cannot compare boolean with number

edit. maybe this could be better??

x = 255

timer = Timer.new(0)
timer:stop()

function colorText()

pad = Controls.read()

if pad:cross() then
timer:start()
end
if timer:time() > 0 < 1000 then
x = x - 1
screen:print(100,100, "text meni farbu!", Color.new(x,x,x))
end
if timer:time() > 1000 < 2000 then
x = x - 1
screen:print(100,100, "text meni farbu!", Color.new(x,x,x))
end
if timer:time() > 2000 < 3000 then
x = x - 1
screen:print(100,100, "text meni farbu!", Color.new(x,x,x))
end
if timer:time() > 3000 < 4000 then
x = x - 1
screen:print(100,100, "text meni farbu!", Color.new(x,x,x))
end
if timer:time() > 4000 < 5000 then
x = x - 1
screen:print(100,100, "text meni farbu!", Color.new(x,x,x))
end
end

while true do

screen:clear()

colorText()

screen.waitVblankStart()
screen.flip()
end

but still same error on line 13