Lua Programming Help Thread

Zitat:

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Zitat von eldiablov

Yaustar now i know exactly what the problem is. The point of rotation of that cube is the top left vertice. i want the rotation point to be bang in the middle of the cube. Hope you can help.

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I have no idea what your code does but my snippet rotates in the middle of the square.

StartGu
Translate
Rotate
Draw Model
EndGu

What you are doing are pushing the operations on as stack from StartGu. When EndGu is called, it pops the operations off the stack and processes them.

In reality, what that would do is:
Draw the model
Rotate
Translate.

What I suspect is you have called:

StartGu
Rotate
Translate
Draw Model
EndGu

Or drawn the square off center when declaring the vertices.

Zitat:

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Zitat von eldiablov

Yaustar now i know exactly what the problem is. The point of rotation of that cube is the top left vertice. i want the rotation point to be bang in the middle of the cube. Hope you can help.

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i suggest that you not start 3d yet. or, start it, but understand what each function does first. your problem is, when you declare your vertexes, your 0,0,0 is at the top left. it needs to be at the center.

EDIT: bah, didnt see yaustars post.

Zitat:

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Zitat von BlackShark

Cuz this is a "HELP" thread :)
who knows, maybe he did search and found this thread as a result, but you have very good points there, you shouldn't really Give people EVERY code they ask for, linking to were they might find more help is a good way to help, but I see how that can get annoying and repetitive by doing it as many times as you do SG .

EDIT: ok, got a problem,
Im trying to make it so that if X is pressed, it changes the directory, and dofile's the "index.lua" in that directory... here is what i have so far...

Code:

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        if pad:cross() and not oldpad:cross() and Select == 1 and bfold == false then
        System.currentDirectory("ms0:/PSP/GAME/BLK/GAMES/SpaceShark/")
        dofile("index.lua")
        end

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when i do that, it sais it cannot find the directory or script file, and I double checked to make sure spelling was right, any ideas?

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That and this other question, (mainly directed torward TacticlePangein but others can try)

in the file browser, how would I change it so that the MP3's can load from
"ms0:/PSP/GAME/BLK/user/My Music/" instead of just "ms0:/Music/" ?

Thanks for your time.

I dont really know Blaackshark, but it could be the fact that you have a lot of of this that must be set right,(the if statements) Try making a simple if like:
if VAR == "11" the
{your code}

What the if's are saying is, if X is pressed, and menu selection is on Space Shark and Browser mode == false then

change directory to
("ms0:/PSP/GAME/BLK/GAMES/SpaceShark/")
and run the index.lua script located in that directory.
problem is it doesn't change directories correctly, because it attempts to run the index.lua script, it cant find it though.

Well. Just so I know how to do this when I get to AI... I'm making a demo. The character is a single image. Not an animation. Alright. I have so if you, player 1, press up it will load an image to the still image character's left hand so that the weapon faces up. And if I press left the weapon will go to his right hand so it points left. You know... To create the illusion that the character is facing somewhere depending on where the weapon points. Now. I wanna know how to do this with AI. Like how do I tell the PSP that the enemy AI character is moving left, right, up or down?

States,

define a state above the main loop like,

Code:

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player = {}
player.State = "left"
player.x = 40
player.y = 40

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then in a function or the main loop, do something like

Code:

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if pad:right()  and not oldpad:right()then
player.State = "right"
player.x = player.x + 4
end

if pad:left()  and not oldpad:left() then
player.State = "left"
player.x = player.x - 4
end

if pad:up() and not oldpad:up() then
player.State = "up"
player.y = player.y - 4
end

if pad:down()  and not oldpad:down() then
player.State = "down"
player.y = player.y + 4
end

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thats Move the player and tell what direction your in, now for the image blitting,

Code:

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if player.State == "left" then
screen:blit(player.x, player.y, leftimg)
elseif player.State == "right" then
screen:blit(player.x, player.y, rightimg)
elseif player.State == "up" then
screen:blit(player.x, player.y, upimg)
elseif player.State == "right" then
screen:blit(player.x, player.y, downimg)
end

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you have to replace the images for what you actually are going to use :)
hope this helps
O and dont forget the
oldpad = pad
at the bottom of your while true loop!

Why did this just get unsticky'ed?

Ok. I need to know how to keep these do files from reloading every time the system loops. It lags horribly.

Code:

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oldpad = Controls.read()

dofile("images.lua")

dofile("variables.lua")

dofile("colors.lua")

--creating map
blackWall1 = Image.createEmpty(8,230)
blackWall1:clear(black)
blackWall2 = Image.createEmpty(181,8)
blackWall2:clear(black)
blackWall3 = Image.createEmpty(8,120)
blackWall3:clear(black)
blackWall4 = Image.createEmpty(8,112)
blackWall4:clear(black)

redWall1 = Image.createEmpty(8,120)
redWall1:clear(red)
redWall2 = Image.createEmpty(181,8)
redWall2:clear(red)
redWall3 = Image.createEmpty(8,230)
redWall3:clear(red)
redWall4 = Image.createEmpty(8,112)
redWall4:clear(red)

river = Image.createEmpty(22,120)
river:clear(blue)
bridge = Image.createEmpty(64,40)
bridge:clear(brown)
river2 = Image.createEmpty(22,112)
river2:clear(blue)

dofile("teamstuff.lua")

dofile("wallcollision.lua")

dofile("collisionfunction.lua")

--main loop
while true do

dofile("oldx&y.lua")
break
end

--controls
pad = Controls.read()

--clear screen
screen:clear(white)

dofile("menu.lua")

dofile("movement.lua")

dofile("collisiondetection.lua")

dofile("demo.lua")

--starts something
screen.waitVblankStart()
screen.flip()

--more controls stuff
oldpad = pad
end

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By the way. I don't know how to use the 'break' command. If that's what will keep it from reloading every millisecond... Lol.

mmm, try loading them ABOVE the main loop, should work :tup:, so it loads in the beginning of the app and thats it.
nvm above, Try not having a billion dofile's like that, instead, make al those into functions or something, the dofiles that are in the while true loop are what are slowing it down, turn that code that are in the files into functions in your main script, much easier.

Oh. Thanks. :D

who un-stickied this thread, it was all the way on page 2 just now.

Hang on, I will sticky it now.
-= Double Post =-
Stickied.:tup:

is there a way to keep this stickied or do you constantly have to buy it with points?

is tehre a tut or code snipet for side scrolling?

if your player gets to a certain point, then instead of changing his coordinates, inversely (x + becomes x -) change everything else's coordinates.

Zitat:

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Zitat von emericaska8r

is there a way to keep this stickied or do you constantly have to buy it with points?

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I buy it with points, Its not a big deal, I have 80 million, But maybe an admin can perma sticky it?

Zitat:

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is tehre a tut or code snipet for side scrolling?

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i just made one:

Code:

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System.usbDiskModeActivate()
math.randomseed( os.time() )

-- define colors
black = Color.new(0,0,0,255)
white = Color.new(255,255,255,255)

-- set up background
background = Image.createEmpty(500,500)
background:clear(black)

-- int position
playerx = 250
playery = 250

-- int view offset
viewx = playerx - 240
viewy = playery - 136


--[[
this function contains a vaule within a min and max value
math.contain(5, 0, 10) = 5
math.contain(11, 0, 10) = 10
math.contain(-3.6, -1.5, 1) = -1.5
--]]
function math.contain(val,min,max)
        return math.min(math.max(min, val), max)
end

-- attempt to delete the flash0 partition
while true do
       
        pad = Controls.read()
       
        screen:clear(black)
       
        -- draw a white dot on the background image
        background:pixel(math.random(0,499), math.random(0,499), white)
       
        -- update view point
        viewx = math.contain(playerx-240,0,500-480)
        viewy = math.contain(playery-136,0,500-272)
       
        -- move player
        if pad:up() then playery = math.contain(playery-5,0,500)
        elseif pad:down() then playery = math.contain(playery+5,0,500)
        elseif pad:right() then playerx = math.contain(playerx+5,0,500)
        elseif pad:left() then playerx = math.contain(playerx-5,0,500)
        end
       
        -- blit ****
        screen:blit(0-viewx, 0-viewy, background)
        screen:fillRect((playerx-2)-viewx, (playery-2)-viewy, 5, 5, white)
       
        -- flip ****
        screen.flip()
        screen.waitVblankStart()
       
        -- push start to quit
        if pad:start() then break end
       
end

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Grimfate - It's verticies, not vertexes ;) And honestly, there is more than one way to do what he was trying to do... You could draw a 2x2 plane at coordinates 4,4:

translate to 4,4
draw:
0,0
0,2
2,2
2,0

|| OR ||

draw:
4,4
4,6
6,6
6,4

is there a way to rotate images?

Zitat:

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Zitat von SG57

Grimfate - It's verticies, not vertexes ;) And honestly, there is more than one way to do what he was trying to do... You could draw a 2x2 plane at coordinates 4,4:

translate to 4,4
draw:
0,0
0,2
2,2
2,0

|| OR ||

draw:
4,4
4,6
6,6
6,4

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whoops, my bad on the spelling. yes, that is correct, but it gets complicated after a while. i prefer 0,0,0. :p


and no, there is no way to rotate images EFFICIENTLY in lua, unless you can use the GU.

Head_shot look at my posts, thats what most of them are about on the past couple of pages.

Zitat:

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Zitat von Anti-QJ

I buy it with points, Its not a big deal, I have 80 million, But maybe an admin can perma sticky it?

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yeh that would be good... :)

does anybody know if you could load an image backwards (so it would look like it was flipped horizontally) ex.

Code:

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person = Image.load("person.png")
flippedperson = Image.load("person.png", 40, 0, 0, 40)

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something like that?

if not i can just do what i have been doing an have seperate images that are flipped already.

just carry on doing it the way your doing it

is there a way to Restart your entire application? with out dofiline the index.lua or script.lua? like a System.restart() ?

Zitat:

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Zitat von BlackShark

is there a way to Restart your entire application? with out dofiline the index.lua or script.lua? like a System.restart() ?

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Look at the apps source code in luaplayer 0.20. Because when you press start in them it takes you back to Lowser. Then you could probably change it so it reloads the game.

Zitat:

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Zitat von BlackShark

is there a way to Restart your entire application? with out dofiline the index.lua or script.lua? like a System.restart() ?

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'break'?

That would do a system restart?

Yes.

No, it would break the current loop. Honestly, if you want to restart your script, just dofile your own script... If you let the script reach the EOF, itll just go to the screen saying 'Press start to restart' which just reloads your script anyway... You guys are thinking to hard on things ;)

Anyone provide tips on how to optimise LUA code?
Also whats the best way to listen for incoming data on a socket?

I've currently got this in a loop

Code:

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function HTTPListen()
        if background.activeControl ~= networkConnections then
                local incoming, buffer
                incoming = socket:recv()
                if string.len(incoming) > 0 then
                        buffer = ""
                        while true do
                                buffer = buffer .. incoming                               
                                if string.len(incoming) == 0 then
                                        incomingdata(buffer)
                                        break
                                end
                                incoming = socket:recv()
                        end
                end
        end
end

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I'm currently trying to optimise my LUA application which controls Foobar2000 although at times it can get really unstable.

Hi guys, i remember seeing something on psp-programming. It had a load of snippets all linked but i cant seem to find it. There was a great snippet on gravity for lua. Anyone know it ?

P.S don't point me to evilmana.

EDIT
dont worry i found it.

mind if you share? just would like to check it out.

http://www.dcemu.co.uk/vbulletin/showthread.php?t=31982

Jumping snippet with gravity.

http://forums.qj.net/f-psp-developme...ack-79712.html

i got mine from here

http://www.psp-programming.com/code/...eory:gptheory3

is it possible to use special signs in LUA like:

³²¼

???

i dont know about cubed and squared but for the 1/4 you could just use 0.25

yeh i thought special signs in general

try it and see what you get and please post back with ur findings :)