Lua Programming Help Thread

[Nielkie]

why not just use the .20 version?

0.16 is much faster.

[emericaska8r]

oh yea true... maybe you could use the updated part in .20 and recompile that in the .16 version? don't know how all that stuff works so i couldn't tell you

[leviadragon]

hi guys , i ve got problem with neo motion kit and lua ...there isn't any compatibility!how i can map psp button? last question:I can ever use motion kit with lua? help please!

[FaT3oYCG]

yes if someone adds the commands into luaplayer

but at the moment they are not included

you will probably have to make a custom lua player to use the motion kit by programming the commands

[HaxxBlaster]

It would just be great if someone took the time on their hands to modify Lua Player to be able to connect with the Motion Kit.

Shouldn't the guys at LuaPlayer.org already have done it? it's over a year since Lua Player 0.20 was released..

0.16 is much faster.

Absolutely right. It has to do with the Image.createEmpty(width, height) extended alpha abilities, and i think it started in Lua Player 0.17, if i remember it right.
I would like to have some kind of switch between the two, like:

Image.createEmpty(width, height, fullapha boolean)

I think that will solve the problem, but maybe i'm wrong.

[FaT3oYCG]

i would do it if i knew the commands or had the motion kit aslong as my compiler worked but at the moment it doesnt

if i get my compiler to work i will ask someone for the commands and do it for you

[Nielkie]

i would do it if i knew the commands or had the motion kit aslong as my compiler worked but at the moment it doesnt

if i get my compiler to work i will ask someone for the commands and do it for you

Well, when/if the SIO lib is fixed in the next luaplayer, it should be possible to do it directly in luaplayer.


Something like this?

System.sioInit(510416)

--wait awhile because it takes a few seconds in initialize...

Xaccel = 0
Yaccel = 0
for i=1,10 do
	System.sioWrite("1") --string.char(tonumber("31",16))
	Xaccel = Xaccel + tonumber(System.sioRead()) --I'm not sure if this will work...
	System.sioWrite("2")
	Yaccel = Yaccel + tonumber(System.sioRead())
end
Xaccel = Xaccel  / 10
Yaccel = Yaccel / 10

Also, Googleing found this, though I'm not sure it is made for the motion kit.

[HaxxBlaster]

Well, when/if the SIO lib if fixed in the next luaplayer, it should be possible to do it directly in luaplayer.

If so, that would be great!

[leviadragon]

If so, that would be great!

yeah...

[%chrono trigger%]

hey everybody got a question about coding for your player to pick up the items (i can do the code up to a point), but my question do i need to have another image with my character with say a gun in his hands to blit and replace the old image of the character without the gun? if so is there a snippet that i could look at to show me how to do that. thnx in advance ofr any help.

[Nielkie]

hey everybody got a question about coding for your player to pick up the items (i can do the code up to a point), but my question do i need to have another image with my character with say a gun in his hands to blit and replace the old image of the character without the gun? if so is there a snippet that i could look at to show me how to do that. thnx in advance ofr any help.

player = {}
player.x = 0
player.y = 0
player.weapon = "gun"
player.img = {
	["gun"] = Image.load("player_gun.png"), 
	["none"] = Image.load("player.png"), 
	["sword"] = Image.load("player_sword.png")
}


screen:blit(player.x,player.y,player.img[player.weapon])

[%chrono trigger%]

thnxs that really helps :)
-----edit---------
ok i implemented that, but my old image isnt being replaced by the new one its just displaying both is there a certain function that would replace it im sort of confused. I think its because im using a if check collision function to deteermine if the image should be blitted which probaly isnt effective ill post that part of the code in a bit if need be
-= Double Post =-
srry for the double post mods, but i found the problem well sort of lol

if collision(Pic,Player) then
screen:blit(Player.x,Player.y,Player.img[Player.weapon])
screen.flip()
screen.waitVblankStart(30)
screen:clear()
end

ok so i solved my first problem by changing that code to:

if Player.x >= Pic[1].x then
screen:blit(Player.x,Player.y,Player.img[Player.weapon])
screen.flip()
screen.waitVblankStart(30)
screen:clear()
end

which works, but my other image is still there, so i have my second image blitted on top of my first image which not only lags my game severly, but makes it look stupid. So basically i need to know how i can i guess replace and image.
thnx in advance for the help

[Nielkie]

Why do you have a random waitVBlankstart there? Why are you fliping and clearing the screen?

I think its because im using a if check collision function to deteermine if the image should be blitted

Yeah, that makes no sense.

You can't just 'replace' an image, I suggest you restructure your code.

Something like this:

player = {}
player.x = 0
player.y = 0
player.weapon = "gun"
player.img = {
	["gun"] = Image.load("player_gun.png"),   --Image of the player with a gun
	["none"] = Image.load("player.png"),  --Image of the player widthout any weapon
	["sword"] = Image.load("player_sword.png") --Image of the player with a sword
}

while true do
	pad = Controls.read()

	screen.clear()
	screen:blit(player.x,player.y,player.img[player.weapon]) --Blits the player

	if player picks up gun then
		player.weapon = "gun"
	end

	if pad:left then
		player.x = player.x - 1
	end
	if pad:right then
		player.x = player.x + 1
	end
	--etc..

	screen.waitVblankStart()
	screen.flip()
end

[%chrono trigger%]

ill look throught that thnx, and also about the random waitVBlankstart and fliping and clearing the screen its because i had it from when i changed my code and didnt take it out thnx for finding that since i have alot more code than this already done and i guess it got copy pasted with it or something, and i had the collision function was because this was part of my other game stickguy wich was a bust, but the coding was good. Again thnx ill take a look through your code and fix mine.

[FaT3oYCG]

i was thinking of making an unreal tournament game for the psp coded in lua but i was just wondering if you think it would be better to do it in 3d and for it to take forever of to do it in 2d not be as good but take half the time just want to know what you think thanks

- if i was doing it in 3d i would also have to take some time to learn 3d too

- if it was in 2d i would probably have an alpha done in 3 weeks thanks

[hakk3r]

Do it in 3D. It would be sooo much cooler.

[FaT3oYCG]

anyone know where i can find some tutorials or simply somewhere that tells me what each of the 3d lua functions do

i have found the functions but i would like to know their meanings anyone know where i can find that out

thanks

- otherwise im doining it in 2d soz

[JustChris]

Someone is already working on a FPS engine in LUA, and it's in 3D. Unfortunately I don't remember who it was since I saw his video of the engine on Youtube. But I'm sure he would be of help.

To answer your question, you have to give more info on your LUA experience. And the way someone asks the questions can already tell a lot about that person's experience. So we already have a start there :)

You don't just "learn" 3D in the programming sense just like you don't "learn" games. The biggest leap in adjusting from 2D to 3D is in the physics. You might be able to do a simple Doom-type FPS but something in Unreal Tournament style has more complex physics and control.

i have found the functions but i would like to know their meanings anyone know where i can find that out

We cannot help explain the functions to you unless you tell us where you found them, right? ;)

[hakk3r]

Can someone create a simple 3D FPS tutorial? Thanks!

[FreePlay]

No. That would be ridiculous.

[hakk3r]

How is it ridiculous?

Fine, just a simple 3D tut.

[FreePlay]

That's still pretty ridiculous.

There's much, much more to a 3D engine than just graphics. And I don't see much chance of calculus being done properly in Lua, so the likelihood of physics being at all accurate is pretty low.

[hakk3r]

Yea but you could still make a 3D tutorial.
All I want it to be able to do is walk around.

[FaT3oYCG]

here is what i have read now i would only like a simple explanation for each please as i dont know what each one specifically does or in which order they are meant to be placed when being used but first of all it would help if i knew what they meant

thanks

3D GU mapping

Gu.start3d(), Gu.clearColor, Gu.clearDepth, Gu.clear, Gum.matrixMode, Gum.loadIdentity, Gum.perspective, Gum.translate, Gum.rotateXYZ, Gu.texImage, Gu.texFunc, Gu.texEnvColor, Gu.texFilter, Gu.texScale, Gu.texOffset, Gu.ambientColor, Gu.enable, Gu.disable, Gu.blendFunc, Gu.light, Gu.lightAtt, Gu.lightColor, Gu.lightMode, Gu.lightSpot and Gum.drawArray.

[Anti-QuickJay]

I am not sure but cant you get an idea of what they do by looking at the LuaPLayer source?

[andyauff]

This is a really basic question, but how would I go about having an image blitted to the screen upon the pressing of a button? I don't want it to be showing only when pressing the button, however, for I can do that fine. Basically, I want an image to appear when a button is pressed, but not go away. This is still a problem I've yet to figure out....

[TuxThePenguin]

showimg = false
img = Image.load("someimg.png")
while true do
pad = Controls.read()
screen:clear()

if pad:cross() then showimg = true end
if showimg then screen:blit(0,0,img) end

screen.waitVblankStart()
screen.flip()
end

[andyauff]

Thanks- I knew it would be a simple solution. Actually, I thought I tried something like that... obviously not!

Another question.... what I am trying to do is blit the same image in many different spots on the screen based on where the "cursor" is at that moment. How would you recommend doing that? Could I save the current (when the button is pressed) coordinates of the "cursor" into an unchanging variable? Because right now the blitted image is moving with the "cursor." Thanks for any help!

[TuxThePenguin]

locations = {}
function addLocation(x,y)
table.insert(locations,{x=x,y=y})
end

while true do
pad = Controls.read()
screen:clear()
if pad:cross() then addLocation(cursorx,cursory) end
for i = 1, table.getn(locations) do
screen:blit(locations[i].x,locations[i].y,img)
end
screen.waitVblankStart()
screen.flip()
end

[Nielkie]

here is what i have read now i would only like a simple explanation for each please as i dont know what each one specifically does or in which order they are meant to be placed when being used but first of all it would help if i knew what they meant

thanks

Have a look at the 3D cube example that comes with Lua. It's pretty much direct PSPgl commands.

I also remember a tut from a while back, I'll see if I can find it.

EDIT: Found it (From the GDI)