Lua Programming Help Thread

[Nielkie]

Just throwing it out there, if you are using an old version of luaplayer (<0.20), the "%" operator is not available (they are based on older versions of lua). Use math.mod instead.
e.g. math.mod(step + 1,6)

[dan369]

I have two questions :
1) if i want an enemy to change direction when it reaches an certain space would i do this;

if Enemy[1].x > 200 then
Enemy[1].x = Enemy[1].x + 2 
end
elseif Enemy[1].x < 100 then 
Enemy[1].x = Enemy[1].x - 2
end

Would something like that work?

2) This is general but concerns lua.
How do you become an better Lua programmer? What books, online tuts to read to become better?

[FaT3oYCG]

I have two questions :
1) if i want an enemy to change direction when it reaches an certain space would i do this;

if Enemy[1].x > 200 then
Enemy[1].x = Enemy[1].x + 2 
end
elseif Enemy[1].x < 100 then 
Enemy[1].x = Enemy[1].x - 2
end

Would something like that work?

2) This is general but concerns lua.
How do you become an better Lua programmer? What books, online tuts to read to become better?

1) yes that would work

2) you dont become a better lua programmer by reading books or online tutorials, the books and online tutorials just teach you the knowledge, you yoursef have to apply that knowledge to become better

over time with your programming you will look at sections of your code and think im sure that can be made smaller, so you make a backup copy and test different methods out, if you dont mange to do it in one day then dont just replace it with the old code, leave it but either work on it again a short time later or come back to it after a while, by which stage you will have probably solved the problem for a different project or peice of code, meaning that you should be able to fix it.

all in all becomming a better programmer is all about coding and trying new things out, when you try new things out you will understand more full where and where not to use certain peices of code, and the method that they are coded in

basically dan practice makes perfect, keep at it and you will get better.

i didnt become as skilled as i am now in a month or two.

[dan369]

Ok, then Thanks Fat :)

[Nielkie]

@dan
Wow, Quadruple Post.

@Fatboy
Stop being so conceited, you have a long way to go before you are regarded as "skilled". I've seen you act in such a way a number of times recently, and it really make you come across as immature.

[dan369]

My bad the computer froze for a bit so i kept clicking post quick reply sorry

[FaT3oYCG]

@Fatboy
Stop being so conceited, you have a long way to go before you are regarded as "skilled". I've seen you act in such a way a number of times recently, and it really make you come across as immature.

and that affects my programming skills how ?

i may be imature at times but what the hey thats just the way i am people need to learn to deal with it or shut up, the people who do deal with it find that i am quite a nice person, the people who dont have outstanding grudges against me which to be honest im not that bothered about.

[dan369]

Fat IS an skilled programmer, just look at this thread Or the Lua examples/snippets Thread. That one might as well be his lol
He's helped me and most people in the forum
-= Double Post =-
Ok, I'm trying to do 3 selectable difficulties But am having trouble I got 3 drifferent .cfg files with the info but don't know how to do it?

I was thinking about having it after you press X on start in the menu then having it print: Easy, Medium, Hard changing colour on each one. Then you press X on anyone of them But i don't really want 3 drifferent files holding the difficultly So could someone maybe tell me how to do it?

[yaustar]

2) This is general but concerns lua.
How do you become an better Lua programmer? What books, online tuts to read to become better?

You become a better Lua programmer by becoming a better programmer. You don't become better overnight, it takes constant learning and practise to accumulate experience over a period of time.

A good book to read would be Code Complete 2nd Edition.
http://cc2e.com/

[dan369]

Ok, thanks I'm also reading an book about lua itself, then after understanding lua really well i'll try C/C++

[FaT3oYCG]

Ok, I'm trying to do 3 selectable difficulties But am having trouble I got 3 drifferent .cfg files with the info but don't know how to do it?

I was thinking about having it after you press X on start in the menu then having it print: Easy, Medium, Hard changing colour on each one. Then you press X on anyone of them But i don't really want 3 drifferent files holding the difficultly So could someone maybe tell me how to do it?

as i said you need the functions that i have made for the saving and loading of a config file, when i have made it a proper function and made it as small as it can be ill post it on my site and tell you so you can take a look

[dan369]

I got the Menu part Set up moving left and right Simply But the loading is quiet hard because i'm not strong with reading/writing to files i know the basics but not advanced stuff

[FaT3oYCG]

hey dan those examples are up on my site, you know which ones to click on

[dan369]

Wow that was quick Thanks Fat will help me and loads off people
Off topic: Fat is it possible for your site to have an mini-forum? that would be cool i'd register :)

[FaT3oYCG]

Wow that was quick Thanks Fat will help me and loads off people

yeah i know how to do it i just couldnt be bothered to code it earlier when i mentioned it

Off topic: Fat is it possible for your site to have an mini-forum? that would be cool i'd register :)

probably but im not quite sure that i need one, if you make a petition and get 50 + people to sign it that will use the forums if i put some up then ill make some

[dan369]

How do you make an petition? Does my name count?

[Moose]

How do you make an petition? Does my name count?

We don't allow petitions on this forum, so it would have to be private.

[PSProgramer]

Hey, how would I code bliting only a section of a sprite sheet so I don't have to make 54 seperate images?? thanx

[FaT3oYCG]

Hey, how would I code bliting only a section of a sprite sheet so I don't have to make 54 seperate images?? thanx

here i dont know if these are any good but i just found them in one of my folders entitled "sprite crap"

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

number = 0
tile_width = 32
tile_height = 32
tile_image = Image.load("tiles.png")
tiles = { }

oldpad = Controls.read()

while true do

pad = Controls.read()

screen:clear()

-- insert your main code here

if pad:left() and not oldpad:left() then
number = number + 1
end

if number >= 9 then
number = 0
end

screen:blit(10, 10, tile_image, 32 * number, 0, 32, 32)

-- insert your main code here

if Controls.read():start() then
	break
end

oldpad = pad

screen.flip()
screen.waitVblankStart()

end

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

number = 0
tile_width = 32
tile_height = 32
tile_image = Image.load("tiles.png")
tiles = { }

oldpad = Controls.read()

while true do

pad = Controls.read()

screen:clear()

-- insert your main code here

number = number + 1

if number >= 9 then
number = 0
end

screen:blit(10, 10, tile_image, 32 * number, 0, 32, 32)
screen.waitVblankStart(60)

-- insert your main code here

if Controls.read():start() then
	break
end

oldpad = pad

screen.flip()
screen.waitVblankStart()

end

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

collumn = 0
row = 0
tile_width = 32
tile_height = 32
tile_image = Image.load("tilesb.png")
tiles = { }

oldpad = Controls.read()

while true do

pad = Controls.read()

screen:clear()

-- insert your main code here

if pad:left() and not oldpad:left() then
collumn = collumn + 1
end

if collumn >= 3 then
collumn = 0
row = row + 1
end

if row >= 3 then
row = 0
end

screen:blit(10, 10, tile_image, 32 * collumn, 32 * row, 32, 32)

-- insert your main code here

if Controls.read():start() then
	break
end

oldpad = pad

screen.flip()
screen.waitVblankStart()

end

[PSProgramer]

thanx, glad to put use to your "sprite crap" by the way did you get my P.M.??

[TurtlesPwn]

screen:blit(x,y,spriteshe etimage,topleftcornerofse ctionofspritesheetyouwant toblitx, topleftcornerofsectionofs pritesheetyouwanttoblity, bottomrightcornerofsectio nofspritesheetyouwanttobl itx, bottomrightcornerofsectio nofspritesheetyouwanttobl ity)

[FaT3oYCG]

thanx, glad to put use to your "sprite crap" by the way did you get my P.M.??

yeah ill take a look when i get time im busy doing a few things this week

and put simply

screen:blit(xpos to blit, ypos to blit, full image to use, x start position for tile, y start position for tile, width of tile, height of tile)

tile is another word for sprite

[PSProgramer]

thank you very much, that helps alot. Makes it way easier, and way more efficient!!! thank you!!

[dan369]

I want to do some type of online highscore system, But don't have a clue how to do this? would i have do make an webpage or sumthing?
My Plan: Have an system that loads your score using "r" (reading&writing functions) Then connecting to somewhere then you enter an name and it Places you in the right place? Is that possible????

[FaT3oYCG]

I want to do some type of online highscore system, But don't have a clue how to do this? would i have do make an webpage or sumthing?
My Plan: Have an system that loads your score using "r" (reading&writing functions) Then connecting to somewhere then you enter an name and it Places you in the right place? Is that possible????

with your own server and sql databse to manage it yes

[TurtlesPwn]

You don't need an SQL DB for a list of scores, but yes, you need some server side scripting and a webserver as well as some good lua online backend stuff.

[alf_fredd]

Hi everyone!
this is my first post here at qj and i wondered if someone can help me im having some trouble making my game which is tile based, so far i have been using this code as a base for mine i got it from http://wiki.ps2dev.org/psp:lua_player:tutorial

-- load graphics
tiles = Image.load("tiles.png")
figure = Image.load("figure.png")

-- the map
mapSource = {
"mmmmmmmmmmmmmmmmmmmmmmmm mmmmmm",
"mmmmmmmmmmmmmmmmmmmmmmmm mmmmmm",
"mmeaaaaaaaaaaaaaaaaaaaaa aaafmm",
"mmdpnnnnnnnnnnnnnnnnnnnn nnpbmm",
"mmdokcccccclnkcccccccccc clnbmm",
"mmdojaaaaafdnbmmmmmmmmmm mdnbmm",
"mmdooooooobdnbmmmmmmmmmm mdnbmm",
"mmdokccclobdnbmmmmmmmmmm mdnbmm",
"mmdobmmmdobdnbmmmmmmmmmm mdnbmm",
"mmdobmmmdobdnjaaaaaaaaaa fdnbmm",
"mmdobmmmdpbdnnnnnnnnnnnn bdnbmm",
"mmdobmmmhcghccccccccccln bdnbmm",
"mmdojaaaaaaaaaaaaaaaaain jinbmm",
"mmdpnnnnnnnnnnnnnnnnnnnn nnpbmm",
"mmhccccccccccccccccccccc cccgmm",
"mmmmmmmmmmmmmmmmmmmmmmmm mmmmmm",
"mmmmmmmmmmmmmmmmmmmmmmmm mmmmmm"
}

-- offsreen image, where the map will be drawn
board = Image.createEmpty(480, 272)

-- draw one tile on the map
function drawTile(tile, x, y)
tile = string.byte(tile, 1) - string.byte("a")
local tileX = math.mod(tile, 4)
local tileY = math.floor(tile / 4)
board:blit(16 * x, 16 * y, tiles, 17 * tileX + 1, 17 * tileY + 1, 16, 16, false)
end

-- copy the map source to an array for easier access and draw the offscreen board
map = {}
for y = 1, 17 do
line = mapSource[y]
map[y] = {}
for x = 1, 30 do
tile = string.sub(line, x, x)
map[y][x] = tile
drawTile(tile, x - 1, y - 1)
end
end



Now i want to use a tileset that it has a total of 64 tiles each tile of 16px by 16px in 8 colums and 8 rows now i cant figure how to number the tiles i have been planning using "aa ab ac ad af" ("aa" beign one tile) etc but i cant figure how to make this code

tile = string.sub(line, x, x)

so it can read the first two characters and then the next two and so on and so forth of each row and then adjust this so it works with the one above

tile = string.byte(tile, 1) - string.byte("a")

well in general how to change the code so it work with the tileset i would like to use
Or if you have a better sugestion on how to do this please i would really appreciate your help

[dan369]

You don't need an SQL DB for a list of scores, but yes, you need some server side scripting and a webserver as well as some good lua online backend stuff.

So how do i start to do this?

[FaT3oYCG]

So how do i start to do this?

get your own website

[dan369]

get your own website

Any suggestions? Though will it be free? If so any good free website places? Then i get the website What do you do after that?