Lua Programming Help Thread

[Bronx]

yeah... but if the AI is slower then the player then he would most likely never catch the player. So you need to incorporate a part in which the enemy predicts where the player is going so it can catch up. (btw, this is what I'm trying to learn to do, the prediction part).

[cwirsing]

http://www.sendspace.com/file/4jg6xl
Can someone PLEASE take a look at my code. There is a problem with putting the animation on the screen. I haven't been able to work on my game for several days now because I can't get the animation to work.

[Access_Denied]

Maybe you want to give us the part that's giving you trouble. That way we don't have to look at the entire code.

[cwirsing]

Here is the code that is giving me trouble.

-- Set Default Image
link = linkfaced

-- Get Default Image Height And Width
link:width()
link:height()

-- Get Screen Height And Width
screenwidth = 480 - link:width()
screenheight = 272 - link:width()

-- Player Info
player = {}
player.x = 220
player.y = 110
player.moving = "no"
player.facing = "down"
player.pad = "none"

-- Link Walking Down Animation Table
linkwalkingd = {}
linkwalkingd[1] = linkwalkingd1
linkwalkingd[2] = linkwalkingd2
linkwalkingd[3] = linkwalkingd3
linkwalkingd[4] = linkwalkingd4
linkwalkingd[5] = linkwalkingd5
linkwalkingd[6] = linkwalkingd6
linkwalkingd[7] = linkwalkingd7
linkwalkingd[8] = linkwalkingd8

-- Display Default Image
screen:clear()
screen:blit(player.x, player.y, link)
screen.flip()
screen:clear()

-- Set loop count
loopCount = 0
loopCounts = 0

-- Make Player Move Down
if pad:down() and player.y < screenheight then
player.y = player.y + 2

player.moving = "yes"
player.facing = "down"
player.pad = "down"

link = linkfaced

end

-- Link Walking Down Animation Loop
if player.moving == "yes" and player.facing == "down" then
if loopCount >= 0 and loopCount < 2 then link = linkwalkingd[1]
elseif loopCount >= 2 and loopCount < 4 then link = linkwalkingd[2]
elseif loopCount >= 4 and loopCount < 6 then link = linkwalkingd[3]
elseif loopCount >= 6 and loopCount < 8 then link = linkwalkingd[4]
elseif loopCount >= 8 and loopCount < 10 then link = linkwalkingd[5]
elseif loopCount >= 10 and loopCount < 12 then link = linkwalkingd[6]
elseif loopCount >= 12 and loopCount < 14 then link = linkwalkingd[7]
elseif loopCount >= 14 and loopCount < 16 then link = linkwalkingd[8] end
if loopCount + 1 >= 16 then loopCount = 0 else loopCount = loopCount + 1 end
end

[Bob Hoil]

i want it so that my character shoots a bullet and it hits him. I also need to now how to get a bullet that comes from my characters gun in his hand.

[Bronx]

ok, Bob, you asking us for us to just give you code and yout putting it together,. Try going to evilmana.com and read the tuts their. Then come back and tell me if you know how to do all this ;)

[Bob Hoil]

i typed up the intro screen and everything but all of the tutorials don't explain very well i have tried that i could only get some of the code i typed to wrok even though it looked right by comparing.

[Bronx]

probably because the tuts are for his game, do not copy, paste. You have to fit it to your own code. Post your code and let me see how much you have as of now.

[Bob Hoil]

well right now access denied is helping me so i will see how it goes first before i post my code.

[pspsalv2]

i need help making my basic menu and so if you can help here is what i have: i know im missing something oh and all iget is flickering when i run it as in the thing i want white is white yet when i push up or down it flickers and doesn't exavtly go to the one under or over the one that is selected so yeah please help

red = Color.new(255, 0, 0)
white = Color.new(255, 255, 255)
p1 = Image.load ("p1.png")
block = Image.load("block.png")
menu = 0
while true do
pad = Controls.read()
if pad:down() then
menu = menu + 1
end
if pad:up() then
menu = menu - 1
end
if menu < 0 then
menu = 2
end
if menu > 2 then
menu = 0
end 
if menu == 0 then
screen:print(200, 60, "Start", white)
screen:print(200, 80, "Options", red)
screen:print(200, 100, "Quit", red)
screen:flip()
end
if menu == 1 then
screen:print(200, 60, "Start", red)
screen:print(200, 80, "Options", white)
screen:print(200, 100, "Quit", red)
screen:flip()
end
if menu == 2 then
screen:print(200, 60, "Start", red)
screen:print(200, 80, "Options", red)
screen:print(200, 100, "Quit", white)
screen:flip()
end
if pad:start() then 
break
end
end

[Access_Denied]

First of all, you don't need to add screen.flip() after every menu option. Second, you need to add this to the end.

screen.waitVblankStart()
screen.flip()

Also add this line above your "while true do"

oldpad = Controls.read()

and add this under the "screen.flip()"

oldpad = pad

and every time you have a "if pad" statement, change it to this:

if pad:button() and oldpad:button() ~= pad:button then
blah blah blah
end

This will make it so it doesn't cycle through the options so fast.

[pspsalv2]

allright ill try it out

Double Post Merge

thanks a lot man that worked

[Access_Denied]

Also, try these changes. The things I changed are in red.

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

white = Color.new(255, 255, 255)
p1 = Image.load ("p1.png")
block = Image.load("block.png")
menu = 0
while true do
screen:clear()-- you can't forget to add this to every program
pad = Controls.read()
screen:print(200,60,"Start",red)
screen:print(200,80,"Options",red)
screen:print(200,100,"Quit",red)
if pad:down() then
menu = menu + 1
end
if pad:up() then
menu = menu - 1
end
if menu < 0 then
menu = 2
end
if menu > 2 then
menu = 0
end 
if menu == 0 then
screen:print(200, 60, "Start", white)
end
if menu == 1 then
screen:print(200, 80, "Options", white)
end
if menu == 2 then
screen:print(200, 100, "Quit", white)
end
if pad:start() then 
break
end
end

By making these changes you are just cleaning up your code by having less lines.

[pspsalv2]

hey thanks again oh and about the screen clear why do you need to put it cuase ive seen it used a lot like that and don't understand why you need it so if you could explain thatwouls be great and thanks again!

[Access_Denied]

Because if you didn't have the screen:clear(), everything would be pasted on top of each other. Say you had a game, where a blue block moves around the screen. If you didn't have the screen:clear(), when the block moved thier would be a trail behind it. Take it out of your program and see what happens.
BTW- Screen:clear() always clears the screen black, but if you want a blue background or something, you could use this:

screen:clear(blue)

or you could use a picture for a background:

screen:clear(Picture you want)

[pspsalv2]

oh allright that makes sense thanks for the explanation and advice

[Access_Denied]

No problem. :)

[TheEmulatorGuy]

Here is the code that is giving me trouble.

There doesn't appear to be anything wrong with the code you've shown (although I may be missing something). A problem is going on somewhere else, and that is with the "linkfaced" variable. But I have no idea what that variable is set to, so I can't help.

[JoeDaStudd]

where can i find lua tuturails on using the psps wifi?
thanks in advance

[Altair]

the only way to use wifi with LUA right now is with netlib. There's no tut for it, but there is a very easy example with it. Ah whatever I'll write a very short tut:

what you need:
- netlib2.0
The file itself is called "netlib.lua". Put it in the same folder as your app (this isn't necessairy, you can also put it somewhere else, the path in the "dofile()" command will just change).

First the stuff that should be before your main loop (also remember to turn on the wifi with "Wlan.init()" and connect to the internet using "Wlan.useConnectionConfig (connection)", where "connection" is the number of the connection you want to use. For example: with Wlan.useConnectionConfig( 1) you would connect to your first connection):

1) In your app you have to import it by saying "dofile("netlib.lua") ".
2) After that you have to connect to the server with this "netconnect()"
3) Now before you can send and receive date, you have to create a variable on the server where you can send and receive your data to. You do this with the following command: netreg(id), where id is the name you want the variable to have.
(This command also makes sure the server sends the valua of the variable, whenever the valua of it changes)

Now comes the part that should be in the main loop itself
4) Now you have created a variable on the server you can send data to it by using "netsend(id, data, attribute)", where "id" is the name of the variable, data is the data in a string format (this means you have to turn tables and numbers and other formats into a string first) and where "attribute" is the way you want the data to be put in the variable. The attribute can either be "w" or "a". "w" means write and you will replace data, "a" means append and you will add the new data to the data that was already in the variable.
5) To receive data, you would say "netrecv()". This will receive all incoming data.
6) You don't have the value of the variable yet though. For that you need to use "netvalue(id)", where "id" is again the name of the variable. You need to put this after the "netrecv()" command.

After the main loop, you will need to delete the variable and close the connection:
7) To delete the variable on the server: netunreg(id), where "id" is the name of the variable
8) To close the connection to the server: netclose()
9) To close wifi: Wlan.term()

As an example I have put the example of yoursam (the author of this app) here:

--[[
netlib example
by youresam
]]

dofile("netlib.lua") -- netlib

Wlan.init()
print("Connecting to "..Wlan.getConnectionConfigs()[1].."...")
Wlan.useConnectionConfig(1)

print("Connecting to netlib server...")
netconnect() -- connect to netlib server

print("Setting up AMW for 'netlibtest' (wont do anything in this example..)")
netreg("netlibtest")

print("Sending 'helloworld' to 'netlibtest'")
netsend("netlibtest","helloworld","w") -- id:netlibtest data:helloworld mode:write

print("Getting 'netlibtest'...(Press start to quit)")
netget("netlibtest")
while true do
	netrecv() --recieve all incoming data
	buffer = netvalue("netlibtest") --what is the value of the id 'netlibtest'?
		if buffer ~= "" then --if it exists...
			print(buffer)
			break
		end
	if Controls.read():start() then break end
end

netunreg("netlibtest") --ALWAYS unregister a variable when your done

netclose() --close the netlib connection

Wlan.term()

print("Program finished, hold start to exit.")

As you can see he uses netget(id) instead of netrecv() and netvalue(id). Eventhough its possible, its way slower (so he said to me). He still uses it because he only needs to get the data once and not continues (I think?). If you want to get the data every loop its better to use netrecv() and netvalue(id).

Hope it's clear enough (and right. If not please correct me anyone). I didn't explain the mail, sms and call functions. I just explained the basic sending and receiving.

[Bronx]

the only way to use wifi with LUA right now is with netlib. There's no tut for it, but there is a very easy example with it. Ah whatever I'll write a very short tut:

what you need:
- netlib2.0
The file itself is called "netlib.lua". Put it in the same folder as your app (this isn't necessairy, you can also put it somewhere else, the path in the "dofile()" command will just change).

First the stuff that should be before your main loop (also remember to turn on the wifi with "Wlan.init()" and connect to the internet using "Wlan.useConnectionConfig (connection)", where "connection" is the number of the connection you want to use. For example: with Wlan.useConnectionConfig( 1) you would connect to your first connection):

1) In your app you have to import it by saying "dofile("netlib.lua") ".
2) After that you have to connect to the server with this "netconnect()"
3) Now before you can send and receive date, you have to create a variable on the server where you can send and receive your data to. You do this with the following command: netreg(id), where id is the name you want the variable to have.
(This command also makes sure the server sends the valua of the variable, whenever the valua of it changes)

Now comes the part that should be in the main loop itself
4) Now you have created a variable on the server you can send data to it by using "netsend(id, data, attribute)", where "id" is the name of the variable, data is the data in a string format (this means you have to turn tables and numbers and other formats into a string first) and where "attribute" is the way you want the data to be put in the variable. The attribute can either be "w" or "a". "w" means write and you will replace data, "a" means append and you will add the new data to the data that was already in the variable.
5) To receive data, you would say "netrecv()". This will receive all incoming data.
6) You don't have the value of the variable yet though. For that you need to use "netvalue(id)", where "id" is again the name of the variable. You need to put this after the "netrecv()" command.

After the main loop, you will need to delete the variable and close the connection:
7) To delete the variable on the server: netunreg(id), where "id" is the name of the variable
8) To close the connection to the server: netclose()
9) To close wifi: Wlan.term()

As an example I have put the example of yoursam (the author of this app) here:

--[[
netlib example
by youresam
]]

dofile("netlib.lua") -- netlib

Wlan.init()
print("Connecting to "..Wlan.getConnectionConfigs()[1].."...")
Wlan.useConnectionConfig(1)

print("Connecting to netlib server...")
netconnect() -- connect to netlib server

print("Setting up AMW for 'netlibtest' (wont do anything in this example..)")
netreg("netlibtest")

print("Sending 'helloworld' to 'netlibtest'")
netsend("netlibtest","helloworld","w") -- id:netlibtest data:helloworld mode:write

print("Getting 'netlibtest'...(Press start to quit)")
netget("netlibtest")
while true do
	netrecv() --recieve all incoming data
	buffer = netvalue("netlibtest") --what is the value of the id 'netlibtest'?
		if buffer ~= "" then --if it exists...
			print(buffer)
			break
		end
	if Controls.read():start() then break end
end

netunreg("netlibtest") --ALWAYS unregister a variable when your done

netclose() --close the netlib connection

Wlan.term()

print("Program finished, hold start to exit.")

As you can see he uses netget(id) instead of netrecv() and netvalue(id). Eventhough its possible, its way slower (so he said to me). He still uses it because he only needs to get the data once and not continues (I think?). If you want to get the data every loop its better to use netrecv() and netvalue(id).

Hope it's clear enough (and right. If not please correct me anyone). I didn't explain the mail, sms and call functions. I just explained the basic sending and receiving.

Damn, thats really good! You should create a seperate thread with this tut in it, so it isnt lost withini all these pages.

[Access_Denied]

I agree. BTW- shouldn't have this thread been stickied by now?

[JoeDaStudd]

Hi
Can anyone tell me if and how you can use the psp ad hoc mode on lua?
Ps. Thanks Altair for answering my previous question

[Bronx]

I agree. BTW- shouldn't have this thread been stickied by now?

It was, but now its linked to in a stickied.

[Access_Denied]

That's pretty stupid.

Yes, JoeDaStudd, you can use ad-hoc in LUA. I don't know how though.

[Altair]

Thx, if you all think so, i guess I will make a seperate thread about it.

@Acces denied: since when is ad-hoc supported with LUA? Do you maybe have a link or something? That would be really great if it's possible. I do know somebody said it would be really easy, but he said he didn't have the time to do it, so im not to sure on his credibility.

[Bronx]

yeah you sould create a thread for it.

[Access_Denied]

Thx, if you all think so, i guess I will make a seperate thread about it.

@Acces denied: since when is ad-hoc supported with LUA? Do you maybe have a link or something? That would be really great if it's possible. I do know somebody said it would be really easy, but he said he didn't have the time to do it, so im not to sure on his credibility.

Maybe it isn't supported in LUA. I always thought it was. Guess I better check my info.
Did a google search and found out it isn't.

[fuxer]

can someone tell me how can i rotate and zoom an image in realtime in lua?what are the functions i have to use?cuz im kinda new to lua and trying to port a game i made in flash.tnx :)

[Grimfate126]

can someone tell me how can i rotate and zoom an image in realtime in lua?what are the functions i have to use?cuz im kinda new to lua and trying to port a game i made in flash.tnx :)

this is from the lua snippets thread:

this will rotate an image by a cretain agle:

function rotateImage(theImage, angle)
screen:blit(0,0,theImage)  
angle = angle*(6 + (1/3))/360
	for x = 1, theImage:width() do
		for y = 1, theImage:height() do
			tX = math.cos(angle)*(x-theImage:width()) - math.sin(angle) * (y-theImage:height())
			tY = math.sin(angle)*(x-theImage:width()) + math.cos(angle) * (y-theImage:height())
			screen:fillRect(tX + 240, tY + 136, 2, 2, screen:pixel(x, y))
		end
	end
end