Lua Programming Help Thread

[BlackShark]

Can someone help me? I have an error when using dofile() and then loading the same file again...Loop ingettable?

yes, print some of your code here and ill try to help ya out

@Anti QJ... Very good point....but still....:)


I got a Question myself...
How would you make your game "pause" if say.. Start was pressed? This has been puzzling me for a while now..

[PSPhakkor]

If you talking about my post (because I think you are) yes actually it will make a difference. Changing that last variable to false will play the song once or once everytime it is called. Trust me I made a app with a tuner in it.

I guess I worded it wrongly because I was talking about his problem of the music playing slowly and laggy.

And actually another possible problem that I just thought of is that if you have your Music.playfile in your while true loop, then it will play over and over without getting a chance to finish

[GuitarGod1134]

then he can put the music.playfile in a if statement.

[PSPhakkor]

yes, print some of your code here and ill try to help ya out

@Anti QJ... Very good point....but still....:)


I got a Question myself...
How would you make your game "pause" if say.. Start was pressed? This has been puzzling me for a while now..

if Controls.read:start() then
pausemenu()

I reccomend making the pause menu a whole different function because then this stops the rest of the game from playing. In that function, you can load and blit some images, a cursor, have some options (continue game, restart game, return to menu, etc.) . if you dont know how to go about doing this, I reccomend using a variable like this:

if pad:up() then x=x+1 end
if pad:down() then x=x-1 end

if x=1 then 
(code for cursor at position 1)
if pad:cross() then
(code for what to do it x is pressed when cursor is at position 1)
end
end

if x==2 then...

I also have a question of my own: How do I blit an image to the screen without disturbing whatever is already there, such as without the screen:clear()?

When I just do it without the screen:clear() then the screen flickers for some reason. But the new image does not flicker. Only the old one.

using screen:save(...) takes up too much time and it's impractical. So is there a better way to do it?

[ZeroMega]

Another question hehe

So I have the variable Player and Object. How can I make it so when the Player collides with the Object it does something? I tried EvilMana's tutorial on collision and it didn't work becuase it didn't use images. Here's the source.
http://shark-flash.com/ryan/lua.rar

Thanks :)

[SG57]

BlackShark - Here's a basic, complete Pong game, with pause menu Ive just wrote up, so you get an example.

(why am i being so generous? i havent wrote a pong game in ages...)

Player = {}
Player[1] = { x=10,y=86,score=0,image=Image.createEmpty(20,50) }
Player[2] = { x=450,y=86,score=0,image=Image.createEmpty(20,50) }

Ball = { x=235,y=131,xs=3,ys=3,image=Image.createEmpty(10,10) }

Player[1].image:clear(Color.new(0,0,255))
Player[2].image:clear(Color.new(0,255,0))
Ball.image:clear(Color.new(255,255,255))

paused = false
oldpad = Controls.read()

while true do
	screen:clear()
	pad = Controls.read()

	-- toggle pause screen on/off
	if pad:start() and oldpad:start() ~= pad:start() then paused = not paused end

	if paused then
		screen:fillRect(210,125,53,20,Color.new(255,255,255))
		screen:print(214,131,"Paused",Color.new(0,0,0))
		-- place other code here, for controls and whatnot...
	else -- game mechanics go here... for pong there simple as pi
		Ball.x = Ball.x + Ball.xs -- Ball.x += horizontal vector speed
		Ball.y = Ball.y + Ball.ys -- Ball.y += vertical vector speed

		if Ball.y < 0 then Ball.ys = 5
		elseif Ball.y + 10 > 272 then Ball.ys = -5 end
	
		if Ball.x <= 30 and Ball.y >= Player[1].y and Ball.y + 10 <= Player[1].y + 50 then Ball.xs = 5 end 
		if Ball.x+10 >= 450 and Ball.y >= Player[2].y and Ball.y + 10 <= Player[2].y + 50 then Ball.xs = -5 end 

		if Ball.x < 0 then
			Ball.xs = 5
			Player[2].score = Player[2].score + 1
		elseif Ball.x + 10 > 480 then
			Ball.xs = -5
			Player[1].score = Player[1].score + 1
		end

		if pad:up() and Player[1].y > 0 then Player[1].y = Player[1].y - 5
		elseif pad:down() and Player[1].y + 50 < 272 then Player[1].y = Player[1].y + 5 end

		if pad:triangle() and Player[2].y > 0 then Player[2].y = Player[2].y - 5
		elseif pad:cross() and Player[2].y + 50 < 272 then Player[2].y = Player[2].y + 5 end	
	end

	-- Main Drawing

	screen:blit(Ball.x,Ball.y,Ball.image)
	screen:blit(Player[1].x,Player[1].y,Player[1].image)
	screen:blit(Player[2].x,Player[2].y,Player[2].image)	

	screen:print(0,0, "Player 1's Score:  " .. Player[1].score .. "                   Player 2's Score:  " .. Player[2].score,Color.new(255,0,255))

	oldpad = pad
	screen.waitVblankStart() -- constant 60 FPS
	screen.flip()
end

Took ~8 minutes - [sarcasm]enjoy[/sarcasm]

ZOMG!!!! CAN I GET DEV STATUS NOW?!?
-= Double Post =-
Zero - EvilMana is gay. They are sooooo specific that all the code there teaches you is how to copy & paste... Try somethign like this:

http://forums.qj.net/f-psp-developme...xes-53916.html

I wrote that ages ago... And i demonstrated it using 2 printed label text things (aka - no images as you suggested)

[ZeroMega]

I wrote that ages ago... And i demonstrated it using 2 printed label text things (aka - no images as you suggested)

I actually meant collision with images XD

[SG57]

Ok, than simply provide the width/height parameters with the width and height of your iamges. Simply logic goes a long way...

[BlackShark]

BlackShark - Here's a basic, complete Pong game, with pause menu Ive just wrote up, so you get an example.

(why am i being so generous? i havent wrote a pong game in ages...)

Spoiler for code:

Player = {}
Player[1] = { x=10,y=86,score=0,image=Image.createEmpty(20,50) }
Player[2] = { x=450,y=86,score=0,image=Image.createEmpty(20,50) }

Ball = { x=235,y=131,xs=3,ys=3,image=Image.createEmpty(10,10) }

Player[1].image:clear(Color.new(0,0,255))
Player[2].image:clear(Color.new(0,255,0))
Ball.image:clear(Color.new(255,255,255))

paused = false
oldpad = Controls.read()

while true do
	screen:clear()
	pad = Controls.read()

	-- toggle pause screen on/off
	if pad:start() and oldpad:start() ~= pad:start() then paused = not paused end

	if paused then
		screen:fillRect(210,125,53,20,Color.new(255,255,255))
		screen:print(214,131,"Paused",Color.new(0,0,0))
		-- place other code here, for controls and whatnot...
	else -- game mechanics go here... for pong there simple as pi
		Ball.x = Ball.x + Ball.xs -- Ball.x += horizontal vector speed
		Ball.y = Ball.y + Ball.ys -- Ball.y += vertical vector speed

		if Ball.y < 0 then Ball.ys = 5
		elseif Ball.y + 10 > 272 then Ball.ys = -5 end
	
		if Ball.x <= 30 and Ball.y >= Player[1].y and Ball.y + 10 <= Player[1].y + 50 then Ball.xs = 5 end 
		if Ball.x+10 >= 450 and Ball.y >= Player[2].y and Ball.y + 10 <= Player[2].y + 50 then Ball.xs = -5 end 

		if Ball.x < 0 then
			Ball.xs = 5
			Player[2].score = Player[2].score + 1
		elseif Ball.x + 10 > 480 then
			Ball.xs = -5
			Player[1].score = Player[1].score + 1
		end

		if pad:up() and Player[1].y > 0 then Player[1].y = Player[1].y - 5
		elseif pad:down() and Player[1].y + 50 < 272 then Player[1].y = Player[1].y + 5 end

		if pad:triangle() and Player[2].y > 0 then Player[2].y = Player[2].y - 5
		elseif pad:cross() and Player[2].y + 50 < 272 then Player[2].y = Player[2].y + 5 end	
	end

	-- Main Drawing

	screen:blit(Ball.x,Ball.y,Ball.image)
	screen:blit(Player[1].x,Player[1].y,Player[1].image)
	screen:blit(Player[2].x,Player[2].y,Player[2].image)	

	screen:print(0,0, "Player 1's Score:  " .. Player[1].score .. "                   Player 2's Score:  " .. Player[2].score,Color.new(255,0,255))

	oldpad = pad
	screen.waitVblankStart() -- constant 60 FPS
	screen.flip()
end

Took ~8 minutes - [sarcasm]enjoy[/sarcasm]

ZOMG!!!! CAN I GET DEV STATUS NOW?!?
-= Double Post =-
Zero - EvilMana is gay. They are sooooo specific that all the code there teaches you is how to copy & paste... Try somethign like this:

http://forums.qj.net/f-psp-developme...xes-53916.html

I wrote that ages ago... And i demonstrated it using 2 printed label text things (aka - no images as you suggested)

Cool, thanks SG.

ZOMG!!!! CAN I GET DEV STATUS NOW?!?

What are you implying :/

[SG57]

That pong games shouldnt get someone a developer status, especially since there are 1 billion of them open source on the internet... What i just typed up and posted was a fully functional pong game... It has score and everything. Technically, it is a game - but the difficulty it took to make it was not worth a Developer title.

[BlackShark]

O Ok, i agree with that :), as My sig sais, Im trying to EARN dev status, and i don't think i should do it with PvP Pong :), again, thanks

[ZeroMega]

Ok, than simply provide the width/height parameters with the width and height of your iamges. Simply logic goes a long way...

The only problem is I don't know where in the world to put the code

[the undead]

The only problem is I don't know where in the world to put the code

post ur code and ill tell u

[ZeroMega]

post ur code and ill tell u

http://shark-flash.com/ryan/lua.rar

Usually if I see some things visually I get a basic understanding of it, just like when I was doing script in Flash.

[SG57]

I need to know WHAT you want to happen... But this is the just of it:

function TestCollsions()
     if Collision(Player[1].x,Player[1].y,playerWidth,playerHeight,object[1].x,object[1].y,objectWidth,objectHeight) then
             -- wahtever you want to happen when they  collide
end
end

Youll need to go get my function from the link i posted and paste it in your code, than you may use this...

Oh and note - to your main while true do loop, add somewhere i nthere 'TestCollisions()'

[ZeroMega]

Still not getting it lol

[GuitarGod1134]

I need to know WHAT you want to happen... But this is the just of it:

function TestCollsions()
     if Collision(Player[1].x,Player[1].y,playerWidth,playerHeight,object[1].x,object[1].y,object.width,object.height) then
             -- wahtever you want to happen when they  collide
end
end

Youll need to go get my function from the link i posted and paste it in your code, than you may use this...

Oh and note - to your main while true do loop, add somewhere i nthere 'TestCollisions()'

And you can put the word object in the parenthasees (spelling ) that way you dont have to rewrite the collision detection for say your player touching zombies and your player touching skeletons like this

function TestCollsions(object)
     if Collision(Player[1].x,Player[1].y,playerWidth,playerHeight,object[1].x,object[1].y,object.width,object.height) then
             -- wahtever you want to happen when they  collide
end
end

now when you call your function
[code]
while true do
screen:clear()
TestCollisions(zombies)
TestCOllisions(skeletons) --see no more object, putting those thier replaces all objects with zombies and skeletons. also remember to declare playerWidth, playerHeight, objectWidth, objectHeight as they are variables not functions so they need values assigned to them. To obtain this you can either open up paint and find thier height and stuff or use skeleton:height() or skeleton:height() but the variable skeleton must be the image being loaded not your coordinates, for coordinates i usually just add a c ie skeletonc.x yata yata.

[BlackShark]

Damn, SG, for some reason its not working for mine, heres part of the code..

Spoiler for code:

--***Main Game Loop***
while true do
screen:clear()
pad = Controls.read()

if pad:start() and oldpad:start() ~= pad:start() and paused == false then paused = true end
if pad:start() and oldpad:start() ~= pad:start() and paused == true then paused = false end

if paused == true then
screen:fillRect(210,125,5 3,20,Color.new(255,255,25 5))
screenrint(214,131,"Paused", red)
elseif paused == false then
rnumber = math.random(1,10)
gamestime=gametimer:time( )


ammunition() --Calls for the Ammo configurations--
screen:blit(100, 0, background1)
screen:blit(0, 0, hud)
mugShot()
playerimg:blit(player.x, player.y, 30)
screenrint(375, 10, "Fighter Name", white)
screenrint(380, 25, ""..user, red)
screenrint(408, 130, "Score:"..score, white)
screenrint(413, 100, "High", red)
screenrint(408, 110, "Score:"..tscore, red)
screenrint(5, 150, "Ammo:"..ammo, white)
screenrint(45, 255, chargebar.number.."%", red)
healthBar()
shootbarS()
chargeShot()
screen:fontPrint(proporti onal, 220, 25, time, red)
--Shoots gun
if pad:r() and oldpad:r() ~= pad:r() and shootbar.number == 50 and player.State == "alive" then
shootbar.number = 0
firelay()
bulletSetup()
end



if player.State == "dead" then
pex:blit(player.x -30, player.y - 30, 100)
boomlay()
end
if pex:getFrame() == 4 then
screen.waitVblankStart(75 )
dofile("menu.lua")
end
highScore()
collisionCheck(enemy1hit)
collisionCheck2(enemy2hit )
collisionCheck3(enemy3hit )
collisionCheckp(playerhit )
enemy1AI()
enemy2AI()
enemy3AI()
EBFire()
EB2Fire()
EB3Fire()
bulletFire()
screen:flip()
pmove()

--Game timer countdown
if gamestime>1000 then time=time - 1 gametimer:reset(0) gametimer:start() end

if time < 0 and score < tscore then
screen:clear()
screenrint(100, 100, user.."'s Score Was:"..score, white)
screen:flip()
screen.waitVblankStart(20 0)
dofile("menu.lua")
elseif time < 0 and score > tscore then
tscore = score
file = io.open("tscore.txt","w")
myText = score
file:write(myText)
file:close()

file = io.open("tuser.txt","w")
myText = user
file:write(myText)
file:close()
screen:clear()
newhilay()
screenrint(100, 100, user.."'s Score Was:"..score, white)
screenrint(100, 110, "A NEW hight score!!!", red)
screen:flip()
screen.waitVblankStart(20 0)
dofile("menu.lua")
end

--This is for Music on/off feature
if pad:triangle() and oldpad:triangle() ~= pad:triangle() and Music.playing() == true then
Music.pause()
end
if pad:circle() and oldpad:circle() ~= pad:circle() and Music.playing() == false then
Music.resume()
end

screen.waitVblankStart()
oldpad = pad
end
end

I also have

paused = false

defined above the main loop, still no luck, any suggestions....

[SG57]

Uh, ya... Optimize your code in 3 ways...

1. Use the pause menu toggling method i did in my little game

-- globally state this in your while true do loop
if pad:start() and pad:start() ~= oldpad:start() then paused = not paused end

2. Indent your code so it's actually understandable without mind boggling mental indentation (if you actually want me to give you an answer tonight, than do this first)
3. Inline some of your code for optimization (above code snippet is inlined the pause toggling), and optimize things here and there such as this:

if paused then
     screen:print(0,0,"Right now the game is Paused")
else
     screen:print(0,0,"Right now the game is NOT Paused")
end

Right now your using unneeded arguments in some if statements. By optimizing them like above, you save in file size (and processign time as welll, as the interpreter doesnt need to read in as much data) so in the end its a good habit all around.

[BlackShark]

I tried it that way, No luck thats why i change it, i just tryed that way again, still no luck.

[Blake1]

I've finished my Pong game! Thanks to everyone for their help.

Next: Breakout!

[eldiablov]

Hey peeps just a quick question. Say if i wanted my player to rotate on a left angle when the left pad was pressed how would i code this? I've never used angles.

[yaustar]

Are you intending to rotate the image?

[eldiablov]

Yes that's what i had in mind

[yaustar]

Then you need to use the GU or vector graphics as any other method will be too slow to use in real time gameplay unless you have strips of your character walking in every direction.

[eldiablov]

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

[BlackShark]

I've finished my Pong game! Thanks to everyone for their help.

Next: Breakout!

Nice if you need any help send me a PM or something :P

[xtreme0915]

i am just getting into coding LUA and am finding myself confused. i am just learning so im trying to keep it simple but i need help. i am trying to display text that says "Bricking" for one second and have that replaced by text that says "Bricking." and "Bricking.." then "Bricking..." and then repeat itself but i cant figure out how, can someone help?

[BlackShark]

mmm, ya know..I already made a prank bricker :) (look in my sig)

[xtreme0915]

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?