Lua Programming Help Thread

[Anti-QuickJay]

I cant get it to work inside homebrew games...

[SG57]

Hmm... Maybe ask around or something? Do you not have a webcam or something?

[BlackShark]

well Shrooms pretty much covered it, it first explodes with white pixels/particles then again with color, it goes out from the center and disappears after going so far, it kind of looks like a star field except the particles don't get bigger as they move out. Thats about it, looks like they do what there supposed to do. Hope this helps

[SG57]

Im an idiot... Damn opaque values got mixed up in my head... Anywho... Someone tell me what they think of this. this version should fade away the particles, as well as have some take longer, and some shorter, to fade away. Now... I just need to do that color scheme method where if 2 particles are on eachother, the color on the screen turns more white...

--[[
     Lua Particle Demo
         By: SG57


     No more than an
      eye looker...
        For now ;)
]]
math.randomseed(os.time( ))
num_particles = 499 -- # of particles to have on screen
particle = {}

for i=0,num_particles do  -- constructs each particle with default values
       particle[i] = { x=240,y=136,                   -- x and y coordinates
                       xspeed,yspeed,                -- speed on x and y planes
                       color=Color.new(255,255,255), -- color of particle
                       life=255,                       -- life determines color ^
                       angle=math.random(360),       -- random angle for particle movement
                       speed=10,                      -- particle speed
                       fade_speed=40,  -- fading speed of particle
                       r=255,g=255,b=255             -- so color can be changed
                     }
       particle[i].xspeed = math.sin(particle[i].angle) * particle[i].speed -- set x axis vector speed
       particle[i].yspeed = math.cos(particle[i].angle) * particle[i].speed -- set y axis vector speed
end

while true do
   screen:clear()
   for i=0,num_particles do
       particle[i].xspeed = math.sin(particle[i].angle) * particle[i].speed -- set x axis vector speed
       particle[i].yspeed = math.cos(particle[i].angle) * particle[i].speed -- set y axis vector speed

       particle[i].x = particle[i].x + particle[i].xspeed -- Vector speeds
       particle[i].y = particle[i].y + particle[i].yspeed -- ^

       particle[i].color = Color.new(particle[i].r,particle[i].g,particle[i].b,particle[i].life)

       if particle[i].life <= 0 then
            particle[i].r=math.random(255)
            particle[i].g=math.random(255)
            particle[i].b=math.random(255)
            particle[i].life = 255
            particle[i].speed=math.random(3,5)
            particle[i].fade_speed=math.random(15,50)
            particle[i].x = 240
            particle[i].y = 136
            particle[i].angle=math.random(360)
       end

       particle[i].life = particle[i].life - particle[i].fade_speed

       screen:fillRect(particle[i].x,particle[i].y,2,2,particle[i].color)
   end

   screen.waitVblankStart()
   screen.flip()
end

[BlackShark]

Just tested it, the particles still don't fade, But they do disappear at different times/places, however most of them disappear before the last usual point, (over all, the entire particle smoke/explosion is smaller)...I'm going to try to rig up some screen shotter so you can at least take a look.

EDIT:, ok, I got a Screen..

Probably doesn't help as much as actuelly watching it, but I hope it helps

[eyece]

nice SG57.

[BlackShark]

Thats it :)
hey eyece, do you mind if I ask how you got that?

[yaustar]

I take a look at it when I get some time tonight but you looking for these type of particle effects?

http://www.youtube.com/watch?v=gh5RzfDU_ew

The reason for the ring like explosion at the beginning is because of this line

fade_speed=40,  -- fading speed of particle

This should be random between 15 and 50.

[HeaD_ShOt]

my ai isnt moving...

math.randomseed(os.time() )

Player = { x = 205, y = 120, img = earth}

ufo1 = { x = 0, y = 120, img = ufo }

function chasePlayer()
stallchase = math.random(2)
if stallchase == 1 then
if ufo1.x > 205 then
ufo1.x = ufo1.x - 2
elseif ufo1.x < ufo1.x then
ufo1.x = ufo1.x + 2
end
end
stallchase = math.random(2)
if stallchase == 1 then
if ufo1.y > ufo1.y then
ufo1.y = ufo1.y - 2
elseif ufo1.y < 120 then
ufo1.y = ufo1.y + 2
end
end
end

thank you for ur help

[eyece]

Thats it
hey eyece, do you mind if I ask how you got that?

I put a screen:save() after screen.flip() and put all the frames into a gif.

@head shot, how is "elseif ufo1.x < ufo1.x then" meant to work?, don't you mean player x?.

[BlackShark]

mm, i don't think your using that math random right...

math.randomseed(os.time() )

Player = { x = 205, y = 120, img = earth}

ufo1 = { x = 0, y = 120, img = ufo }

function chasePlayer()

if math.random(1,2) == 1 then
if ufo1.x > 205 then
ufo1.x = ufo1.x - 2
elseif ufo1.x < ufo1.x then
ufo1.x = ufo1.x + 2
end
if ufo1.y > ufo1.y then
ufo1.y = ufo1.y - 2
elseif ufo1.y < 120 then
ufo1.y = ufo1.y + 2 end
end
end
end

Give that a try, not sure if it works, but its worth a try, ( I eliminated the stall variable itself cuz you didn't really need it in that code, but you can always add it in again if you'd like. What I did with the math.random is ever loop it will come up with, either a 1 or a 2, if it comes up as a 1, your if statements will come into play, Hope this helps
-= Double Post =-

I put a screen:save() after screen.flip() and put all the frames into a gif.

ahh, cool, how did you get it to save as different names?

[eyece]

ahh, cool, how did you get it to save as different names?

i put

imgc = 0

above the while loop and

if Controls.read():start() then break end
   screen:save("screen"..imgc..".png")
   imgc = imgc + 1

below the flip.

[BlackShark]

ah, i see, cool, Thanks :)

[HeaD_ShOt]

still not moving...

[Anti-QuickJay]

In your main loop add

chasePlayer()

This calls the chase player function

[HeaD_ShOt]

i know that
obviously i have that in my main loop

[Anti-QuickJay]

Then post your whole code, It will really help.

[HeaD_ShOt]

--game
--by HeaD_ShOt
System.usbDiskModeActivat e()

bg = Image.load("space.png")
Bullet = Image.load("bullet.png")
ufo = Image.load("ufo.png")
s1 = Image.load("satelite1.png ")
s2 = Image.load("satelite2.png ")
s3 = Image.load("satelite3.png ")
s4 = Image.load("satelite4.png ")
earth = Image.load("earth.png")
dofile("ai.lua")
dofile("bullet.lua")

function collisionCheck()
if ufo1.x == 190 then
Player.x = 205
Player.y = 120
ufo1.x = 0
ufo1.y = 120
player.health = player.health - 10
end
end

black = Color.new(0,0,0)
green = Color.new(0,255,0)
white = Color.new(255,255,255)
red = Color.new(255,0,0)

healthbar = {}
healthbar.y = 10

player = {}
player.health = 100

current = 1
oldpad = Controls.read()
while true do
pad = Controls.read()
screen:clear()

screen:blit(0,0,bg)
screen:fillRect(10,10,100 ,10,white)
screen:fillRect(10,10,pla yer.health,healthbar.y,re d)
screenrint(10,30,player.health, white)
chasePlayer()
screen:blit(ufo1.x,ufo1.y ,ufo1.img)
screen:blit(205,100,earth )

if pad:start() then
break
end
if pad:left() then
current = 1
end
if pad:right() then
current = 2
end
if pad:up() then
current = 3
end
if pad:down() then
current = 4
end
if pad:circle() and player.health < 100 then
player.health = player.health + 0.5
end

if pad:square() and player.health > 0 then
player.health = player.health - 0.5 end

collisionCheck()

if current == 1 then
screen:blit(180,128,s1)
end
if current == 2 then
screen:blit(285,128,s2)
end
if current == 3 then
screen:blit(230,70,s3)
end
if current == 4 then
screen:blit(230,180,s4)
end

if current == 1 then
if pad:cross() and oldpad:cross() ~= pad:cross() then
bulletSetup()
end
end

chasePlayer()
bulletFire()

screen.waitVblankStart()
screen.flip()
oldpad = pad
end

math.randomseed(os.time() )

Player = { x = 205, y = 120, img = earth}

ufo1 = { x = 0, y = 120, img = ufo }

function chasePlayer()
if math.random(1,2) == 1 then
if ufo1.x > 205 then
ufo1.x = ufo1.x - 2
elseif ufo1.x < ufo1.x then
ufo1.x = ufo1.x + 2
end
end
if ufo1.y > ufo1.y then
ufo1.y = ufo1.y - 2
elseif ufo1.y < 120 then
ufo1.y = ufo1.y + 2 end
end

there it is

[Anti-QuickJay]

Ok, Before i start seeing what your problem is, Why is your AI in another file? You dont need a dofile for that.

[SG57]

yaustar - I know why the explosion is at the start, andsince people complemented it, i kept it in.

Ill taek a look at that vid right now - and what im looking for is basiclly:

if particle[i].x == particle[j].x and particle[i].y == particle[j].y and i~=j then particle color.g += 3 else particle color.g -= 3 end

The j would be a for loops incrementing variable, and would be right inside the first for loop.... That SHOULD make it turn more greenish, if 2 particles or more over lap... STill needs work i know.

[HeaD_ShOt]

--game
--by HeaD_ShOt
System.usbDiskModeActivat e()

bg = Image.load("space.png")
Bullet = Image.load("bullet.png")
ufo = Image.load("ufo.png")
s1 = Image.load("satelite1.png ")
s2 = Image.load("satelite2.png ")
s3 = Image.load("satelite3.png ")
s4 = Image.load("satelite4.png ")
earth = Image.load("earth.png")
dofile("bullet.lua")

math.randomseed(os.time() )

Player = { x = 205, y = 120, img = earth}

ufo1 = { x = 0, y = 120, img = ufo }

function chasePlayer()
if math.random(1,2) == 1 then
if ufo1.x > 205 then
ufo1.x = ufo1.x - 2
elseif ufo1.x < ufo1.x then
ufo1.x = ufo1.x + 2
end
end
if ufo1.y > ufo1.y then
ufo1.y = ufo1.y - 2
elseif ufo1.y < 120 then
ufo1.y = ufo1.y + 2 end
end

function collisionCheck()
if ufo1.x == 190 then
Player.x = 205
Player.y = 120
ufo1.x = 0
ufo1.y = 120
player.health = player.health - 10
end
end

black = Color.new(0,0,0)
green = Color.new(0,255,0)
white = Color.new(255,255,255)
red = Color.new(255,0,0)

healthbar = {}
healthbar.y = 10

player = {}
player.health = 100

current = 1
oldpad = Controls.read()
while true do
pad = Controls.read()
screen:clear()

screen:blit(0,0,bg)
screen:fillRect(10,10,100 ,10,white)
screen:fillRect(10,10,pla yer.health,healthbar.y,re d)
screenrint(10,30,player.health, white)
chasePlayer()
screen:blit(ufo1.x,ufo1.y ,ufo1.img)
screen:blit(205,100,earth )

if pad:start() then
break
end
if pad:left() then
current = 1
end
if pad:right() then
current = 2
end
if pad:up() then
current = 3
end
if pad:down() then
current = 4
end
if pad:circle() and player.health < 100 then
player.health = player.health + 0.5
end

if pad:square() and player.health > 0 then
player.health = player.health - 0.5 end

collisionCheck()

if current == 1 then
screen:blit(180,128,s1)
end
if current == 2 then
screen:blit(285,128,s2)
end
if current == 3 then
screen:blit(230,70,s3)
end
if current == 4 then
screen:blit(230,180,s4)
end

if current == 1 then
if pad:cross() and oldpad:cross() ~= pad:cross() then
bulletSetup()
end
end

chasePlayer()
bulletFire()

screen.waitVblankStart()
screen.flip()
oldpad = pad
end

there u go

[SG57]

Wow... this is a sight to be hold ;) Lua Help Thread without an unanswered question :)

[EminentJonFrost]

quite beautiful isnt it SG?

[eyece]

it's almost like a little community up in this thread

[Anti-QuickJay]

Loading an image from memory, Is this a good idea? I know it involves more code but does it improve anything to your game? Or does it just take up memory?

jpegFile = io.open("anim0.jpg", "rb")
   data = jpegFile:read("*a")
jpegFile:close()
image = Image.loadFromMemory(data)

[myschoo]

ive seen this on wiki.ps2dev too... anyone can answer?

[SG57]

This would be good, im guessing, if you wanted to reload an image. It should be muuuuch faster than loading from memory stick.

[TacticalPenguin]

But when you set an image to nil it drops from memory.

[SG57]

Why would you free than load an image? Im sure you can load an image into another one....

image = Image.load("blah.png")

image = Image.load("blah2.png")

while true do
     screen:blit(0,0,image)
     screen.waitVblankStart()
     screen.flip()
end

Im too lazy to test that out.

[EminentJonFrost]

faster maybe...but how many images would you need so that a noticable difference in speed occurs?
-= Double Post =-

Why would you free than load an image? Im sure you can load an image into another one....

image = Image.load("blah.png")

image = Image.load("blah2.png")

while true do
     screen:blit(0,0,image)
     screen.waitVblankStart()
     screen.flip()
end

Im too lazy to test that out.

lol
like that, its like you never loaded "blah.png" at all. but i'm sure you know that. :)