pong help plz :(

[FakeSound]

My friend and i are making a game of pong; just a simple game for extra marks in our programming class.
However, we're facing a few problems right now...
a] i can't get the paddles to stay in the screen (I need to set boundaries, but don't know how)
b] the ball doesn't bounce off the paddles (We're not very experienced using whatdotcolor or collision)
so ... i'll post my code right here, any help is greatly appreciated.

code:

setscreen ("graphics:630;420, Title: Pong?") var x, y, x1, y1, a, b, a1, b1,oy,ox,os: int var chars : array char of boolean var nx,ny:int:=1 % changes direction of ball and checks boundries colorback (255) x := 10 y := 10 x1 := 20 y1 := 100 a := 10 b := 10 a1 := 20 b1 := 100 oy:=200 ox:=170 os:=10 ox := Rand.Int (10, 100) %set the x quadrant for the 1st oval oy := Rand.Int (10, 100) %set the y quadrant for the 1st oval loop             /* omit if ox <= 0 then %check to see if it goes off to the left         nx := +1 %chages the direction */     if oy <= 0 then %check to see if it goes off the top         ny := +1 %chages the direction     end if     /* omitif ox >= maxx then %check to see if it goes off to the right         nx := - 1 %chages the direction */     if oy >= maxy then %check to see if it goes off the bottom         ny := - 1 %chages the direction     end if             if ox <= a then         nx := +1     elsif oy <= b then         nx:= +1         end if     Input.KeyDown (chars)         if chars ('w') then         y := y + 5         y1 := y1 + 5     end if     if chars ('s') then         y := y - 5         y1 := y1 - 5     end if     drawfillbox (x, y, x1, y1, brightgreen)     drawfillbox (a + 600, b, a1 + 600, b1, brightred)     drawfilloval (ox,oy,os,os,brightblue)     delay (10)     cls     Input.KeyDown (chars)     if chars (KEY_UP_ARROW) then         b := b + 5         b1 := b1 + 5     end if     if chars (KEY_DOWN_ARROW) then         b := b - 5         b1 := b1 - 5     end if     ox += nx     oy += ny   end loop

[Clayton]

hello welcome to compsci, plz dont post "I need help" or "help plz" as we know you need help, thats why you posted here (in a perfect world), now on to your problem, for the use of whatdotcolor (aka View.WhatDotColor) all you are doing is checking to see if a pixel is a color right? and if your ball has a radius, the best place to check for a collision is on the edge of the ball right? so do something like this

Turing:

if View.WhatDotColor(x,y)=black then     bounce backwards end if

its as simple as that, if you are having any problems with anything check out the Turing Walkthrough good luck on the project!!

[FakeSound]

I just tried inputting that, it didn't work
Sorry for posting the 'help plz' . .
ummm ... yeah, that didn't work ... if it means anything, i'm using version 4.0.3
but when i tried using that, it said that bounce needs to be declared ... i just can't seem to make the ball bounce off of the paddles. I can get the ball to bouncce off of the walls, that's no problem; however, gettting the paddles to stay within bounds is another thing i can't figure out ... i know this is pretty much a repost of my first post, but .. uhhh... i've clarified as much as i can, sorry

ps its making me kinda mad

[Cervantes]

1. 
   

   code:

   if paddle.y < 0 then     paddle.y := 0 elsif paddle.y > maxy - paddle.height then     paddle.y := maxy - paddle.height end if

   
   Or more simply,
   

   code:

   paddle.y := min (max (paddle.y, 0), maxy - paddle.height)

   
   
2. 
   In pseudocode (note that this code will not run, and the same is true for the pseudocode SuperFreak82 gave you that had "bounce backwards" in it)
   

   code:

   If there is a collision between the ball and either paddle then     reverse ball's horizontal velocity end

   
   In Turing,
   

   code:

   if ball.x - ball.radius < paddle.x + paddle.width and ball.x + ball.radius > paddle.x and ball.y - ball.radius < paddle.y + paddle.height and ball.y + ball.radius > paddle.y then     ball.vx *= -1  % Multiply the ball's horizontal velocity by -1 and reassign that value to itself end if

   
   

[wtd]

Cervantes wrote:

code:

if ball.x - ball.radius < paddle.x + paddle.width and ball.x + ball.radius > paddle.x and ball.y - ball.radius < paddle.y + paddle.height and ball.y + ball.radius > paddle.y then     ball.vx *= -1  % Multiply the ball's horizontal velocity by -1 and reassign that value to itself end if

That condition so very much needs to be factored out into a function.