Need Help- ball won't stay on scroll bar

[The_Triangle]

i been trying forever to make this ball bounce off of the paddle (its not pong, but something like it) and its just not happening.

i tried to make that if the ball_x is equal to the scroll's x, the ball_y would remain on the same y cordinate as the scrolls y.

New Code:

code:

View.Set ("graphics:max,max,offscreenonly") %-------------------------------------- ball ------------------------------------------- proc ball (var x, y, mx, my, mb, loadBall, size : int)     colourback (black)     cls     var speed : int := 10     %Pic.Draw (loadBall, mx - 7, 74, picCopy)     drawfillbox (mx - 45, 74, 1000, 100, black)     % erases first ball     y -= 2         % gravity     drawfilloval (mx + 30, y, size, size, brightblue)     mousewhere (mx, my, mb)     % click3 to bounce ball off the scrollbar(paddle)     if mb = 1 then         y += speed         %Pic.Draw (loadBall, mx - 7, y, picCopy)     end if end ball %-------------------------------------- moveScroll ----------------------------------------- proc moveScroll (mx, scroll : int)     drawfillbox (mx + 21, 20, maxx, 80, black)           % old drawBox scroll     drawfillbox (mx, 20, -20, 80, black)     drawfillbox (mx, 20, mx + 70, 80, blue) end moveScroll %-------------------------------------- collisionDetect ------------------------------------ proc collisionDetect (y, font1 : int)     if y <= 1 then         Font.Draw ("You Lose", 250, 200, font1, black)     end if end collisionDetect %-------------------------------------- Mainline ------------------------------------------- var x, y : int := 100 var size : int := 10 var mx, my, mb : int var scroll : int := Pic.FileNew ("scroll.JPG") var loadBall : int := Pic.FileNew ("ball.JPG") var font1 : int := Font.New ("verdana:50:bold") loop     mousewhere (mx, my, mb)     ball (x, y, mx, my, mb, loadBall, size)     moveScroll (mx, scroll)     collisionDetect (y, font1)     delay (10)     View.Update end loop

[MysticVegeta]

Please post the necessary images and zip it please. Thank you.

[Cervantes]

Think about storing the velocity of the ball in variables.

ball_x
ball_y
ball_vx
ball_vy

That way, you can use a little Collision Detection to check if the ball has hit the paddle. If it has, you reverse the velocity that is perpendicular to the plane of the paddle. In other words, if the paddle moves from left to right and the ball hits the top of it, reverse its y velocity.

[The_Triangle]

Cervantes wrote:

Think about storing the velocity of the ball in variables.

ball_x
ball_y
ball_vx
ball_vy

That way, you can use a little Collision Detection to check if the ball has hit the paddle. If it has, you reverse the velocity that is perpendicular to the plane of the paddle. In other words, if the paddle moves from left to right and the ball hits the top of it, reverse its y velocity.

that would help if i knew what velocity was...

[The_Triangle]

MysticVegeta wrote:

Please post the necessary images and zip it please. Thank you.

I'll re-edit the code , so that there are no pictures

[[Gandalf]]

Please don't double post.

Velocity is just speed with direction. So if you had a speed of 10km/h then an equal velocity could be 10km/h east. Translating this to more programmable terms, you have an x velocity and a y velocity. Now, each of those has a direction, so it can be either + or -.

Lets say your ball hits the paddle going vy=0 and vx=4, then once it hits the paddle vx=vx*-1 or vx=-4.

[The_Triangle]

[Gandalf] wrote:

Please don't double post.

Velocity is just speed with direction. So if you had a speed of 10km/h then an equal velocity could be 10km/h east. Translating this to more programmable terms, you have an x velocity and a y velocity. Now, each of those has a direction, so it can be either + or -.

Lets say your ball hits the paddle going vy=0 and vx=4, then once it hits the paddle vx=vx*-1 or vx=-4.

Ok, say I use ball_vx and ball_vy.

What use would I have for my ball_x and my ball_y variables ?

[Cervantes]

You would add the x velocity to the x position and the y velocity to the y position, each time though the loop:

code:

loop    x := x + vx   %Note this could be rewritten as x += vx    y += vy    %other things end loop

[Albrecd]

Right now, your only collision detection is that if the ball hits the bottom of the screen then it puts "you lose." You need another procedure or proc or whatever you want to use (procedure would be the best) to determine if the ball has hit the paddle.

Ex:

code:

if x_ball >= x_paddle and x_ball <= x_paddle + paddlewidth any y_ball = y_Paddle then %put whatever you want to happen next here.

Also, you should probably not have x_ball be equal to x_paddle (which it currently is) or you can't lose.

[Albrecd]

Sorry, that "any" in the code is supposed to be "and." I would have edited it but for some reason It won't give me that option sorry

[do_pete]

or you could go

code:

function Hit:boolean      if Ball_X>=Paddle_X and Ball_X<=Paddle_X+Paddle_Width and           Ball_Y<=Paddle_Y+PaddleWidth then                result true      end if end Hit