Pong Paddle Movement in Java

It takes ProgrammingForums.org days to respond to anything, so I'll just post this here.

I'm working on a Pong game for my portfolio right now in Java, and I'm just having a slight problem with the Pong paddle movement. Obviously, I don't want the paddles moving off-screen, so I'm trying to make it so when it reaches a certain point on its Y-axis, it will not move any farther. I've gotten it to work for the top of the screen, but not the bottom, and I can't figure out why. The conditional I'm using SHOULD work, but it will just move right off the bottom of the screen if I go far enough. Here's the conditionals for each paddle's movement. If you need more of my code, just ask.


// Check for Left Paddle movement.
if( ( wKey ) && ( paddle_left.getY() >= ( paddle_speed * 2 ) ) ) paddle_left.setY( paddle_left.getY() - paddle_speed );
else if( ( sKey ) && ( paddle_left.getY() <= ( boardHeight - 10 ) ) ) paddle_left.setY( paddle_left.getY() + paddle_speed );
    
// Check for Right Paddle movement.
if( ( upKey ) && ( paddle_right.getY() >= ( paddle_speed * 2 ) ) ) paddle_right.setY( paddle_right.getY() - paddle_speed );
else if( ( downKey ) && ( paddle_right.getY() <= ( boardHeight - 10 ) ) ) paddle_right.setY( paddle_right.getY() + paddle_speed );


The variable "paddle_speed" is a constant equal to 5. Also, boardHeight is the height of the screen on which everything is drawn, which is equal to 480.

Also, this isn't as important, but I've noticed a slight delay from when I start to hold down the key to when the paddle starts moving. I know it's because of the initial key press delay set on the user's computer, but how can I compensate for this?

boardHeight is wrong?

as for the delay, it depends on the kind of notifications you're getting, if you were polling the keyboard matrix then this problem doesn't exist

What do you mean "boardHeight" is wrong? It's the same value I used when I used setSize() on the JFrame.

Also, what does "polling the keyboard matrix" mean?

Post it in Stack Overflow.

So, it seems that 10 the paddle length (I don't know why you use speed*2 for setting the upper limit while you use 10 directly for the downward one).

For what i can see, the error may be that the Y you use for the paddle is the coordinate of the top part. If it is so, you have that you can go up until the top part has y=10 (so it stops right at the top), while if you press down when y=470 the paddle goes to y=475, which means that half of it goes offscreen.

If it is not that, check you haven't misassigned the coordinates (confused X with Y?).

It's not going off-screen by a little bit. It continues to move off-screen until it's not longer visible. Also, it moves up by 5 per tick, not 10. I did 10 so that it will stop just 5 pixels short of the edge of the screen.

And no, I haven't confused X and Y...

Eh, if there isn't any problem with coordinates assignments I can't figure it out, sorry, hope someone else will be more helpful.

>>6
Haven't you ever been subjected to the "drawing triangles" or "drawing simple geomtric patterns" with a combination of asterisks and spaces exercises in any programming class?

Well, StackOverflow was certainly helpful, and I feel like an idiot for not seeing this before. I neglected to take the size of the paddle into account, considering the origin point that it is checking for collision with is at the top of the paddle.

>>10
No one knows this because you didn't post any kind of complete working code. I hate to tell you this, but some of us can't read the mind of an idiot. Now go away. You suck.

>>9

6 here.
No, why you asked? Anyway the problem was the one i said, maybe i explained it badly, sorry.

>>11

I said that I would post the rest of the code if asked. Nobody asked. Fuck off.

>>13
Usually most people would post some complete working code the first time around instead of posting "relevant" code snippets. I believe this is what as known as being clear and concise.

Perhaps you should take a break from your shit programming, and insted, take a class on basic english composition.

insted

Fuck off.
Inviting to being helped.

I neglected to take the size of the paddle into account
laughing_gabe_newells.jpg

>>16
polecat kebabs

>>17
Fuck off, ``faggot''.

>>10
That is what >>6 said you fucking moron!

>>19
Go scrub another toilet princess.

>>22
nice dubs bro

>>21
thanks man

pseudo-code  (dont know java)

if(paddle.y >= 480)
{
 paddle.y = 480; //same for other positions
}

also the "delay" with movement after an keypress is because of as you already said.. windows...
you can however avoid this by doing something like this

function "your key down handler"
{
  speedY = 5;
}

function Update()
{
   paddle.y += speedY;
}

pleasure to help you

>>23
Go away. Go far far away. And then, don't come back you fucking moron.

I can highly suggest using Min and Max function to make sure you don't go out of bounds