[SOLVED] Help in Pong Physics

[xx6heartless6xx]

I want to make a Pong game, but I have no idea how to make the gravity in the game that pulls the ball towards the floor and sends it flying in different directions when it is hit.

Can you guys point me to a good site or can you guys just start me off and I'll take it from there.

[davidthefat]

I want to make a Pong game, but I have no idea how to make the gravity in the game that pulls the ball towards the floor and sends it flying in different directions when it is hit.

Can you guys point me to a good site or can you guys just start me off and I'll take it from there.

http://en.wikipedia.org/wiki/Kinematics

[xx6heartless6xx]

I want to make a Pong game, but I have no idea how to make the gravity in the game that pulls the ball towards the floor and sends it flying in different directions when it is hit.

Can you guys point me to a good site or can you guys just start me off and I'll take it from there.

http://en.wikipedia.org/wiki/Kinematics

How can I apply these equations into a program?

[k1net1k]

there are loads of pong examples for all programming languages.
just google "Pong tutorial <my language>"
i mean seriously, have you even looked ?

[dandymcgee]

There's not really any gravity in pong. If it hits the top or bottom of the screen reverse the y velocity, if it hits a paddle reverse the x velocity.

Each frame update the position based on the current velocity:

Code: Select all

//Update position
ball.position.x = ball.position.x + ball.velocity.x;
ball.position.y = ball.position.y + ball.velocity.y;

[Ginto8]

if it hits a paddle reverse the x velocity.

Actually, it also changes the y velocity. It goes bouncing off at an angle that's determined by where on the paddle it hits. What you might want to do is make the ball move along the vector from the center of the paddle to the center of the ball. It should be a fairly realistic representation, while still being very easy to make.

[xx6heartless6xx]

if it hits a paddle reverse the x velocity.

Actually, it also changes the y velocity. It goes bouncing off at an angle that's determined by where on the paddle it hits. What you might want to do is make the ball move along the vector from the center of the paddle to the center of the ball. It should be a fairly realistic representation, while still being very easy to make.

Making the ball go in a reverse direction makes some sense. How would I make the ball move along a vector? You say its still very easy to make but can you explain some more?

[Ginto8]

well, if you have the (x,y) coordinates of the ball's center, and the (x,y) coordinates of the paddle's center, then

Code: Select all

xvel = ball.x - paddle.x;
yvel = ball.y - paddle.y

if you want to increase the speed, follow this algorithm:

Code: Select all

float mag = sqrt(xvel*xvel+yvel*yvel); // get the vector's magnitude
// next two lines normalize the vector (give it a length of 1)
xvel /= mag;
yvel /= mag;
// Now, scale the vector to the "speed" you want
xvel *= speed;
yvel *= speed;

[xx6heartless6xx]

well, if you have the (x,y) coordinates of the ball's center, and the (x,y) coordinates of the paddle's center, then

Code: Select all

xvel = ball.x - paddle.x;
yvel = ball.y - paddle.y

if you want to increase the speed, follow this algorithm:

Code: Select all

float mag = sqrt(xvel*xvel+yvel*yvel); // get the vector's magnitude
// next two lines normalize the vector (give it a length of 1)
xvel /= mag;
yvel /= mag;
// Now, scale the vector to the "speed" you want
xvel *= speed;
yvel *= speed;

Thanks man, I'll definitely try this out.

[dandymcgee]

if it hits a paddle reverse the x velocity.

Actually, it also changes the y velocity. It goes bouncing off at an angle that's determined by where on the paddle it hits. What you might want to do is make the ball move along the vector from the center of the paddle to the center of the ball. It should be a fairly realistic representation, while still being very easy to make.

Oh right, pong doesn't use real physics. :P