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collision example (Read 633 times)

algo

collision example
Nov 14^th, 2006, 4:28pm

hi

sorry for following simple question, i'm sure there is an easy solution!

in the collision example:

http://processing.org/learning/examples/collision.html

i would like to increase the speed of the ball, i did this here:

Code:

ball_x += ball_dir * 10.0; // change here
  ball_y += dy;
  if(ball_x > width+ball_size) {
    ball_x = -width/2 - ball_size;
    ball_y = random(0, height);
    dy = 0;
  }

but now the ball doesn't collide with the paddle or walls. what am i doing wrong?

thanks

matthew.thompson

Re: collision example
Reply #1 - Nov 18^th, 2006, 3:35pm

It seems that by changing the constant to 10.0, the steps the ball takes in figuring out if it hit the paddle each draw cycle are too large. The paddle itself is only 5px wide

Consider: if the ball is at px=300, and paddle is from 303 to 308, for example, the ball will simply seem to pass through the paddle, as it's next position is 310, which isn't on the paddle, so the collision test fails.

Try either lowering the constant, or increasing the size of the paddle. That should do the trick. You just have to make sure that there's no chance that between two different draw cycles, the ball totally bypasses the paddle.

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