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Index › Programming Questions & Help › Programs › Bouncing off of diagonal surfaces
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Bouncing off of diagonal surfaces (Read 713 times)
junebug
Bouncing off of diagonal surfaces
May 2nd, 2010, 8:58pm  
I'm working on a sketch in which balls bounce off of ledges that the user can move around. The problem I'm having is how to check if the ball is hitting a ledge when the ledge is diagonal. I found a formula for the distance between a point a line and tried to implement it, but now the balls simply bounce when they reach the highest y position of any ledge (regardless of whether or not they're near the ledge)

The formula I'm using right now is
Code:

int A = ballX - ledgeX1;
int B = ballY - ledgeY1;
int C = ledgeX2 - ledgeX1;
int D = ledgeY2 - ledgeY1;

float dist = abs(A * D - C * B) / sqrt(C * C + D * D);

if(dist <= ballRadius){
    ball.bounce();
}


Does anyone see what I'm doing wrong or know a better way of doing this?
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TfGuy44
Re: Bouncing off of diagonal surfaces
Reply #1 - May 2nd, 2010, 10:47pm  
Posting a block of working code is extremely useful for us helpful people.
Seriously. Post something that we can copy, paste, run, understand, and edit.
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NoahBuddy
Re: Bouncing off of diagonal surfaces
Reply #2 - May 2nd, 2010, 11:54pm  
The examples Reflection1 and Reflection2 might give you some ideas.
http://processing.org/learning/topics/reflection1.html
http://processing.org/learning/topics/reflection2.html
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