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Index › Programming Questions & Help › Programs › Racing game
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Racing game (Read 827 times)
FMC123
Racing game
Nov 28th, 2005, 8:44pm  
Hello,

I was wondering if anyone could give me any ideas on a problem I'm having: I am currently trying to create a small game: A button tapper racing game that will allow the users to race four balls around an oval track.  I'm fairly new to graphics based programming so I'm having a wee bit of trouble getting my head around it. My main difficulty is getting the balls to move in the direction of an oval in small iterations of the key press. From my understanding of the examples on the site it would be necessary to use the formula of an oval which in, my basic understanding of maths, I know is pages long. If anybody knows of any examples I could reference or even a starting point this would be much appreciated.

Many thanks.
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cchoge
Re: Racing game
Reply #1 - Nov 28th, 2005, 9:29pm  
The math shouldn't be too hard. If you want to start simple you can use the parametric equation for an ellipse.

x = a * cos( t );
y = b * sin( t );

A simple start:

//---
float x;
float y;
float t;
float delta_t;
float a;
float b;

void setup()
{
 size( 640, 480 );
 
 t = 0.0;
 delta_t = 0.05;
 a = 300;
 b = 200;
}

void keyPressed()
{
 t += delta_t;
}

void draw()
{
 translate( width/2, height/2 );
 noStroke();
 fill( 0, 0, 0, 1 );
 rect( -width/2, -height/2, width, height );
 
 fill( 255, 50, 20 );
 x = a * cos( t );
 y = b * sin( t );
 ellipse( x, y, 10, 10 ); // this draws a circle on the screen
 
}
//---
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FMC123
Re: Racing game
Reply #2 - Nov 28th, 2005, 9:42pm  
Sir, you are a gentleman and a scholar.

Thank you very much for you help - This is exactly what I needed.

Smiley
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