Hi to all I found a message sent to this mailing list just 1.5 months ago and I quote it here.
It implements Bresenham algorithm (though this term isn't mentioned in the original message). This is not my code and I reproduce it verbatim. I had no time to test, but as the code suggests it draws a circle of radius r with the centre in (x, y). Drawing arcs is a bit trickier because of no symmetry. Michael -----Original Message----- From: manish jaggi [mailto:[EMAIL PROTECTED]] Sent: Wednesday, 21 November 2001 8:07 PM To: Palm Developer Forum Cc: [EMAIL PROTECTED] Subject: Circle Drawing source /* The following is my only add-on. M.G. */ static void plotcircle ( int x, int y, int x1, int y1 ); void Circle(int x, int y, int r) { int i, j, x1, y1, r, p, a ; x1 = 0 ; y1 = r ; p = 3 - 2 * r ; while ( x1 < y1 ) { plotcircle ( x, y, x1, y1 ) ; if ( p < 0 ) p = p + 4 * x1 + 6 ; else { p = p + 4 * ( x1 - y1 ) + 10 ; y1 = y1 - 1 ; } x1 = x1 + 1 ; } if ( x1 == y1 ) plotcircle ( x, y, x1, y1 ) ; } static void plotcircle ( int x, int y, int x1, int y1 ) { WinDrawPixel ( x + x1, y + y1 ) ; WinDrawPixel ( x - x1, y + y1 ) ; WinDrawPixel ( x + x1, y - y1 ) ; WinDrawPixel ( x - x1, y - y1 ) ; WinDrawPixel ( x + y1, y + x1 ) ; WinDrawPixel ( x - y1, y + x1 ) ; WinDrawPixel ( x + y1, y - x1 ) ; WinDrawPixel ( x - y1, y - x1 ) ; } -- For information on using the Palm Developer Forums, or to unsubscribe, please see http://www.palmos.com/dev/tech/support/forums/
