*** UNIX MANUAL PAGE BROWSER ***

CIRCLE(9.3) CIRCLE(9.3) NAME circle, disc, arc, ellipse, eldisc, elarc - circle-drawing functions SYNOPSIS #include <jerq.h> void circle(bp, p, r, f) Bitmap *bp; Point p; int r; Code f; void disc(bp, p, r, f) Bitmap *bp; Point p; int r; Code f; void arc(bp, p0, p1, p2, f) Bitmap *bp; Point p0, p1, p2; Code f; void ellipse(bp, p, a, b, f) Bitmap *bp; Point p; int a, b; Code f; void eldisc(bp, p, a, b, f) Bitmap *bp; Point p; int a, b; Code f; void elarc(bp, p0, a, b, p1, p2, f) Bitmap *bp; Point p0, p1, p2; int a, b; Code f; DESCRIPTION Circle draws the best approximate circle of radius r centered at Point p in the Bitmap bp with Code f. The circle is guaranteed to be symmet- rical about the horizontal, vertical and diagonal axes. Disc draws the corresponding disc. Arc draws a circular arc centered on p0, traveling counter-clockwise from p1 to the point on the circle closest to p2. Ellipse draws an ellipse centered at p with horizontal semi-axis a and vertical semi-axis b in Bitmap bp with Code f. Eldisc draws the corre- sponding elliptical disc. Elarc draws the corresponding elliptical arc, traveling counter-clockwise from the ellipse point closest to p1 to the point closest to p2. (Beware the regrettable difference between the calling conventions for arc and elarc.) BUGS When an endpoint of an arc lies near a tail of an ellipse so thin that its ends degenerate into straight lines, elarc does not try to distin- guish which side of the tail the point belongs on. CIRCLE(9.3)