plot
plot(object, x, y, reverse, color);
plot(object, x1, y1, reverse, color); /* plot first two points */
plot(object, x, y, reverse, color);
plot(object, ++x, y, reverse, color);
plot(object, x1, y1, reverse, color);
plot(object, --x1, y1, reverse, color);
plot(object, x, y, reverse, color);
plot(object, ++x, y += step, reverse,
plot(object, x1, y1, reverse, color);
plot(object, --x1, y1 -= step, reverse,
plot(object, x, y += step, reverse, color);
plot(object, ++x, y, reverse, color);
plot(object, x1, y1 -= step, reverse,
plot(object, --x1, y1, reverse, color);
plot(object, ++x, y, reverse, color); /* pattern 1 */
plot(object, ++x, y, reverse, color);
plot(object, --x1, y1, reverse, color);
plot(object, ++x, y, reverse, color); /* pattern 2 */
plot(object, ++x, y += step, reverse, color);
plot(object, --x1, y1, reverse, color);
plot(object, ++x, y += step, reverse, color);
plot(object, ++x, y, reverse, color);
plot(object, --x1, y1 -= step, reverse, color);
plot(object, x, y += step, reverse, color);
plot(object, ++x, y += step, reverse, color);
plot(object, x1, y1 -= step, reverse, color);
plot(object, --x1, y1 -= step, reverse, color);
plot(object, x, y, reverse, color);
plot(object, ++x, y += step, reverse,
plot(object, x1, y1, reverse, color);
plot(object, --x1, y1 -= step, reverse,
plot(object, x, y += step, reverse, color);
plot(object, ++x, y, reverse, color);
plot(object, x1, y1 -= step, reverse, color);
plot(object, --x1, y1, reverse, color);
plot(object, ++x, y += step, reverse, color); /* pattern 4 */
plot(object, ++x, y += step, reverse,
plot(object, --x1, y1 -= step, reverse,
plot(object, ++x, y, reverse, color); /* pattern 2 */
plot(object, ++x, y += step, reverse, color);
plot(object, --x1, y1, reverse, color);
plot(object, ++x, y += step, reverse, color);
plot(object, ++x, y, reverse, color);
plot(object, --x1, y1 -= step, reverse, color);
plot(object, --x1, y1, reverse, color);
static struct plot plot;
struct plot *pl;
pl = &plot;
struct plot *pl;
pl = &plot;
struct plot *pl;
pl = &plot;
struct plot *pl;
pl = &plot;