public void erase(gnu.app.displayhack.DisplayHack hack) {
gnu.x11.Window window = hack.window;
/* Minimum radius = L/sqrt(2) ~= 0.707*L,
* where L = max(width, heigth)
* sqrt(2) = 1.414213562373095
*
* Take radius = L for faster (easier) computation.
*/
int radius = Math.max(window.width, window.height);
int full = 360 * 64;
int delta = (full / 200) * hack.eraser_delta;
int step_count = (int) Math.ceil(1 + full / delta);
int start = hack.random.nextInt(full);
// clockwise or counter-clockwise
if (hack.random.nextBoolean()) delta = -delta;
for (int i = 0; i < step_count; i++) {
window.fill_arc(
hack.display.default_gc,
window.width / 2 - radius,
window.height / 2 - radius,
2 * radius,
2 * radius,
(start + i * delta) % full,
delta);
if (sleep(hack)) return;
}
hack.sleep(hack.delay / 2); // before next screen
}
/** @see <a href="XdbeGetBackBufferAttributes.html">XdbeGetBackBufferAttributes</a> */
public Window attributes() {
int atts;
RequestOutputStream o = display.out;
synchronized (o) {
o.begin_request(major_opcode, 7, 2);
o.write_int32(id);
ResponseInputStream i = display.in;
synchronized (i) {
i.read_reply(o);
i.skip(8);
atts = i.read_int32();
i.skip(20);
}
}
return (Window) Window.intern(this.display, atts);
}