/**
* Erase in x-direction. Exactly the same as {@link
* #vertical_erase(DisplayHack)} with x and y-related swapped.
*/
public void horizontal_erase(DisplayHack hack)
{
Window window = hack.window;
int dx = Math.Max (1, window.width / DELAY * hack.eraser_delta);
int dy = Math.Max (1, window.height / SLICE * hack.eraser_delta);
for (int x=0; x<window.width; x+=dx) {
for (int y=0; y<window.height; y+=dy) {
int from_x, to_x, clear_x;
if ((y/dy) % 2 == 1) {
from_x = x;
to_x = x + dx;
clear_x = x;
} else {
from_x = dx;
to_x = 0;
clear_x = window.width - x - dx;
}
window.copy_area (window, hack.eraser_gc, from_x, y,
window.width-x-dx, dy, to_x, y);
window.clear_area (clear_x, y, dx, dy, false);
}
if (sleep (hack)) return;
}
}
public override void erase(DisplayHack hack)
{
// no useless notify events
hack.eraser_gc.set_graphics_exposures (false);
if (DisplayHack.random.Next()%2==0)
horizontal_erase (hack);
else
vertical_erase (hack);
hack.sleep (hack.delay/2); // before next screen
}
/**
* Erase in y-direction. Exactly the same as {@link
* #horizontal_erase(DisplayHack)} with x and y-related swapped.
*/
public void vertical_erase(DisplayHack hack)
{
Window window = hack.window;
int dx = Math.Max (1, window.width / SLICE * hack.eraser_delta);
int dy = Math.Max (1, window.height / DELAY * hack.eraser_delta);
for (int y=0; y<window.height; y+=dy) {
for (int x=0; x<window.width; x+=dx) {
int from_y, to_y, clear_y;
if ((x/dx) % 2 == 1) {
from_y = y;
to_y = y + dy;
clear_y = y;
} else {
from_y = dy;
to_y = 0;
clear_y = window.height - y - dy;
}
window.copy_area (window, hack.eraser_gc, x, from_y,
dx, window.height-y-dy, x, to_y);
window.clear_area (x, clear_y, dx, dy, false);
}
if (sleep (hack)) return;
}
}
public bool sleep(DisplayHack hack)
{
bool interrupted = hack.sleep (hack.eraser_delay);
if (interrupted) hack.window.clear (false);
return interrupted;
}
public abstract void erase(DisplayHack hack);