static void blackout_nearby_tiles(x, y, dt) {
static void blackout_nearby_tiles(int x, int y, int dt) {
static void blackout_nearby_tiles(x, y, dt) {	int sx, sy, n, b;	int tx = x/tile_x;	int ty = y/tile_y;		if (! blackouts) {		return;	}	if (dt < 1) {		dt = 1;	}	/* loop over a range of tiles, blacking out as needed */	for (sx = tx - dt; sx <= tx + dt; sx++) {		if (sx < 0 || sx >= tile_x) {			continue;		}		for (sy = ty - dt; sy <= ty + dt; sy++) {			if (sy < 0 || sy >= tile_y) {				continue;			}			n = sx + sy * ntiles_x;			if (tile_blackout[n].cover == 0) {				continue;			}			for (b=0; b <= tile_blackout[n].count; b++) {				int x1, y1, x2, y2;				x1 = tile_blackout[n].bo[b].x1;				y1 = tile_blackout[n].bo[b].y1;				x2 = tile_blackout[n].bo[b].x2;				y2 = tile_blackout[n].bo[b].y2;				zero_fb(x1, y1, x2, y2);			}		}	}}