private static DirPoint binSearch(long f, int dir, int old_d) {
int d = (int) (Math.log(f) / Math.log(2d));
long froof = (long) Math.pow(2d, (double) (d));
pos += froof;
long f_diff = f - froof;
// System.out.println("d: " + d + " froof: " +
// froof+ " fdiff " + f_diff);
if (f != froof) {
froof *= 2;
}
System.out.println(
"\nf "
+ (st - f)
+ " dir "
+ dir
+ " realdir: "
+ poss[(int) (st - f)]
+ " d "
+ d
+ " f_diff "
+ f_diff);
// System.out.println("froof " + froof);
if (froof != 0) {
DirPoint dp = getXY(d, dir);
if (old_d > d + 1) {
direction = (direction + 4) % 8;
} else {
// direction = 2;
}
// System.out.println("dp "+dp +" poss " +poss[pos] );
DirPoint dp2 = binSearch(f_diff, dp.dir, d);
dp.Add(dp2);
return dp;
}
return null;
}
private static DirPoint getXY(int d, int dir) {
/*
i 0 x 0 y 1 dir: 0
i 1 x 1 y 1 dir: 1
i 3 x 2 y 0 dir: 2
i 7 x 2 y -2 dir: 3
i 15 x 0 y -4 dir: 4
i 31 x -4 y -4 dir: 5
i 63 x -8 y 0 dir: 6
i 127 x -8 y 8 dir: 7
i 255 x 0 y 16 dir: 0
i 511 x 16 y 16 dir: 1
i 1023 x 32 y 0 dir: 2
0:y+1
6:x-1 dir 2:x+1
4:y-1
*/
DirPoint p = new DirPoint();
long value = (long) Math.pow(2d, (double) (d / 2));
switch ((dir + d) % 8) {
case 0:
p.x = 0;
p.y = value;
break;
case 1:
p.x = value;
p.y = value;
break;
case 2:
p.x = value;
p.y = 0;
break;
case 3:
p.x = value;
p.y = -value;
break;
case 4:
p.x = 0;
p.y = -value;
break;
case 5:
p.x = -value;
p.y = -value;
break;
case 6:
p.x = -value;
p.y = 0;
break;
case 7:
p.x = -value;
p.y = value;
break;
}
p.dir = (dir + direction) % 8;
return p;
}