Sha256: 45438ac3fbd4be8d5dbc4566278433ca782ea1bec703ad83861f0be2c3690770
Contents?: true
Size: 1.39 KB
Versions: 6
Compression:
Stored size: 1.39 KB
Contents
package org.sunflow.core.bucket;
import org.sunflow.core.BucketOrder;
public class RandomBucketOrder implements BucketOrder {
@Override
public int[] getBucketSequence(int nbw, int nbh) {
int[] coords = new int[2 * nbw * nbh];
for (int i = 0; i < nbw * nbh; i++) {
int by = i / nbw;
int bx = i % nbw;
if ((by & 1) == 1) {
bx = nbw - 1 - bx;
}
coords[2 * i + 0] = bx;
coords[2 * i + 1] = by;
}
long seed = 2463534242L;
for (int i = 0; i < coords.length; i++) {
// pick 2 random indices
seed = xorshift(seed);
int src = mod((int) seed, nbw * nbh);
seed = xorshift(seed);
int dst = mod((int) seed, nbw * nbh);
int tmp = coords[2 * src + 0];
coords[2 * src + 0] = coords[2 * dst + 0];
coords[2 * dst + 0] = tmp;
tmp = coords[2 * src + 1];
coords[2 * src + 1] = coords[2 * dst + 1];
coords[2 * dst + 1] = tmp;
}
return coords;
}
private int mod(int a, int b) {
int m = a % b;
return (m < 0) ? m + b : m;
}
private long xorshift(long y) {
y = y ^ (y << 13);
y = y ^ (y >>> 17); // unsigned
y = y ^ (y << 5);
return y;
}
}
Version data entries
6 entries across 6 versions & 1 rubygems