package squidpony.squidmath;
/**
* Performance-oriented "white noise" generator for 1D, 2D, 3D, 4D, and 6D. Produces noise values from -1.0 inclusive
* to 1.0 exclusive. Should produce a completely different double even for extremely-nearby points, so this is not a
* kind of continuous noise like {@link PerlinNoise}. It is not actually random, and the value is always determined by
* the exact double positions (and possibly an int seed) given to it. Even a slight change should drastically alter the
* returned value, though below some very small epsilon the results might not be different between two very close points
* in space.
* <br>
* Meant for cases where you want to use a different number for every pixel, tile, or other unit of noise generated,
* often coupled with another kind of noise but with the result of the ValueNoise made less significant to add a "fuzzy"
* effect to the appearance.
* <br>
* Implementation is based on {@link CrossHash.Wisp#hash64(int[])}, treating doubles as ints
* by using {@link NumberTools#doubleToMixedIntBits(double)}, which XORs the bottom and top halves of the long bits of
* each double, and does it efficiently enough on GWT. Finishes by passing the top 52 bits as a significand to
* {@link NumberTools#longBitsToDouble(long)}, using an exponent that allows this to produce numbers between -1.0 and
* 1.0. Has special treatment for the seed when present (since it is an int).
* <br>
* This can also be used as a sort of hashing function that produces a double, if you find a need for such a thing, with
* {@link #hash(double...)}.
*/
public class ValueNoise implements Noise.Noise1D, Noise.Noise2D, Noise.Noise3D, Noise.Noise4D, Noise.Noise6D {
public static final ValueNoise instance = new ValueNoise();
public ValueNoise() {
}
@Override
public double getNoise(double x) {
long a = 0x632BE59BD9B4E019L,
result = 0x9E3779B97F4A7C94L +
(a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(x*0x11.9E3779B9p3));
return NumberTools.longBitsToDouble(((result * (a | 1L) ^ (result >>> 27 | result << 37)) >>> 12) | 0x4000000000000000L) - 3.0;
}
@Override
public double getNoiseWithSeed(double x, int seed) {
long a = 0x632BE59BD9B4E019L,
result = 0x9E3779B97F4A7C94L +
(a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(x*0x11.9E3779B9p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * seed);
return NumberTools.longBitsToDouble(((result * (a | 1L) ^ (result >>> 27 | result << 37)) >>> 12) | 0x4000000000000000L) - 3.0;
}
@Override
public double getNoise(double x, double y) {
long a = 0x632BE59BD9B4E019L,
result = 0x9E3779B97F4A7C94L +
(a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(x*0x11.9E3779B9p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(y*0x11.8329C6DFp3));
return NumberTools.longBitsToDouble(((result * (a | 1L) ^ (result >>> 27 | result << 37)) >>> 12) | 0x4000000000000000L) - 3.0;
}
@Override
public double getNoiseWithSeed(double x, double y, int seed) {
long a = 0x632BE59BD9B4E019L,
result = 0x9E3779B97F4A7C94L +
(a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(x*0x11.9E3779B9p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(y*0x11.8329C6DFp3))
+ (a ^= 0x8329C6EB9E6AD3E3L * seed);
return NumberTools.longBitsToDouble(((result * (a | 1L) ^ (result >>> 27 | result << 37)) >>> 12) | 0x4000000000000000L) - 3.0;
}
@Override
public double getNoise(double x, double y, double z) {
long a = 0x632BE59BD9B4E019L,
result = 0x9E3779B97F4A7C94L +
(a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(x*0x11.9E3779B9p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(y*0x11.8329C6DFp3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(z*0x11.85157AF5p3));
return NumberTools.longBitsToDouble(((result * (a | 1L) ^ (result >>> 27 | result << 37)) >>> 12) | 0x4000000000000000L) - 3.0;
}
@Override
public double getNoiseWithSeed(double x, double y, double z, int seed) {
long a = 0x632BE59BD9B4E019L,
result = 0x9E3779B97F4A7C94L +
(a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(x*0x11.9E3779B9p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(y*0x11.8329C6DFp3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(z*0x11.85157AF5p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * seed);
return NumberTools.longBitsToDouble(((result * (a | 1L) ^ (result >>> 27 | result << 37)) >>> 12) | 0x4000000000000000L) - 3.0;
}
@Override
public double getNoise(double x, double y, double z, double w) {
long a = 0x632BE59BD9B4E019L,
result = 0x9E3779B97F4A7C94L +
(a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(x*0x11.9E3779B9p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(y*0x11.953976F9p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(z*0x11.85157AF5p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(w*0x11.8329C6DFp3));
return NumberTools.longBitsToDouble(((result * (a | 1L) ^ (result >>> 27 | result << 37)) >>> 12) | 0x4000000000000000L) - 3.0;
}
@Override
public double getNoiseWithSeed(double x, double y, double z, double w, int seed) {
long a = 0x632BE59BD9B4E019L,
result = 0x9E3779B97F4A7C94L +
(a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(x*0x11.9E3779B9p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(y*0x11.953976F9p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(z*0x11.85157AF5p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(w*0x11.8329C6DFp3))
+ (a ^= 0x8329C6EB9E6AD3E3L * seed);
return NumberTools.longBitsToDouble(((result * (a | 1L) ^ (result >>> 27 | result << 37)) >>> 12) | 0x4000000000000000L) - 3.0;
}
@Override
public double getNoise(double x, double y, double z, double w, double u, double v) {
long a = 0x632BE59BD9B4E019L,
result = 0x9E3779B97F4A7C94L +
(a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(x*0x11.9E3779B9p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(y*0x17.08329C6DFp2))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(z*0x29.085157AF5p1))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(w*0x11.85157AF5p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(u*0x17.09E3779B9p2))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(v*0x29.08329C6DFp1));
return NumberTools.longBitsToDouble(((result * (a | 1L) ^ (result >>> 27 | result << 37)) >>> 12) | 0x4000000000000000L) - 3.0;
}
@Override
public double getNoiseWithSeed(double x, double y, double z, double w, double u, double v, int seed) {
long a = 0x632BE59BD9B4E019L,
result = 0x9E3779B97F4A7C94L +
(a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(x*0x11.9E3779B9p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(y*0x17.08329C6DFp2))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(z*0x29.085157AF5p1))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(w*0x11.85157AF5p3))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(u*0x17.09E3779B9p2))
+ (a ^= 0x8329C6EB9E6AD3E3L * NumberTools.doubleToMixedIntBits(v*0x29.08329C6DFp1))
+ (a ^= 0x8329C6EB9E6AD3E3L * seed);
return NumberTools.longBitsToDouble(((result * (a | 1L) ^ (result >>> 27 | result << 37)) >>> 12) | 0x4000000000000000L) - 3.0;
}
/**
* Hashes the input double array or vararg and produces a double with unpredictable value, between -1.0 inclusive
* and 1.0 exclusive.
* @param data an array or vararg of double items; should not include NaN or infinite values but has no other limits
* @return an unpredictable double between -1.0 inclusive and 1.0 exclusive
*/
public static double hash(double... data) {
if(data == null) return 0.0;
long a = 0x632BE59BD9B4E019L, result = 0x9E3779B97F4A7C94L;
double t = 0x13.9E3779B9p-5;
int len = data.length;
for (int i = 0; i < len; i++) {
result += (a ^= 0x8329C6EB9E6AD3E3L * (NumberTools.doubleToMixedIntBits((t *= t - data[i]))));
}
return NumberTools.longBitsToDouble(((result * (a | 1L) ^ (result >>> 27 | result << 37)) >>> 12) | 0x4000000000000000L) - 3.0;
}
}