Added SimplexNoise
Signed-off-by: Ralph Niemitz <ralph.niemitz@gmx.de>
This commit is contained in:
Ralph Niemitz
parent
e4827bdb23
commit
6d2fa795f7
135
src/main/java/com/generation/SimplexNoise.java
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135
src/main/java/com/generation/SimplexNoise.java
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package src.main.java.com.generation;
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import java.util.Random;
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/**
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* Implementation of the simplex noise algorithm.
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* @see <a href="https://en.wikipedia.org/wiki/Simplex_noise">Wikipedia</a>
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*/
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public class SimplexNoise {
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private SimplexNoiseOctave[] octaves;
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private double[] frequencys;
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private double[] amplitudes;
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private int largestFeature;
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private double persistance;
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private long seed;
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/**
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* @param largestFeature size of the largest possible feature
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* @param persistence the persistence
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* @param seed the seed
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*/
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public SimplexNoise(int largestFeature, double persistence, long seed) {
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this.largestFeature = largestFeature;
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this.persistance = persistence;
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this.seed = seed;
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int octaveCount = (int)Math.ceil(Math.log10(largestFeature) / Math.log10(2.0D));
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this.octaves = new SimplexNoiseOctave[octaveCount];
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this.frequencys = new double[octaveCount];
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this.amplitudes = new double[octaveCount];
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Random random = new Random(seed);
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for(int index = 0; index < octaveCount; index++) {
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this.octaves[index] = new SimplexNoiseOctave(random.nextInt());
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this.frequencys[index] = Math.pow(2, index);
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this.amplitudes[index] = Math.pow(persistence, octaveCount - index);
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}
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}
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/**
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* Generates a height map.
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* @param x X coordinate
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* @param y Y coordinate
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* @param width width
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* @param height height
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* @return the generated height map
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*/
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public float[][] generateHeightMap(int x, int y, int width, int height) {
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int xEnd = x + width;
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int yEnd = y + height;
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float[][] result = new float[width][height];
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for(int i = 0; i < width; i++) {
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for(int j = 0; j < height; j++) {
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int posX = x + i * ((xEnd - x) / width);
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int posY = y + j * ((yEnd - y) / height);
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result[i][j] = Math.min(1.0F, Math.max(0.0F, (float)(0.5D * (1 + this.getNoise(posX, posY)))));
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}
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}
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return result;
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}
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/**
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* Generates a two dimensional noise.
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* @param x X coordinate
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* @param y Y coordinate
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* @return the generated noise
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*/
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public double getNoise(int x, int y) {
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double result = 0;
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for(int index = 0; index < this.octaves.length; index++) {
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result += this.octaves[index].noise(x / this.frequencys[index], y / this.frequencys[index]) * this.amplitudes[index];
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}
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return result;
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}
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/**
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* Generates a three dimensional noise.
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* @param x X coordinate
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* @param y Y coordinate
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* @param z Z coordinate
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* @return the generated noise
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*/
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public double getNoise(int x, int y, int z) {
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double result = 0;
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for(int index = 0; index < this.octaves.length; index++) {
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double frequency = Math.pow(2, index);
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double amplitude = Math.pow(this.persistance, this.octaves.length - index);
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result += this.octaves[index].noise(x / frequency, y / frequency, z / frequency) * amplitude;
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}
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return result;
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}
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/**
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* @return the largest possible feature
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*/
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public int getLargestFeature() {
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return this.largestFeature;
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}
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/**
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* @return the persistence
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*/
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public double getPersistance() {
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return this.persistance;
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}
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/**
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* @return the seed
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*/
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public long getSeed() {
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return this.seed;
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}
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}
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392
src/main/java/com/generation/SimplexNoiseOctave.java
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392
src/main/java/com/generation/SimplexNoiseOctave.java
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package src.main.java.com.generation;
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import java.util.Random;
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/**
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* Implementation of a simplex noise octave.
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*/
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public class SimplexNoiseOctave {
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private static final Gradient[] GRADIENTS = {
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new Gradient( 1, 1, 0), new Gradient(-1, 1, 0), new Gradient( 1, -1, 0),
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new Gradient(-1, -1, 0), new Gradient( 1, 0, 1), new Gradient(-1, 0, 1),
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new Gradient( 1, 0, -1), new Gradient(-1, 0, -1), new Gradient( 0, 1, 1),
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new Gradient( 0, -1, 1), new Gradient( 0, 1, -1), new Gradient( 0, -1, -1)
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};
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private static final short P_SUPPLY[] = {
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151, 160, 137, 91, 90, 15, 131, 13, 201, 95, 96, 53, 194, 233, 7, 225,
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140, 36, 103, 30, 69, 142, 8, 99, 37, 240, 21, 10, 23, 190, 6, 148,
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247, 120, 234, 75, 0, 26, 197, 62, 94, 252, 219, 203, 117, 35, 11, 32,
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57, 177, 33, 88, 237, 149, 56, 87, 174, 20, 125, 136, 171, 168, 68, 175,
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74, 165, 71, 134, 139, 48, 27, 166, 77, 146, 158, 231, 83, 111, 229, 122,
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60, 211, 133, 230, 220, 105, 92, 41, 55, 46, 245, 40, 244, 102, 143, 54,
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65, 25, 63, 161, 1, 216, 80, 73, 209, 76, 132, 187, 208, 89, 18, 169,
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200, 196, 135, 130, 116, 188, 159, 86, 164, 100, 109, 198, 173, 186, 3, 64,
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52, 217, 226, 250, 124, 123, 5, 202, 38, 147, 118, 126, 255, 82, 85, 212,
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207, 206, 59, 227, 47, 16, 58, 17, 182, 189, 28, 42, 223, 183, 170, 213,
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119, 248, 152, 2, 44, 154, 163, 70, 221, 153, 101, 155, 167, 43, 172, 9,
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129, 22, 39, 253, 19, 98, 108, 110, 79, 113, 224, 232, 178, 185, 112, 104,
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218, 246, 97, 228, 251, 34, 242, 193, 238, 210, 144, 12, 191, 179, 162, 241,
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81, 51, 145, 235, 249, 14, 239, 107, 49, 192, 214, 31, 181, 199, 106, 157,
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184, 84, 204, 176, 115, 121, 50, 45, 127, 4, 150, 254, 138, 236, 205, 93,
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222, 114, 67, 29, 24, 72, 243, 141, 128, 195, 78, 66, 215, 61, 156, 180
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};
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private static final int LENGTH = P_SUPPLY.length * 2;
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private static final int SWAP_COUNT = 20;
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private static final double F2 = 0.5D * (Math.sqrt(3.0D) - 1.0D);
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private static final double G2 = (3.0D - Math.sqrt(3.0D)) / 6.0D;
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private static final double F3 = 1.0D / 3.0D;
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private static final double G3 = 1.0D / 6.0D;
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private final short[] p = P_SUPPLY.clone();
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private final short[] perm = new short[LENGTH];
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private final short[] permMod12 = new short[LENGTH];
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/**
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* @param seed the seed for this octave
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*/
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public SimplexNoiseOctave(long seed) {
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Random random = new Random(seed);
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for(int index = 0; index < SWAP_COUNT; index++) {
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int swapFrom = random.nextInt(this.p.length);
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int swapTo = random.nextInt(this.p.length);
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short temp = this.p[swapFrom];
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this.p[swapFrom] = this.p[swapTo];
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this.p[swapTo] = temp;
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}
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for(int index = 0; index < LENGTH; index++) {
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this.perm[index] = this.p[index & 255];
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this.permMod12[index] = (short)(this.perm[index] % 12);
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}
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}
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/**
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* A method with the functionality of {@link Math#floor(double)} but it is faster.
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* @param x the value
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* @return the result
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* @see Math#floor(double)
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*/
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private static final int fastfloor(double x) {
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int xAsInt = (int)x;
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return x < xAsInt ? xAsInt - 1 : xAsInt;
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}
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/**
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* Dot function for a gradient.
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* @param gradient the gradient
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* @param x X
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* @param y Y
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* @return the dot value
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*/
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private static final double dot(Gradient gradient, double x, double y) {
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return gradient.x * x + gradient.y * y;
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}
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/**
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* Dot function for a gradient.
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* @param gradient the gradient
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* @param x X
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* @param y Y
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* @param z Z
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* @return the dot value
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*/
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private static final double dot(Gradient gradient, double x, double y, double z) {
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return gradient.x * x + gradient.y * y + gradient.z * z;
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}
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/**
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* Makes a two dimensional noise.
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* @param x X
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* @param y Y
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* @return the noise
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*/
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public double noise(double x, double y) {
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double n0;
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double n1;
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double n2;
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double s = (x + y) * F2;
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int i = fastfloor(x + s);
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int j = fastfloor(y + s);
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double t = (i + j) * G2;
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double X0 = i - t;
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double Y0 = j - t;
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double x0 = x - X0;
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double y0 = y - Y0;
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int i1;
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int j1;
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if(x0 > y0) {
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i1 = 1;
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j1 = 0;
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} else {
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i1 = 0;
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j1 = 1;
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}
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double x1 = x0 - i1 + G2;
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double y1 = y0 - j1 + G2;
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double x2 = x0 - 1.0D + 2.0D * G2;
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double y2 = y0 - 1.0D + 2.0D * G2;
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int ii = i & 0xFF;
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int jj = j & 0xFF;
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int gi0 = this.permMod12[ii + this.perm[jj]];
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int gi1 = this.permMod12[ii + i1 + this.perm[jj + j1]];
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int gi2 = this.permMod12[ii + 1 + this.perm[jj + 1]];
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double t0 = 0.5D - x0 * x0 - y0 * y0;
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if(t0 < 0) {
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n0 = 0.0;
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} else {
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t0 *= t0;
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n0 = t0 * t0 * dot(GRADIENTS[gi0], x0, y0);
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}
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double t1 = 0.5D - x1 * x1 - y1 * y1;
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if(t1 < 0.0D) {
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n1 = 0.0;
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} else {
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t1 *= t1;
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n1 = t1 * t1 * dot(GRADIENTS[gi1], x1, y1);
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}
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double t2 = 0.5D - x2 * x2 - y2 * y2;
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if(t2 < 0.0D) {
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n2 = 0.0D;
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} else {
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t2 *= t2;
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n2 = t2 * t2 * dot(GRADIENTS[gi2], x2, y2);
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}
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return 70.0D * (n0 + n1 + n2);
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}
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/**
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* Makes a three dimensional noise.
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* @param x X
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* @param y Y
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* @param z Z
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* @return the noise
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* @since 21.08.2018/0.2.0
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*/
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public double noise(double x, double y, double z) {
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double n0;
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double n1;
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double n2;
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double n3;
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double s = (x + y + z) * F3;
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int i = fastfloor(x + s);
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int j = fastfloor(y + s);
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int k = fastfloor(z + s);
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double t = (i + j + k) * G3;
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double X0 = i - t;
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double Y0 = j - t;
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double Z0 = k - t;
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double x0 = x - X0;
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double y0 = y - Y0;
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double z0 = z - Z0;
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int i1;
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int j1;
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int k1;
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int i2;
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int j2;
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int k2;
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if(x0 >= y0) {
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if(y0 >= z0) {
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i1 = 1;
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j1 = 0;
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k1 = 0;
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i2 = 1;
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j2 = 1;
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k2 = 0;
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} else if(x0 >= z0) {
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i1 = 1;
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j1 = 0;
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k1 = 0;
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i2 = 1;
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j2 = 0;
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k2 = 1;
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} else {
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i1 = 0;
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j1 = 0;
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k1 = 1;
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i2 = 1;
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j2 = 0;
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k2 = 1;
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}
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} else {
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if(y0 < z0) {
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i1 = 0;
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j1 = 0;
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k1 = 1;
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i2 = 0;
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j2 = 1;
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k2 = 1;
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} else if(x0 < z0) {
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i1 = 0;
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j1 = 1;
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k1 = 0;
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i2 = 0;
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j2 = 1;
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k2 = 1;
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} else {
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i1 = 0;
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j1 = 1;
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k1 = 0;
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i2 = 1;
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j2 = 1;
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k2 = 0;
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}
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}
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double x1 = x0 - i1 + G3;
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double y1 = y0 - j1 + G3;
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double z1 = z0 - k1 + G3;
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double x2 = x0 - i2 + 2.0D * G3;
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double y2 = y0 - j2 + 2.0D * G3;
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double z2 = z0 - k2 + 2.0D * G3;
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double x3 = x0 - 1.0D + 3.0D * G3;
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double y3 = y0 - 1.0D + 3.0D * G3;
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double z3 = z0 - 1.0D + 3.0D * G3;
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int ii = i & 0xFF;
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int jj = j & 0xFF;
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int kk = k & 0xFF;
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int gi0 = this.permMod12[ii + this.perm[jj + this.perm[kk]]];
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int gi1 = this.permMod12[ii + i1 + this.perm[jj + j1 + this.perm[kk + k1]]];
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int gi2 = this.permMod12[ii + i2 + this.perm[jj + j2 + this.perm[kk + k2]]];
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int gi3 = this.permMod12[ii + 1 + this.perm[jj + 1 + this.perm[kk + 1]]];
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double t0 = 0.6D - x0 * x0 - y0 * y0 - z0 * z0;
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if(t0 < 0) {
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n0 = 0.0D;
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} else {
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t0 *= t0;
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n0 = t0 * t0 * dot(GRADIENTS[gi0], x0, y0, z0);
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}
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double t1 = 0.6D - x1 * x1 - y1 * y1 - z1 * z1;
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if(t1 < 0) {
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n1 = 0.0D;
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} else {
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t1 *= t1;
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n1 = t1 * t1 * dot(GRADIENTS[gi1], x1, y1, z1);
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}
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double t2 = 0.6D - x2 * x2 - y2 * y2 - z2 * z2;
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if(t2 < 0) {
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n2 = 0.0D;
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} else {
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t2 *= t2;
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n2 = t2 * t2 * dot(GRADIENTS[gi2], x2, y2, z2);
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}
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double t3 = 0.6D - x3 * x3 - y3 * y3 - z3 * z3;
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if(t3 < 0) {
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n3 = 0.0D;
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} else {
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t3 *= t3;
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n3 = t3 * t3 * dot(GRADIENTS[gi3], x3, y3, z3);
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}
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return 32.0D * (n0 + n1 + n2 + n3);
|
||||
}
|
||||
|
||||
/**
|
||||
* Represents a gradient.
|
||||
* Inner classes are faster than arrays.
|
||||
*/
|
||||
private static final class Gradient {
|
||||
|
||||
private final double x;
|
||||
private final double y;
|
||||
private final double z;
|
||||
|
||||
/**
|
||||
* @param x X
|
||||
* @param y Y
|
||||
* @param z Z
|
||||
* @since 21.08.2018/0.2.0
|
||||
*/
|
||||
private Gradient(double x, double y, double z) {
|
||||
|
||||
this.x = x;
|
||||
this.y = y;
|
||||
this.z = z;
|
||||
}
|
||||
}
|
||||
}
|
||||
50
src/test/java/com/generation/SimplexNoiseTest.java
Normal file
50
src/test/java/com/generation/SimplexNoiseTest.java
Normal file
@ -0,0 +1,50 @@
|
||||
package src.test.java.com.generation;
|
||||
|
||||
import static org.junit.jupiter.api.Assertions.*;
|
||||
|
||||
import java.awt.Color;
|
||||
import java.awt.image.BufferedImage;
|
||||
import java.io.IOException;
|
||||
import java.io.InputStream;
|
||||
|
||||
import javax.imageio.ImageIO;
|
||||
|
||||
import org.junit.jupiter.api.Test;
|
||||
|
||||
import src.main.java.com.generation.SimplexNoise;
|
||||
|
||||
public class SimplexNoiseTest {
|
||||
|
||||
@Test
|
||||
public void testGenerateHeightMap() {
|
||||
|
||||
final int WIDTH = 256;
|
||||
final int HEIGHT = 256;
|
||||
final int X = 0;
|
||||
final int Y = 0;
|
||||
final String RESOURCE_NAME = "src/test/java/com/generation/expected-result.png";
|
||||
|
||||
float[][] heightmap = new SimplexNoise(50, 0.3F, 1111111111111111L).generateHeightMap(X, Y, WIDTH, HEIGHT);
|
||||
BufferedImage image = null;
|
||||
|
||||
try(InputStream in = this.getClass().getClassLoader().getResourceAsStream(RESOURCE_NAME)) {
|
||||
|
||||
image = ImageIO.read(in);
|
||||
|
||||
assertEquals(WIDTH, image.getWidth());
|
||||
assertEquals(HEIGHT, image.getHeight());
|
||||
|
||||
} catch(IOException | IllegalArgumentException exception) {
|
||||
|
||||
fail(exception);
|
||||
}
|
||||
|
||||
for(int x = 0; x < WIDTH; x++) {
|
||||
|
||||
for(int y = 0; y < HEIGHT; y++) {
|
||||
|
||||
assertEquals(new Color(image.getRGB(x, y)).getRed(), (int)(heightmap[x][y] * 255));
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
BIN
src/test/java/com/generation/expected-result.png
Normal file
BIN
src/test/java/com/generation/expected-result.png
Normal file
Binary file not shown.
|
After Width: | Height: | Size: 60 KiB |
Loading…
Reference in New Issue
Block a user