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@ -4,164 +4,165 @@ import java.util.Random;
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import java.util.Scanner;
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/**
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* For detailed info and implementation see: <a href="http://devmag.org.za/2009/04/25/perlin-noise/">Perlin-Noise</a>
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* For detailed info and implementation see: <a
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* href="http://devmag.org.za/2009/04/25/perlin-noise/">Perlin-Noise</a>
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*/
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public class PerlinNoise {
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/**
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* @param width width of noise array
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* @param height height of noise array
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* @param octaveCount numbers of layers used for blending noise
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* @param persistence value of impact each layer get while blending
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* @param seed used for randomizer
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* @return float array containing calculated "Perlin-Noise" values
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*/
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static float[][] generatePerlinNoise(int width, int height, int octaveCount, float persistence, long seed) {
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final float[][] base = new float[width][height];
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final float[][] perlinNoise = new float[width][height];
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final float[][][] noiseLayers = new float[octaveCount][][];
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/**
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* @param width width of noise array
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* @param height height of noise array
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* @param octaveCount numbers of layers used for blending noise
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* @param persistence value of impact each layer get while blending
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* @param seed used for randomizer
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* @return float array containing calculated "Perlin-Noise" values
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*/
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static float[][] generatePerlinNoise(
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int width, int height, int octaveCount, float persistence, long seed) {
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final float[][] base = new float[width][height];
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final float[][] perlinNoise = new float[width][height];
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final float[][][] noiseLayers = new float[octaveCount][][];
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Random random = new Random(seed);
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//fill base array with random values as base for noise
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for (int x = 0; x < width; x++) {
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for (int y = 0; y < height; y++) {
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base[x][y] = random.nextFloat();
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}
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}
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//calculate octaves with different roughness
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for (int octave = 0; octave < octaveCount; octave++) {
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noiseLayers[octave] = generatePerlinNoiseLayer(base, width, height, octave);
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}
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float amplitude = 1f;
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float totalAmplitude = 0f;
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//calculate perlin noise by blending each layer together with specific persistence
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for (int octave = octaveCount - 1; octave >= 0; octave--) {
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amplitude *= persistence;
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totalAmplitude += amplitude;
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for (int x = 0; x < width; x++) {
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for (int y = 0; y < height; y++) {
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//adding each value of the noise layer to the noise
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//by increasing amplitude the rougher noises will have more impact
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perlinNoise[x][y] += noiseLayers[octave][x][y] * amplitude;
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}
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}
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}
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//normalize values so that they stay between 0..1
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for (int x = 0; x < width; x++) {
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for (int y = 0; y < height; y++) {
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perlinNoise[x][y] /= totalAmplitude;
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}
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}
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return perlinNoise;
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Random random = new Random(seed);
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// fill base array with random values as base for noise
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for (int x = 0; x < width; x++) {
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for (int y = 0; y < height; y++) {
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base[x][y] = random.nextFloat();
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}
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}
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/**
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* @param base base random float array
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* @param width width of noise array
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* @param height height of noise array
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* @param octave current layer
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* @return float array containing calculated "Perlin-Noise-Layer" values
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*/
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static float[][] generatePerlinNoiseLayer(float[][] base, int width, int height, int octave) {
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float[][] perlinNoiseLayer = new float[width][height];
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// calculate octaves with different roughness
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for (int octave = 0; octave < octaveCount; octave++) {
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noiseLayers[octave] = generatePerlinNoiseLayer(base, width, height, octave);
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}
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//calculate period (wavelength) for different shapes
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int period = 1 << octave; //2^k
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float frequency = 1f / period; // 1/2^k
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float amplitude = 1f;
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float totalAmplitude = 0f;
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for (int x = 0; x < width; x++) {
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//calculates the horizontal sampling indices
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int x0 = (x / period) * period;
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int x1 = (x0 + period) % width;
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float horizintalBlend = (x - x0) * frequency;
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// calculate perlin noise by blending each layer together with specific persistence
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for (int octave = octaveCount - 1; octave >= 0; octave--) {
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amplitude *= persistence;
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totalAmplitude += amplitude;
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for (int y = 0; y < height; y++) {
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//calculates the vertical sampling indices
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int y0 = (y / period) * period;
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int y1 = (y0 + period) % height;
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float verticalBlend = (y - y0) * frequency;
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//blend top corners
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float top = interpolate(base[x0][y0], base[x1][y0], horizintalBlend);
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//blend bottom corners
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float bottom = interpolate(base[x0][y1], base[x1][y1], horizintalBlend);
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//blend top and bottom interpolation to get the final blend value for this cell
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perlinNoiseLayer[x][y] = interpolate(top, bottom, verticalBlend);
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}
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for (int x = 0; x < width; x++) {
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for (int y = 0; y < height; y++) {
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// adding each value of the noise layer to the noise
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// by increasing amplitude the rougher noises will have more impact
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perlinNoise[x][y] += noiseLayers[octave][x][y] * amplitude;
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}
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return perlinNoiseLayer;
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}
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}
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/**
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* @param a value of point a
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* @param b value of point b
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* @param alpha determine which value has more impact (closer to 0 -> a, closer to 1 -> b)
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* @return interpolated value
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*/
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static float interpolate(float a, float b, float alpha) {
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return a * (1 - alpha) + alpha * b;
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// normalize values so that they stay between 0..1
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for (int x = 0; x < width; x++) {
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for (int y = 0; y < height; y++) {
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perlinNoise[x][y] /= totalAmplitude;
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}
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}
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public static void main(String[] args) {
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Scanner in = new Scanner(System.in);
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return perlinNoise;
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}
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final int width;
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final int height;
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final int octaveCount;
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final float persistence;
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final long seed;
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final String charset;
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final float[][] perlinNoise;
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/**
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* @param base base random float array
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* @param width width of noise array
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* @param height height of noise array
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* @param octave current layer
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* @return float array containing calculated "Perlin-Noise-Layer" values
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*/
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static float[][] generatePerlinNoiseLayer(float[][] base, int width, int height, int octave) {
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float[][] perlinNoiseLayer = new float[width][height];
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System.out.println("Width (int): ");
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width = in.nextInt();
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// calculate period (wavelength) for different shapes
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int period = 1 << octave; // 2^k
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float frequency = 1f / period; // 1/2^k
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System.out.println("Height (int): ");
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height = in.nextInt();
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for (int x = 0; x < width; x++) {
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// calculates the horizontal sampling indices
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int x0 = (x / period) * period;
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int x1 = (x0 + period) % width;
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float horizintalBlend = (x - x0) * frequency;
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System.out.println("Octave count (int): ");
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octaveCount = in.nextInt();
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for (int y = 0; y < height; y++) {
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// calculates the vertical sampling indices
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int y0 = (y / period) * period;
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int y1 = (y0 + period) % height;
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float verticalBlend = (y - y0) * frequency;
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System.out.println("Persistence (float): ");
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persistence = in.nextFloat();
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// blend top corners
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float top = interpolate(base[x0][y0], base[x1][y0], horizintalBlend);
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System.out.println("Seed (long): ");
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seed = in.nextLong();
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// blend bottom corners
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float bottom = interpolate(base[x0][y1], base[x1][y1], horizintalBlend);
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System.out.println("Charset (String): ");
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charset = in.next();
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// blend top and bottom interpolation to get the final blend value for this cell
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perlinNoiseLayer[x][y] = interpolate(top, bottom, verticalBlend);
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}
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}
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return perlinNoiseLayer;
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}
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perlinNoise = generatePerlinNoise(width, height, octaveCount, persistence, seed);
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final char[] chars = charset.toCharArray();
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final int length = chars.length;
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final float step = 1f / length;
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//output based on charset
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for (int x = 0; x < width; x++) {
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for (int y = 0; y < height; y++) {
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float value = step;
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float noiseValue = perlinNoise[x][y];
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/**
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* @param a value of point a
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* @param b value of point b
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* @param alpha determine which value has more impact (closer to 0 -> a, closer to 1 -> b)
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* @return interpolated value
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*/
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static float interpolate(float a, float b, float alpha) {
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return a * (1 - alpha) + alpha * b;
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}
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for (char c : chars) {
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if (noiseValue <= value) {
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System.out.print(c);
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break;
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}
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public static void main(String[] args) {
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Scanner in = new Scanner(System.in);
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value += step;
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}
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}
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final int width;
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final int height;
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final int octaveCount;
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final float persistence;
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final long seed;
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final String charset;
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final float[][] perlinNoise;
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System.out.println();
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System.out.println("Width (int): ");
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width = in.nextInt();
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System.out.println("Height (int): ");
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height = in.nextInt();
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System.out.println("Octave count (int): ");
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octaveCount = in.nextInt();
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System.out.println("Persistence (float): ");
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persistence = in.nextFloat();
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System.out.println("Seed (long): ");
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seed = in.nextLong();
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System.out.println("Charset (String): ");
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charset = in.next();
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perlinNoise = generatePerlinNoise(width, height, octaveCount, persistence, seed);
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final char[] chars = charset.toCharArray();
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final int length = chars.length;
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final float step = 1f / length;
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// output based on charset
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for (int x = 0; x < width; x++) {
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for (int y = 0; y < height; y++) {
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float value = step;
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float noiseValue = perlinNoise[x][y];
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for (char c : chars) {
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if (noiseValue <= value) {
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System.out.print(c);
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break;
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}
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value += step;
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}
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in.close();
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}
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System.out.println();
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}
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in.close();
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}
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}
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