Генерация карт высот на основе симплекс шума (Код - Java) - Программирование - Статьи по созданию игр

Код

package whitefoxy;

import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;

public class SimplexNoise {

  private Gradient grad3[] = { new Gradient(1,1), new Gradient(-1,1), new Gradient(1,-1), new Gradient(-1,-1),
  new Gradient(1,0), new Gradient(-1,0), new Gradient(1,0), new Gradient(-1,0),
  new Gradient(0,1), new Gradient(0,-1), new Gradient(0,1), new Gradient(0,-1) };

  private short p[] = { 151,160,137,91,90,15,
  131,13,201,95,96,53,194,233,7,225,140,36,103,30,69,142,8,99,37,240,21,10,23,
  190, 6,148,247,120,234,75,0,26,197,62,94,252,219,203,117,35,11,32,57,177,33,
  88,237,149,56,87,174,20,125,136,171,168, 68,175,74,165,71,134,139,48,27,166,
  77,146,158,231,83,111,229,122,60,211,133,230,220,105,92,41,55,46,245,40,244,
  102,143,54, 65,25,63,161, 1,216,80,73,209,76,132,187,208, 89,18,169,200,196,
  135,130,116,188,159,86,164,100,109,198,173,186, 3,64,52,217,226,250,124,123,
  5,202,38,147,118,126,255,82,85,212,207,206,59,227,47,16,58,17,182,189,28,42,
  223,183,170,213,119,248,152, 2,44,154,163, 70,221,153,101,155,167, 43,172,9,
  129,22,39,253, 19,98,108,110,79,113,224,232,178,185, 112,104,218,246,97,228,
  251,34,242,193,238,210,144,12,191,179,162,241, 81,51,145,235,249,14,239,107,
  49,192,214, 31,181,199,106,157,184, 84,204,176,115,121,50,45,127, 4,150,254,
  138,236,205,93,222,114,67,29,24,72,243,141,128,195,78,66,215,61,156,180 };

  private short perm[] = new short[512];
  private short permMod12[] = new short[512];

  private final float F2 = (float) (0.5 * (Math.sqrt(3) - 1));
  private final float G2 = (float) ((3 - Math.sqrt(3)) / 6);

  public SimplexNoise(int seed) {
  for(int i = 0; i < 512; i++) {
  perm[i] = p[i + seed & 255];
  permMod12[i] = (short) (perm[i] % 12);
  }
  }

  public BufferedImage generateHeightmap(int size, int interationCount, float persistance, float scale, int low, int high) {
  BufferedImage heightmap = new BufferedImage(size, size, BufferedImage.TYPE_INT_RGB);
  Graphics g = heightmap.getGraphics();
  int colorValue;

  for(int i = 0; i < size; i++){
  for(int j = 0; j < size; j++){
  colorValue = (int) sumOctaves(interationCount, i, j, persistance, scale, low, high);
  g.setColor(new Color(colorValue, colorValue, colorValue));
  g.drawLine(i, j, i, j);
  }
  }

  return heightmap;
  }

  public void saveImage(BufferedImage image, String pathToSave, String name, String ext) {
  try {
  BufferedImage bi = image;
  File outputfile = new File(pathToSave + "/" + name + "." + ext);
  ImageIO.write(bi, ext, outputfile);
  } catch (IOException ex) { }
  }

  private float sumOctaves(int interationCount, int x, int y, float persistance, float scale, int low, int high) {
  float maxAmplitude = 0;
  float amplitude = 1;
  float frequency = scale;
  float noiseValue = 0;

  for (int i = 0; i < interationCount; ++i) {
  noiseValue += generateSimplexNoise(x * frequency, y * frequency) * amplitude;
  maxAmplitude += amplitude;
  amplitude *= persistance;
  frequency *= 2;
  }

  noiseValue /= maxAmplitude;
  return noiseValue * (high - low) / 2 + (high + low) / 2;
  }

  private static int fastFloor(float x) {
  int xi = (int) x;
  return x < xi ? xi - 1 : xi;
  }

  private float dot(Gradient gradient, float x, float y) {
  return gradient.X * x + gradient.Y * y;
  }

  private float generateSimplexNoise(float x, float y) {
  float n0, n1, n2;
  float s = (x + y) * F2;

  int i = fastFloor(x + s);
  int j = fastFloor(y + s);

  float t = (i + j) * G2;

  float X0 = i - t;
  float Y0 = j - t;

  float x0 = x - X0;
  float y0 = y - Y0;

  int i1, j1;

  if(x0 > y0) {
  i1 = 1; j1 = 0;
  } else {
  i1 = 0; j1 = 1;
  }

  float x1 = x0 - i1 + G2;
  float y1 = y0 - j1 + G2;

  float x2 = x0 - 1.0F + 2.0F * G2;
  float y2 = y0 - 1.0F + 2.0F * G2;

  int ii = i & 255;
  int jj = j & 255;

  int gi0 = permMod12[ ii + perm[jj] ];
  int gi1 = permMod12[ ii + i1 + perm[jj + j1] ];
  int gi2 = permMod12[ ii + 1 + perm[jj+1] ];

  float t0 = 0.5F - x0 * x0 - y0 * y0;

  if(t0 < 0.0F) {
  n0 = 0.0F;
  } else {
  t0 *= t0;
  n0 = t0 * t0 * dot(grad3[gi0], x0, y0);
  }

  float t1 = 0.5F - x1 * x1 - y1 * y1;

  if(t1 < 0.0F) {
  n1 = 0.0F;
  } else {
  t1 *= t1;
  n1 = t1 * t1 * dot(grad3[gi1], x1, y1);
  }

  float t2 = 0.5F - x2 * x2 - y2 * y2;

  if(t2 < 0.0F) {
  n2 = 0.0F;
  } else {
  t2 *= t2;
  n2 = t2 * t2 * dot(grad3[gi2], x2, y2);
  }
  return 40.0F * (n0 + n1 + n2);
  }

  private class Gradient {

  float X, Y;

  Gradient(float x, float y) {
  this.X = x;
  this.Y = y;
  }

  }

}