singleSimplex3 method

double singleSimplex3(int seed, int x, int y, int z,)

Implementation

double singleSimplex3(int seed, int x, int y, int z) {
  var t = (x + y + z) * _f3;
  final i = x + t.floor();
  final j = y + t.floor();
  final k = z + t.floor();

  t = (i + j + k) * _g3;

  final x0 = x - (i - t);
  final y0 = y - (j - t);
  final z0 = z - (k - t);

  int i1;
  int j1;
  int k1;
  int i2;
  int j2;
  int k2;

  if (x0 >= y0) {
    if (y0 >= z0) {
      i1 = 1;
      j1 = 0;
      k1 = 0;
      i2 = 1;
      j2 = 1;
      k2 = 0;
    } else if (x0 >= z0) {
      i1 = 1;
      j1 = 0;
      k1 = 0;
      i2 = 1;
      j2 = 0;
      k2 = 1;
    } else // x0 < z0
    {
      i1 = 0;
      j1 = 0;
      k1 = 1;
      i2 = 1;
      j2 = 0;
      k2 = 1;
    }
  } else // x0 < y0
  {
    if (y0 < z0) {
      i1 = 0;
      j1 = 0;
      k1 = 1;
      i2 = 0;
      j2 = 1;
      k2 = 1;
    } else if (x0 < z0) {
      i1 = 0;
      j1 = 1;
      k1 = 0;
      i2 = 0;
      j2 = 1;
      k2 = 1;
    } else // x0 >= z0
    {
      i1 = 0;
      j1 = 1;
      k1 = 0;
      i2 = 1;
      j2 = 1;
      k2 = 0;
    }
  }

  final x1 = x0 - i1 + _g3;
  final y1 = y0 - j1 + _g3;
  final z1 = z0 - k1 + _g3;
  final x2 = x0 - i2 + _f3;
  final y2 = y0 - j2 + _f3;
  final z2 = z0 - k2 + _f3;
  final x3 = x0 + _g33;
  final y3 = y0 + _g33;
  final z3 = z0 + _g33;
  final double n0;
  final double n1;
  final double n2;
  final double n3;

  t = 0.6 - x0 * x0 - y0 * y0 - z0 * z0;

  if (t < 0) {
    n0 = .0;
  } else {
    t *= t;
    n0 = t * t * gradCoord3D(seed, i, j, k, x0, y0, z0);
  }

  t = 0.6 - x1 * x1 - y1 * y1 - z1 * z1;
  if (t < 0) {
    n1 = .0;
  } else {
    t *= t;
    n1 = t * t * gradCoord3D(seed, i + i1, j + j1, k + k1, x1, y1, z1);
  }

  t = 0.6 - x2 * x2 - y2 * y2 - z2 * z2;
  if (t < 0) {
    n2 = .0;
  } else {
    t *= t;
    n2 = t * t * gradCoord3D(seed, i + i2, j + j2, k + k2, x2, y2, z2);
  }

  t = 0.6 - x3 * x3 - y3 * y3 - z3 * z3;
  if (t < 0) {
    n3 = .0;
  } else {
    t *= t;
    n3 = t * t * gradCoord3D(seed, i + 1, j + 1, k + 1, x3, y3, z3);
  }

  return 32 * (n0 + n1 + n2 + n3);
}