#pragma once
 
/*--------------------------------------------------------------------
 Simplex Noise C++ implementation
 Based on a public domain code by Stefan Gustavson.
 (The original header is below)
--------------------------------------------------------------------*/
/*-- start of the original header --*/
/*
* A speed-improved simplex noise algorithm for 2D, 3D and 4D in Java.
*
* Based on example code by Stefan Gustavson (stegu@itn.liu.se).
* Optimisations by Peter Eastman (peastman@drizzle.stanford.edu).
* Better rank ordering method by Stefan Gustavson in 2012.
*
* This could be speeded up even further, but it's useful as it is.
*
* Version 2012-03-09
*
* This code was placed in the public domain by its original author,
* Stefan Gustavson. You may use it as you see fit, but
* attribution is appreciated.
*
*/
/*-- end of the original header --*/
 
#ifndef IWA_SIMPLEXNOISE_H
#define IWA_SIMPLEXNOISE_H
 
struct Grad {
  int x, y, z, w;
  Grad(int x_, int y_, int z_) : x(x_), y(y_), z(z_), w(0) {}
  Grad(int x_, int y_, int z_, int w_) : x(x_), y(y_), z(z_), w(w_) {}
};
 
struct CellIds {
  int i, j, k;
  int i1, j1, k1;
  int i2, j2, k2;
  CellIds(int _i = 0, int _j = 0, int _k = 0, int _i1 = 0, int _j1 = 0,
          int _k1 = 0, int _i2 = 0, int _j2 = 0, int _k2 = 0) {
    i  = _i;
    j  = _j;
    k  = _k;
    i1 = _i1;
    j1 = _j1;
    k1 = _k1;
    i2 = _i2;
    j2 = _j2;
    k2 = _k2;
  }
 
  bool operator==(const CellIds &right) const {
    return i == right.i && j == right.j && k == right.k && i1 == right.i1 &&
           j1 == right.j1 && k1 == right.k1 && i2 == right.i2 &&
           j2 == right.j2 && k2 == right.k2;
  }
};
 
class SimplexNoise {
  // This method is a *lot* faster than using (int)Math.floor(x)
  static int fastfloor(double x) {
    int xi = (int)x;
    return x < xi ? xi - 1 : xi;
  }
 
  static double dot(Grad g, double x, double y) { return g.x * x + g.y * y; }
 
  static double dot(Grad g, double x, double y, double z) {
    return g.x * x + g.y * y + g.z * z;
  }
 
  static double dot(Grad g, double x, double y, double z, double w) {
    return g.x * x + g.y * y + g.z * z + g.w * w;
  }
 
public:
  SimplexNoise();
  // 2D simplex noise
  static double noise(double xin, double yin);
  // 3D simplex noise
  static double noise(double xin, double yin, double zin);
  // 4D simplex noise
  static double noise(double x, double y, double z, double w);
 
  /*- セルまたぎを防ぐために、現在の所属セルを得る -*/
  static CellIds getCellIds(double xin, double yin, double zin);
};
 
#endif