#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