bytev-charts/lib/plugin/three.js/examples/js/math/SimplexNoise.js

基于echarts和JavaScript及ES6封装的一个可以直接调用的图表组件库，内置主题设计，简单快捷，且支持用户自定义配置； npm 安装方式: npm install bytev-charts 若启动提示还需额外install插件,则运行 npm install @babel/runtime-corejs2 即可;

console.warn("THREE.SimplexNoise: As part of the transition to ES6 Modules, the files in 'examples/js' were deprecated in May 2020 (r117) and will be deleted in December 2020 (r124). You can find more information about developing using ES6 Modules in https://threejs.org/docs/#manual/en/introduction/Installation."); // Ported from Stefan Gustavson's java implementation
// http://staffwww.itn.liu.se/~stegu/simplexnoise/simplexnoise.pdf
// Read Stefan's excellent paper for details on how this code works.
//
// Sean McCullough banksean@gmail.com
//
// Added 4D noise

/**
 * You can pass in a random number generator object if you like.
 * It is assumed to have a random() method.
 */

THREE.SimplexNoise = function (r) {
  if (r == undefined) r = Math;
  this.grad3 = [[1, 1, 0], [-1, 1, 0], [1, -1, 0], [-1, -1, 0], [1, 0, 1], [-1, 0, 1], [1, 0, -1], [-1, 0, -1], [0, 1, 1], [0, -1, 1], [0, 1, -1], [0, -1, -1]];
  this.grad4 = [[0, 1, 1, 1], [0, 1, 1, -1], [0, 1, -1, 1], [0, 1, -1, -1], [0, -1, 1, 1], [0, -1, 1, -1], [0, -1, -1, 1], [0, -1, -1, -1], [1, 0, 1, 1], [1, 0, 1, -1], [1, 0, -1, 1], [1, 0, -1, -1], [-1, 0, 1, 1], [-1, 0, 1, -1], [-1, 0, -1, 1], [-1, 0, -1, -1], [1, 1, 0, 1], [1, 1, 0, -1], [1, -1, 0, 1], [1, -1, 0, -1], [-1, 1, 0, 1], [-1, 1, 0, -1], [-1, -1, 0, 1], [-1, -1, 0, -1], [1, 1, 1, 0], [1, 1, -1, 0], [1, -1, 1, 0], [1, -1, -1, 0], [-1, 1, 1, 0], [-1, 1, -1, 0], [-1, -1, 1, 0], [-1, -1, -1, 0]];
  this.p = [];

  for (var i = 0; i < 256; i++) {
    this.p[i] = Math.floor(r.random() * 256);
  } // To remove the need for index wrapping, double the permutation table length


  this.perm = [];

  for (var i = 0; i < 512; i++) {
    this.perm[i] = this.p[i & 255];
  } // A lookup table to traverse the simplex around a given point in 4D.
  // Details can be found where this table is used, in the 4D noise method.


  this.simplex = [[0, 1, 2, 3], [0, 1, 3, 2], [0, 0, 0, 0], [0, 2, 3, 1], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [1, 2, 3, 0], [0, 2, 1, 3], [0, 0, 0, 0], [0, 3, 1, 2], [0, 3, 2, 1], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [1, 3, 2, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [1, 2, 0, 3], [0, 0, 0, 0], [1, 3, 0, 2], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [2, 3, 0, 1], [2, 3, 1, 0], [1, 0, 2, 3], [1, 0, 3, 2], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [2, 0, 3, 1], [0, 0, 0, 0], [2, 1, 3, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [2, 0, 1, 3], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [3, 0, 1, 2], [3, 0, 2, 1], [0, 0, 0, 0], [3, 1, 2, 0], [2, 1, 0, 3], [0, 0, 0, 0], [0, 0, 0, 0], [0, 0, 0, 0], [3, 1, 0, 2], [0, 0, 0, 0], [3, 2, 0, 1], [3, 2, 1, 0]];
};

THREE.SimplexNoise.prototype.dot = function (g, x, y) {
  return g[0] * x + g[1] * y;
};

THREE.SimplexNoise.prototype.dot3 = function (g, x, y, z) {
  return g[0] * x + g[1] * y + g[2] * z;
};

THREE.SimplexNoise.prototype.dot4 = function (g, x, y, z, w) {
  return g[0] * x + g[1] * y + g[2] * z + g[3] * w;
};

THREE.SimplexNoise.prototype.noise = function (xin, yin) {
  var n0, n1, n2; // Noise contributions from the three corners
  // Skew the input space to determine which simplex cell we're in

  var F2 = 0.5 * (Math.sqrt(3.0) - 1.0);
  var s = (xin + yin) * F2; // Hairy factor for 2D

  var i = Math.floor(xin + s);
  var j = Math.floor(yin + s);
  var G2 = (3.0 - Math.sqrt(3.0)) / 6.0;
  var t = (i + j) * G2;
  var X0 = i - t; // Unskew the cell origin back to (x,y) space

  var Y0 = j - t;
  var x0 = xin - X0; // The x,y distances from the cell origin

  var y0 = yin - Y0; // For the 2D case, the simplex shape is an equilateral triangle.
  // Determine which simplex we are in.

  var i1, j1; // Offsets for second (middle) corner of simplex in (i,j) coords

  if (x0 > y0) {
    i1 = 1;
    j1 = 0; // lower triangle, XY order: (0,0)->(1,0)->(1,1)
  } else {
    i1 = 0;
    j1 = 1;
  } // upper triangle, YX order: (0,0)->(0,1)->(1,1)
  // A step of (1,0) in (i,j) means a step of (1-c,-c) in (x,y), and
  // a step of (0,1) in (i,j) means a step of (-c,1-c) in (x,y), where
  // c = (3-sqrt(3))/6


  var x1 = x0 - i1 + G2; // Offsets for middle corner in (x,y) unskewed coords

  var y1 = y0 - j1 + G2;
  var x2 = x0 - 1.0 + 2.0 * G2; // Offsets for last corner in (x,y) unskewed coords

  var y2 = y0 - 1.0 + 2.0 * G2; // Work out the hashed gradient indices of the three simplex corners

  var ii = i & 255;
  var jj = j & 255;
  var gi0 = this.perm[ii + this.perm[jj]] % 12;
  var gi1 = this.perm[ii + i1 + this.perm[jj + j1]] % 12;
  var gi2 = this.perm[ii + 1 + this.perm[jj + 1]] % 12; // Calculate the contribution from the three corners

  var t0 = 0.5 - x0 * x0 - y0 * y0;
  if (t0 < 0) n0 = 0.0;else {
    t0 *= t0;
    n0 = t0 * t0 * this.dot(this.grad3[gi0], x0, y0); // (x,y) of grad3 used for 2D gradient
  }
  var t1 = 0.5 - x1 * x1 - y1 * y1;
  if (t1 < 0) n1 = 0.0;else {
    t1 *= t1;
    n1 = t1 * t1 * this.dot(this.grad3[gi1], x1, y1);
  }
  var t2 = 0.5 - x2 * x2 - y2 * y2;
  if (t2 < 0) n2 = 0.0;else {
    t2 *= t2;
    n2 = t2 * t2 * this.dot(this.grad3[gi2], x2, y2);
  } // Add contributions from each corner to get the final noise value.
  // The result is scaled to return values in the interval [-1,1].

  return 70.0 * (n0 + n1 + n2);
}; // 3D simplex noise


THREE.SimplexNoise.prototype.noise3d = function (xin, yin, zin) {
  var n0, n1, n2, n3; // Noise contributions from the four corners
  // Skew the input space to determine which simplex cell we're in

  var F3 = 1.0 / 3.0;
  var s = (xin + yin + zin) * F3; // Very nice and simple skew factor for 3D

  var i = Math.floor(xin + s);
  var j = Math.floor(yin + s);
  var k = Math.floor(zin + s);
  var G3 = 1.0 / 6.0; // Very nice and simple unskew factor, too

  var t = (i + j + k) * G3;
  var X0 = i - t; // Unskew the cell origin back to (x,y,z) space

  var Y0 = j - t;
  var Z0 = k - t;
  var x0 = xin - X0; // The x,y,z distances from the cell origin

  var y0 = yin - Y0;
  var z0 = zin - Z0; // For the 3D case, the simplex shape is a slightly irregular tetrahedron.
  // Determine which simplex we are in.

  var i1, j1, k1; // Offsets for second corner of simplex in (i,j,k) coords

  var i2, j2, k2; // Offsets for third corner of simplex in (i,j,k) coords

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

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

  } // A step of (1,0,0) in (i,j,k) means a step of (1-c,-c,-c) in (x,y,z),
  // a step of (0,1,0) in (i,j,k) means a step of (-c,1-c,-c) in (x,y,z), and
  // a step of (0,0,1) in (i,j,k) means a step of (-c,-c,1-c) in (x,y,z), where
  // c = 1/6.


  var x1 = x0 - i1 + G3; // Offsets for second corner in (x,y,z) coords

  var y1 = y0 - j1 + G3;
  var z1 = z0 - k1 + G3;
  var x2 = x0 - i2 + 2.0 * G3; // Offsets for third corner in (x,y,z) coords

  var y2 = y0 - j2 + 2.0 * G3;
  var z2 = z0 - k2 + 2.0 * G3;
  var x3 = x0 - 1.0 + 3.0 * G3; // Offsets for last corner in (x,y,z) coords

  var y3 = y0 - 1.0 + 3.0 * G3;
  var z3 = z0 - 1.0 + 3.0 * G3; // Work out the hashed gradient indices of the four simplex corners

  var ii = i & 255;
  var jj = j & 255;
  var kk = k & 255;
  var gi0 = this.perm[ii + this.perm[jj + this.perm[kk]]] % 12;
  var gi1 = this.perm[ii + i1 + this.perm[jj + j1 + this.perm[kk + k1]]] % 12;
  var gi2 = this.perm[ii + i2 + this.perm[jj + j2 + this.perm[kk + k2]]] % 12;
  var gi3 = this.perm[ii + 1 + this.perm[jj + 1 + this.perm[kk + 1]]] % 12; // Calculate the contribution from the four corners

  var t0 = 0.6 - x0 * x0 - y0 * y0 - z0 * z0;
  if (t0 < 0) n0 = 0.0;else {
    t0 *= t0;
    n0 = t0 * t0 * this.dot3(this.grad3[gi0], x0, y0, z0);
  }
  var t1 = 0.6 - x1 * x1 - y1 * y1 - z1 * z1;
  if (t1 < 0) n1 = 0.0;else {
    t1 *= t1;
    n1 = t1 * t1 * this.dot3(this.grad3[gi1], x1, y1, z1);
  }
  var t2 = 0.6 - x2 * x2 - y2 * y2 - z2 * z2;
  if (t2 < 0) n2 = 0.0;else {
    t2 *= t2;
    n2 = t2 * t2 * this.dot3(this.grad3[gi2], x2, y2, z2);
  }
  var t3 = 0.6 - x3 * x3 - y3 * y3 - z3 * z3;
  if (t3 < 0) n3 = 0.0;else {
    t3 *= t3;
    n3 = t3 * t3 * this.dot3(this.grad3[gi3], x3, y3, z3);
  } // Add contributions from each corner to get the final noise value.
  // The result is scaled to stay just inside [-1,1]

  return 32.0 * (n0 + n1 + n2 + n3);
}; // 4D simplex noise


THREE.SimplexNoise.prototype.noise4d = function (x, y, z, w) {
  // For faster and easier lookups
  var grad4 = this.grad4;
  var simplex = this.simplex;
  var perm = this.perm; // The skewing and unskewing factors are hairy again for the 4D case

  var F4 = (Math.sqrt(5.0) - 1.0) / 4.0;
  var G4 = (5.0 - Math.sqrt(5.0)) / 20.0;
  var n0, n1, n2, n3, n4; // Noise contributions from the five corners
  // Skew the (x,y,z,w) space to determine which cell of 24 simplices we're in

  var s = (x + y + z + w) * F4; // Factor for 4D skewing

  var i = Math.floor(x + s);
  var j = Math.floor(y + s);
  var k = Math.floor(z + s);
  var l = Math.floor(w + s);
  var t = (i + j + k + l) * G4; // Factor for 4D unskewing

  var X0 = i - t; // Unskew the cell origin back to (x,y,z,w) space

  var Y0 = j - t;
  var Z0 = k - t;
  var W0 = l - t;
  var x0 = x - X0; // The x,y,z,w distances from the cell origin

  var y0 = y - Y0;
  var z0 = z - Z0;
  var w0 = w - W0; // For the 4D case, the simplex is a 4D shape I won't even try to describe.
  // To find out which of the 24 possible simplices we're in, we need to
  // determine the magnitude ordering of x0, y0, z0 and w0.
  // The method below is a good way of finding the ordering of x,y,z,w and
  // then find the correct traversal order for the simplex we’re in.
  // First, six pair-wise comparisons are performed between each possible pair
  // of the four coordinates, and the results are used to add up binary bits
  // for an integer index.

  var c1 = x0 > y0 ? 32 : 0;
  var c2 = x0 > z0 ? 16 : 0;
  var c3 = y0 > z0 ? 8 : 0;
  var c4 = x0 > w0 ? 4 : 0;
  var c5 = y0 > w0 ? 2 : 0;
  var c6 = z0 > w0 ? 1 : 0;
  var c = c1 + c2 + c3 + c4 + c5 + c6;
  var i1, j1, k1, l1; // The integer offsets for the second simplex corner

  var i2, j2, k2, l2; // The integer offsets for the third simplex corner

  var i3, j3, k3, l3; // The integer offsets for the fourth simplex corner
  // simplex[c] is a 4-vector with the numbers 0, 1, 2 and 3 in some order.
  // Many values of c will never occur, since e.g. x>y>z>w makes x<z, y<w and x<w
  // impossible. Only the 24 indices which have non-zero entries make any sense.
  // We use a thresholding to set the coordinates in turn from the largest magnitude.
  // The number 3 in the "simplex" array is at the position of the largest coordinate.

  i1 = simplex[c][0] >= 3 ? 1 : 0;
  j1 = simplex[c][1] >= 3 ? 1 : 0;
  k1 = simplex[c][2] >= 3 ? 1 : 0;
  l1 = simplex[c][3] >= 3 ? 1 : 0; // The number 2 in the "simplex" array is at the second largest coordinate.

  i2 = simplex[c][0] >= 2 ? 1 : 0;
  j2 = simplex[c][1] >= 2 ? 1 : 0;
  k2 = simplex[c][2] >= 2 ? 1 : 0;
  l2 = simplex[c][3] >= 2 ? 1 : 0; // The number 1 in the "simplex" array is at the second smallest coordinate.

  i3 = simplex[c][0] >= 1 ? 1 : 0;
  j3 = simplex[c][1] >= 1 ? 1 : 0;
  k3 = simplex[c][2] >= 1 ? 1 : 0;
  l3 = simplex[c][3] >= 1 ? 1 : 0; // The fifth corner has all coordinate offsets = 1, so no need to look that up.

  var x1 = x0 - i1 + G4; // Offsets for second corner in (x,y,z,w) coords

  var y1 = y0 - j1 + G4;
  var z1 = z0 - k1 + G4;
  var w1 = w0 - l1 + G4;
  var x2 = x0 - i2 + 2.0 * G4; // Offsets for third corner in (x,y,z,w) coords

  var y2 = y0 - j2 + 2.0 * G4;
  var z2 = z0 - k2 + 2.0 * G4;
  var w2 = w0 - l2 + 2.0 * G4;
  var x3 = x0 - i3 + 3.0 * G4; // Offsets for fourth corner in (x,y,z,w) coords

  var y3 = y0 - j3 + 3.0 * G4;
  var z3 = z0 - k3 + 3.0 * G4;
  var w3 = w0 - l3 + 3.0 * G4;
  var x4 = x0 - 1.0 + 4.0 * G4; // Offsets for last corner in (x,y,z,w) coords

  var y4 = y0 - 1.0 + 4.0 * G4;
  var z4 = z0 - 1.0 + 4.0 * G4;
  var w4 = w0 - 1.0 + 4.0 * G4; // Work out the hashed gradient indices of the five simplex corners

  var ii = i & 255;
  var jj = j & 255;
  var kk = k & 255;
  var ll = l & 255;
  var gi0 = perm[ii + perm[jj + perm[kk + perm[ll]]]] % 32;
  var gi1 = perm[ii + i1 + perm[jj + j1 + perm[kk + k1 + perm[ll + l1]]]] % 32;
  var gi2 = perm[ii + i2 + perm[jj + j2 + perm[kk + k2 + perm[ll + l2]]]] % 32;
  var gi3 = perm[ii + i3 + perm[jj + j3 + perm[kk + k3 + perm[ll + l3]]]] % 32;
  var gi4 = perm[ii + 1 + perm[jj + 1 + perm[kk + 1 + perm[ll + 1]]]] % 32; // Calculate the contribution from the five corners

  var t0 = 0.6 - x0 * x0 - y0 * y0 - z0 * z0 - w0 * w0;
  if (t0 < 0) n0 = 0.0;else {
    t0 *= t0;
    n0 = t0 * t0 * this.dot4(grad4[gi0], x0, y0, z0, w0);
  }
  var t1 = 0.6 - x1 * x1 - y1 * y1 - z1 * z1 - w1 * w1;
  if (t1 < 0) n1 = 0.0;else {
    t1 *= t1;
    n1 = t1 * t1 * this.dot4(grad4[gi1], x1, y1, z1, w1);
  }
  var t2 = 0.6 - x2 * x2 - y2 * y2 - z2 * z2 - w2 * w2;
  if (t2 < 0) n2 = 0.0;else {
    t2 *= t2;
    n2 = t2 * t2 * this.dot4(grad4[gi2], x2, y2, z2, w2);
  }
  var t3 = 0.6 - x3 * x3 - y3 * y3 - z3 * z3 - w3 * w3;
  if (t3 < 0) n3 = 0.0;else {
    t3 *= t3;
    n3 = t3 * t3 * this.dot4(grad4[gi3], x3, y3, z3, w3);
  }
  var t4 = 0.6 - x4 * x4 - y4 * y4 - z4 * z4 - w4 * w4;
  if (t4 < 0) n4 = 0.0;else {
    t4 *= t4;
    n4 = t4 * t4 * this.dot4(grad4[gi4], x4, y4, z4, w4);
  } // Sum up and scale the result to cover the range [-1,1]

  return 27.0 * (n0 + n1 + n2 + n3 + n4);
};