118Echarts - 热力图（Heatmap - Discrete Mapping of Color）

效果图

源代码

app.title = '热力图 - 颜色的离散映射';

var noise = getNoiseHelper();
var xData = [];
var yData = [];
noise.seed(Math.random());
function generateData(theta, min, max) {
    var data = [];
    for (var i = 0; i 8) & 255);
      }

      perm[i] = perm[i + 256] = v;
      gradP[i] = gradP[i + 256] = grad3[v % 12];
    }
  };

  module.seed(0);

  /*
  for(var i=0; iy0) { // lower triangle, XY order: (0,0)->(1,0)->(1,1)
      i1=1; j1=0;
    } else {    // upper triangle, YX order: (0,0)->(0,1)->(1,1)
      i1=0; j1=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 + 2 * G2; // Offsets for last corner in (x,y) unskewed coords
    var y2 = y0 - 1 + 2 * G2;
    // Work out the hashed gradient indices of the three simplex corners
    i &= 255;
    j &= 255;
    var gi0 = gradP[i+perm[j]];
    var gi1 = gradP[i+i1+perm[j+j1]];
    var gi2 = gradP[i+1+perm[j+1]];
    // Calculate the contribution from the three corners
    var t0 = 0.5 - x0*x0-y0*y0;
    if(t0= z0) { i1=1; j1=0; k1=0; i2=1; j2=0; k2=1; }
      else              { i1=0; j1=0; k1=1; i2=1; j2=0; k2=1; }
    } else {
      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             { i1=0; j1=1; k1=0; i2=1; j2=1; k2=0; }
    }
    // 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
    var y1 = y0 - j1 + G3;
    var z1 = z0 - k1 + G3;

    var x2 = x0 - i2 + 2 * G3; // Offsets for third corner
    var y2 = y0 - j2 + 2 * G3;
    var z2 = z0 - k2 + 2 * G3;

    var x3 = x0 - 1 + 3 * G3; // Offsets for fourth corner
    var y3 = y0 - 1 + 3 * G3;
    var z3 = z0 - 1 + 3 * G3;

    // Work out the hashed gradient indices of the four simplex corners
    i &= 255;
    j &= 255;
    k &= 255;
    var gi0 = gradP[i+   perm[j+   perm[k   ]]];
    var gi1 = gradP[i+i1+perm[j+j1+perm[k+k1]]];
    var gi2 = gradP[i+i2+perm[j+j2+perm[k+k2]]];
    var gi3 = gradP[i+ 1+perm[j+ 1+perm[k+ 1]]];

    // Calculate the contribution from the four corners
    var t0 = 0.6 - x0*x0 - y0*y0 - z0*z0;
    if(t0