add empty eslintignore, original source maps

client/app/scripts/utils/color-utils.js

@@ -0,0 +1,74 @@
+const d3 = require('d3');
+
+const PSEUDO_COLOR = '#b1b1cb';
+const hueRange = [20, 330]; // exclude red
+const hueScale = d3.scale.linear().range(hueRange);
+// map hues to lightness
+const lightnessScale = d3.scale.linear().domain(hueRange).range([0.5, 0.7]);
+const startLetterRange = 'A'.charCodeAt();
+const endLetterRange = 'Z'.charCodeAt();
+const letterRange = endLetterRange - startLetterRange;
+
+/**
+ * Converts a text to a 360 degree value
+ */
+function text2degree(text) {
+  const input = text.substr(0, 2).toUpperCase();
+  let num = 0;
+  let charCode;
+  for (let i = 0; i < input.length; i++) {
+    charCode = Math.max(Math.min(input[i].charCodeAt(), endLetterRange), startLetterRange);
+    num += Math.pow(letterRange, input.length - i - 1) * (charCode - startLetterRange);
+  }
+  hueScale.domain([0, Math.pow(letterRange, input.length)]);
+  return hueScale(num);
+}
+
+function colors(text, secondText) {
+  let hue = text2degree(text);
+  // skip green and shift to the end of the color wheel
+  if (hue > 70 && hue < 150) {
+    hue += 80;
+  }
+  const saturation = 0.6;
+  let lightness = 0.5;
+  if (secondText) {
+    // reuse text2degree and feed degree to lightness scale
+    lightness = lightnessScale(text2degree(secondText));
+  }
+  const color = d3.hsl(hue, saturation, lightness);
+  return color;
+}
+
+const NodeColorMixin = {
+  getNodeColor: function(text, secondText) {
+    return colors(text, secondText);
+  },
+  getNodeColorDark: function(text, secondText) {
+    if (!text) {
+      return PSEUDO_COLOR;
+    }
+    const color = d3.rgb(colors(text, secondText));
+    let hsl = color.hsl();
+
+    // ensure darkness
+    if (hsl.l > 0.7) {
+      hsl = hsl.darker(1.5);
+    } else {
+      hsl = hsl.darker(1);
+    }
+
+    return hsl.toString();
+  },
+  brightenColor: function(color) {
+    let hsl = d3.rgb(color).hsl();
+    if (hsl.l > 0.5) {
+      hsl = hsl.brighter(0.5);
+    } else {
+      hsl = hsl.brighter(0.8);
+    }
+    return hsl.toString();
+  }
+};
+
+module.exports = NodeColorMixin;