split utils

utils/colorUtils.js

@@ -0,0 +1,33 @@
+"use strict";
+// FMG utils related to colors
+
+// convert RGB color string to HEX without #
+function toHEX(rgb) {
+  if (rgb.charAt(0) === "#") return rgb;
+
+  rgb = rgb.match(/^rgba?[\s+]?\([\s+]?(\d+)[\s+]?,[\s+]?(\d+)[\s+]?,[\s+]?(\d+)[\s+]?/i);
+  return rgb && rgb.length === 4
+    ? "#" +
+        ("0" + parseInt(rgb[1], 10).toString(16)).slice(-2) +
+        ("0" + parseInt(rgb[2], 10).toString(16)).slice(-2) +
+        ("0" + parseInt(rgb[3], 10).toString(16)).slice(-2)
+    : "";
+}
+
+// return array of standard shuffled colors
+function getColors(number) {
+  const c12 = ["#dababf", "#fb8072", "#80b1d3", "#fdb462", "#b3de69", "#fccde5", "#c6b9c1", "#bc80bd", "#ccebc5", "#ffed6f", "#8dd3c7", "#eb8de7"];
+  const cRB = d3.scaleSequential(d3.interpolateRainbow);
+  const colors = d3.shuffle(d3.range(number).map(i => (i < 12 ? c12[i] : d3.color(cRB((i - 12) / (number - 12))).hex())));
+  return colors;
+}
+
+function getRandomColor() {
+  return d3.color(d3.scaleSequential(d3.interpolateRainbow)(Math.random())).hex();
+}
+
+// mix a color with a random color
+function getMixedColor(color, mix = 0.2, bright = 0.3) {
+  const c = color && color[0] === "#" ? color : getRandomColor(); // if provided color is not hex (e.g. harching), generate random one
+  return d3.color(d3.interpolate(c, getRandomColor())(mix)).brighter(bright).hex();
+}