Color stream ids to make them easier to differentiate

src/web/colors.js

@@ -0,0 +1,32 @@
+import Color from 'color'
+
+export function hashText(text, range) {
+  // DJBX33A-ish
+  // based on https://github.com/euphoria-io/heim/blob/978c921063e6b06012fc8d16d9fbf1b3a0be1191/client/lib/hueHash.js#L16-L45
+  let val = 0
+  for (let i = 0; i < text.length; i++) {
+    // Multiply by an arbitrary prime number to spread out similar letters.
+    const charVal = (text.charCodeAt(i) * 401) % range
+
+    // Multiply val by 33 while constraining within signed 32 bit int range.
+    // this keeps the value within Number.MAX_SAFE_INTEGER without throwing out
+    // information.
+    const origVal = val
+    val = val << 5
+    val += origVal
+
+    // Add the character to the hash.
+    val += charVal
+  }
+
+  return (val + range) % range
+}
+
+export function idColor(id) {
+  if (!id) {
+    return Color('white')
+  }
+  const h = hashText(id, 360)
+  const sPart = hashText(id, 40)
+  return Color({ h, s: 20 + sPart, l: 50 })
+}