Merge branch 'master' into alyssa-starter

1 files changed, 20 insertions, 0 deletions

diff --git a/src/ClientUtils.ts b/src/ClientUtils.ts
index e8165d5ab..e7aee1c2a 100644
--- a/src/ClientUtils.ts
+++ b/src/ClientUtils.ts
@@ -316,6 +316,26 @@ export namespace ClientUtils {
         return { h: h, s: s, l: l };
     }
 
+    export function lightenRGB(rVal: number, gVal: number, bVal: number, percent: number): [number, number, number] {
+        const amount = 1 + percent / 100;
+        const r = rVal * amount;
+        const g = gVal * amount;
+        const b = bVal * amount;
+
+        const threshold = 255.999;
+        const maxVal = Math.max(r, g, b);
+        if (maxVal <= threshold) {
+            return [Math.round(r), Math.round(g), Math.round(b)];
+        }
+        const total = r + g + b;
+        if (total >= 3 * threshold) {
+            return [Math.round(threshold), Math.round(threshold), Math.round(threshold)];
+        }
+        const x = (3 * threshold - total) / (3 * maxVal - total);
+        const gray = threshold - x * maxVal;
+        return [Math.round(gray + x * r), Math.round(gray + x * g), Math.round(gray + x * b)];
+    }
+
     export function scrollIntoView(targetY: number, targetHgt: number, scrollTop: number, contextHgt: number, minSpacing: number, scrollHeight: number) {
         if (!targetHgt) return targetY; // if there's no height, then assume that
         if (scrollTop + contextHgt < Math.min(scrollHeight, targetY + minSpacing + targetHgt)) {