Add text color based off luminance for full video label

src/utils/genericUtils.ts

@@ -44,7 +44,30 @@ function getErrorMessage(statusCode: number, responseText: string): string {
     return errorMessage + postFix;
 }
 
+/* Gets percieved luminance of a color */
+function getLuminance(color: string): number {
+    const {r, g, b} = hexToRgb(color);
+    return Math.sqrt(0.299 * (r * r) + 0.587 * (g * g) + 0.114 * (b * b));
+}
+
+/* From https://stackoverflow.com/a/5624139 */
+function hexToRgb(hex: string): {r: number, g: number, b: number} {
+    // Expand shorthand form (e.g. "03F") to full form (e.g. "0033FF")
+    const shorthandRegex = /^#?([a-f\d])([a-f\d])([a-f\d])$/i;
+    hex = hex.replace(shorthandRegex, function(m, r, g, b) {
+      return r + r + g + g + b + b;
+    });
+  
+    const result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
+    return result ? {
+      r: parseInt(result[1], 16),
+      g: parseInt(result[2], 16),
+      b: parseInt(result[3], 16)
+    } : null;
+  }
+
 export const GenericUtils = {
     wait,
-    getErrorMessage
+    getErrorMessage,
+    getLuminance
 }