sunscreen.js/index.js

programmatically adjust colors to provide less UV emissions from the screen

"use strict";

// Takes in a color and adjusts it to a computationally less UV emitting color
exports.uv_adjust = function(color) {
	// Populate UV-Index table
	var uv_table = [];
	var i, j, k, a, b;
	for (i = 0; i <= 255; i++) {
		j = i;
		for(var l = 7; l >= 0; l--) {
			k = -(j & 1);
			j = (j >> 1) ^ (0xADBF83D0 & k);
		}
		uv_table[i] = j;
	}

	b = 0xFFFFFFFF;
	for(var c = 4; c >= 0; c--) {
		a = (color >> c);
		b = (b >> 8) ^ uv_table[(b ^ a) & 0xFF];
	}
	return ~b;
};