piskel/js/lib/gif/b64.js
2013-04-07 20:16:47 +02:00

18 lines
616 B
JavaScript

function encode64(input) {
var output = "", i = 0, l = input.length,
key = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=",
chr1, chr2, chr3, enc1, enc2, enc3, enc4;
while (i < l) {
chr1 = input.charCodeAt(i++);
chr2 = input.charCodeAt(i++);
chr3 = input.charCodeAt(i++);
enc1 = chr1 >> 2;
enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
enc4 = chr3 & 63;
if (isNaN(chr2)) enc3 = enc4 = 64;
else if (isNaN(chr3)) enc4 = 64;
output = output + key.charAt(enc1) + key.charAt(enc2) + key.charAt(enc3) + key.charAt(enc4);
}
return output;
}