fixed negative modulus bug in socket

1 files changed, 9 insertions, 1 deletions

diff --git a/socket.js b/socket.js
index f2502e8..e819e17 100644
--- a/socket.js
+++ b/socket.js
@@ -2,6 +2,8 @@
 const ws = require('ws')
 const EventEmitter = require('events');
 
+let mod = (div, end) => ( ( (div % end) + end ) % end ) // Makes it such that (-2) % 3 = 1 instead of -2.
+
 class retryws extends EventEmitter{ // a wrapper on ws that retries on failure
   constructor(addr) {
     super();
@@ -63,7 +65,13 @@ class Socket extends retryws {
       for (var i=0; i<chars.length; i++){
         let char = chars[i]
         let coord = char[0];
-        chars[i] = [Math.floor(coord[0]/8),Math.floor(coord[1]/16),(coord[0] % 8),(coord[1] % 16),char[1]];
+        chars[i] = [
+          Math.floor(coord[0]/8),
+          Math.floor(coord[1]/16),
+          mod(coord[0], 8),
+          mod(coord[1], 16),
+          char[1]
+        ];
         chars[i].splice(4,0,0);
         chars[i].push(i);
       }