Fixing the pixel wrapping algorithm.

reu · Mar 24, 2013 · 7b916c6 · 7b916c6
1 parent 29c4ede
commit 7b916c6
Showing 1 changed file with 4 additions and 10 deletions.
diff --git a/src/screen.js b/src/screen.js
@@ -28,17 +28,11 @@
      */
     this.setPixel = function(x, y) {
       // Wrap around pixels that overflow the screen
-      if (x > this.columns) {
-        x -= this.columns;
-      } else if (x < 0) {
-        x += this.columns;
-      }
+      if (x > this.columns - 1) while (x > this.columns - 1) x -= this.columns;
+      if (x < 0)                while (x < 0)                x += this.columns;
 
-      if (y > this.rows) {
-        y -= this.rows;
-      } else if (y < 0) {
-        y += this.rows;
-      }
+      if (y > this.rows - 1) while (y > this.rows - 1) y -= this.rows;
+      if (y < 0)             while (y < 0)             y += this.rows;
 
       var location = x + (y * this.columns);
       this.bitMap[location] = this.bitMap[location] ^ 1;