Update bresenham

mgechev · mgechev · commit 94b706a95cc8 · 2014-10-07T11:02:49.000+03:00
diff --git a/src/graphics/bresenham-line-drawing.js b/src/graphics/bresenham-line-drawing.js
@@ -1,38 +1,45 @@
-/**
- * Bresenham's line drawing algorithm.
- * It has complexity O(n)
- * @param  {number} x1 The first coordinate of the beginning of the line
- * @param  {number} y1 The second coordinate of the beginning of the line
- * @param  {number} x2 The first coordinate of the end of the line
- * @param  {number} y2 The second coordinate of the end of the line
- */
-function drawLine(x1, y1, x2, y2) {
-  var dx = Math.abs(x2 - x1),
-    dy = Math.abs(y2 - y1),
-    cx = (x1 < x2) ? 1 : -1,
-    cy = (y1 < y2) ? 1 : -1,
-    error = dx - dy,
-    doubledError;
-  
-  while (x1 !== x2 || y1 !== y2) {
-    drawPoint(x1, y1);
-    doubledError = error + error;
-    if (doubledError > -dy) {
-      error -= dy;
-      x1 += cx;
-    }
-    if (doubledError < dx) {
-      error += dx;
-      y1 += cy;
+(function (exports) {
+  'use strict';
+
+  /**
+   * Bresenham's line drawing algorithm.
+   * It has complexity O(n)
+   * @param  {number} x1 The first coordinate of the beginning of the line
+   * @param  {number} y1 The second coordinate of the beginning of the line
+   * @param  {number} x2 The first coordinate of the end of the line
+   * @param  {number} y2 The second coordinate of the end of the line
+   */
+  function drawLine(x1, y1, x2, y2) {
+    var dx = Math.abs(x2 - x1),
+      dy = Math.abs(y2 - y1),
+      cx = (x1 < x2) ? 1 : -1,
+      cy = (y1 < y2) ? 1 : -1,
+      error = dx - dy,
+      doubledError;
+
+    while (x1 !== x2 || y1 !== y2) {
+      drawPoint(x1, y1);
+      doubledError = error + error;
+      if (doubledError > -dy) {
+        error -= dy;
+        x1 += cx;
+      }
+      if (doubledError < dx) {
+        error += dx;
+        y1 += cy;
+      }
     }
   }
-}
 
-/**
- * Draws (prints) the given coordinates
- * @param  {number} x The first coordinate of the point
- * @param  {number} y The second coordinate of the point
- */
-function drawPoint(x, y) {
-  console.log(x, y);
-}
+  /**
+   * Draws (prints) the given coordinates
+   * @param  {number} x The first coordinate of the point
+   * @param  {number} y The second coordinate of the point
+   */
+  function drawPoint(x, y) {
+    console.log(x, y);
+  }
+
+  exports.drawLine = drawLine;
+
+}(typeof exports === 'undefined' ? window : exports));
