optimize drawing circle issue #331

Author: lauren mccarthy

lib/p5.js

@@ -1,4 +1,4 @@
-/*! p5.js v0.3.3 August 25, 2014 */
+/*! p5.js v0.3.3 August 26, 2014 */
 var shim = function (require) {
     window.requestDraw = function () {
       return window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || window.oRequestAnimationFrame || window.msRequestAnimationFrame || function (callback, element) {
@@ -3929,20 +3929,24 @@ var shape2d_primitives = function (require, core, canvas, constants) {
       }
       return this;
     };
-    p5.prototype.ellipse = function (x, y, width, height) {
+    p5.prototype.ellipse = function (x, y, w, h) {
       if (!this._doStroke && !this._doFill) {
         return;
       }
       var ctx = this.drawingContext;
-      var vals = canvas.modeAdjust(x, y, width, height, this._ellipseMode);
-      var kappa = 0.5522848, ox = vals.w / 2 * kappa, oy = vals.h / 2 * kappa, xe = vals.x + vals.w, ye = vals.y + vals.h, xm = vals.x + vals.w / 2, ym = vals.y + vals.h / 2;
+      var vals = canvas.modeAdjust(x, y, w, h, this._ellipseMode);
       ctx.beginPath();
-      ctx.moveTo(vals.x, ym);
-      ctx.bezierCurveTo(vals.x, ym - oy, xm - ox, vals.y, xm, vals.y);
-      ctx.bezierCurveTo(xm + ox, vals.y, xe, ym - oy, xe, ym);
-      ctx.bezierCurveTo(xe, ym + oy, xm + ox, ye, xm, ye);
-      ctx.bezierCurveTo(xm - ox, ye, vals.x, ym + oy, vals.x, ym);
-      ctx.closePath();
+      if (w === h) {
+        ctx.arc(vals.x, vals.y, vals.w / 2, 0, 2 * Math.PI, false);
+      } else {
+        var kappa = 0.5522848, ox = vals.w / 2 * kappa, oy = vals.h / 2 * kappa, xe = vals.x + vals.w, ye = vals.y + vals.h, xm = vals.x + vals.w / 2, ym = vals.y + vals.h / 2;
+        ctx.moveTo(vals.x, ym);
+        ctx.bezierCurveTo(vals.x, ym - oy, xm - ox, vals.y, xm, vals.y);
+        ctx.bezierCurveTo(xm + ox, vals.y, xe, ym - oy, xe, ym);
+        ctx.bezierCurveTo(xe, ym + oy, xm + ox, ye, xm, ye);
+        ctx.bezierCurveTo(xm - ox, ye, vals.x, ym + oy, vals.x, ym);
+        ctx.closePath();
+      }
       if (this._doFill) {
         ctx.fill();
       }