title: On iOS, why UIBezierPath drawing doesn't require a context?
body: <p>On iOS, we can draw a line in <code>drawRect</code> using</p>
  
  <pre><code>CGContextRef context = UIGraphicsGetCurrentContext();
  CGContextBeginPath (context);
  CGContextMoveToPoint(context, 0, 0);
  CGContextAddLineToPoint(context, 100, 100);
  CGContextStrokePath(context);
  </code></pre>
  
  <p>but we can also draw a rectangle if we remove the above code, and just use:</p>
  
  <pre><code>UIBezierPath *path = [UIBezierPath bezierPathWithRect:CGRectMake(0, 0, 100, 100)];
  [path stroke];
  </code></pre>
  
  <p>Two related questions:</p>
  
  <p>1) Why doesn't <code>UIBezierPath</code> need to get or use the current context?  </p>
  
  <p>2) What if I have two context: one for screen, and one is a bitmap context, then how to tell which context to draw to for <code>UIBezierPath</code>?  I thought it might be <code>UIGraphicsSetCurrentContext</code> but it doesn't exist.</p>