problem to draw and fill rect after cgcontextclip
<p>I want to clip a rectangle from cgpath with the following code. I don't get any output. What's wrong?</p>

<pre><code>    CGContextRef context = UIGraphicsGetCurrentContext();
    CGMutablePathRef thePath = CGPathCreateMutable();
    CGPathMoveToPoint(thePath,NULL,(self.x1),(self.y1));
    CGPathAddLineToPoint(thePath,NULL,(self.x2),(self.y2));
    CGPathAddLineToPoint(thePath,NULL,bx2,by2);
    CGPathAddLineToPoint(thePath,NULL,bx1,by1);
    CGContextAddPath(context, thePath);
    CGContextClip(context);
    CGContextSetRGBFillColor(context, 1.0, 1.0, 1.0, 1.0);
    CFRelease(thePath);
</code></pre>
