Core Text: Render to an Odd Shape

问题

I am trying to render text to a shape that isn't a rectangle. The following code works when I add a rectangular path but not when I add an elliptical path. Ultimately, I'd like to draw to any path (L shape, etc), has anyone had any luck with this?

-(void)drawRect:(CGRect)rect {
    CGContextRef context = UIGraphicsGetCurrentContext();
    CGContextSetTextMatrix(context, CGAffineTransformIdentity);

    CGMutablePathRef path = CGPathCreateMutable();
    float w = 200.0;
    float h = 300.0;
    CGRect bounds = CGRectMake(10.0, 10.0, w, h);

    // I draw using only one of the following lines
    CGPathAddRect(path, NULL, bounds); // THIS LINE WILL WORK
    //CGPathAddEllipseInRect(path, NULL, bounds); // THIS LINE WILL CRASH IT


    // Initialize an attributed string.
    CFStringRef string = CFSTR("Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.");
    CFMutableAttributedStringRef attrString = CFAttributedStringCreateMutable(kCFAllocatorDefault, 0);
    CFAttributedStringReplaceString (attrString, CFRangeMake(0, 0), string);

    // Create the framesetter with the attributed string.
    CTFramesetterRef framesetter = CTFramesetterCreateWithAttributedString(attrString); 
    CFRelease(attrString);

    // Create the frame and draw it into the graphics context
    CTFrameRef frame = CTFramesetterCreateFrame(framesetter, CFRangeMake(0, 0), path, NULL);

    // Flip the text
    CGAffineTransform flip = CGAffineTransformMake(1.0, 0.0, 0.0, -1.0, 0, self.frame.size.height);
    CGContextConcatCTM(context, flip);

    CTFrameDraw(frame, context);
    CFRelease(framesetter);
    CFRelease(frame);
}

Any help or ideas would be greatly appreciated. I'm stumped.