Alternative to CGPathGetPathBoundingBox() for iPad (iOS 3.2)

I'm trying to get my head around using QuartzCore to render semi-complex text/gradient/image UITableViewCell composites. Thankfully, Opacity will let me visually build the view and then spit out source code to drop in to cocoa touch. Trouble is, Opacity assumes the code is running on iOS 4, which is a problem if you want to draw Quartz views on an iPad.

For m开发者_运维百科e, the offending method is CGPathGetPathBoundingBox ... would someone mind pointing me to a suitable alternative or workaround to this (presumably simple) method?

If you care to have some context (no pun intended), here you go:

transform = CGAffineTransformMakeRotation(1.571f);
tempPath = CGPathCreateMutable();
CGPathAddPath(tempPath, &transform, path);
pathBounds = CGPathGetPathBoundingBox(tempPath);
point = pathBounds.origin;
point2 = CGPointMake(CGRectGetMaxX(pathBounds), CGRectGetMinY(pathBounds));
transform = CGAffineTransformInvert(transform);

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The alternative is to iterate on the points of the path and note down the leftmost, rightmost, upmost, and downmost co-ordinates of the anchor points yourself, then work out origin and size from those numbers.

You should wrap this in a function, and name it something like MyPathGetPathBoundingBox, and use that until you drop support for iOS 3.x. That will make it easy to switch to CGPathGetPathBoundingBox once you can.