CGContextRef unit conversion
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Some month ago I created a PDF Creator using FPDF (PHP Class). Now I was using NSData to fetch the PDF data from a URL into a UIWebView.
Because I'm implementing offline functionalities into my app I want to convert the FPDF PHP Script into cocoa touch. 

The unit used in my PHP script is mm. Now I want to know how I can convert mm to the unit used in CGRectMake() (I think it is pixels, am I right?).

Thanks for help, with kind regards, Julian