QR Code Tickets?

Anyone aware of an existing or in development add-on that can produce QR-Codes for purchases. IN my use it would be to produce a qr-code for a ticket sale which would be scanned and checked in via mobile phone.
If not, is there a need for it in this community? I might be able to get something developed. We wrote one for joomla that works, but the integration to get it working in joomla has been somewhat of a challenge. I feel it may be easier to get working in concrete.

I’ve written add-ons for Concrete that output QR Codes, but the actual code generation is the easy part, as there’s lot of libraries around to do that.

I’ve also written add-ons that generate PDF certificates after purchases (in Community Store), emailing them to the customer. And I’ve combined QR Codes on PDFs before, so that would be doable.

But the question is what does the QR Code store? A URL? A bit of text?
If it’s a URL, where does it go, and how would the checking process work?
Would it need to handle things like preventing ticket copies?

As @mesuva notes, generating codes is just part of the process. You also need the processes to handle them.

My Form Reform addon can attach a QR code reader to a form input or group of inputs, so a device camera (phone camera, webcam) can read whatever text is in your QR code into a form and hence into form processing.

That gets you further along the process, but you would still need to work out what to do with the content of the QR code.