VGA mirroring with iPhone / iPad


Has anyone achieved VGA mirroring (output from the 30-pin iPad dock connector through the VGA out adapter) using openFrameworks on the iPad (or iPhone)? I began looking into this and found a class that was doing so in a low-framerate manner by taking screenshots:

My thought is to integrate more elegantly in ofxiPhone, detecting when a VGA display is connected and then calling “draw” twice for each of the two displays. With openGL mirroring rather than bitmap replication, performance should improve.

Probably requires some modifcations to ofxiPhoneAppDelegate and ofAppiPhoneWindow.

Best wishes,


I’m pretty sure its a private framework which means it won’t be allowed in the app store.

check this page -

In the comments it mentions ways to have an iphone output any app to the VGA cable - needs to be jail-broken though.

Scott- have you made any progress on this? I hope to something similar to what you’re describing, but I’m not sure how I should go about implementing the switch between screens.

The library you link to looks OK, but is only suitable for mirroring. I’d like to draw something different to the external screen (but still through OF, preferably).

I don’t think there are any issues with private frameworks, see this Apple doc:


I’ve found an online resource that clearly explains how to create the second display with an OpenGL context:…-al-screen/

Let me know if anyone make progress integrating directly into OF, with the automatic adding of a second OpenGL display on app launch and when the adapter is plugged in. It’s not a top priority for my development at the moment, but I plan to get dual-displays working within a month or so. I’ll do my best to download the latest OF and see if I can integrate systematically and post the results here if no one else has done it before then.