yup, i’ve done exactly this using cocoa / IB / OF, and works great
also, this is quite possible w/out someting like cocoa -
a) there are gui toolkits available with sliders.
b) OF apps can do a horizontally spanning fullscreen (ie, fullscreen on both monitors)
c) you can draw the projector screen into an offscreen image FBO to draw it twice, or just draw it twice, once smaller on the control screen and once at the larger projection size.
I use this technique tons, if I can help with any examples, let me know.
ps: you can see it in action here (on software I helped create for a magician):
towards the end you can see the control screen on the laptop.
I use this technique of horizontally spanning fullscreen on the VJ app Quase-Cinema (http://www.quasecinema.org).
The control screen (using ofxGui sliders) is setup at 1024x768 and the output screen in configurable at many sizes (640x480, 800x600, 1024x768, 1600x600 - for two output screens…).
Wow, thanks everyone for your suggestions
Plenty of reading to do for me for now - I’ll start with memo’s code and see where I can get with that…otherwise, spanning two displays doesn’t seem too bad a work around!
actually to get off the ground as quickly as possible, I would also second what Zach suggests (and Alexandre seconds). Using this method you can have your app working in no time. You also get the benefit of having the app potentially cross-platform (so it could work on windows or linux too). Going down the Cocoa route makes your app look like a native cocoa app (native sliders, buttons etc), other than that doesn’t bring much (actually there may be a performance advantage, but I haven’t fully tested that yet).
So the horizontal spanning 2 screen is the way to go then? There is no way I can just open 2 separate OF windows on 2 separate screens? (and then make them full screen)
It seems this would make migrating to different multi-screen set-ups easier.
Probably I should just move to the big single full screen, but I’m interested to know.