Saw this blog post and thought some of ya'll developer types might like it:

http://blog.jerrynixon.com/2012/12/walkthrough-building-swee t-dial-in-xaml.html

In particular, in the Comments after the post, the author, Jerry Nixon, gives a link to the Cartesian coordinates math that's used

http://codepaste.net/j7839b



The graphics are nothing fancy, but it's a start if you happen to be making knobs for a Windows Store Metro app or somesuch.

Why would anyone make an app using the Windows RT API? It doesn't even work in Windows 7, nobody knows if the Metro store going to bomb, etc... Plus, you'll have to recode everything you did on that API when you have to port to OSX/IOS/Android/Win32/etc...

Because they own a multi-touch tablet, because Windows 8 easily transfers any weird HID input (multiple touches, gestures, stylus, etc.) to another PC via Remote Desktop (which allows the audio to be on the powerful host desktop computer with its nice ASIO DAC/ADC and DAW and plugins), as well as the fact that "Snapped" Metro apps, which are still visible on the traditional desktop, whereupon the DAW window and Taskbar are resized to fill the rest of the area (even on multiple monitors, finally), allowing for a VST-Host/Metro App MIDI GUI combo workspace.

I'd already have done so if I were a programmer. I have studied .NET 4.5 and Windows Store app specs in great depth for a long time and know what is, and isn't, possible. Touch GUIs transmitting MIDI to desktop apps, or to other wirelessly linked PCs, shouldn't really be a problem. They'll never host VSTs or anything cool like that, though.

As an aside, there's something akin to an updated DX standard of DSP for audio and video which I've very little insight into, but once again MS seems blithely unaware of our particular ecosystem and its needs, though at least Windows 8 is a great improvement for our needs in many other areas - surprisingly (at least, to me).

I already have a Guitar Tuner App in the store. Seems quite easy to make Windows 8 apps.

The main issues are lack of MIDI, and lack of low-latency audio.

Dunno for video but for audio you have Xaudio2, which is just a software mixer that you use over DirectSound or Wasapi as far as I can tell, and is geared towards games (with stuff like ADPCM decoding). And then you have Wasapi, which already existed in Vista/7 and is essentially a remake of mmsystem and has a low latency "exclusive" mode, where you can get about 96 samples latency on windows7 (almost as good as WDM kernel streaming/Asio4all, which gets about 64 samples). No idea if the exclusive mode works in Metro apps.

Metro has really nothing to offer for pro audio applications imho. Multi touch/gestures are overrated - they're fine if you're on a bus or in your bed. But if you have the space for a real keyboard and mouse, touch is worse due to the low precision and 100ms input latency and filtering and built-in delays to differentiate the gestures. This is acceptable in a watered down iPad game that practically plays itself, but for a DAW, this slows you down a lot and even tends to make the end result worse (since usually the faster you sequence, the better).

I saw your guitar tuner app. It is quite easy to make apps so far as I can see, though obviously I won't be doing so, sadly.

If you'd like to bitch at MS about MIDI implementation, here's the place, though I heard (via Cakewalk devs, if I remember correctly) that MS said its got a high priority of being implemented. I've been bitching about this, including on KVR, for 8 years now, so obviously the whole tablet/mobile/touch ecosystem is no surprise to me.

http://social.msdn.microsoft.com/Forums/en-US/winappswithnat ivecode/thread/72f78574-02c3-4986-8d5f-623b31c89765

I have some extremely use-specific desires for multitouch GUI applications, likely not what would immediately come to mind, but there's no reason to get into that here. Perhaps it'll matter when DAWs actually adopt the VST 3.5.2 standard.

Low-latency audio is possible in Store apps (jeez, they need to think of a better name for the Metro side of things), see here:
http://blog.cakewalk.com/windows-8-a-benchmark-for-music-pro duction-applications/

Not that it'd matter to me, being a hardcore VST junkie.

I wasn't aware of the 100ms latency for touch events. That's pretty severe. The charger on my IconiaTab broke, so I haven't been able to use it for quite some while.