Various issues

[iosdeveloper]

From CocoaControls.com:

Awesome work. I'd love to see a metal gradient knob (rendered in Core Graphics), but I just don't know if that's even possible.

Looking very nice. Is it just me or is the on/off text too far down by 1 pixel?

[grgcombs]

Yep, that was my comment ;-) Looking a little deeper into it, I've found one Core Graphics gradient that looks ok for metal knobs, but to do it right we need some means of creating a conical/angle gradient, which isn't easy. From the sounds of it, it takes a good deal of math to get it, and the chances are it'll draw slow as hell on mobile hardware. I'm still trying to find a workable alternative, or even just a proof of concept, but I didn't take calculus, so I'm probably screwed.

[grgcombs]

Here's the discussion about the gradient on stackoverflow, with code from Rob Napier.

http://stackoverflow.com/questions/6905466/cgcontextdrawanglegradient/6907597#6907597

[domesticcatsoftware]

Ah that looks interesting.. I might throw it in and see what the performance is like. I had to do a lot of workarounds to get this thing performing OK in scrolling lists etc. so I'll see how it works. I think it might actually be OK since the thing is static unless the switch mechanism is actually moving.

[grgcombs]

Don't know if it would do any better as a kernel filter in Core Image, but I'll see if I can get it working as a proof at some point. I'm still trying to find something that could do a conical/angle gradient in iOS, but so far I'm having no luck.