tequila bomb

Pressure-Sensitive Drawing on the iPad

Ten One Design have come up with a fairly neat demonstration of pressure sensitive drawing on the iPad. I for one would love to get hold of this framework to play with – even though it breaks Apple’s Software Development Agreement at the moment because it uses Private APIs.

I’d also like to know if this is possible on the iPhone…

We plan to release this capability as a free software library so it can be included in any application. However, this may not be possible for a while as the library now uses a private function call to access the required information.

We hope the UIKit framework can be updated to make the required information available, but there are no guarantees this will ever happen. In the meantime, we hope the video provides some insight into what is possible on this amazing piece of hardware.

I was initially concerned by how slow the drawing was on their demonstration, and assumed perhaps it was to do with the level of processing associated with getting this effect just right. But they assure us that is not the case…

Note: The small drawing lag in the video is an issue with our demo application code, and isn’t a limitation of the iPad or the pressure-sensitive library.

How do they do it?

Unless the iPad has some pressure level functionality in the touch panel that I don’t know about, I think that what they are doing is detecting the size of the area touched on the screen.

This would explain how a palm, and a finger (which is bigger than the stylus tip used – even when it is squished) can be ignored so effectively in the video.

I will need to do some more digging myself before I can confirm that theory.

Their demo is neat though.