Question

I don’t know if it is possible using Objective-C, but I would like to find all the pixels/points that have been sensibilized in a touch event.

For example, if I use my thumb to touch the screen, then I will ‘activate’ certain pixels. If I use a pen to do the same thing, then I should get fewer pixels activated.

Is there a way to retrieve the coordinates of these pixels?

Answer 1

This is currently not supported in the SDK (I actually submitted a request for the very same feature).

Ten One Design created a framework and demo’d it: http://www.macrumors.com/2010/07/01/pressure-sensitive-sketching-on-ipad-demoed/

Unfortunately, they used private APIs, and have yet to release it to the public (although it would still not be very valuable for a distribution build).

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.