A long, long time ago, I wrote a piece on the mouse coordinates system in Quartz Composer and how to translate it to a device screen in the Origami Phone patch. Soon after that, Facebook introduced a new Phone patch supporting landscape mode and my simple solution became obsolete. With the release of Origami 1.4 and the introduction of new devices, things got even more complicated. For example, the bitmaps representing Apple Watch and iPhone 6+ are not 1:1 in pixel size scale, creating some wacky edge cases you need to take into consideration.
It’s been ages since my last article, especially in light of the breakneck speed with which prototyping with Quartz Composer is evolving. People contribute so much it’s hard to keep up with everything that’s going on. Nevertheless, I hope the basics I cover in the second part of my Snapping Scroll tutorial will still prove to be helpful to you.