What should computer graphics look like? How should drawing on a virtual screen work?
I happened this week upon Tactilis, a new iPad drawing application by Satyakam Khadilkar. It's full of fascinating ideas. Many early iPad "drawing" apps have been disappointing: because of the lack of a stylus, the sheer size of your finger reduces these tools to finger painting. Some surprisingly sophisticated results have emerged, but they're the exception rather than the rule, and they still use finger painting as the metaphor. Touch can support other paradigms, and that's what Khadilkar exploits here.
The best part of Tactilis, though, is what it does with straight lines. Recalling what's possible with the ruler and compass, it focuses on precision rather than haphazard finger gestures.
Oddly, the interface I think was very possibly the best drawing interface in the history of computing was also the first – Ivan Sutherland's Sketchpad, introduced, incredibly, in 1963. See the video below, narrated by another mind-blowing pioneer of, um, just about everything you use today. Whether intentional or unintentional, Sketchpad appears reflected in Tactilis' virtual compass and ruler.
I still think Sketchpad has plenty to teach us today. (Less often mentioned about Sketchpad is that it was also the first application to move beyond procedural code, as Kay here observes.) I wonder if anyone has recreated the Sketchpad interface. iSutherland seems a natural extension.
The genius of Sketchpad is that it doesn't just recreate pen-and-paper drawing; it's a hybrid tool that involves both "drawing" and "rules," in equal measure. The genius of Sutherland: not knowing the problem was "supposed" to be hard. And if you take those two axioms, I think there are near-limitless ideas in drawing yet to be discovered. So, off we go.