Lissajous

Twoville serves two purposes: to create SVG images that can be used as input to laser and vinyl cutters to create animations To support the second of these, I have been using time blocks to define geometric properties at particular keyframes, and then letting the animation system interpolate between the keyframes. Like this: Here we […]

Polar Graph

A year ago I decided to see if fifth graders could create shapes using polar coordinates. I bet myself that they could if we spent some time first traversing a polar grid, identifying the labels of the rings and the spokes. We didn’t think of them as angles and radii, because those semantics weren’t important […]

SENG 440: Lecture 16 – Camera, Part 2

Dear students, Last time we met we tried something new. I assigned in-class exercises, you worked on them, and that’s all we had time for. We will discuss and implement your solutions today, which will wrap up our work on the Backlog app. I’d like to keep getting you involved in the writing of our […]

Phone Programming

Twoville now supports masking, which means we can subtract shapes from other shapes. Since I’m teaching a course on mobile app programming this semester, phones have been on my mind. Accordingly, here’s one of the first runs of the masking feature: In this code, hole is a container of other shapes that will be subtracted […]