Every animation should have a beginning, a middle, and an end: A case study of using a functor-based animation language

Abstract

Animations are sequences of still images chained together to tell a story. Every story should have a beginning, a middle, and an end. We argue that this advice leads to a simple and useful idiom for creating an animation Domain Specific Language (DSL). We introduce our animation DSL, and show how it captures the concept of beginning, middle, and end inside a Haskell applicative functor we call Active. We have an implementation of our DSL inside the image generation accelerator, ChalkBoard, and we use our DSL on an extended example, animating a visual demonstration of the Pythagorean Theorem. © 2011 Springer-Verlag.