From Functional Animation
to Sprite-Based Display

Conal Elliott

Abstract

Functional animation encourages a highly modular programming style, by supplying a set of arbitrarily composable functions for building up animations. In contrast, libraries for sprite-based display impose rigid structure, in order to allow acceleration by hardware and low level software. This paper presents a method to bridge the gap between functional specification and stateful, sprite-based presentation of animation. The method's correctness is proved informally by derivation from a simple non-effective specification, exploiting algebraic properties of the animation data types that are made explicit in the functional approach. We have implemented this method in the {\em Fran} system, which is freely available.

This paper appeared in the Proceedings of PLILP/ALP '98 (© Springer-Verlag)

Content:

Postscript (453K)
Animations
Expanded version with more detail
Partial C++ implementation

BibTeX:

@InProceedings{Elliott99:Spritify,
  author       = {Conal Elliott},
  title        = {From Functional Animation to Sprite-Based Display},
  url          = {http://conal.net/papers/padl99/},
  booktitle    = {Practical Aspects of Declarative Languages},
  year         = 1999
}