Functional Programming of Geometry Shaders

Abstract

This paper focuses on graphical shader programming, which is essential for real-time rendering. Opposite to classical low level, structured languages, functional approach is used in this work and existing work is extended to cover geometry shader programming. The compiler is able to transform the program in a way that is hard to achieve with classical languages. The program is written for all pipeline stages at once and the compiler does the partitioning. This allows the programmer to focus on program semantics and let the compiler take care of the efficient execution. First, this paper describes shader stages as functions in a mathematical manner. The process of program partitioning and transformation to one of the classical languages is described. Several examples show the differences between functional description and equivalent structured code.