The Fundamentals of PREMO

Abstract

To date, standards for computer graphics APIs have inevitably implemented in a lowlevel procedural language such as FORTRAN [82] or C [58]. The principle abstractions that these languages support are function and procedure headers, and type or constant definitions. An API standard could be described as a collection of data types and abstract procedures, which would then be mapped through a language binding into function or procedure definitions in a specific host language. Critically, there were few, if any, assumptions in the standard itself about how functions or procedures behaved. The main difficulty, at least in the early language bindings, was deciding how to cope with differences in the expressive power of the programming languages, e.g. FORTRAN did not allow enumerated type definitions, so any use of ‘conceptual’ enumeration types in the standard needed to map onto a set of constants within a FORTRAN binding.