Developing for Multiple High-Performance Graphics APIs Simultaneously: A Case Study

In today’s world of interactive computer graphics applications the choice of graphics API is crucial, but still far from clear-cut. Especially when developing for consumer-level hardware the choice of API is very important, since it will have a tremendous impact on the potential market share, as well as performance and flexibility. Nevertheless, there is no single API that is definitely better in every respect than its competitors − particularly when developing for multiple platforms. The most important APIs, like OpenGL and Direct3D, support a multitude of graphics hardware via vendor-supplied graphics drivers. There are also proprietary APIs supporting only the hardware of a specific vendor. Although these are rapidly becoming more and more obscure, the Glide API by 3dfx Interactive is still ubiquitous in the area of entertainment software. This paper describes the process of simultaneously developing for multiple graphics APIs. We use Parsec, a three-dimensional space-combat computer game we are currently working on, as a case study. Parsec transparently supports OpenGL, Glide, and a proprietary software-renderer through an abstract interface layer encapsulating the underlying graphics API, without compromising performance.