SMASH: A Next-Generation API for Programmable Graphics Accelerators

The SMASH API is a testbed for real-time, low-level graphics con-cepts. It is being developed to serve as a concrete target for thedevelopment of advanced extensions to OpenGL as well as a driverto test hardware architectures to support these extensions. SMASHis syntactically and conceptually similar to OpenGL but supports(along with other experimental features) a programmable shadersub-API that is compatible with both multi-pass and single-pass im-plementations of shaders.Arbitrary numbers of shader parameters of various types can bebound to vertices of geometric primitives using a simple immediate-mode mechanism. Run-time specification, manipulation, and com-pilation of shaders is supported. The intermediate-level shad-ing language includes integrated support for per-vertex and per-fragment shaders under a common programming model.Implementation of real-time rendering effects using SMASHcould be enhanced with metaprogramming toolkits and techniques,up to and including RenderMan-like textual shading languages andC++ toolkits with similar levels of compactness and functional-ity. We give several examples of how a two-term separable BRDFapproximation could be implemented using such higher-level con-structs. CR Categories: I.3.1 [Computer Graphics]: HardwareArchitecture—Graphics Processors; I.3.7 [Computer Graphics]:Three-Dimensional Graphics and Realism—Color, shading, shad-owing, and texture.