We develop a datapath generator for various arithmetic function units required in the design of the geometry subsystem in the 3D graphics application. The operations considered in the geometry subsystem include coordinate transformations and lighting. The generator will automatically generate efficient designs of function units based on the requirements of area, speed and accuracy. The major function units designed in this thesis are divided into two parts: multiplier-related function units and single-value arithmetic function units. In the generation of multipliers, we consider the design of truncated multipliers to reduce the area cost. In the design of other function evaluators, we consider two table-based methods: piecewise interpolation table-based method and the multipartite table-based method.