Phong shading by binary interpolation

This paper presents a new vector interpolation method for Phong shading, referred to as binary interpolation. It can calculate the reflection model by a scalar method. A pre-defined table is used to convert scan lines into segments, each of which is a power of two in length. Then binary interpolation is carried out in each segment. The new method has been tested in two situations; firstly with various sizes of right angled triangles, secondly with the Utah teapot. The results show that, excluding plot to screen time, binary interpolation can decrease the calculation time for a reflection model by about 20%.