Abstract: An interface for a graphics system includes simple yet powerful constructs that are easy for an application programmer to use and learn. Features include a unique vertex representation allowing the graphics pipeline to retain vertex state information and to mix indexed and direct vertex values and attributes; a projection matrix value set command; a display list call object command; and an embedded frame buffer clear/set command.

Abstract: An interface for a graphics system includes simple yet powerful constructs that are easy for an application programmer to use and learn. Features include a unique vertex representation allowing the graphics pipeline to retain vertex state information and to mix indexed and direct vertex values and attributes; a projection matrix value set command; a display list call object command; and an embedded frame buffer clear/set command.

Abstract: The present invention provides a method for shading an image comprised of polygons in a graphics system. Each vertex of a polygon has x, y, and z coordinates, a normalized light source vector (L), a normalized surface normal vector (N), a normalized half-angle vector (H), and a specular exponent (s). The present invention selects a polygon and computes the angles between vectors N and L for each of the vertices. It also computes the difference terms between vectors N and H for each of the vertices. Then, the method of the present invention selects a pixel in the polygon to shade. It interpolates an angle between vectors N and L for the pixel based on the angles evaluated for the vertices. Based on the interpolated angle, a diffuse term for the pixel is determined. The present invention also determines a specular term for the selected pixel. It first interpolates a difference term between vectors N and H for the pixel based difference terms for each of the vertices.