Abstract: Lighting parameters are received as floating-point numbers from a software application via an application programming interface (API). The floating-point numbers are converted to a fixed-point representation having a preselected number of bits. The number of bits is selected in accordance with a predetermined number of bits required by a frame buffer, which thus establishes the number of color values supported by the graphics display system. In order to preserve accuracy to within the number of bits in each value in the frame buffer, the representation in the fixed-point engine includes additional bits relative to the number of bits in the color values sent to the frame buffer. Floating-point values received via the graphics API are converted to fixed-point representations by first prescaling the floating-point values.

Abstract: A graphics adapter capable of supporting lighting models from multiple Application Programming, Interfaces (APIs) within a graphics system is disclosed. The graphics adapter includes a dot product machine and a control means. The dot product machine can perform geometry computations regardless of the API format in which the graphics data is expressed. The control means is utilized to multiplex between a set of graphics data having a first API format and a set of graphics data having a second API format in order to determine the inputs of the dot product machine. As a result, lighting models from multiple APIs can be supported by a single graphics adapter.

Abstract: A method and implementing multiprocessor computer system 200 in which graphics applications 101 are executed in conjunction with a graphics interface 103 to graphics hardware 115. The methodology is also applicable to an implementing distributed network system. A master thread 105, or master node in a distributed network system, receives commands from a graphics application 101 and assembles 313 the commands into workgroups with an associated workgroup control block 315 and a synchronization tag 317. For each workgroup, the master thread flags changes in the associated workgroup control block. At the end of each workgroup, the master thread copies the changed attributes into the associated workgroup control block 319. The workgroup control blocks are scanned 403 by the rendering threads, or rendering node in a distributed network system, and unprocessed workgroups are locked 406, and the rendering threads attribute state is updated 413 from the previous workgroup control blocks.