Terrence L Coleman

US Patent:

47258314, Feb 16, 1988

Filed:

Apr 27, 1984

Appl. No.:

6/604863

Inventors:

Terrence J. Coleman - Des Plaines IL

Assignee:

XTAR Corporation - San Diego CA

International Classification:

G09G 116

US Classification:

340747

Abstract:

A real-time video graphics system for generating solid polygons on a raster display screen from X-Y vertex coordinates of the polygons. Solid objects are defined in a host processor system as three-dimensional polygons. The host processor calculates the X-Y vertex coordinates for each polygon and deposits them, along with a corresponding instruction and pixel video data, in a shared RAM. The video graphics system obtains the instruction and data from the shared RAM and calculates from the X-Y vertex coordinates the X coordinates of the left and right edges of each solid polygon for each horizontal line of the display. The system writes pixel data for a horizontal stripe of 32 pixels into a frame buffer in one frame buffer memory write cycle of approximately 320 nanoseconds. Pixel data is periodically read out of the frame buffer, one complete stripe at a time, and shifted out serially to refresh the display screen.