Patents Assigned to XTAR Corporation
  • Patent number: 4725831
    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.
    Type: Grant
    Filed: April 27, 1984
    Date of Patent: February 16, 1988
    Assignee: XTAR Corporation
    Inventor: Terrence J. Coleman