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Automatic Mask Generator for Line Drawing in Computer Display Systems

IP.com Disclosure Number: IPCOM000057980D
Original Publication Date: 1988-Aug-01
Included in the Prior Art Database: 2005-Feb-15

Publishing Venue

IBM

Related People

Authors:
Larkey, SP Peevers, AW St Clair, JC [+details]

Abstract

A technique is described whereby a mask representing a single pixel, as specified by the input address of a computer display system, is automatically generated through the use of multiplexer gating circuitry. The concept uses half as many circuit gates when it is necessary to write a subset of pixels, as used in line drawing. In computerized display systems, which incorporate hardware line drawing capability, a sequence of pixel addresses are generated that correspond to the pixels along a line. Each pixel must be converted into both a memory word address and an offset within the word of the pixel to be written. Generating a mask is complex in systems that Continued (Image Omitted) support multiple pixel depths, such as 1, 2, 4, and 8 bits per pixel.