Browse Prior Art Database

Minimal Resource Real Time Italics Algorithm

IP.com Disclosure Number: IPCOM000102167D
Original Publication Date: 1990-Nov-01
Included in the Prior Art Database: 2005-Mar-17
Document File: 2 page(s) / 53K

Publishing Venue

IBM

Related People

Eby, KE: AUTHOR

Abstract

Disclosed is an algorithm for deriving an italic font on the fly quickly using little overhead.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 89% of the total text.

Minimal Resource Real Time Italics Algorithm

       Disclosed is an algorithm for deriving an italic font on
the fly quickly using little overhead.

      This algorithm uses two sets of three varying length queues to
apply a different degree of slant to different printed characters.
The algorithm can be used during printing and does not require any
preprocessing or formation of a print line buffer.

      Fig. 1 shows the block diagram of one queue in which the
topmost sixth of the character is delayed by five wire fire cycles,
the next sixth down is delayed by four wire fire cycles, and so on
until the bottom sixth of the character which is printed immediately.

      The data flows through the queue in Fig. 1 in the following
order.  First, the contents of the queue pointer Q1(QP) are placed in
the italics font slice.  Second, the previous nibble six (PN6) is
paired with nibble five (N5) and placed into the top queue to be
printed four wire cycles later when the queue pointer wraps back to
that location. Third, nibble six (N6) is placed in storage to become
PN6 for the next slice processed.  Nibble pairs N4, N3 and N2, N1 are
processed in a similar manner, only with shorter queues after
pairing.  After all three pairs have been processed, the common queue
pointer (QP) is advanced to the next locations in the queues.

      Two sets of six queues can be used to double the slant as shown
in the letter quality example in Fig. 2.  The two sets are u...