Browse Prior Art Database

Pre-Selection Highlighting

IP.com Disclosure Number: IPCOM000099425D
Original Publication Date: 1990-Jan-01
Included in the Prior Art Database: 2005-Mar-14
Document File: 2 page(s) / 44K

Publishing Venue

IBM

Related People

Bryan, RE: AUTHOR [+4]

Abstract

The concept of Pre-Selection Highlighting (PSH) is to provide automatically generated highlighting of vectors (this includes vectors, symbols and/or characters). This function is enabled by setting a bit in a control register. The hardware required to assist this function include four (4) registers to save X and Y position counter values, the control logic to transfer this data to a bus (when the feature is enabled), as well as the hardware to compare draw location to a cursor/ pick-window location. (See the drawing.)

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

Pre-Selection Highlighting

       The concept of Pre-Selection Highlighting (PSH) is to
provide automatically generated highlighting of vectors (this
includes vectors, symbols and/or characters).  This function is
enabled by setting a bit in a control register. The hardware required
to assist this function include four (4) registers to save X and Y
position counter values, the control logic to transfer this data to a
bus (when the feature is enabled), as well as the hardware to compare
draw location to a cursor/ pick-window location.  (See the drawing.)

      The function is accomplished through microcode.  The microcode
tests the match condition after each vector draw. If the bit is set
(i.e., the last vector drawn passed through the pick window), a
service routine is called to handle the highlighting.  The code is
written such that the user has the option of highlighting:
    -    all vectors that pass through the pick window;
    -    the first vector that passes through the pick window;
    -    the last vector that passes through the pick window.
    Highlighting all vectors is accomplished by immediately redrawing
the vector just drawn, with the highlight color. If the choice has
been made for the first or last vector to be highlighted, then the
start and end points of the vector are stored.  At the end of this
pass through the graphics list, these vectors are redrawn with the
highlight color.