Dismiss
InnovationQ will be updated on Sunday, Oct. 22, from 10am ET - noon. You may experience brief service interruptions during that time.
Browse Prior Art Database

Extended Graphical Cursor Support

IP.com Disclosure Number: IPCOM000113872D
Original Publication Date: 1994-Oct-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 6 page(s) / 206K

Publishing Venue

IBM

Related People

Alderson, GR: AUTHOR [+3]

Abstract

Disclosed is a method providing a richer set of graphical input locators without the high cost of implementing support for dynamic segments, and an interpreter for the procedural language that manipulates them. It allows low-end IBM Host Graphics workstations to provide a wider choice of interactive graphics input locators, like Rubber Band and Rubber Box. The described embodiment of extended cursor support is applicable to other graphics workstations or terminals.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 43% of the total text.

Extended Graphical Cursor Support

      Disclosed is a method providing a richer set of graphical input
locators without the high cost of implementing support for dynamic
segments, and an interpreter for the procedural language that
manipulates them.  It allows low-end IBM Host Graphics workstations
to provide a wider choice of interactive graphics input locators,
like Rubber Band and Rubber Box.  The described embodiment of
extended cursor support is applicable to other graphics workstations
or terminals.

      Graphical input locators are used by graphics applications for
pointing or indicating an angle or rectangular area.  Locators such
as Rubber Band or Rubber Box are generally only available on
workstations which fully support dynamic segments (portions of
graphics that can be retained in the workstation and transformed in
various ways).  This is because these locators are implemented using
dynamic segments.  The Host Graphics Program (e.g., GDDM) sends a
dynamic segment definition, with a program to manipulate it, to the
workstation.  The workstation displays the dynamic segment and then
interprets the segment manipulation program.

      High-end graphics workstations, such as IBM's GWSP and
3270-PC/G (GCP) support dynamic segments and a complex procedural
language (BP1) to support the manipulation of these segments, and use
these facilities to support the use of graphical input locator
cursors such as Rubber Band & Rubber Box.  These are referred to as
GOCA-DR3 devices.

      The new method of the invention, in comparison with DR3
devices, effects a reduction in the datastream required to implement
equivalent locators with enhanced BP1.  Potentially, there may be no
change to the datastream size required to use the new locators,
compared with the old.  It is easily extendable to accommodate any
future locator echoes.  (A knowledge of existing graphics cursor
support, methods, systems and acronyms is assumed.)

      The current scenario in workstations which do not support
dynamic segments is that the workstation user decides what type of
cursor to draw, but the workstation cannot construct either Rubber
Band or Rubber Box cursors as the cursor data only contains one pair
of X-Y coordinates.  A typical transmission to a low-end graphics
device, from a host graphics program (GDDM) that was requesting input
data, would consist of the following collection of Structured Fields
(SF):

      All the workstation needs to construct ANY type of cursor is
the Cursor type required and the additional data required to draw the
cursor.  For example an additional XY coordinate, to be used as the
FIXED POINT in cases where the cursor type requires it (i.e., Rubber
Band/Rubber Box cursors).  For Rubber Band/Rubber Box cursor, this
amounts to only 5 bytes of datastream extra to be passed to the
workstation.  The proposal is to add a new flag in the
RequestBlockEntry to define if any additional data is available...