Browse Prior Art Database

Method to Distribute graPHIGS Applications to Multiple Graphics Workstations

IP.com Disclosure Number: IPCOM000114877D
Original Publication Date: 1995-Feb-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 4 page(s) / 118K

Publishing Venue

IBM

Related People

Fuqua, TW: AUTHOR

Abstract

Disclosed is a method for enabling graPHIGS applications to be shared among multiple users.

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

Method to Distribute graPHIGS Applications to Multiple Graphics Workstations

      Disclosed is a method for enabling graPHIGS applications to be
shared among multiple users.

Sharing a graPHIGS application among a set of users on multiple
workstations requires that:
  1.  Each user on each workstation must see the same application
view.
  2.  Each user on each workstation must be able to interact with the
       application.

      The inventive idea is to broadcast graPHIGS API calls to
multiple users, thus enabling each user to see the same view of the
application.

The new functions or ideas needed for each user to see the same
application are:
  1.  Repeating API calls multiple times, once for each user.
  2.  Broadcasting the application view to multiple users.
  3.  A classification of the graPHIGS API which identifies the API
       calls for which broadcasting is appropriate.

      Repeating API Calls - A prerequisite to broadcasting graPHIGS
API calls to multiple users is the ability to take a graPHIGS
function call made by the application and repeat this function call
multiple times, once for each user.

      graPHIGS applications use the graPHIGS API.  The graPHIGS API
consists of a large number of API calls.  Each API call collects
parameters provided by the application and passes them to a single
graPHIGS function of the form:
  afmaic(aab, APIcode, APIparms)
  where aab is an application anchor block used to store graPHIGS
data
structure, APIcode is an integer identifying the current API call,
and APIparms is an array of pointers to the current API call
parameters.  Each parameter referred to in APIparms is either an
INPUT or OUTPUT parameter, there are no INOUT parameters in the
graPHIGS API.

      The application anchor block is provided by the application and
is initially empty.  The anchor block provides a context for the
execution of graPHIGS API calls.  API calls may change the state of
data structures within the anchor block.

      Applications may use one or more anchor blocks at a time,
providing multiple contexts for the execution of graPHIGS API calls.
The execution of an API call using one anchor block has no effect on
any other anchor block.

      The inventive idea is to enable a graPHIGS function invoked by
the application with an anchor block, aab, to be repeated N times by:
  1.  Intercepting the graPHIGS function at the afmaic level.
  2.  Associating N anchor blocks AAB{1.N} with the application's
       anchor block aab where each anchor block AAB{i} is associated
       with user{i}.
  3.  Invoking afmaic on each AAB{1.N}.

      The effect is to repeat the application's function call on each
user's anchor block thereby repeating the function call, once for
each user.

      Broadcasting to Multiple Users - graPHIGS applications may be
viewed as having three layers as shown in Fig. 1.
                 Appl...