VISUALISING A SIMULATION USING ANIMATED PICTURES
Date
1983-11-01
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Abstract
We examine an application of Jaggies, a 2D graphics system
designed as part of the Jade software prototyping environment. The Jade
research project is aimed at building an environment which comfortably
supports the design, construction, and testing of distributed computer systems.
Jaggies is based on a hierarchical data structure and avoids storage of large
picture files. In this application, Jaggies provides versatile support
for the graphical display of the state of the Andes simulation interpreter.
Jaggies pictures are represented as linked lists of objects. An object
describes an instance of a picture or a primitive. The Jaggies data
structure is accessed via a set of procedures which may be called from an
application program. Some of the more unusual features of Jaggies are: the
system maintains an internal model of the display which may be altered
incrementally; the system may be distributed across several processors;
and recursively structured pictures may be defined. In Andes a
simulation running on a host machine communicates with one or more Jaggies
programs running on a Jade graphics workstation using Jade Inter Process
Communication (JIPC).
The user first goes through a design phase in which graphical icons
are defined to represent specific entities in the simulation. These
icons are represented in a compact form as a Jaggies data structure which
resides on the workstation. Simple real-time animation functions may
also be specified. As the simulation progresses the icons appear when
entities are created and move in accordance with commands from the simulation
program. The user may interact with the graphics; for example, different
views may be created and areas of interest may be re-scaled to show
details. Andes is being implemented on a VAX/780 host machine and a
Corvus Concept workstation.
Description
Keywords
Computer Science