High-Resolution Spider Distribution   
===================================
November 1999 Update
  
Michael Feldman
Department of Computer Science
The George Washington University
Washington, DC 20052
mfeldman@seas.gwu.edu
http://www.seas.gwu.edu/~mfeldman
  
Contents
========
  
This distribution contains a set of high-resolution spider 
demonstration programs taken, and extended, from Appendix A 
of "Ada 95 Problem Solving and Program Design, 3rd edition", 
by Michael B. Feldman and Elliot B. Koffman, published
1999 by Addison-Wesley. The Internet support site for the
text is at http://www.seas.gwu.edu/~mfeldman/cs1book
from which you can read the two sections relevant to this
distribution and download the software.

The spider is a simple animated turtle graphics-like package
for studying basic algorithmic control structures and
exception handling. The spider is introduced in the text in
Chapter 2, "Introducing Algorithms: Adventures of the Spider";
discussion of the high-resolution color version appears in
Appendix A, "High-Resolution Color Graphics." You can read these
on the web at

http://www.seas.gwu.edu/~mfeldman/cs1book/chap2.html
http://www.seas.gwu.edu/~mfeldman/cs1book/appendixa.html

Requirements
============

This distribution depends upon the GNU Ada 95 compiler (GNAT)
and the AdaGraph graphics package for Windows 95/98/NT, or
Apple Power Macintosh running Tenon MachTen CodeBuilder. 
The textbook is packaged with a CD-ROM containing CodeBuilder
and versions of GNAT for CodeBuilder, Windows, Linux, and DOS.

The spider package and its application programs are platform-
independent. For convenience we are packaging distribution
archives for different platforms. This archive contains
executable demos for Windows.

If you are running a Mac, you can download the spider distribution, 
bundled with AdaGraph and Mac executable demos, from the book website 
given above.

If you are running Windows, the latest AdaGraph version can be
downloaded from the website of its author, Jerry van Dijk, at
http://stad.dsl.nl/~jvandyk. If you do have have GNAT, download
the latest Windows version from ftp://cs.nyu.edu/pub/gnat/winnt.

Versions of AdaGraph and Spider are under development for other
platforms.

Spider Demonstration Programs
=============================

The program files in the Spider demo set are:

-- spider_hires.ads - interface for Spider package

-- spider_hires.adb - implementation (body) of Spider package

-- polygons.adb - a simple polygon-drawing application

-- spiral.adb - a simple rectangular-spiral program

-- polystars.adb - draws a series of "stars" with odd numbers of
   points from 3 to 25 inclusive 

-- snowflakes.adb - draws several "Koch snowflakes", a common fractal

-- drunken_spider.adb - a non-terminating random walk

Demo executables (*.exe files) are provided as well. You should
first run polystars.exe, then drunken_spider.exe

The first uses a mouse click to advance from one star to the
next; the second is a non-terminating program that runs until it 
is aborted by closing the DOS window from which AdaGraph opens 
its graphic window.

