====================================================================== LINK FOUR Version 1.30 - A Strategy Game for Windows 3.1 Copyright (C) 1992,1994 by R&R Engineering - All Rights Reserved ====================================================================== THE GAME OF LINK FOUR --------------------- Link Four is a strategy game where two players take turns stacking red and blue marbles in a 7x7 grid in an attempt to be the first player to establish a linear arrangement of four or more marbles in adjacent grid positions (i.e. to "get four in a row"). Two grid positions are considered adjacent if neither their rows nor columns differ by more than one (thus "four in a row" can be achieved either vertically, horizontally, or diagonally). The game ends when one player achieves a "link" of at least four marbles, or when the grid has been filled. In addition to allowing to human players to compete, Link Four implements four levels of computer play. The computer can be assigned to play red, blue, or both. Also, In addition to these "canned" search modes, Link Four implements a unique "rule-based" mode which allows the move search heuristics to be programmed by the players. LICENSE ------- This program is free software; you may redistribute the following files so long as all files are distributed together in their original, unmodified form: LINK4.TXT - This document LINK4.EXE - The Link Four program executable LINK4.HLP - The Link Four online help document SAMPLE.RUL - The sample rule set from the online help EXAMPLE.RUL - A more extensive example rule set STARS.BMP - A sample bitmap for use as a background This software is distributed in the hope that it will be useful, but BECAUSE THE SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE LINK FOUR SOURCE CODE ------------------------- Link Four was programmed using Borland Pascal version 7.0. Link Four was initially designed as an instructional program for a beginning Windows programming class using the Borland Pascal language. As an instructional program, the code has been carefully organized, cleanly written, and contains extensive internal documentation to aid in the Windows programming learning process. It is intended that the source code will ultimately be published in an introductory text on Windows programming using the Borland Pascal language. Following the initial design and implementation of the Link Four program, a module was added to assist in teaching the artificial intelligence concepts of pattern matching and heuristic search to gifted junior high and high school level students. The resulting Rule-Based Play feature has proven highly successful, not to mention being a great deal of fun. The intent was to design an instructive program which was an entire, moderately sized application, to bring together the fundamentals of Windows programming concepts. In addition to basic program structure, the program illustrates several important and useful Windows programming concepts and techniques, including cooperative multitasking, handling 256 color bitmaps, smooth dragging of bitmap objects, design and integration of Windows help files, and more. Also, not limited to the realm of only Windows programming, the Link Four program illustrates fundamental techniques of game-playing programs. The computer-based strategy used by the program plays very well, though it is actually quite simple. The strategy of the game was not a primary design issue, but programmers new to game trees and heuristic searching can learn a great deal from the simple but effective algorithms used by the Link Four program. The author of the Link Four program is Ron Pacheco. He holds an M.S. in Computer Science from the University of Missouri, and a B.S. in Computer Science from Harding University. Ron presently teaches mathematics and computer science at Harding University, and operates a private consulting business in the central Arkansas area. Ron has been programming under the Windows operating system for over six years, and has recently begun teaching Windows programming to others. The Link Four project is a part of these efforts. For those interested in using the code as a learning tool, experimenting with the code, or contributing to the Link Four project, the complete Borland Pascal 7.0 source code and all associated files, including all resources and help project files, can be obtained from the author for $15 U.S. For this fee the author grants the right to use any or all of the code in any commercial or non-commercial programming project, so long as modified versions of the Link Four program itself nor any of the source code is distributed without the express written permission of the author. For those interested, a portion of the fee will be used for postage, packaging, and media, and the remainder will be used by the author in his efforts toward developing an introductory Windows programming text using the Borland Pascal language. To obtain the latest version of all source files on a high-density, 3.5 inch floppy disk, send a $15 check or money order, payable to Ronald T. Pacheco, to: R&R Engineering Link Four Project 4 Marshall Drive Searcy, AR 72143-5011 For those with Internet access who are interested in contacting the author, he can be reached via e-mail at pacheco@acs.harding.edu. The author welcomes questions, comments, and suggestions regarding the Link Four project or ideas for developing an introductory Windows programming text based on the Borland Pascal programming language.