Here is a simple two player tank game written with C++Builder.

  Written by  : Chuck Kelly
                www.monroe.cc.mi.us/ckelly

  Date        : November 29th, 2000


  Copyright   : This program is public domain. Use at your own risk. I assume
                no responsibilities for anything that may go wrong. You're on
                your own. Parts of this program are derived from an Internet
                source. Refer to comments in "timer.cpp" for further information
                reqarding copyright information on those files.

  Description : This game demonstrates several techniques that may be useful
                to you in your programs. In no certain order they are:

		Network Communications - This game utilizes Winsock and UDP/IP
		to allow players to compete via a LAN or the Internet. 

                Resource File - The graphic images and sounds are contained
                in a resource file. This makes it possible to place the entire
                game in a single executable file. The resource file that I
                created is "tanks.rc" . Its nothing more than a simple text
                file. You can view its contents with notepad or any text editor.
                The resource file is included in the C++Builder project file
                and compiled with the rest of the source files. The compiled
                resource file is "tanks.res". Once the images and sounds are
                in a resouce you can use routines like "LoadFromResourceName"
                and "PlaySound" to use them. Each resource needs a name. I chose
                names like "ID_TANKSR", but you can use whatever you want. Look
                in the FormActivate routine for an example of loading
                images from a resource file.

                High Resolution Windows Timer - I can't take credit for this
                code. I found it on the Web. It does seem to work quite well.
                Look in the file "timer.cpp" for comments and the web address.

                Keyboard Scanning - Games need to respond to simultaneous key
                presses. In order to accomplish this, I use C++Builder's
                "FormKeyDown" and "FormKeyUp" functions. An array is used to
                keep track of which keys are depressed. (Note! Some keyboards
                have limited support for multiple keypresses. If you experience
                problems playing this game, try a different keyboard :)

                Double Buffering - Also called Dirty Rectangle Animation. This
                technique uses offscreen buffers to minimize accesses to the
                display screen and reduces image flicker.

                Display Scaling - If your using DirectX you can change the
                resolution of the screen. Since I wanted this game to run
                without requiring DirectX I scale the images based on the
                current screen resolution. This makes the tanks appear to be
                the same size no matter what the screen resolution is. In order
                for the game to play the same on machines with different
                screen resolutions I use two coordinate systems. That is, there
                are two sets of X,Y coordinates for each object. The game
                coordinate system is the same no matter what the screen
                resolution is set to. The screen coordinates are derived from
                the game coordinates by applying a scaling factor.