I wrote this little oldskool demo program in a morning. First fire is seeded at the bottom of the screen, then the program scans downward, calculating each pixel's value by averaging four pixels below it and applying a random factor. This makes the flames appear to spread upward.
Double click the executable to run the program.
Press any key to quit.
Copyright © 2012 David Watson david@watzon.co.uk
Anyone is permitted to copy, modify, distribute and/or sell this program, provided that the copyright notice and permission notices appear in all copies.
Anyone is permitted to use this program, provided that the user accepts that the program is provided "as is" and comes without any warranty.
Anyone is permitted to integrate parts of the source code of this program into their own, provided that the author of this program is duly credited.