ASCII Smoke, Fire and Flames with Ncurses

By Frank Cox
(January 31, 2016)

Here is a really cool ASCII animation of flames.

/*
 * ncurses-fire.c
 * ---------------------------
 * This C function adapted from python cfire by Matthew Simpson (https://gist.github.com/msimpson/1096950)
 *
 * Email from Matthew Simpson (Jan 31, 2016):
 * Thanks for the complements, but I didn't invent the effect. I too adapted it from someone else's work.
 * Originally it was written in JavaScript by Thiemo Mättig, found here: http://maettig.com/code/javascript/asciifire.html
 * ---------------------------
 * 
 * Copyright 2016 Frank Cox <theatre@melvilletheatre.com>
 * 
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided
 * that the following conditions are met:
 * 
 *     Redistributions of source code must retain the above copyright notice, this list of conditions and
 *     the following disclaimer.
 *     Redistributions in binary form must reproduce the above copyright notice, this list of conditions
 *     and the following disclaimer in the documentation and/or other materials provided with the
 *     distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
 * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
 * TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 */

#include <ncurses.h>
#include <stdlib.h>
#include <time.h>

void flames(void);

int main(int argc, char** argv)
	{
	initscr();
	start_color();

	flames();

	endwin();
	return 0;
	}

void flames(void)
	{
	int width, height, size, *b, i;
	const char characters[] = {' ', '.', ':', '^', '*', 'x', 's', 'S', '#', '$'};
	
	getmaxyx(stdscr,height,width);
	size=width*height;
	init_pair(1,0,0);
	init_pair(2,1,0);
	init_pair(3,3,0);
	init_pair(4,4,0);
	clear();
	
	b=calloc((size+width+1),sizeof(int));
	nodelay(stdscr,TRUE);
	srand(time(NULL));

	for (;;)
		{
		for (i =0; i < width/9; i++)
			b[(int)(((float)rand()/(float)RAND_MAX)*width+width*(height-1))]=65;
		for (i=0; i < size; i++)
			{
			b[i]=(b[i]+b[i+1]+b[i+width]+b[i+width+1])/4;
			if (b[i] > 15)
				attrset(COLOR_PAIR(4)|A_BOLD);
			else if (b[i] > 9)
				attrset(COLOR_PAIR(3)|A_BOLD);
			else if (b[i] > 4)
				attrset(COLOR_PAIR(2)|A_BOLD);
			else
				attrset(COLOR_PAIR(1)|A_BOLD);
			if (i < size-1)
				{
				move(i/width, i%width);
				if (b[i] > 9)
					addch(characters[9]);
				else
					addch(characters[b[i]]);
				}
			}
		refresh();
		timeout(30);
		if (getch() != ERR)
			break;
		}
	
	free(b);
	return;
	}

Other articles written by Frank Cox can be found here.

Frank Cox owns and operates the Melville Theatre in Melville, Saskatchewan, Canada, and has been playing with computers for over 40 years.

This work is licensed under a Creative Commons Attribution-Share Alike 2.5 Canada License.