This is a adaption of Fire2012 to work on a 2D-LED-Array. The original 1-dimensional version "Fire2012" was created by Mark Kriegsman.

This basic one-dimensional 'fire' simulation works roughly as follows: There's a underlying array of 'heat' cells, that model the temperature at each point along the line. Every cycle through the simulation, four steps are performed:

1. All cells cool down a little bit, losing heat to the air
2. The heat from each cell drifts 'up' and diffuses a little
3. Sometimes randomly new 'sparks' of heat are added at the bottom
4. The heat from each cell is rendered as a color into the leds array The heat-to-color mapping uses a black-body radiation approximation.

Temperature is in arbitrary units from 0 (cold black) to 255 (white hot).

This simulation scales it self a bit depending on NUM_LEDS; it should look "OK" on anywhere from 20 to 100 LEDs without too much tweaking.

I recommend running this simulation at anywhere from 30-100 frames per second, meaning an interframe delay of about 10-35 milliseconds.

Looks best on a high-density LED setup (60+ pixels/meter).

The 2D-Version just uses multiple of these heat-columns and puts them side by side.