Minecraft wiki entry for Procedural_animated_texture_generation, associated text: Calculates a local_soup_heat equal to the sum of the 3x3 soup_heat neighborhood around the current element but offset vertically by colSin******* and offset horizontally by rowSin*********.
rowSin is 1.2 times the sign of an angle that starts at 0 and changes by 22.5 degrees every row.
colSin is 1.2 times the sign of an angle that starts at 0 and changes by 22.5 degrees every column.
Calculates a local_pot_heat equal to the sum of a 2x2 pot_heat neighborhood around the current pot_heat, with the current position being the upper left of the 2x2 neighborhood.
Calculates the new soup_heat as the sum of the local_soup_heat divided by 10 plus the local_pot_heat divided by 4 times 0.8.
Calculates the new pot_heat as the current pot_heat plus the flame_heat times 0.01***************. pot_heat is clamped to a minimum of 0.
Calculates the new flame_heat as the current flame_heat minus 0.06.
However, there is a 0.005 in 1 random chance that flame_heat is set to 1.5.