Procedural animated texture generation/Lava

Still lava
Adapted from https://github.com/UnknownShadow200/ClassiCube/wiki/MInecraft-Classic-lava-animation-algorithm#lava

Every frame, for each position in the still water texture array, the respective values for soup_heat, pot_heat and flame_heat are calculated as detailed below:


 * 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.

Once the above arrays have been updated, for each pixel in the lava texture, the color values are calculated based on soup_heat (alpha is always opaque for lava):


 * Calculates a color_heat as double the soup_heat clamped between 0 and 1 inclusive.
 * Then it calculates the color components of the pixel as follows:

The red, green and blue values are then converted to bytes and assigned to the texture accordingly.

Flowing lava
Flowing lava uses the exact same texture as still lava, however there is also a spatial translation to give the appearance of movement. This transformation moves the lava texture downwards by one pixel after a fixed amount of time, wrapping the bottom layer of the texture back to the top.