Procedural animated texture generation/Lava

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

Flowing lava
Flowing lava uses the exact same texture as still lava, however there is also a spatial translation to give the appearence 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.