Icons.png

icons.png is a texture sheet used by the game to store the textures of several UI elements.

Content
icons.png contains the sprites of all UI elements, including health, hunger, experience, and armor.

Unlike a large amount of texture sheets, it is still used in the current version, and has not been split into constituent elements.

Logic for determining what heart or haunch icon to use:

There are a few additional invisible textures that have alpha set to zero but still have color data.