Package-level declarations

A 'endpoint display' is one of the red/green displays that indicates a block's fluid input/output.

A 'intersection display' is one of the gray displays that indicates one or more pipes being joined together.

A 'fluid pipe connector' is one of the small gray displays that appears on pipe corners/junctions.

An item that represents a fluid pipe. All the logic regarding placing the pipe is handled automatically.

A display that visually represents a pipe.

An invisible block (structure block) that exists purely to represent a pipe and prevent blocks from being placed on top of them.