Puppy's Buffer Combinator
The purpose of this mod is to achieve a zero UPS combinator which is specialised to computing buffer sizes. This is used in buffered circuit-controlled request/demand situations, such as LTN train stops, or SE delivery cannons/multi-item rockets.
How to use it
After researching the circuit network, you will receive a new entity, the Buffer Combinator. This costs just one constant combinator and one green circuit. When you place the combinator and click to open the GUI, you will receive a custom UI which lets you set the buffer sizes. The typical usage is to create a requesting train station/SE delivery chest/etc which has a fixed buffer, like a 200 slot chest. Then fill in the buffer stacks (probably as a negative) or fluid buffer size and then blueprint. Then every time you place the blueprint, you only have to pick the item type and the combinator will generate the proper item request for you.
This calculation is a one-off at configuration time so has no ongoing cost, unlike using the Stack Combinator mod or arithmetic/decider combinators, and also includes the stack size for you for items so one blueprint serves all item requests regardless of stack size. Unlike LTNC the stack count/fluid buffer size is recorded in blueprints.
To connect it to the circuit network, use the regular constant combinator connectivity. Similar to a normal constant combinator, the buffer combinator does not require power. The UI allows you to pick signals as the item type, but in this case, no signal will be generated; it must be an item or a fluid.
If you destroy a buffer combinator and then undo, a buffer combinator will be placed but the settings are lost.
Can't prevent the user from picking something that's not an item or a fluid.
This is the first release of my first mod, although I've stolen a lot of code from people more experienced than me. It works as far as I've tested it which is strictly not very much. If you encounter any issues, please raise an issue.