Let Landmines Emit a 1-Tick Circuit Signal before Detonation

[Friant]

What?

With the new ability to connect landmines to the circuit network introduced in 2.1, it would provide an interesting use case to landmines if they were able to emit a signal for a single tick before detonation. This may require delaying the detonation by a tick from the current implementation, but that is unlikely to be problematic in
actual gameplay. The signal emitted could be configurable, but even a statically assigned value would be sufficient.

Why?

One of the long-running problems with defensive combat in Factorio is the tendency of bots to throw themselves to their deaths on the way to replace and repair broken buildings and detonated landmines. There are some known ways to prevent this, such as only putting bots into the network after an attack, but this requires circuitry to detect when an attack occurs. This can be done by detecting the swing of inserters handling ammo, but that depends on combat having already started. Landmines can be placed well outside the range of turrets, allowing them to function in the same fashion, but before combat begins properly.

Further, allowing a 1-tick signal to be emitted could be used in conjunction with the ability to enable/disable landmines to activate chains of of them with one (or more) mines acting as a trigger. This could be a way to optimize the damage and effect of landmines by detonating them in the center of massed biter attacks instead of at the leading edge.

Thanks for the 2.1 update, devs! I hope this is a small enough change to warrant consideration.

[radical_larry]

The devs didn't spell it out, but:
- connect your landmines so that any one detonating will break the circuit
- add a constant combinator with a signal on one side of the circuit
- add an edge detector for that signal on the other side

[Friant]

That would work decently well for the first use case (detecting incoming biters), but is rather more complicated than simply detecting 1 tick pulses like inserters as it requires the edge detector. Allowing the mines to send the signal themselves would also allow for resetting a "danger, do not insert bots" clock on every mine detonation vs the system resetting once for every circuit that is broken. Not a huge problem if the clock is long enough, but worth a consideration.

It would substantially complicate the second as it would require a constant combinator for every chain of mines, possibly resulting in many many combinators being required and thus making this use case far less viable. This is actually the situation for the first case as well, where every circuit you want to detect being broken would require a separate signal source combinator at a minimum (maybe that number divided by two as you have two colors of wires to play with). This also requires that the combinators be powered. In the event of a power loss, the mines would revert to their normal behavior instead of the desired behavior. while The landmines generating their own signals would remove that concern entirely.