Shooting

A turret shoots well enough on its own. Logic is for when it matters who exactly it shoots

mediumYou need: Switching on and off, Properties of buildings

Without logic a turret picks its target itself: the nearest one in range. Logic steps in when that choice will not do — when one enemy has to be finished off instead of spreading fire, or when the more dangerous one has to be hit.

steptick 0

Control0

set shoot of

xy

shoot

Sensor1

=

 in

Sensor2

=

 in

Sensor3

=

 in

@counter0number

shootingnullnull

ammonullnull

facingnullnull

Press “run”. The duo turns east and starts firing at the point 13 4, where a dagger stands: ammo goes down, and so does the dagger’s health.

control shoot turret x y shoot

Field	What is in it
first	the turret
second and third	a point in map tiles, not in world units
fourth	shoot or only aim: zero means turn silently

The coordinates are the same as any block’s @x and @y, so aiming at a building is just taking its coordinates and handing them to the turret.

Note

The last field is worth separating from the aiming: a turret can be held pointing the right way without spending ammo. control shoot duo1 13 4 0 turns the barrel and leaves it there.

The order lasts two seconds

A turret obeys logic for 120 ticks after the last command, then returns to its own aim and starts choosing targets by itself again.

Silent failure

One command is not an order for ever. A program that issued control shoot once and went off into a long wait will find the turret back about its own business two seconds later.

So the command is repeated every iteration — it is cheap, and it works as holding a target.

Shooting a unit: control shootp

steptick 0

Radar0

target1enemytarget2anytarget3anysortdistanceradarsortOrderoutput

Control1

set shoot predict of

unitshoot

Sensor2

=

 in

Sensor3

=

 in

@counter0number

aimnullnull

shootingnullnull

ammonullnull

Here the target is found by a radar, and shootp aims the turret with lead: it fires not where the unit is now but where it will be when the bullet arrives.

radar enemy any any distance duo1 1 aim
control shootp duo1 aim 1

Field	What is in it
first	the turret
second	a unit, not coordinates
third	shoot or only aim

The lead is worked out by the game, from the target’s speed and the bullet’s. So a duo leads a flying flare and puts its shot straight into a standing dagger.

Note

The lead is taken from whichever ammo is on top: graphite’s bullet is faster, so the lead is smaller. Change the ammo and the aiming point changes with it.

What a turret will tell you about itself

Property	What it gives
@shooting	whether it is firing right now
@ammo	how many units of ammunition are left
@ammoCapacity	how many fit
@currentAmmoType	the item it is loaded with: @copper, @graphite
@progress	how ready the next shot is, from 0 to 1
@rotation	where the barrel points
@shootX, @shootY	where it is aiming

Ammo is counted not in items but in units of ammunition: one lump of copper gives two, graphite four. So a full duo’s @ammo is 30 while it holds fifteen items of copper.

Silent failure

The command does not check range. control shoot will turn a turret towards the far side of the map and it will honestly fire — the bullet just will not get there: it has a lifetime of its own.

Range is worth checking yourself: sensor range duo1 @range and a comparison with the distance to the target through op len.

Remember

• control shoot hits a point in tiles, control shootp a unit with lead.
• The last field separates aiming from firing.
• The order lasts two seconds, so it is repeated every iteration.
• Logic checks neither range nor ammo — that is the program’s job.
• @ammo is counted in units of ammunition, not in items.

Task

Change the last field of control shoot in the first example from 1 to 0 and run it: the turret turns but does not fire — shooting stays zero and ammo does not change.

Then set the target to 3 4 — a point behind the turret. The barrel starts turning, and until it comes round there are no shots: a turret fires only if the target is inside its cone.