Conditions

Mother Core 1.2.0 adds conditional logic: when rules that run a routine when a condition changes, and if steps that branch inside any routine. Printed by Mother gives projectors their own predicates and properties, such as busy, stalled and progress, so a condition can ask what a printer is doing. The rule syntax itself belongs to Mother Core and is described in Conditional Logic.

Properties and Predicates

They apply to projectors. The target is a projector's name, a group of projectors or a #tag, exactly as in the projector commands. Printer names and merge blocks are not targets.

Every predicate except idle is also a property that is 1 or 0, so "Bay 1 Projector" busy and "Bay 1 Projector" busy == 1 mean the same. Write ratios as percentages: "Bay 1 Projector" progress > 50%.

An arrow that leaves a frame stands for the same arrow from every state inside it. What the drawing does not show:

• busy is true in every state except Idle. busy and idle follow the projector's own job, not its printer: when two projectors share a printer and one of them prints, the other is still idle. To ask whether a printer is busy, use a group of its projectors.
• welding and timedout follow the projector rather than the job, so both also turn false when the projection is removed.
• onComplete can also come from the job's completion check with no welding pass open. A projection that is already complete when the job commits goes straight to Complete without onComplete. See Stalls and Failures.
• For a group, a predicate is true when any projector in the group matches, and a property is the average of the projectors that have a value. A projector with nothing projected has no progress and is left out, but counts as 0 in remaining.
• progress and remaining count placed blocks, so they can reach 100% and 0 a little before onComplete. Use complete to know that the print is finished.

Using Conditions

Rules live in the [rules] section of a Mother programmable block's Custom Data: the Printed by Mother programmable block, or any other Mother programmable block on the construct. The first step of a rule is when; the steps after it run when the condition becomes true, and the steps after an optional else; run when it becomes false again. if, else and end work in any routine, including [commands] entries and hooks.

Bay Lights and Doors

The bay lights and door follow the projector. The else branch puts them back when the job ends, however it ends.

[rules]
Bay1Busy=
| when "Bay 1 Projector" busy;
|   light/color "Bay 1 Lights" yellow;
|   door/close "Bay 1 Door";
| else;
|   light/color "Bay 1 Lights" white;
|   door/open "Bay 1 Door";

A Stall Notice

stalled turns true when the welders are on a block whose integrity has not risen for longer than maxWeldGap, which usually means they ran out of components. --for=30 waits until the stall has lasted 30 seconds, so a short wait for an assembler does not raise the notice. A stall lasts only until the projector's timeout trips, so the wait needs a longer timeout than the default 15 seconds, which ends a stall after about 12. Give the welders time to be resupplied, for example with projector/settings "Bay 1 Projector" --timeout=300 --save;.

[variables]
SCREEN="Bay Control:0"

[rules]
Bay1Stalled=
| when "Bay 1 Projector" stalled --for=30;
|   view/notify $SCREEN "Bay 1 is short of components." --level=warning;

view/notify comes from a Mother GUI programmable block on the construct. Unlike onTimedOut, the rule warns while the welders are still on the block, before the projector's timeout gives up on it. A print whose welders never start does not stall; catch that with onTimedOut, or with printing and --for. See Stalls and Failures.

Halfway and Long Prints

[rules]
Bay1Halfway=
| when "Bay 1 Projector" progress > 50%;
|   screen/print "Bay 1 Status" "Bay 1 is halfway.";

Bay1Long=
| when "Bay 1 Projector" printtime > 1800 --cooldown=600;
|   screen/print "Bay 1 Status" "Bay 1 has been welding for 30 minutes.";

Bay1Halfway runs when the share of placed blocks passes half, and becomes ready again once nothing is projected. Bay1Long runs when a print has welded for 30 minutes; --cooldown=600 keeps it from running again within 10 minutes of the last time.

Only Print into an Idle Bay

blueprint/print into a busy printer fails with an error. An if step can check first and say why instead.

[variables]
SCREEN="Bay Control:0"

[commands]
StartBay1=
| if "Bay 1 Projector" idle;
|   blueprint/print "Bay 1 Projector";
| else;
|   view/notify $SCREEN "Bay 1 is busy." --level=warning;
| end;

Hooks Versus Rules

Hooks and rules both react to a print, in different ways:

• A hook fires once, at the moment something happens, inside Printed by Mother. onWeldStart, onWeldEnd, onTimedOut and onComplete, and the job hooks onLoad, onPrint, onClear and onFailed, are events.
• A rule watches a state. Its else branch runs on the way back, --for ignores a state that does not last, --cooldown limits how often it runs, and the rule can sit in another script's Custom Data.

Use a hook for a step of the print itself, such as switching the welders on in onPrint. Use a rule for anything that should follow the printer's state for as long as it lasts, such as lights, doors and screens.

Predicates from Other Scripts

Every Mother script on a construct shares its predicates and properties with the others, so the projector's predicates work in the rules of Mother OS and Mother GUI with nothing to register, and Printed by Mother's rules can use theirs. See Shared Vocabulary.

On the Printed by Mother programmable block, a rule can hold the print while Mother OS reports the batteries low:

[variables]
BATTERIES=Batteries

[rules]
Bay1Power=
| when $BATTERIES low --for=5;
|   printer/pause bay-1;
| else;
|   if "Bay 1 Projector" paused;
|     printer/resume bay-1;
|   end;

low is a Mother OS battery predicate. The if matters: printer/resume commits a job that is still starting, so the rule only resumes a job that is paused. A pause stops the print clocks, not the welders; see Pausing a Job.

On a Mother GUI programmable block, a rule can follow every printer on the construct:

[rules]
PrintersBusy=
| when "Printers" busy;
|   block/on "Hangar Beacon";
| else;
|   block/off "Hangar Beacon";

Printers is a group of the construct's projectors, so the beacon is on while any of them prints.