0cf75f998f
sub_822748D0, called from ScriptPhase::Update every frame, walks the table at [phase+240]: stride 24, each record carrying a coroutine offset (rec+4), an f32 threshold (rec+12) and a timer index (rec+20). It compares the previous and current copies of the 32-entry float register file ([phase+104] and [phase+88]) and starts the coroutine at codebase+off on a RISING EDGE, prev <= t < cur, so each fires once. Verified instruction by instruction. The table comes from the mission-level begin_phase opcode 0x83's fourth operand (the fifth is the phase end-event); sub_82270DF8 stores them at [phase+240] and [phase+236]. On disc it is tagged constants -- 0x819 int, 0x81A float, both past the ISL dispatcher's bound so they never execute. Verified on Stage 02: counts 25/13/18 with the tag triple correct in every record. Only timers 0 (1-1170s, mission clock) and 5 (0-5s, phase intro) are used corpus-wide. This explains the poke results. Two experiments set a squadron to 'destroyed' and nothing happened; the leading explanation was that the condition coroutine is not polling. It is not -- coroutines are started on a schedule by timer crossings, so state written between firings is read by nobody. It also reframes the arrival timetable: the routes' t=170 and these thresholds are the same kind of thing. The mission is substantially a timeline, with unit predicates deciding what happens at each scheduled point rather than when. Open: which built-in arms or resets each timer.
3.5 KiB
What starts a phase's coroutines: a timer table, scanned every frame
Status: ✅ mechanism and table format, verified against the disassembly and all 28 scripts. This answers the question every phase experiment has been circling.
✅ The scanner
sub_822748D0, called from ScriptPhase::Update each frame:
822748e0 lwz r11, 240(r30) ; the table at [phase+240]
822748e4 lwz r10, 4(r11) ; record count
822748f4 addi r31, r11, 20 ; first record (+8 header, +12 into it)
822748fc lwz r11, 0(r31) ; TIMER INDEX (rec+20)
82274900 lfs f0, -8(r31) ; THRESHOLD, f32 (rec+12)
82274904 lwz r10, 104(r30) ; PREVIOUS timers [phase+104]
82274910 fcmpu f13, f0 / bgt ; skip if prev > thr
82274918 lwz r10, 88(r30) ; CURRENT timers [phase+88]
82274920 fcmpu f0, f13 / bge ; skip if thr >= cur
8227492c lwz r5, -16(r31) ; COROUTINE OFFSET (rec+4)
82274930 lwz r4, 232(r30) ; phase code base
82274934 bl 0x822737C8 ; START THE COROUTINE
8227493c addi r31, r31, 24 ; stride 24
So each record says: when timer i crosses t seconds, start the coroutine at
codebase + off — a rising-edge test, prev ≤ t < cur, so it fires once.
[phase+88] and [phase+104] are the current and previous copies of the
32-entry float register file; sub_822710D0(phase, dt) copies cur→prev and adds
dt to the running ones each frame. They are timers, in seconds.
✅ The table, and where it comes from
The mission-level bytecode's begin_phase (op 0x83) carries five operands; the
fourth is this table's offset and the fifth is the phase's end-event routine.
sub_82270DF8 stores them as [phase+240] = base + w4 and [phase+236] = w5.
On disc the table is tagged constants, same <len><op> shape as the bytecode
(tags 0x819 = int, 0x81A = float — both past the ISL dispatcher's
cmplwi 0x18 bound, so they are data and never execute):
tbl+0 : 0819 <count>
rec+0 : 0819 <coroutine offset>
rec+8 : 081A <threshold seconds, f32>
rec+16 : 0819 <timer index>
Verified here on Stage 02's three phases — counts 25 / 13 / 18, and the tag
triple (0x819, 0x81A, 0x819) correct in 25/25, 13/13, 18/18 records:
phase 1 base 0xE4 tbl 0x14848 end 0x1482C
rec0: off 0x2B20 thr 0.0 timer 5
rec1: off 0x2B88 thr 0.5 timer 5
rec2: off 0x2BFC thr 1.0 timer 5
Only two timers are ever used corpus-wide: 0 (thresholds 1–1170 s — the mission clock) and 5 (0/0.5/1/4/5 s — a phase-intro clock).
🔑 Why this matters: it explains the poke results
Two experiments set a squadron's state to "destroyed" and watched nothing happen (script-runtime-probe). The leading explanation was that the condition coroutine "is not polling" — this is why. A phase's coroutines are started on a schedule, by timer crossings. They are not running continuously waiting to notice a state change, so writing state between firings changes data nobody is looking at.
It also reframes the arrival timetable: the routes' t=170 entry
(mission-wave-arrivals) and these thresholds are the
same kind of thing — the mission is substantially a timeline, with unit
predicates deciding what happens at each scheduled point rather than when.
🟡 Not settled
- Which built-in arms or resets each timer. Indices 0 and 5 are named from
the
+= dtaccumulator and the threshold magnitudes, not from a writer. - Whether a coroutine started this way can re-arm its own trigger.