# 2026-07-05 — The SPACE bar is dead: continuous simulation lands

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Type: log
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Commits: `7f6cf5b` (sim pivot), `05048e4` (fmt), plus the design doc.

## The design session

Sat down to answer "what is this game, actually?" The repo was a competent
wave-defense roguelike, but the stated vision was always Evil Genius x Dwarf
Fortress: persistent lair-empire, simulation-driven pressure, a villain you
grow, no campaign ceiling. Wrote DESIGN.md and locked the big calls:

- **Stylized Bevy 2D/2.5D**, not 3D. 3D roughly triples asset/readability cost
  for a game whose soul is simulation density.
- **Hybrid loop pivot**: keep the raid machinery, replace its trigger. Raids
  become consequences (DF sieges), not scheduled waves.
- **Real-time with pause, fixed tick.** One clock for everything.
- **Schemes = abstract world-map dispatch** (Evil Genius style), designed so big
  ones can become playable set pieces later.
- **Minions get needs/morale** (middle depth) — not full DF inner lives yet.
- **Multiplayer = async shared world, later** — but determinism + full
  serializability are day-one requirements so the door stays open.
- **The villain is all four layers**: chargen, avatar power tree, org infamy,
  cosmetic style. Phased in that order-ish.

## What shipped

The wave loop is gone. `src/sim.rs` now owns all game state behind a
renderer-agnostic `Sim` with a fixed-tick `advance()`:

- Economy accrues every 20 ticks, schemes progress and heat decays every 40,
  raid combat runs every tick. Everything keeps running during raids — that's
  the point.
- **Threat model v1:** heat >= 10 starts a raid countdown; hotter burns the
  countdown faster (1 + heat/50 per tick); notoriety + heat set raid strength;
  an intel warning fires ~12s before arrival; repelling a raid vents 10 heat
  and pays salvage. A cold lair is simply never raided.
- Terminal frontend rewrote down to a thin view (~430 lines): SPACE/p pauses,
  +/- scales time, powers work anytime, world map is a modal not a phase.
- Deleted the 1,900-line legacy binary (`src/main.rs` + friends) that predated
  the lib split. Net diff: **-1,434 lines** while adding a whole system. Great
  feeling.
- Save format grew a `SIM` line (tick, raid countdown), backward compatible.
- 130 tests (19 new on the sim), clippy clean.

## Notes & gotchas

- The old code only accrued income inside `update_resources()`, which was
  called on *build actions* — passive income basically didn't exist unless you
  kept clicking. The economy tick fixes that structurally.
- Smoke-testing the TUI through a pty caught a real crash: `script` reports a
  0x0 terminal, layout math went negative, `as usize` produced a capacity
  overflow panic. Added a 60x20 minimum-size guard. Lesson: pty smoke tests
  are cheap and find real bugs — keep doing them.
- `Instant::now()` still lives in the frontend only. The sim itself never
  reads the wall clock — protect this; it's the multiplayer/replay seam.

## Known debts (deliberate)

- Scheme minions are **consumed**, not deployed-and-returned. Wrong tradeoff
  long-term; fix when schemes get risk/failure rolls.
- One global "agency" pool. The escalation ladder (investigator → infiltrator
  → strike team → siege) and per-agency heat are the next threat iteration.
- RNG is unseeded (`rand::rng()`) — fine for now, but determinism guardrail
  says this becomes a seeded, serialized RNG before any multiplayer work.
- Raids in progress aren't persisted; on load the raiders politely withdraw.