Verdigris

A living 1890s city district that brings its troubles to your desk.

Named for the green patina on its brass. White stone, gold leaf, civic bunting, arc lamps, pneumatic post, one tram line, one dirigible mooring mast. Toned-down steampunk, in the register of inkle's 80 Days and BioShock Infinite's Columbia.

The theme is civic pride papering over rot. The district presents beautifully and is quietly failing underneath. That is not flavour text: rot is a simulation variable that decides whether a repair that was ordered actually happened, and the courts behind the gold-leaf frontages are a spatial fact the generator produces.

You are Verdigris's alderman. You never place a building. Named residents bring real conditions to your desk: a failing house, aggrieved hands, a public door needed before the rain, sickness behind doors, or a disputed public account. You inspect the people and place, follow them through the day, and spend a small number of measures of influence. The ledger judges what the city actually did, not which button you pressed. Every seventh dawn, named patrons and opponents physically come to the square and put your record before the ratepayers; their vote changes how much influence the chair can move during the following week.

Running it#

npm install
npm run dev        # the local dev server
npm test           # vitest
npm run build      # tsc && vite build
VERDIGRIS_WEB_ROOT=/path/to/webroot ./deploy.sh   # build, then rsync dist/

?seed=coppergate generates a different district. ?ui=3 scales the panels up.

Docs#

• Architecture: the layer split, the determinism contract, the render contracts, and the decisions that are load bearing.
• Simulation reference: what each system models, and the rule that keeps it honest.
• Playing Verdigris: what an alderman actually does.
• Contributing: the rules a change must not break.

Shape of the code#

• src/sim/ is pure and deterministic. Zero DOM, zero Math.random, zero Date.now. Integers only in state. The world is a pure function of (seedStr, tickCount, nudges), which is why the save format is the nudge log and why hashWorld() can anchor every determinism test.
• src/render/ never writes to the sim. Buildings are flattened once into their own sprites and sorted per object; the ID buffer is stamped in the same painter's order so picking is pixel-exact through roofs and overhangs.
• src/ui/ is HTML and CSS over the canvas, not drawn in it.

Three contracts that nothing may violate:

1. Integer transform. Zoom is 1, 2 or 3 and never fractional. Every atlas pixel lands on an exact N by N block of device pixels.
2. Palette. Every non-transparent pixel belongs to a finite render palette, and alpha is 0 or 255. Lighting variants quantize into palette banks. This keeps the ID buffer exact and prevents blended browser colours from creeping into the art.
3. No gradients on the world canvas. Baked dithered sprites only. Smooth gradients live in the UI DOM layer.

Where it is#

Live at https://lakesidegames.net/games/verdigris/

Built and playing:

• The deterministic core. The world is a pure function of (seedStr, tickCount, nudges), so the save format is the nudge log and hashWorld() anchors every determinism test.
• Worldgen on a 64 by 64 grid: seeded coves and headlands, polite and working banks, two or three crossings, a variable civic square, five to eight edge gates, least-cost arterials, block subdivision, six named wards, plot slicing, courts, ward-aware assignment, gas and drain and post networks, tram, and a prehistory of grudges that predate tick 0. Civic, garden, merchant, works, courts, and quayside wards share identity across block grain, building mix, materials, paving, vegetation, street furniture, and inspector text.
• All-pairs next-hop street graph, usually 400 to 520 nodes. No runtime pathfinding. A 64-seed corpus guards density, connectivity, variation and caps.
• Schedules with jitter plus an ambient errand layer, so the district has people in it whenever you look and not only at the two rushes.
• Eight pressures with a cause ring, and baselines that are functions of world state rather than constants.
• Claims that spread over a relationship graph, distort on transmission, and keep a lineage you can walk back.
• Six incidents with hysteresis and cooldowns, each carrying the cause chain that produced it.
• Eleven interventions, each with a second-order effect and a backfire that is a documented state condition rather than a dice roll.
• The Alderman's Desk: a bounded daily agenda derived from live city state, with named petitioners, inspectable places, visible causes, deadlines, a political standing, persistent patrons and opponents, and delayed verdicts. A filed repair counts only if the fabric is actually made good; a strike faces a real four-hour clearing contest; a refuge counts only when somebody vulnerable reaches it; sanitation is judged by sickness on the named street; an inquiry needs a detention that still holds or an account that remains credible; and turnout is judged by the actual weekly vote. Pending promises can be pressed at further political cost, and work filed before a petition receives its proper credit.
• Street politics: petitioners walk to Civic Hall without delaying an actionable case. Kept promises send a named patron to speak at the newspaper; broken or declined promises send a named opponent to a public house. Their support or opposition changes the ward only after the person reaches the destination.
• The ratepayers' sitting: every seventh day, a named supporter and opponent test the chair's standing and exposed clandestine record. Up to eight named adults travel to a fixed 8AM vote, and only those who reach the square count. Confidence grants four daily measures next week, a divided room keeps three, and a loss narrows the chair to two. No result ends play, and the next sitting can reverse it.
• Intervention forecasts taken from the same deterministic predicates as the sim. Each available move is marked public or deniable and settled, contested or unclear; a selected petition marks relevant measures without choosing one for the player.
• The Works Register: file a fabric, drain or gas case on a building. Pneumatic post access changes lead time; coin, rot and workshop state decide whether it is repaired, cosmetically skimmed or shelved. Survey marks, scaffold, blue sheeting, completion plaques, gutters, broken pipes, damp and puddles put that state directly on the building.
• Predicate-gated prose that cannot assert anything the sim does not contain.
• Seeded six-hour weather watches with rain, storms, fog, wind, wet streets, umbrellas, exposure, failed-drain wear, altered wharf output, and weather-gated fires and floods.
• A fixed civic record at every address. Disasters, works cases, hearings and storm relief leave bounded household burdens, institutional evidence and persistent inspector history after the temporary event has cleared.
• Civic Market Day: a seeded public occasion whose vendors and visitors walk to the square, whose goods appear only after vendors arrive, and whose turnout can be thinned or cancelled by weather, public order, a deputation or storm relief.
• Isometric renderer: gable, hip, pyramid, flat, mansard, gambrel, sawtooth and dome roofs; chimneys, dormers, facade materials, window rhythm, vehicles, smoke, lit windows, trees, ground texture, flatten-per-building compositor, one depth merge for buildings, props, people, trams, and carts, pixel-exact ID-buffer picking and discrete zoom.
• The full UI shell, and a keyboard equivalent for every verb.
• A single-surface phone shell with persistent LOOK, ACT, DESK, VESTRY and HELP routes, dynamic bottom-bar clearance, stepped pinch zoom, coarse-pointer person picking, and 44px decision and close targets.

Measured behaviour: undisturbed, the district settles at an average facade of 610 against an average fabric of 520. Fourteen days of funding the bunting takes facade to 669 and fabric to 462. The city looks better and is structurally worse.

Not built:

• art/bake.py and a baked pixel atlas. The city renders from vector primitives drawn in code. The compositor, depth sort, ID buffer and camera contract were all built against those primitives, so an atlas drops in behind an unchanged blit(). atlas.ts's contract is that a missing frame falls back to a primitive, so art can never blank the game.
• The 9-slice panel frames and the two pixel fonts. Panels use flat CSS borders and a system monospace stack.

Time is forward only. The sim is deterministic so a true rewind is a replay, and a replay of a day costs about 300ms; affordable, but it needs a snapshot ring to stay affordable over a month. The control says "advance to" and means it.