# grade The finish on the frame, run last so the vignette and the grain sit on top of the bloom rather than under it. Two lights fight over this world, so the grade is a split-tone: shadows pulled toward earthlight, highlights toward cinnamon, and the midtones left where they are. Then contrast about mid grey, a little saturation, a vignette measured on the frame's own diagonal — the same falloff on a tall screen and a wide one — and enough grain that a wide flat plain of regolith is not a staircase of banding. `pulse` is the beat: a colour hit that pushes in from the edges when the cargo starts to cook or freeze. `game.dawn.Dawn` raises it on a `band` event and decays it, and any slice can raise it through `dawn.pulse(kind, strength)`.

# terminator The line of first light, drawn where it actually falls. The dawn line is a plane of constant world Z crawling north, and the ground it crosses is craters, rims and boulder fields. So this pass takes each pixel's world position back out of the depth buffer and asks that position which side of the line it is on. The band therefore lies over the terrain instead of floating above it — it bends into every crater and climbs every rim wall — and it costs one fullscreen pass rather than any geometry. Four zones, cut at the two distances `NS.DAWN` carries, so the picture and the rules divide the ground in the same places: | zone | where | look | |---|---|---| | hot | more than `hot_behind` south of the line | bleached, warm, over-lit | | warm | the band just south of the line | cinnamon; the copper the cargo lives in | | dusk | up to `cold_ahead` north | earthlit indigo, dim | | cold | beyond that | near-black blue | `light_at` here is `NS.lightAt` transcribed, deliberately unchanged. Sky pixels carry no world position, so the line never touches them. `amount` at 0 leaves the frame exactly as it rendered.

# ns The shared contract of *First Light: Nearside*. Every slice of the game requires this module and nothing else of each other's. ```luau local NS = require("game.ns") ``` ## What it carries - **Constants** — `NS.ROUTE` (the corridor: `startZ`, `finishZ`, `halfWidth`), `NS.DAWN` (the terminator's start, speed and the hot/cold distances), `NS.CARGO`, `NS.FUEL`, `NS.ROVER`, `NS.PALETTE`, `NS.AUDIO`, `NS.NAMES` (the entity names the scene authors) and `NS.COMPONENTS` (the component identities the entrypoint mounts). - **The light** — `NS.lightAt(dz)` and `NS.bandAt(dz)` read the sunlight at a distance from the dawn line, `dz = z - terminatorZ`. The rules and the lighting both read these, so the meter and the picture agree. - **The screen** — `NS.screen()` and `NS.unit(fraction)`: every layout is stated against the live screen size, never in pixels chosen for one frame. - **Events** — `NS.on(name, fn)` / `NS.emit(name, payload)`; the names are in `NS.EVENTS`. - **Phases** — `NS.phase()`, `NS.setPhase(p)`, `NS.resume()`, `NS.tick(dt)`, `NS.runTime()`. Phases: `title → howto → intro → playing ⇄ paused → won | lost`. - **Surfaces** — `NS.provide(name, table)` / `NS.get(name)` / `NS.whenProvided(name, fn)`. The shapes are in `/zero/source/design/spec.md`. - **Maths** — `clamp`, `lerp`, `smooth`, `approach`, `hash`, `rgb`. ## Notes - Module-local state (phase, surfaces, handlers) resets on hot reload of this file; components re-provide their surfaces in `awake`. - The route runs north, +Z. South of the terminator is sunlight.