makepad/apps/vj/resources/effects/95_lightcycle_arena.splash
Admin f44616b2a7 makepad-vj effects: the effect renderstack, with the shaders inside the documents
The VJ's EFFECT surface is a small renderer of its own. An effect is a
`.splash` DOCUMENT — engine choice, stages, fields, parameters and now the
SHADERS THEMSELVES live in the document rather than in Rust. That is the
shape this commit introduces (dev has never seen an intermediate one): a
document is the whole effect, and the Rust side is the engine families that
documents draw with.

The engine families: particles and emitters, GPU sim swarms and fluid, static
meshes (firefly synchrony, harmonograph loom, domino liturgy), tiles, flock,
clouds, city, pipes, stock charts, an SDF raymarcher with a subclassable
`scene_sdf`, and a mountain-jet endless range with a beat-pulsed fighter.

Three things make them a system rather than a demo reel:

  - SIM FIELDS — a float simulation-texture primitive, so an engine can carry
    GPU state across frames (wind, particles, fluid) instead of being a pure
    function of the clock.
  - CONTENT COUPLING — `content:` in a document and `input0` on every engine's
    tex0, so an effect can consume the program video: drapes, backdrops,
    mirrors, billboards, chrome, frescoes, canopy, glass, silk, wall, swarm,
    pen and mosaic families all take the picture playing behind them.
  - MUSIC BINDING — shaders read the beat, so the whole library moves with the
    track rather than on its own clock.

Roughly a hundred seeded preset documents ship with it, each with a lazily
rendered animated thumbnail (rendered 4x and box-downscaled, 16-tap SSAA);
the thumbnail pass went from four minutes to eleven seconds. CONTRACT.md is
the document contract and its verify recipe; IDEAS.md is the campaign tracker.
2026-08-23 01:35:44 +02:00

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2.3 KiB
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// LIGHTCYCLE ARENA — the tron mood: a dark fine-grid floor, edge-lit black
// towers, and ten light-cycle trail walls sweeping the street lattice IN
// TEMPO. Each trail's front is a pure function of the beat (one lap per
// `trail_beats`, per-trail phase offsets so the arena never syncs into one
// pulse), the head burns white and the wall ages behind it. Pattern
// taught: `trails` is the tron ingredient — walls collapse ahead of their
// front in the vertex shader, so the sweep costs nothing on the CPU.
{
name: "Lightcycle Arena"
engine: "city"
seed: 7
style: "tron"
blocks: 9
block: 6.0
street: 0.30
towers: 180
max_h: 7.5
win: 0.5
density: 0.10
flicker: 0.06
trails: 10
trail_beats: 8
wall_h: 1.5
alt: 8.0
fly: 1.5
bank: 1.8
beat_pulse: 0.7
p1: "0.4 + 1.0*pulse" // trail heads flare on the kick
p2: 0.8 // tower edge glow
// PERFORMANCE DIALS — the city engine's own p-levers: DENS lights
// tower windows, HEAD holds the trail-head flare when touched, EDGE
// gains the tower edge glow.
dials: [
{name: "DENS", bind: "p0", default: 0.0},
{name: "HEAD", bind: "p1", default: 0.5},
{name: "EDGE", bind: "p2", default: 0.8}
]
color_bg: #x02060a
color_a: #x22d8ff
color_b: #xff9a1e
color_c: #xeaffff
fog: 0.020
glow: 1.25
stages: [
{kind: "bloom", threshold: 0.38, strength: 1.8, levels: 3}
]
// THE LOOK LIVES HERE. This block is not a reference to the
// engine's shader — it IS the pixel math this effect runs.
// Rewrite it and the effect looks different; everything else
// (geometry, motion, the content coupling, the beat) keeps
// working, because the block SUBCLASSES the engine shader.
// Inputs: t = height 0..1, attr = (class, id, hash, height/phase).
// Signals: self.time_beat (time, beat, phase, pulse),
// self.sig (bar, bpm, energy, dt), self.user (p0..p3),
// self.col_a/b/c/bg, self.fog (density, glow, content, -).
shader: draw.DrawVjFxCity {
fx_color: fn(t: float, attr: vec4, normal: vec3, wpos: vec3) -> vec4 {
let v = 0.8 + 0.4 * attr.z
return self.col_a.mix(self.col_b, clamp(t * 0.8 + attr.z * 0.3, 0.0, 1.0)) * v
}
}
}