// PULSE WORMHOLE — the binding layer at work on a mesh engine: glow and
// fog both ride the beat envelope, the radial-blur stage hits on the pulse,
// and the declared dials (p0..p2) scale those bindings live.
{
    name: "Pulse Wormhole"
    engine: "tunnel"

    knot_p: 2.0
    knot_q: 5.0
    major: 6.0
    tube: 1.4
    rings: 800
    sides: 20
    fly: 5.0
    bands: 130.0

    beat_pulse: "0.8 * (0.2 + 1.6*p2)"
    glow: "(0.8 + env(phase) * 1.3) * (0.2 + 1.6*p0)"
    fog: "0.08 + env(phase) * 0.05"
    // PERFORMANCE DIALS — the dial params are SIGNALS in any binding
    // (p0..p2), so knobs ride the same expressions music does. Mid-knob
    // reproduces the stock look exactly.
    p0: 0.5  p1: 0.5  p2: 0.5
    dials: [
        {name: "SURGE", bind: "p0", default: 0.5},
        {name: "WARP", bind: "p1", default: 0.5},
        {name: "PUMP", bind: "p2", default: 0.5}
    ]

    color_bg: #x000208
    color_a: #x00ffcc
    color_b: #x0066ff
    color_c: #xccffee

    stages: [
        {kind: "radial_blur", p1: "(pulse * 0.7) * (0.2 + 1.6*p1)", p2: 0.5},
        {kind: "bloom", threshold: 0.4, strength: 1.5, 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 = along the bore 0..1, attr = (around, along, ring hash,
    // radius), content = the wall texel at this vertex, cmix = the
    // pre-gated content strength (0 without real channel video). The
    // wall DRAPE has its own pixel hook, `fx_wall` — this tunnel keeps
    // the stock one.
    // 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.DrawVjFxTunnel {
        fx_color: fn(t: float, attr: vec4, normal: vec3, wpos: vec3,
                     content: vec4, cmix: float) -> vec4 {
            return self.col_a.mix(self.col_b, t)
        }
    }
}