// OCEAN SWELL — low rolling water: smooth (unridged) noise, small height,
// slow scroll, blue-on-blue with a tiltshift horizon. Calm ambient.
{
    name: "Ocean Swell"
    engine: "heightmap"

    res: 120
    size: 32.0
    height: 1.3
    noise_scale: 0.13
    scroll: 1.2

    beat_pulse: "0.2 * (0.2 + 1.6*p0)"
    beat_rate: 0.25
    // PERFORMANCE DIALS — mid-knob = the stock look, exact.
    p0: 0.5  p1: 0.42  p2: 0.5
    dials: [
        {name: "PUMP", bind: "p0", default: 0.5},
        {name: "FOCUS", bind: "p1", default: 0.42},
        {name: "GLOW", bind: "p2", default: 0.5}
    ]

    color_bg: #x030a16
    color_a: #x1a55aa
    color_b: #x44bbee
    color_c: #xcceeff

    cam_fov: 58.0
    cam_height: 2.2
    fog: 0.045
    glow: "1.1 * (0.25 + 1.5*p2)"

    stages: [
        {kind: "tiltshift", focus: "p1", width: 0.3, levels: 3},
        {kind: "bloom", threshold: 0.6, strength: 1.0, levels: 2}
    ]

    // 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 = (slope, grid line, uv.x, uv.y).
    // 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.DrawVjFxTerrain {
        fx_color: fn(t: float, attr: vec4, content: vec4, cmix: float) -> vec4 {
            let grad = self.col_a.mix(self.col_b, t).xyz
            let beat_glow = 1.0 + self.time_beat.w * 1.1
            let drape = content.xyz * (0.42 + 0.85 * attr.x)
                * (1.0 + self.time_beat.w * 0.30)
            let surface = (grad * 0.30 * attr.x)
                .mix(drape, clamp(cmix * 1.25, 0.0, 1.0))
            let gline = grad.mix(content.xyz * 1.3, cmix * 0.55)
            let neon = gline * attr.y * beat_glow * 1.6
                + self.col_c.xyz * attr.y * t * 0.6
            return vec4(surface + neon, 1.0)
        }
    }
}