// ACID BLOOM — the shader-hook demo: an L-system dome whose look comes
// from a custom fx_color IN THIS DOCUMENT, compiled into the draw shader
// at load. Iridescent bands cycle along the birth order with the beat.
{
    name: "Acid Bloom"
    engine: "lsystem"
    seed: 19

    axiom: "X"
    rules: ["X=F[/+X][\\-X]F[^X]X", "F=FF"]
    iterations: 5
    angle: 22.0
    step: 0.13
    radius: 0.06
    sides: 6
    copies: 3

    grow: "loop"
    grow_beats: 12
    sway: "0.9 * (0.25 + 1.5*p0)"
    sway_freq: 0.8
    beat_pulse: "0.55 * (0.2 + 1.6*p1)"
    beat_rate: 1.0
    glow: "0.25 + 1.5*p2"
    // PERFORMANCE DIALS — mid-knob = the stock look, exact.
    p0: 0.5  p1: 0.5  p2: 0.5
    dials: [
        {name: "WIND", bind: "p0", default: 0.5},
        {name: "PUMP", bind: "p1", default: 0.5},
        {name: "GLOW", bind: "p2", default: 0.5}
    ]

    color_bg: #x060010
    color_a: #x40ff80
    color_b: #xff4080
    color_c: #xffffff

    cam_orbit: 0.14
    fog: 0.035

    stages: [
        {kind: "bloom", threshold: 0.35, strength: 1.7, levels: 3}
    ]

    // Shader hooks SUBCLASS the engine's draw shader (that is what keeps
    // the vertex/pixel structure intact — a plain {} would replace it).
    shader: draw.DrawVjFxMesh {
        fx_color: fn(t: float, attr: vec4, normal: vec3, wpos: vec3) -> vec4 {
            // Iridescent bands: hue cycles along the arc and the beat
            // (cosine-palette technique, own constants).
            let ph = t * 14.0 + self.time_beat.y * 0.5 + attr.z * 3.0
            let rgb = vec3(
                0.5 + 0.5 * sin(ph),
                0.5 + 0.5 * sin(ph + 2.094),
                0.5 + 0.5 * sin(ph + 4.188)
            )
            let flash = self.time_beat.w * 0.7
            return vec4(rgb + vec3(flash, flash, flash), 1.0)
        }
    }
}