// TILE JITTER — the picture holds together but will not sit still: every
// tile jumps to a new hashed offset ON THE BEAT and settles back before the
// next one, spinning a little as it goes.
//
// Pattern taught here: BEAT-QUANTISED HASHES. The jump seed is
// `floor(bar * 4)` — which beat of the bar we are on — so it steps four
// times a bar and repeats forever; nothing accumulates, and cueing the deck
// anywhere lands mid-pattern instead of mid-drift. The settle is
// `1 - beat phase`, a plain 1..0 saw, so every jump decays exactly on time
// whatever the tempo.
{
    name: "Tile Jitter"
    engine: "tiles"
    mode: "hook"
    seed: 23

    grid: 26
    spread: 8.6
    aspect: 0.66
    gap: 0.05

    input0: "test"

    speed: 1.0
    beat_pulse: 0.8
    beat_rate: 1.0
    bar_beats: 4

    // PERFORMANCE DIALS — mid-knob = the stock look, exact.
    p0: 0.5  p1: 0.5
    p2: "0.06 + 0.22 * pulse"
    dials: [
        {name: "THROW", bind: "p0", default: 0.5},
        {name: "SPIN", bind: "p1", default: 0.5},
        {name: "GROUT", bind: "p2", default: 0.5}
    ]

    color_bg: #x0a0610
    color_a: #xff5fa8
    color_b: #x40206a
    color_c: #xffd9f0

    fog: 0.0
    glow: 1.05

    stages: [
        {kind: "chroma", p1: "(0.05 + 0.12 * pulse)", p2: 0.25},
        {kind: "bloom", threshold: 0.66, strength: 0.95, 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 = the mode highlight drive, attr = (shade, edge, stagger, tumble).
    // Vertex hooks: fx_tile(id, grid, uv_window, t) -> (dx, dy, dz, scale),
    // fx_tile_spin(id, grid, uv_window, t) -> (axis.xyz, angle).
    // 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.DrawVjFxTiles {
        fx_tile: fn(id: float, grid: vec2, uv_window: vec4, t: float) -> vec4 {
            // Which beat of the bar: 0..3, stepping, bounded forever.
            let slot = floor(clamp(self.sig.x, 0.0, 0.9999) * 4.0)
            let seed = id * 1.371 + slot * 37.19
            let jx = self.hash1(seed + 1.0) - 0.5
            let jy = self.hash1(seed + 2.0) - 0.5
            let jz = self.hash1(seed + 3.0) - 0.5
            // Snap on the beat, settle across it.
            let settle = 1.0 - clamp(self.time_beat.z, 0.0, 1.0)
            let ease = settle * settle
            let throw = (0.25 + 1.5 * clamp(self.user.x, 0.0, 1.0))
                * self.shape.w * 0.85
            let pop = 1.0 + 0.18 * ease
            return vec4(jx * throw, jy * throw, jz * throw * 0.5, pop)
        }

        fx_tile_spin: fn(id: float, grid: vec2, uv_window: vec4, t: float) -> vec4 {
            let slot = floor(clamp(self.sig.x, 0.0, 0.9999) * 4.0)
            let seed = id * 2.113 + slot * 53.71
            let ax = self.hash1(seed + 5.0) - 0.5
            let ay = self.hash1(seed + 6.0) - 0.5
            let az = self.hash1(seed + 7.0) - 0.5 + 0.05
            let a = vec3(ax, ay, az)
            let al = max(length(a), 0.05)
            let settle = 1.0 - clamp(self.time_beat.z, 0.0, 1.0)
            let ease = settle * settle
            let spin = (0.2 + 1.6 * clamp(self.user.y, 0.0, 1.0)) * 0.32
            return vec4(a.x / al, a.y / al, a.z / al, ease * spin)
        }

        fx_color: fn(t: float, attr: vec4, content: vec4, cmix: float) -> vec4 {
            let border = attr.y
            let lit = content.xyz * (attr.x * (0.35 + 0.65 * border))
            // The grout flares while the tiles are still moving.
            let heat = 1.0 - clamp(self.time_beat.z, 0.0, 1.0)
            let glowline = self.col_c.xyz.mix(self.col_a.xyz, heat)
                * (1.0 - border)
                * (t + clamp(self.user.z, 0.0, 4.0) + heat * 0.35)
            return vec4((lit + glowline) * self.fog.y, 1.0)
        }
    }
}