// AMBER EXCHANGE — the after-hours amber terminal: a faster two-candles-
// per-beat tape in old-monitor amber, drifting sideways with a slow orbit
// so the plane catches parallax, and a soft feedback smear that makes the
// phosphor linger. Pattern taught: the chart is a MESH in 3D space — a
// whisper of cam_orbit turns the flat terminal into a floating pane.
{
    name: "Amber Exchange"
    engine: "stockcharts"
    seed: 58

    candles: 140
    per_beat: 2
    vol: 1.2
    drift: 0.0
    spike: 1.2
    ma: 8
    grid_x: 8
    grid_y: 6
    scan: 12
    width: 16
    height: 7

    beat_pulse: 0.4
    p0: 0.1
    p1: "0.2 + 0.5*pulse"

    // PERFORMANCE DIALS — the chart engine's own p-levers: GAIN drives
    // the phosphor, XHAIR holds the crosshair pump when touched, PANIC
    // floods the board red.
    dials: [
        {name: "GAIN", bind: "p0", default: 0.1},
        {name: "XHAIR", bind: "p1", default: 0.5},
        {name: "PANIC", bind: "p2", default: 0.0}
    ]

    color_bg: #x0a0602
    color_a: #xffb433
    color_b: #x8a5410
    color_c: #xffe6b0

    cam_orbit: 0.045
    cam_fov: 42
    fog: 0.0
    glow: 1.15

    stages: [
        {kind: "bloom", threshold: 0.45, strength: 1.1, levels: 2},
        {kind: "feedback", amount: 0.35, zoom: 1.0, rotate: 0.0, dim: 0.94}
    ]

    // 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 = candle age 0..1, attr = (element class, age, up/down, move size).
    // 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.DrawVjFxCharts {
        fx_color: fn(t: float, attr: vec4, normal: vec3, wpos: vec3) -> vec4 {
            let class = attr.x
            if class < 0.5 {
                // Candle body: col_a up / col_b down, big moves burn.
                let base = self.col_b.mix(self.col_a, step(0.5, attr.z))
                let burn = 0.75 + attr.w * 0.7 + self.time_beat.w * (1.0 - t) * 0.6
                return vec4(base.xyz * burn, 1.0 - t * 0.55)
            }
            if class < 1.5 {
                let base = self.col_b.mix(self.col_a, step(0.5, attr.z))
                return vec4(base.xyz * 0.55, (1.0 - t * 0.55) * 0.8)
            }
            if class < 2.5 {
                return vec4(self.col_a.xyz * 0.16, 0.5)
            }
            if class < 3.5 {
                // Kept modest: the bloom stage amplifies this line, and an
                // over-gained crosshair blows out into a white bar.
                let g = 0.55 + self.user.y * 0.5 + self.time_beat.w * 0.25
                return vec4(self.col_c.xyz * g, 0.8)
            }
            if class < 4.5 {
                return vec4(self.col_c.xyz * 0.5 + self.col_a.xyz * 0.4, 0.85)
            }
            return vec4(self.col_a.xyz * 0.6, 0.9)
        }
    }
}