// CHANNEL OFFSET — red and blue split away from green along one axis,
// the axis itself rotatable and the split reach riding the beat, so the
// tear reads as a controlled RGB fringe rather than a fixed glitch.
{
    name: "Channel Offset"
    engine: "screen"
    seed: 206
    input0: "test"

    speed: 1.0
    beat_pulse: 0.5
    beat_rate: 1.0
    bar_beats: 4
    glow: 1.0
    // PERFORMANCE DIALS — mid-knob = the stock look, exact.
    p0: 0.5  p1: 0.5  p2: 0.5
    dials: [
        {name: "ANGLE", bind: "p0", default: 0.5},
        {name: "DEPTH", bind: "p1", default: 0.5},
        {name: "PUMP", bind: "p2", default: 0.5}
    ]

    color_bg: #x03040a
    color_a: #x30ffd0
    color_b: #xff3a86
    color_c: #xfff0d0

    stages: [
        {kind: "bloom", threshold: 0.6, strength: 1.0, levels: 2}
    ]

    // THE LOOK LIVES HERE: the whole frame is this function. The split
    // axis is a full rotation of ANGLE; DEPTH sets its reach; PUMP gates
    // how much the eased beat pulse adds on top of the base split.
    // Inputs: uv, content = input0 at uv, cmix = pre-gated content
    // strength. 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.DrawVjFxScreen {
        fx_color: fn(uv: vec2, content: vec4, cmix: float) -> vec4 {
            let angle = self.user.x * 6.2831853
            let depth = 0.002 + 0.05 * self.user.y
            let pump = 1.0 + 1.4 * self.time_beat.w * clamp(self.user.z, 0.0, 1.0)
            let dir = vec2(cos(angle), sin(angle)) * depth * pump
            let ruv = clamp(uv + dir, vec2(0.0, 0.0), vec2(1.0, 1.0))
            let buv = clamp(uv - dir, vec2(0.0, 0.0), vec2(1.0, 1.0))
            let r = self.tex0.sample_as_bgra(ruv)
            let b = self.tex0.sample_as_bgra(buv)
            return vec4(r.x, content.y, b.z, 1.0)
        }
    }
}