// EMBER PIT — Kick Forge with the shard material OVERRIDDEN: obsidian
// chips at rest that ignite ember→white while airborne and cool as they
// fall (the hook's `t` is flight heat — 1 at launch, 0 landed). Pattern
// taught: `shader:` must SUBCLASS the engine's draw shader
// (draw.DrawVjFxForge), and a feedback stage streaks the embers into
// fire-trails. Low glint: this one glows, it doesn't sparkle.
{
    name: "Ember Pit"
    engine: "forge"
    seed: 23

    shards: 2600
    radius: 4.0
    impulse: 9.5
    gravity: 38.0
    spin: 0.8
    membrane_wave: 0.4
    shard_size: 0.15
    scatter: 0.7
    falloff: 0.45
    pile: 0.75
    glint: 0.3

    beat_pulse: 0.5
    p0: "0.5 + 2.8*bass"
    p1: "0.25 + 1.0*bass"
    p2: 0.1

    // PERFORMANCE DIALS — the engine's own p-levers (impulse gain,
    // membrane ring, glint fire).
    dials: [
        {name: "HEAT", bind: "p0", default: 0.5},
        {name: "RING", bind: "p1", default: 0.5},
        {name: "EMBER", bind: "p2", default: 0.1}
    ]

    color_bg: #x0a0505
    color_a: #x232030      // obsidian
    color_b: #x3a2a28      // scorched rock
    color_c: #xffc890      // ember light

    cam_orbit: 0.08
    cam_fov: 50.0
    fog: 0.040
    glow: 1.2

    // The material hook: cold obsidian → ember → white-hot by flight heat.
    shader: draw.DrawVjFxForge {
        fx_color: fn(t: float, attr: vec4, normal: vec3, wpos: vec3) -> vec4 {
            let ember = vec4(1.0, 0.42, 0.08, 1.0)
            let hot = ember.mix(vec4(1.0, 0.95, 0.85, 1.0), pow(t, 3.0))
            let cold = self.col_a.mix(self.col_b, fract(attr.w * 7.9))
            return cold.mix(hot, pow(clamp(t, 0.0, 1.0), 0.7))
        }
    }

    stages: [
        {kind: "feedback", amount: "0.5 + 0.25*pulse", zoom: 1.006, dim: 0.94},
        {kind: "bloom", threshold: 0.45, strength: 1.6, levels: 3}
    ]
}