// CROP — a hard inset window onto the frame; everything outside it goes
// to black, the classic letterbox/pillarbox crop. BIAS weights the crop
// toward top/bottom vs left/right.
{
    name: "Crop"
    engine: "screen"
    input0: "test"

    p0: 0.5  p1: 0.5  p2: 0.5
    dials: [
        {name: "CROP", bind: "p0", default: 0.5},
        {name: "BIAS", bind: "p1", default: 0.5},
        {name: "GLOW", bind: "p2", default: 0.5}
    ]

    stages: [
        {kind: "bloom", threshold: 0.55, strength: "1.1 * (0.25 + 1.5*p2)", levels: 2}
    ]

    shader: draw.DrawVjFxScreen {
        fx_color: fn(uv: vec2, content: vec4, cmix: float) -> vec4 {
            let inset = 0.02 + 0.30 * self.user.x
            let bias = self.user.y
            let insetx = inset * (1.3 - bias)
            let insety = inset * (0.3 + bias * 1.4)
            let lo = vec2(insetx, insety)
            let hi = vec2(1.0 - insetx, 1.0 - insety)
            let inside = step(lo.x, uv.x) * step(uv.x, hi.x) * step(lo.y, uv.y) * step(uv.y, hi.y)
            let tex = self.tex0.sample_as_bgra(uv)
            return vec4(tex.xyz * inside, 1.0)
        }
    }
}