/*{
    "DESCRIPTION": "Window Deep Field: domain-warped fractal caustics in deep cobalt and living teal. A rich animated card background; light lives on the ridges, text sits in the dark valleys.",
    "CREDIT": "TaoBot",
    "CATEGORIES": ["Generator", "Backdrop"],
    "INPUTS": [
        { "NAME": "speed", "LABEL": "Speed", "TYPE": "float", "DEFAULT": 0.7, "MIN": 0.0, "MAX": 2.0 },
        { "NAME": "depth", "LABEL": "Depth", "TYPE": "float", "DEFAULT": 1.0, "MIN": 0.4, "MAX": 1.8 }
    ]
}*/

float hash(vec2 p) { return fract(sin(dot(p, vec2(127.1, 311.7))) * 43758.5453); }
float noise(vec2 p) {
    vec2 i = floor(p), f = fract(p);
    vec2 u = f * f * (3.0 - 2.0 * f);
    return mix(mix(hash(i), hash(i + vec2(1, 0)), u.x),
               mix(hash(i + vec2(0, 1)), hash(i + vec2(1, 1)), u.x), u.y);
}
float fbm(vec2 p) {
    float v = 0.0, a = 0.5;
    mat2 rot = mat2(0.80, 0.60, -0.60, 0.80);
    for (int i = 0; i < 5; i++) { v += a * noise(p); p = rot * p * 2.02; a *= 0.5; }
    return v;
}

void main() {
    vec2 uv = gl_FragCoord.xy / RENDERSIZE;
    vec2 p = uv * vec2(3.2, 1.9) * depth;
    float t = TIME * speed * 0.16;

    // domain warp: q and r fields push the base field around
    vec2 q = vec2(fbm(p + vec2(0.0, 0.0) + t * 0.7),
                  fbm(p + vec2(5.2, 1.3) - t * 0.5));
    vec2 r = vec2(fbm(p + 2.4 * q + vec2(1.7, 9.2) + t * 0.9),
                  fbm(p + 2.4 * q + vec2(8.3, 2.8) - t * 0.6));
    float f = fbm(p + 2.2 * r);

    vec3 deep   = vec3(0.006, 0.020, 0.070);
    vec3 cobalt = vec3(0.020, 0.300, 0.720);
    vec3 teal   = vec3(0.040, 0.680, 0.620);
    vec3 foam   = vec3(0.550, 0.920, 0.860);

    vec3 col = mix(deep, cobalt, clamp(f * f * 1.6, 0.0, 1.0));
    col = mix(col, teal, clamp(length(q) * 0.55, 0.0, 1.0) * smoothstep(0.25, 0.85, f));
    col = mix(col, foam, clamp(pow(length(r), 2.0) * 0.28, 0.0, 1.0) * smoothstep(0.55, 0.95, f));

    // darken the middle band where card text usually lives
    float textZone = smoothstep(0.55, 0.15, abs(uv.y - 0.52));
    col *= 1.0 - 0.35 * textZone;
    float vig = smoothstep(1.3, 0.4, length(uv - vec2(0.5, 0.48)));
    col *= 0.45 + 0.55 * vig;
    gl_FragColor = vec4(col, 1.0);
}