#version 450

// Name: New Leaked 3I/Atlas NASA Footage
// Author: msm01
// URL: https://www.shadertoy.com/view/3ftcRr

layout(location = 0) in  vec2 vUV;
layout(location = 0) out vec4 FragColor;

layout(set = 3, binding = 0) uniform ShadertoyUBO {
    float iTime;
    vec2  iResolution;
};

#define s(a,b,c) smoothstep(a,b,c)
#define PI     3.14159
#define NBCaps 3.

mat2 r2d(float a) { float c = cos(a), s = sin(a); return mat2(c, s, -s, c); }
float metaDiamond(vec2 p, vec2 pixel, float r) { vec2 d = abs(p - pixel); return r / (d.x + d.y); }

float hash12(vec2 p) {
    vec3 p3 = fract(vec3(p.xyx) * .1031);
    p3 += dot(p3, p3.yzx + 33.33);
    return fract((p3.x + p3.y) * p3.z);
}

float fbm(in vec2 v_p) {
    float pvpx = v_p.x;
    vec2 V1 = vec2(floor(pvpx));
    vec2 V2 = vec2(floor(pvpx + 1.0));
    return mix(hash12(V1), hash12(V2), smoothstep(0.0, 1.0, fract(pvpx)));
}

void mainImage(out vec4 fragColor, in vec2 fragCoord) {
    vec2 p = vec2((1.0 / iResolution.y) * (fragCoord.x - iResolution.x / 2.0),
                  fragCoord.y / iResolution.y - 0.5);

    p.x = -p.x;
    p *= 150.0;

    vec4 col = vec4(0.05, 0.05, 0.15, 1.0);

    vec2 save1 = p;
    vec2 save2 = p;

    p *= r2d(-0.05);
    col = mix(col, vec4(0.2, 0.3, 0.5, 1.0),
              smoothstep(75.0, 0.0, abs(p.y - 5.0 * fbm(vec2(0.01 * (p.x - 33.333 * iTime))) + 3.5)));
    p *= r2d(0.05);

    p *= r2d(-0.05);
    p *= 0.35;
    p += vec2(-5.0 * iTime, 0.0);

    vec2 b = fract(5.0 * p);
    p = floor(5.0 * p);
    if (fbm(vec2(p.x * p.y)) > 0.996) col += clamp(1.0 - pow(3.0 * length(b + vec2(-0.5)), 0.5), 0.0, 1.0);

    p = save1;
    vec2 save3;

    float Nb_Capsules = clamp(NBCaps, 0.0, 4.0);
    for (float i = 0.0; i < Nb_Capsules; i++) {
        p = save1;
        p *= r2d(-0.05);
        p *= 2.5;
        p *= 1.0 - 0.25 * i;
        p += vec2(150.0 * fbm(vec2(0.15 * iTime + i * 54.321)) - 75.0,
                  50.0 * sin(0.25 * iTime + i * 54.321) - 25.0);
        save3 = p;

        p *= 0.04;
        p.y = abs(p.y);

        if (p.x > 0.0) {
            col += vec4(0.0, 1.0, 0.5, 1.0) * smoothstep(0.2, 0.0, abs(p.y - 0.05 * fbm(vec2(1.5 * p.x - 40.0 * iTime))) - 0.05) * smoothstep(29.0, 0.0, abs(p.x));
            col += vec4(1.0, 1.0, 1.0, 1.0) * smoothstep(0.1, 0.0, abs(p.y - 0.05 * fbm(vec2(1.5 * p.x - 40.0 * iTime))) - 0.05) * smoothstep(29.0, 0.0, abs(p.x));
        }

        p = save3;
        p.y = abs(p.y);
        p += vec2(-10.0, 0.0);
        p *= vec2(0.75, 1.0);

        col += 0.8 * vec4(0.0, 1.0, 0.5, 1.0) * s(20.0, 0.0, length(p) - 25.0 + 7.0 * sin(0.30 * length(p) * atan(p.y, p.x) + 55.0 * iTime));
        col += 0.8 * vec4(1.0, 1.0, 1.0, 1.0) * s(20.0, 0.0, length(p) - 20.0 + 7.0 * sin(0.30 * length(p) * atan(p.y, p.x) + 55.0 * iTime));

        p = save3;

        col = mix(col, vec4(1.0), 0.5 * s(10.0, 0.0, length(p + vec2(5.0, 0.0)) - 20.0) * abs(sin(50.0 * iTime)));
        col = mix(col, vec4(1.0), 0.5 * s(20.0, 0.0, length(p + vec2(5.0, 0.0)) - 20.0));

        col = mix(col, vec4(1.0), s(0.01, 0.0, length(p) - 20.0));

        if (length(p) - 20.0 < 0.0) {
            col = mix(col, vec4(0.65, 0.68, 0.68 + 0.1 * (3.0 - i), 1.0), s(0.5, 0.0, length(p - vec2(2.0, 0.0)) - 17.0));
            if (s(0.0, 1.0, length(vec2(3.0, 2.0) * p + vec2(33.5, 0.0)) - 23.0) > 0.0)
                col = mix(col, vec4(0.45, 0.55, 0.55 + 0.1 * (3.0 - i), 1.0),
                          0.75 * s(0.5, 0.0, length(p - vec2(2.0, 0.0) + 0.5 * fbm(vec2(4.5 * atan(p.y, p.x)))) - 9.0));

            col = mix(col, vec4(0.0), s(0.2, 0.0, abs(length(p) - 19.9) - 0.20));
            col = mix(col, vec4(0.5, 0.2, 0.3, 1.0)
                          - s(5.0, 0.0, length(p + vec2(-6.0, 15.0)) - 20.0)
                          - s(0.25, 0.0, abs(length(p + vec2(0.0, 3.0)) - 15.0) - 0.4)
                          - s(0.0, 1.5, p.y - 8.5)
                          + 0.25 * vec4(1.0, 0.5, 0.0, 1.0) * s(10.0, 0.0, abs(p.y))
                          ,
                          s(0.5, 0.0, length(vec2(3.0, 2.0) * p + vec2(35.0, 0.0)) - 19.9));

            col = mix(col, vec4(0.0, 0.0, 0.0, 1.0), s(1.0, 0.0, abs(length(vec2(3.0, 2.0) * p + vec2(35.0, 0.0)) - 19.9) - 0.1));
            col = mix(col, vec4(0.0, 0.0, 0.0, 1.0), s(1.0, 0.0, abs(length(vec2(3.0, 2.0) * p + vec2(33.5, 0.0)) - 23.0) - 0.1));

            if (p.y > 0.0) col = mix(col, vec4(0.0, 0.0, 0.0, 1.0), s(1.0, 0.0, abs(length(vec2(3.0, 2.0) * p + vec2(29.0, 0.0)) - 30.0) - 0.1));
            if (p.y < 0.0) col = mix(col, vec4(0.0, 0.0, 0.0, 1.0), s(1.0, 0.0, abs(length(vec2(3.0, 2.0) * p + vec2(-31.0, 0.0)) - 30.0) - 0.1));
        }
    }

    fragColor = clamp(col, 0.0, 1.0);
}

void main() {
    vec2 fragCoordPixels = vUV * iResolution;
    vec4 outColor;
    mainImage(outColor, fragCoordPixels);
    FragColor = outColor;
}