#version 430 core

uniform float u_time;
out vec4 outColor;
in vec2 vtc;
in vec3 worldPos;

vec2 u_resolution = vec2(1024, 1024);

float random (in vec2 st) {
    return fract(sin(dot(st.xy,
                         vec2(12.9898,78.233)))*
        43758.5453123);
}

// Based on Morgan McGuire @morgan3d
// https://www.shadertoy.com/view/4dS3Wd
float noise (in vec2 st) {
    vec2 i = floor(st);
    vec2 f = fract(st);

    // Four corners in 2D of a tile
    float a = random(i);
    float b = random(i + vec2(1.0, 0.0));
    float c = random(i + vec2(0.0, 1.0));
    float d = random(i + vec2(1.0, 1.0));

    vec2 u = f * f * (3.0 - 2.0 * f);

    return mix(a, b, u.x) +
            (c - a)* u.y * (1.0 - u.x) +
            (d - b) * u.x * u.y;
}

#define OCTAVES 6
float fbm (in vec2 st) {
    // Initial values
    float value = 0.0;
    float amplitude = .5;
    float frequency = 0.;
    //
    // Loop of octaves
    for (int i = 0; i < OCTAVES; i++) {
        value += amplitude * noise(st);
        st *= 2.;
        amplitude *= .5;
    }
    return value;
}

void main() {

/*
    vec2 st = vtc;
    float cloudIntensity = 15.0;

    

    // Efekt lustrzanego odbicia
    vec2 mirroredSt = vec2(1.0 - st.x, st.y);
    mirroredSt.x += u_time * 0.07;
    vec3 mirroredColor = vec3(0.0);
    mirroredColor += fbm(mirroredSt * cloudIntensity);

    st.x -= u_time * 0.07;
    // Efekt oryginalny
    vec3 color = vec3(0.0);
    color += fbm(st * cloudIntensity);

    // Dodaj gradientowe mieszanie między oryginałem a lustrzanym odbiciem
    float gradient = smoothstep(0.45, 0.55, st.x);
    vec3 finalColor = mix(color, mirroredColor, gradient);

    outColor = vec4(finalColor, 1.0);
    */
    
    vec2 st = vtc;
    st.x -= u_time * 0.07;

    vec3 color = vec3(0.0);
    color += fbm(st*10.0);

    //vec3 mixedColor = mix(vec3(0.4), color, color.r);
    //color = mix(vec3(1.0), fbm(st*3.0), 0.1);

    outColor = vec4(color,1.0);
    
}