#version 430 core

/*float PI = 3.14159f;

uniform sampler2D colorTexture;

uniform float exposition;

in vec3 vecNormal;
in vec3 worldPos;
in vec2 vtc;

out vec4 outColor;

in vec3 viewDirTS;
in vec3 lightDirTS;
in vec3 sunDirTS;

uniform float u_time;
float pi = 3.14159;
// 2D Random
float random (in vec2 st) {
    return fract(sin(dot(st.xy,
                         vec2(12.9898,78.233)))
                 * 43758.5453123);
}

// 2D Noise 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 randA = vec2(a *2.0 *pi);
    vec2 randB = vec2(b *2.0 *pi);
    vec2 randC = vec2(c *2.0 *pi);
    vec2 randD = vec2(d *2.0 *pi);
    
    vec2 offsetA = a-st;
    vec2 offsetB = b-st;
    vec2 offsetC = c-st;
    vec2 offsetD = d-st;
    
    offsetA = offsetA*randA;
    offsetB = offsetB*randB;
    offsetC = offsetC*randC;
    offsetD = offsetD*randD;
    
    float resA = smoothstep(offsetA.x,offsetA.y, f.y);
    float resB = smoothstep(offsetB.x,offsetB.y, f.y);
    float resC = smoothstep(offsetC.x,offsetC.y, f.y);
    float resD = smoothstep(offsetD.x,offsetD.y, f.y);

	vec2 u = smoothstep(0.,1.,f);


    float ab= mix(a, b, u.x);
    float cd = mix(c, d, u.x);
    return mix(ab,cd,u.y);
  
}

void main()
{

    vec2 st = vtc;
    vec2 pos = vec2(st*3.776);
    pos.x -= u_time * 0.07;
    // Use the noise function
    float n = 1.836 * 0.676*noise(pos*2.576);
    n = smoothstep(-0.096, 1.176, n);

	outColor = vec4(vec3(n), 1);
}
*/

out vec4 outColor;
uniform float u_time;

in vec2 vtc;

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 NUM_OCTAVES 5

float fbm ( in vec2 _st) {
    float v = 0.0;
    float a = 0.5;
    vec2 shift = vec2(100.0);
    // Rotate to reduce axial bias
    mat2 rot = mat2(cos(0.5), sin(0.5),
                    -sin(0.5), cos(0.50));
    for (int i = 0; i < NUM_OCTAVES; ++i) {
        v += a * noise(_st);
        _st = rot * _st * 3.0 + shift;
        a *= 0.6;
    }
    return v;
}

void main() {
    vec2 st = vtc;
    // st += st * abs(sin(u_time*0.1)*3.0);
    vec3 color = vec3(0.0);

    vec2 q = vec2(0.);
    q.x = fbm( st + 0.00*u_time);
    q.y = fbm( st + vec2(1.0));

    vec2 r = vec2(0.);
    r.x = fbm( st + 1.0*q + vec2(1.7,9.2)+ 0.15*u_time );
    r.y = fbm( st + 1.0*q + vec2(8.3,2.8)+ 0.126*u_time);

    float f = fbm(st+r);

    color = mix(vec3(0.101961,0.619608,0.666667),
                vec3(0.666667,0.666667,0.498039),
                clamp((f*f)*4.0,0.0,1.0));

    color = mix(color,
                vec3(0.995,0.077,0.220),
                clamp(length(q),0.0,1.0));

    color = mix(color,
                vec3(1.000,0.925,0.132),
                clamp(length(r.x),0.0,1.0));

    outColor = vec4((f*f*f+.9*f*f+.9*f)*color,1.);
}
/*
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;
    //vec2 st = vtc.xy/worldPos.xy;
    //st += st * abs(sin(u_time*0.1)*10.0);
    //st.x *= worldPos.x/worldPos.y;

    vec3 color = vec3(0.0);
    color += fbm(st*3.0);

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

    outColor = vec4(mixedColor,1.0);

}*/