/**
 * https://www.shadertoy.com/view/4ts3z2
 */

//Audio by Dave_Hoskins


vec2 add = vec2(1.0, 0.0);
#define MOD2 vec2(.16632,.17369)
#define MOD3 vec3(.16532,.17369,.15787)
//----------------------------------------------------------------------------------------
//  1 out, 1 in ...

float hash11(float p)
{
	vec2 p2 = fract(vec2(p) * MOD2);
    p2 += dot(p2.yx, p2.xy+19.19);

    return fract(p2.x * p2.y);
}

//----------------------------------------------------------------------------------------
//  2 out, 1 in...
vec2 hash21(float p)
{
    //p  = fract(p * MOD3);
    vec3 p3 = fract(vec3(p) * MOD3);
    p3 += dot(p3.xyz, p3.yzx + 19.19);
   return fract(vec2(p3.x * p3.y, p3.z*p3.x))-.5;
}
//----------------------------------------------------------------------------------------
///  2 out, 2 in...
vec2 hash22(vec2 p)
{
    vec3 p3 = fract(vec3(p.xyx) * MOD3);
    p3 += dot(p3.zxy, p3.yxz+19.19);
    return fract(vec2(p3.x * p3.y, p3.z*p3.x));
}

//----------------------------------------------------------------------------------------
//  2 out, 1 in...
vec2 Noise21(float x)
{
    float p = floor(x);
    float f = fract(x);
    f = f*f*(3.0-2.0*f);
    return  mix( hash21(p), hash21(p + 1.0), f)-.5;

}


//----------------------------------------------------------------------------------------
//  2 out, 1 in...
float Noise11(float x)
{
    float p = floor(x);
    float f = fract(x);
    f = f*f*(3.0-2.0*f);
    return mix( hash11(p), hash11(p + 1.0), f)-.5;

}

//----------------------------------------------------------------------------------------
//  2 out, 2 in...
vec2 Noise22(vec2 x)
{
    vec2 p = floor(x);
    vec2 f = fract(x);
    f = f*f*(3.0-2.0*f);

    vec2 res = mix(mix( hash22(p),          hash22(p + add.xy),f.x),
                    mix( hash22(p + add.yx), hash22(p + add.xx),f.x),f.y);
    return res-.5;
}

//----------------------------------------------------------------------------------------
// Fractal Brownian Motion...
vec2 FBM21(float v)
{
    vec2 r = vec2(0.0);
    vec2 x = vec2(v, v*1.3+23.333);
    float a = .6;

    for (int i = 0; i < 8; i++)
    {
        r += Noise22(x * a) / a;
        a += a;
    }

    return r;
}

//----------------------------------------------------------------------------------------
// Fractal Brownian Motion...
vec2 FBM22(vec2 x)
{
    vec2 r = vec2(0.0);

    float a = .6;

    for (int i = 0; i < 8; i++)
    {
        r += Noise22(x * a) / a;
        a += a;
    }

    return r;
}


vec2 mainSound(float time)
{
    vec2 audio = vec2(.0);
    for (float t = 0.0; t < 1.0; t+=.5)
    {
        time = time+t;
        vec2 n1 = FBM22( time*(Noise21(time*3.25)*40.0+Noise21(time*.03)*3500.0+8500.0)) * (abs(Noise21(time*.8)))*.25;
        vec2 n2 = FBM22( time*(Noise21(time*.4)+900.0))*abs(Noise21(time*1.5));
        vec2 n3 = FBM22( time*(Noise21(time*1.3)+Noise21(-time*.03)*200.0+540.0))*(.5+abs(Noise21(time-99.)))*1.5;
        vec2 s1 = sin(time*1300.+(Noise21(time*.23))*(Noise21(-time*.12)*3000.0+4000.0))*abs(Noise21(time*42.3+199.))*abs(Noise21(-time*.04+9.))*1.7;

        audio += (n1+n2+n3+s1)/4.0;
    }
    float foot = sin(time*.9*3.141);
    audio += Noise11(time*380.0)*Noise11(time*880.0)* smoothstep(0.7,1.1,abs(foot)) * 2.;

    return clamp(audio, -1.0, 1.0) * smoothstep(0.0, 3.0, time) * smoothstep(60.0, 55.0, time);
}