#version 430 core

///////////////////////////////////////////////////////////////////////////////
// shader inputs/outputs
///////////////////////////////////////////////////////////////////////////////
uniform float iGlobalTime; // in seconds
uniform vec2 iResolution; // viewport resolution (in pixels) (1080p or 720p)

// all samplers have linear filtering applied, wraping set to repeat
//
uniform sampler1D iFFTTexture; // 1024
uniform float iFFT[8]; // latest frame
uniform float iFFTs[8]; // smoothed latest frame
uniform sampler2D iFFTsHistory; // smoothed fft history, 8x1024, x coord = bin, y coord n-frames earlier, y=0 is latest frame

// predefined textures
//
uniform sampler2D iTex1; // generic textures
uniform sampler2D iTex2;
uniform sampler2D iTex3;
uniform sampler2D iTex4;
uniform sampler2D iTex5;
uniform sampler2D iTex6; // noise
uniform sampler2D iTex7; // moqui
uniform sampler2D iTex8; // okkie
uniform sampler2D iNoise; // perlin noise
uniform sampler2D iChecker; // checker pattern

// out_color must be written in order to see anything
//
layout(location = 0) out vec4 out_color;
///////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////

float df(vec3 p)
{
       p = mod(p+4.0,8.0)-4.0;
       p += sin(p*(4.0+iFFT[5]*1.0)) + sin(p*16*4.0)*.0;
       return (length(p)-5.0 + iFFT[0] + sin(iFFT[1])*.5)*.2 ;
}

vec3 nf(vec3 p)
{
       vec2 e= vec2(.001,.0);
       vec3 n = normalize(vec3(df(p)-df(p+e.xyy),df(p)-df(p+e.yxy),df(p)-df(p+e.yyx)));
       return normalize(n+sin(p*100.0)*.2);
}


void main(void)
{
       float amp = iFFT[0];
       vec2 uv = vec2( gl_FragCoord.xy ) / iResolution * vec2(1,-1);
       float f = texture( iFFTTexture, pow(uv.x*.8*(amp+.2)+.2,4.0)  ).r * 1;
       f -= uv.y+.5;
       f = 0.05/(.05+abs(f));
       //vec4 t = texture( iTex7, uv.xy*(1.0+amp)  )*amp*.5;


       vec3 bgcol = vec3(iFFT[0],iFFT[2],iFFT[6]);
       bgcol = normalize(bgcol);

       float t = iGlobalTime;
       mat3 rot = mat3( sin(t), .0, cos(t),
       .0,1.,.0,-cos(t),.0,sin(t));

       vec3 pos = vec3(2.0 +sin(iGlobalTime),2.0 +sin(iGlobalTime*4.0),-4.0);
       vec2 uv2 = uv -vec2 (.5,-.5);
       vec3 dir = vec3(uv2,1.0 - length(uv2*vec2(.6,.9))*2.0);
       dir.x*=1.5;
       dir = normalize(dir);

       pos *= rot;
       dir *= rot;

       pos.z+=iGlobalTime*2.0+iFFT[0]*4.0;

       float td = .0;

       for (int i=0 ;i<200; i++)
       {
               float dd = df(pos);
               pos += dir*dd;
               td += dd;

       }



       vec3 color = f*bgcol*.3 + dot(nf(pos),normalize(vec3(sin(iGlobalTime),sin(iGlobalTime*3.2),.2)))*.2*bgcol.zyx+.2 + pow(1.0-dot(dir,nf(pos)),4.0)*.5;
       color = min(vec3(1.0),color);
       color = mix(f*bgcol,color,1.0/(1.0+td*.001));

       color += length(color);
       color -= length(uv)*.56;
       out_color = vec4(color,1.);
}