#version 410 core

uniform float fGlobalTime; // in seconds
uniform vec2 v2Resolution; // viewport resolution (in pixels)
uniform float fFrameTime; // duration of the last frame, in seconds

uniform sampler1D texFFT; // towards 0.0 is bass / lower freq, towards 1.0 is higher / treble freq
uniform sampler1D texFFTSmoothed; // this one has longer falloff and less harsh transients
uniform sampler1D texFFTIntegrated; // this is continually increasing
uniform sampler2D texPreviousFrame; // screenshot of the previous frame
uniform sampler2D texChecker;
uniform sampler2D texNoise;
uniform sampler2D texTex1;
uniform sampler2D texTex2;
uniform sampler2D texTex3;
uniform sampler2D texTex4;


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

const float E = 0.001;
const float FAR = 100.0;
const int STEPS = 128;

float time = pow(texture(texFFTIntegrated,0.05).r*.01,1)+fGlobalTime*.003;
float fft = texture(texFFTIntegrated, 0.01).r*.01;
float fft2 = texture(texFFTSmoothed,0.15).r;
vec3 glow = vec3(0);



float sphere(vec3 p, float r){
  return length(p)-r;
}

float box(vec3 p, vec3 b){
  vec3 d = abs(p)-b;
  return length(max(d, 0.0))+min(max(d.x, max(d.y, d.z)), 0.0);
}

float torus(vec3 p, vec2 t){
  
  vec2 q= vec2(length(p.xz)-t.x,p.y);
  return length(q)-t.y;
  }

void rot(inout vec2 p, float a){
  p = cos(a)*p + sin(a)*vec2(-p.y, p.x);
}

float scene(vec3 p, vec3 ro, vec3 rd){
  vec3 pp = p;
  float fpp= texture(texFFTSmoothed,(pow(dot(p,ro)*.001,2.5))).r*100;
  float keski = sphere(pp,2*(.5+fpp*1));
  float pallo = box((pp-ro)*rd,vec3(1));
  rot(pp.xy, time*0.1);
  for(int i = 0; i < (floor(abs(p.x*.2)+1.5)); ++i){
    pp = abs(pp)-vec3(1.8);
    pp = abs(pp)-vec3(10,10,0)*.2;
    rot(pp.yz, time*1);
    pp = abs(pp)-vec3(0.1*i, 0.3, 0.1*i);
  }
  
  float d = distance(p,pp); //distance(p, pp);
  float sp = box(pp, vec3(d*0.05, d*0.04, d*0.02)*(vec3(1+fft2*0)));
  
  vec3 g = vec3(.2)*0.01 / (abs(sp)+0.05);
  glow += g;
  glow *= d*.05;
  
  sp = abs(sp*0.5);
  
  return max(sp,-pallo);//max(min(sp,keski),-pallo);
}

float scene2(vec3 p, vec3 ro, vec3 rd){
  vec3 pp = p;
  
  for(int i = 0; i < 20; ++i) {
    pp = abs(pp)-vec3(2);
  }
  
  float d = distance(p,pp); //distance(p, pp);
  
  float sp = box(pp,vec3(0.5));
  vec3 g = vec3(.2)*0.01 / (abs(sp)+0.05);
  
  glow += g;
  glow *= d*.03;
  
  return sp;
}

float scene3(vec3 p, vec3 ro, vec3 rd){
  vec3 pp = p;
  //float d = distance(p,pp);
  
  for(int i = 0; i < 20; ++i) {
    //pp = abs(pp)-vec3(0,0,8);
  }
  
  pp+=vec3(0,-10,0);
  rot(pp.xy,sin(fft2*10));
  pp+=vec3(0,10,0);
  
  float sp = torus(pp,vec2(5,2));
  
  return sp;
}

float march(vec3 ro, vec3 rd){
  float t = E;
  vec3 p = ro;
  for(int i = 0; i < STEPS; ++i){
    float d = scene2(p,ro,rd);
    t += d;
    p = ro + rd * t;
    if(d <= E || t >= FAR){
      break;
    }
  }
  return t;
}

vec3 hsl2rgb( in vec3 c )
{
  vec3 rgb = clamp( abs(mod(c.x*6.0+vec3(0.0,4.0,2.0),6.0)-3.0)-1.0, 0.0, 1.0 );
  return c.z + c.y * (rgb-0.5)*(1.0-abs(2.0*c.z-1.0));
}

vec3 HueShift (in vec3 Color, in float Shift)
{
  vec3 P = vec3(0.55735)*dot(vec3(0.55735),Color);
  vec3 U = Color-P;
  vec3 V = cross(vec3(0.55735),U);    
  Color = U*cos(Shift*6.2832) + V*sin(Shift*6.2832) + P;
  return vec3(Color);
}

vec3 rgb2hsl( in vec3 c ){
  float h = 0.0;
	float s = 0.0;
	float l = 0.0;
	float r = c.r;
	float g = c.g;
	float b = c.b;
	float cMin = min( r, min( g, b ) );
	float cMax = max( r, max( g, b ) );
	l = ( cMax + cMin ) / 2.0;
	if ( cMax > cMin ) {
		float cDelta = cMax - cMin;     
        //s = l < .05 ? cDelta / ( cMax + cMin ) : cDelta / ( 2.0 - ( cMax + cMin ) ); Original
		s = l < .0 ? cDelta / ( cMax + cMin ) : cDelta / ( 2.0 - ( cMax + cMin ) );
		if ( r == cMax ) {
			h = ( g - b ) / cDelta;
		} else if ( g == cMax ) {
			h = 2.0 + ( b - r ) / cDelta;
		} else {
			h = 4.0 + ( r - g ) / cDelta;
		}
		if ( h < 0.0) {
			h += 6.0;
		}
		h = h / 6.0;
	}
	return vec3( h, s, l );
}

float sdPen( in vec2 p, in float r)
{
    const vec3 k = vec3(0.809016994,0.587785252,0.726542528);
  p.x = abs(p.x);
  p -= 2*min(dot(vec2(-k.x,k.y),p),0)*vec2(-k.x,k.y);
  p -= 2*min(dot(vec2( k.x,k.y),p),0)*vec2( k.x,k.y);
  p -= vec2(clamp(p.x,-r*k.z,r*k.z),r);
  return length(p)*sign(p.y);
}


void main(void)
{
	vec2 uv = vec2(gl_FragCoord.x / v2Resolution.x, gl_FragCoord.y / v2Resolution.y);
  vec2 zom = uv;
  vec2 kzom = uv;
  vec2 uv_=uv;
  uv_-=0.5;
  uv_*=vec2(1,.6)*vec2(2);
  float fw = (1/(texture(texFFTSmoothed, (cos(abs(uv.x-.5)+.025)+cos(abs(uv.y-.5)+.025))).r*3000))*.01;
  uv -= 0.5;
  uv /= vec2(v2Resolution.y / v2Resolution.x, 1);
  uv += 0.5;
  //uv-=vec2(0.5);
  //uv=abs(uv)+vec2(sin(time*10));
  uv=round(uv/(fw*.2))*(fw*.2);
  
  glow=vec3(0);
  
	vec2 q = uv -0.5;
	//q /= vec2(v2Resolution.y / v2Resolution.x, 1);
  
  
  vec3 ro = vec3(10,0,10);// vec3(4+sin(time*.7*cos(time*.1))*15, 0, cos(time*.7*sin(time*.01))*20); 
  rot(ro.xz,sin(time*.2)*10);
  rot(ro.yz,cos(time*.2)*10);
  vec3 rt = vec3(0, 0, 0);
  
  vec3 z = normalize(rt-ro);
  vec3 x = normalize(cross(z, vec3(0, 1, 0)));
  vec3 y = normalize(cross(x, z));
  
  vec3 rd = normalize(mat3(x,y,z) * vec3(q, 1/radians(90.0)));
  
  float t = march(ro, rd);
  vec3 p = ro+rd*t;
  
  
  float dis = distance(ro,p);
  
  vec2 ffuv = uv.xy*1-vec2(.5);
  
  ffuv *= vec2(.5);
  
  ffuv.y=log(1+pow(abs(ffuv.y+.002),2));
  
  float fy = texture(texFFT, ffuv.y).r*2;
  float fx = texture(texFFT, pow(abs(p.x*.4),3)*.2).r*20;
  
  float fz = texture(texFFTSmoothed, 0.02).r*-10;
  
  float fuv = texture(texFFT, pow(uv.y,1.5)).r*(10+pow(uv.y,1.5));
  
  
  zom-=vec2(.5);
  zom*=vec2(0.998)-pow(fz,2)*0.008;
  rot(zom.xy,fz*.0001-fy*.0001);
  zom+=vec2(.5);
  
  kzom-=vec2(.75);
  kzom*=vec2(1-fz*8);
  kzom+=vec2(.75);
  
  vec3 prev = texture(texPreviousFrame, zom).rgb*.99;
  
  vec3 col = vec3(0.,0.,0.0);
  if(t < FAR){
    col = vec3(0.2);//vec3(length(p))*.1;
  }
  
  glow*=vec3(.2,.5,.9);//vec3(abs(ro.x*2+.5*sign(ro.y*.4+5)),0.8, (ro.y*4+2)+0.6);
  
  
  col += dis*0.02;
  col += glow*.8*(.4+(fy*fx)*4);
  
  
  //col*=vec3(.2,.2,.5); 
  vec3 hs = vec3(0);
  /*
  vec3 hs = rgb2hsl(col);
  hs.x+=0.1;//time*.03*(p.x*.001)+dis*.8;
  //hs.z-=.001;
  //hs.z=clamp(hs.z,0,1);
  col = hsl2rgb(hs);
  */
  
  
  col-=glow*100;
  
  
  hs = rgb2hsl(prev);
  hs.x+=time*.002;
  hs.y+=0.08;
  hs.z-=0.01;
  prev = hsl2rgb(hs);
  
  float pen = sdPen(uv_*vec2(-1),.4-fx*.2+fx*10);
  
  //col = abs(vec3(p.x*0.002));
  
  col = smoothstep(-0.1, 1.2, col);
  col=vec3(prev)*.8+vec3(col)*.9;
  
  col+=vec3(FAR-dis*5);
  
  if(col.x<.02 && col.y<.02 && col.z<.02){
    col=prev*vec3(1.8,.2,.8);//*vec3(2,1.8,1.2);
  }
  if(col.x>.9 && col.y>.9 && col.z>.9){
    col*=vec3(.01,.5,8);
  }
  col=clamp(col,0.0,1.0);
  col=HueShift(col,.5+floor(time*50)*.8);
  
  col*=1.5-smoothstep(0.0,pen,1.0);
  col+=smoothstep(0.0,1/pen,1.0)*pen;
  //col=vec3(uv,0);
  
  vec3 inter = vec3(pow(texture(texFFTSmoothed,length(p)*.2).x*4,1.8));
  
  if(length(p)>=FAR) {
    inter = vec3(1);
  }
  
	out_color =vec4(col,1);
//  out_color =vec4(length(p)/FAR);
  out_color =vec4(inter,1);
  
  
}