#version 410 core

uniform float fGlobalTime; // in seconds
uniform vec2 v2Resolution; // viewport resolution (in pixels)

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 texChecker;
uniform sampler2D texKC;
uniform sampler2D texNoise;
uniform sampler2D texPegasus;
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

float x = 0.2;
//mat3 rot(cos(x),-sin(x),0, sin(x),cos(x),0,0,0,1);

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

float box (vec3 m, vec3 t)
{
  return length(max(abs(m)-t,0.0));
}

float map (vec3 pos)
{
  return sphere(pos,1.0);
  //return max(-sphere(pos,0.3), box(pos,vec3(0.0,0.0,0.0)));
}
/*vec4 plas( vec2 v, float time )
{
  float c = 0.5 + sin( v.x * 10.0 ) + cos( sin( time + v.y ) * 20.0 );
  return vec4( sin(c * 0.2 + cos(time)), c * 0.15, cos( c * 0.1 + time / .4 ) * .25, 1.0 );
}*/
void main()
{
  vec2 uv = vec2(gl_FragCoord.x / v2Resolution.x, gl_FragCoord.y / v2Resolution.y);
  uv -= 0.5;
  uv /= vec2(v2Resolution.y / v2Resolution.x, 1);
  vec3 pos = vec3 (uv,-5.0);
  vec3 dir = normalize(vec3(uv,1.0));

  float prout = 0.001;
  float STEP = 250.0;
  /*vec2 m;
  m.x = atan(uv.x / uv.y) / 3.14;
  m.y = 1 / length(uv) * .2;
  float d = m.y;

  float f = texture( texFFT, d ).r * 100;
  m.x += sin( fGlobalTime ) * 0.1;
  m.y += fGlobalTime * 0.25;

  vec4 t = plas( m * 3.14, fGlobalTime ) / d;
  t = clamp( t, 0.0, 1.0 );*/
  float cd = 0;
  for (cd = 0; cd < STEP; cd++)
    {
      float d = map(pos);
      if (cd < prout)
        break;
      pos += dir*d;
    }
  float ratio = cd/STEP;
  out_color = vec4(pos,1.0);
}