shader-stream-2018-08-15.glsl

#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 texNoise;
uniform sampler2D texTex1;
uniform sampler2D texTex2;
uniform sampler2D texTex3;
uniform sampler2D texTex4;

#define iTime fGlobalTime

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

float height(vec2 uv)
{
  float curve = smoothstep(1,0,length(uv)) * .5;
  float sinus = 0;

  //sinus += sin(uv.x*30.+iTime*20.);
  //sinus += sin(uv.y*30.+iTime*20.);
  sinus += .8-length(fract(uv*6.+iTime*4.)-.5);
  //sinus = sinus * .25 + .5;
  return curve * sinus;
}

float funnysphere(vec3 p)
{
  p.y *= 1.5;
  vec3 n = normalize(p);
  vec2 sg = p.xz / (1. + p.y);

  float offset = length(fract(sg*6.+iTime*4.)-.5)*.35;

  return length(p+vec3(0,.4,0))-1. + offset;
}

float _smin( float a, float b, float k )
{
    float res = exp( -k*a ) + exp( -k*b );
    return -log( res )/k;
}

float smin( float a, float b)
{
    return _smin(a,b,25.);
}

float metaballs(vec3 p)
{
    p -= vec3(0,.65,0);

    vec3 p0 = p + sin(vec3(2.13, 2.17, 2.37)*iTime)*.2;
    vec3 p1 = p + sin(vec3(2.15, 2.87, 2.57)*iTime)*.2;
    vec3 p2 = p + sin(vec3(2.11, 2.47, 2.97)*iTime)*.2;

    return smin(
      smin(
        length(p0)-.13,
        length(p1)-.13
      ),
      length(p2)-.13
    );
}

float scene(vec3 p)
{
  float a = metaballs(p);

  return smin(
    smin(
      p.y,
      funnysphere(p)
    ),
    metaballs(p)
  );

  float scale = pow(.3,p.y);
  return p.y - height(p.xz * scale);
  return length(p)-1.;
}

vec2 rotate(vec2 a, float b)
{
  float c = cos(b);
  float s = sin(b);
  return vec2(
    a.x * c - a.y * s,
    a.x * s + a.y * c
  );
}

float sawtooth(float x)
{
  x *= 10.;
  return (fract(x)+fract(x*1.337))/2.;
}

void main(void)
{
  vec2 uv = vec2(gl_FragCoord.x / v2Resolution.x, gl_FragCoord.y / v2Resolution.y);
  uv -= 0.5;
  uv /= vec2(v2Resolution.y / v2Resolution.x, 1);

#if defined(CHROMAB)
  for(int c =0; c < 3;++c)
  {
#endif
  vec3 cam = vec3(0,0,-5);
  vec3 dir = normalize(vec3(uv, 4));

  cam.xz = rotate(cam.xz, iTime*.2);
  dir.xz = rotate(dir.xz, iTime*.2);

  cam.y = .45;
  //dir.y = -abs(dir.y);

  float t = 0.;
  int i = 0;
  for (i = 0; i< 100; ++i)
  {
    float k = scene(cam + dir * t);
    t += k * .3;
    if(k < .001)
      break;
  }
  float iter = 1.-float(i)/100.;

  vec3 h = cam + dir * t;

  vec2 o = vec2(.001, 0);
  vec3 n = normalize(vec3(
    scene(h+o.xyy)-scene(h-o.xyy),
    scene(h+o.yxy)-scene(h-o.yxy),
    scene(h+o.yyx)-scene(h-o.yyx)
  ));

  float fresnel = pow(1.-max(0.,dot(n,-dir)),5.)*.96+.04;
  //fresnel += pow(max(0.,dot(n,-dir)),30.)*.96+.04;
#if defined(CHROMAB)
  out_color[c] = fresnel;
#else
  out_color = vec4(fresnel);
#endif

  //out_color -= step(.1,fract(h.x*4.))*.2;
  //out_color -= step(.1,fract(h.z*4.))*.2;

  /*out_color = mix(
    vec4(0,1,1,0),
    vec4(1,0,1,0),
    out_color//fract(out_color+iTime)
  );*/
#if defined(CHROMAB)
    uv *= 1.02;
  }
#endif
}