uniform float time;
uniform float seed;
uniform vec2 resolution;
#pragma glslify:noise=require('../../includes/noise/simplex-3d')
#pragma glslify:grain=require(glsl-film-grain)
#define PI 3.1415926535897932384626433832795
const float rSpeed=.2;
const float blobFrequency=3.;
const float blobAmplitude=.03;
vec2 sdBlob(in vec2 p,in vec2 center,in float size,float timeOffset){
float a=(degrees(atan(center.y-p.y,center.x-p.x))+180.)/360.;
float lt=fract((time+timeOffset)*rSpeed);
float v1=noise(vec3(p.x*blobFrequency+time*rSpeed+timeOffset*25.46362,p.y*blobFrequency+time*rSpeed+timeOffset*1.23267,center.x*46.32582));
float d=distance(center,p)-size+v1*blobAmplitude;
return vec2(d,a);
}
float impulse(float x,float k){
float h=k*x;
return h*exp(1.-h);
}
float pcurve(float x,float a,float b)
{
float k=pow(a+b,a+b)/(pow(a,a)*pow(b,b));
return k*pow(x,a)*pow(1.-x,b);
}
vec4 bubble(vec2 p,in float timeOffset){
float lt=fract((time+timeOffset)*rSpeed);
vec2 bl=sdBlob(p,vec2(0.),.07,timeOffset);
float d=bl.x;
float i=impulse(-d*5.,max((pow(pcurve(lt,5.,20.),.8)*40.),0.));
return vec4(vec3(i),i);
}
void main(){
vec2 uv=gl_FragCoord.xy/resolution.xy;
vec4 color=vec4(0.,0.,0.,1.);
uv-=vec2(.5);
uv*=vec2(1.,resolution.y/resolution.x);
vec4 c=vec4(0.);
for(float i=-1.;i<=1.;++i){
c=bubble(uv+vec2(i*.2,0.),1.*i);
color=max(color,c);
}
color+=noise(vec3(uv+time*rSpeed*.13596,time*rSpeed*.2425))*.2;
color=mix(color,vec4(1.,1.,1.,1.),grain(uv,resolution.xy*.5,time*2.,3.)*.1);
gl_FragColor=color;
}
