sketch_160216a.pde

float t;
float size = 40; //50
boolean makeGIF = true;

void setup(){
  //size(540, 540);
  size(270,270);
}

void draw(){
  background(#00FFCC); // bright green
  //background(#331940); // dark purple
  
  for (int i = 0; i < height/size + 1; i++){
      
    oneline(t,0+size*i,1,0+20*i);
    
    oneline(1.5*t,size/4+size*i,1,0+20*i);
    
    oneline(2*t,size/2+size*i,1,0+20*i);
    
    oneline(2.5*t,3.*size/4+size*i,1,0+20*i);
  
  }
  
  // increment time
  t++;
  t++;
  //t++;
  //t++;
  
  // save frames for animated gif
  if(frameCount <= 320/2 && makeGIF){
    TImage frame = new TImage(width,height,RGB,sketchPath("frame_"+nf(frameCount,3)+".png"));
    frame.set(0,0,get());
    frame.saveThreaded();
  }
  
}

void oneline(float t, float offset, int direction, float phase){
  
  noStroke();
  
  //fill(#0CCA98); // dark green
  fill(#331940); // dark purple
  
  // line of moving circles
  for (int i = -2; i < width/size+2; i++){
    float xloc = size*i - direction*((t+phase)/4)%size;
    ellipse(xloc, 0+offset-10.*sin(xloc/10.),
            size*direction*(2.+cos(xloc/10.))/3., 
            size*direction*(2.+cos(xloc/10.))/3.);
  }
  
  fill(#0CCA98); // dark green
  //fill(#00FFCC); // bright green
  
  // line of moving circles
  for (int i = -2; i < width/size+2; i++){
    float xloc = size*i + direction*((t+phase)/4)%size;
    ellipse(xloc, 1+offset+10.*cos(xloc/10.),  
            size*direction*(2.+cos(xloc/10.))/3., 
            size*direction*(2.+cos(xloc/10.))/3.);
  }
  
  fill(#5E366A); // purple
  
  // line of moving circles
  for (int i = -2; i < width/size+2; i++){
    float xloc = size*i - direction*((t+phase)/4)%size;
    ellipse(xloc, 0+offset-10.*cos(xloc/10.),
            size*direction*(2.+cos(xloc/10.))/5., 
            size*direction*(2.+cos(xloc/10.))/5.);
  }
  
}
  
// from http://stackoverflow.com/questions/22124039/exporting-a-gif-from-a-processing-sketch-w-gif-animation-library
class TImage extends PImage implements Runnable{//separate thread for saving images
  String filename;

  TImage(int w,int h,int format,String filename){
    this.filename = filename;
    init(w,h,format);
  }

  public void saveThreaded(){
    new Thread(this).start();
  }

  public void run(){
    this.save(filename);
  }

}