Procedural texture

I wanted to create a new cover for my twitter, so I used code to make a procedural texture. I want to share the code:

float [] sizeX= new float [10000];
float [] sizeY= new float [10000];

void setup(){
  size (700,400);
  colorMode(HSB);
  
   for(int i=0; i<2000;i++){
     for(int j=0; j<2000;j++){
       sizeX[i]=random (5,50);
       sizeY[i]=random (5,50);
    }
  }
}

void draw (){
  background (0);
  if(mousePressed){
      for(int i=0; i<2000;i++){
    for(int j=0; j<2000;j++){
   sizeX[i]=random (5,50);
   sizeY[i]=random (5,50);
      }
    } 
  }
  for(int i=0; i<2000;i+=20){
    for(int j=0; j<2000;j+=20){
      //noStroke();
      rectMode(CENTER);
      fill(i%360,300,300,i%50);
      rect (i,j,sizeX[i+j],sizeX[i+j]); 
      fill(255);
      //ellipse (i,j,2,2);  
    }
  }
  if(keyPressed){
    if (key== 's'||key=='S'){
      save("image.jpg");
    }
  }
  else{
   text("Press 's' to save image, click to generate new texture", 30,30); 
   text("PS. Don't worry, this text will desapear when you hit the key", 30,50);
  }
}

With few changes in the code, the result changes radically,