int cnt;
BGraphics buf;
BImage offscreenImage;
boolean doSave;

void setup() {
  size(400,400);
  background(200);
  
  // set up large virtual image
  buf=new BGraphics(3000,3000);
  buf.ellipseMode(CENTER_DIAMETER);
//  buf.smooth();

  offscreenImage = new BImage(buf.pixels, buf.width, buf.height, RGB);
  doSave=false;

}

void loop() {

  float rad=random(10,200);
  buf.ellipse(random(buf.width),random(buf.height), rad,rad);

  image(offscreenImage, 0, 0);

  if(doSave) {
    String filename="BIG_";
    if(cnt<10) filename=filename+"000";
    else if(cnt<100) filename=filename+"00";
    else if(cnt<1000) filename=filename+"0";

    println("Saving "+filename+cnt+".tga");

    buf.save(filename+cnt+".tga");
    cnt++;
    doSave=false;
  }
}

void mousePressed() {
  doSave=true;
}