Sorry, but I don't see the connection between your two sentences. Perhaps because I can make no sense of the first one. What do you mean by "return String.format"?

I use this to save an image :

String timestamp() {
  return String.format("%1$ty%1$tm%1$td_%1$tH%1$tM%1$tS", Calendar.getInstance());
}

this will capture the full screen, but I need a specific dimension, not all the screen.

Hope this makes it clearer.

Ah, that's much clearer indeed, although I still fail to see the connection between the building of a file name (if that's the usage of the function) and capturing and saving an image.
Anyway, to save only part of the sketch (if you mean "sketch", not "screen"), you can copy it to a PGraphics, then save the content of the PGraphics itself (like capt.save(...)).

thanks phi.lho.

I'm using a GUI in the upper part of the sketch and I don't want to capture the controllers.
So the render area for PGraphics must be x=0 and y=200 to x=0 and y=800.

But how can I do that? It seems that PGraphics will always start at x=0 and y=0. (pg = createGraphics(854, 458, JAVA2D);)


Thanks!

See get(); or alternatively the pixels[] array.

get seems to be the way to go:

 size(854,650,JAVA2D);
  pg = createGraphics(854, 650, JAVA2D);
  PImage myImage = pg;
  myImage= pg.get(0, 170, width, 458);

but how can I tell PGraphics now to take myImage?

thanks

but how can I tell PGraphics now to take myImage?

For what purpose?

get() returns a PImage - you can just draw this onto your PGraphics surface; but I'm not sure I understand why you need to do this.

You can probably do something like:

1. PImage pi = get(0, 200, 854, 450);
2. pi.save( ... );

Indeed, no need for PGraphics, I forgot you can save a simple PImage.

thanks guys but when I use pi.save() now I get an N.P.E

PImage pi = get(0, 170, 854, 450);
pi.save( savePic()+".png");

Exception in thread "Animation Thread" java.lang.NullPointerException
    at GD_tool.keyPressed(GD_tool.java:502)
    at processing.core.PApplet.handleKeyEvent(PApplet.java:1973)
    at processing.core.PApplet.dequeueKeyEvents(PApplet.java:1956)
    at processing.core.PApplet.handleDraw(PApplet.java:1618)
    at processing.core.PApplet.run(PApplet.java:1503)
    at java.lang.Thread.run(Thread.java:637)

sure I'm missing something.