saveImage entire window

I’m trying to save a really big image about 3500 pixels wide, rigth now I’m using the clasic saveImage method:

  
  
imgOutput.grabScreen(0,0,3500, 1300);  
imgOutput.saveImage("test.png");  
  

but the image saved only show the visible portion of the window, the hidden sections are saved as black pixels.

Exist a method to save an image of the entire window? not only the visible part?

Thanks

you will need to render to an fbo and then get the pixels from it. there’s several implementations around the forum, and some of them have getPixels.

also i haven’t tried it but i think ofxTileSaver will do:
http://forum.openframeworks.cc/t/ofxtilesaver—high-resolution-opengl-screen-grabs/1783/0