I am looking for a method to control the brightness of all pixels on the sketch.  That is, I have already coded a "program" and am looking for a simple way to fade in and out the overall brightness of everything displayed in the sketch code.  As the code is not easily changed it would be so helpful if there is a way to control all sketch brightness values in real-time.

My first inclinations are that there is some java command to do this or maybe a way to treat my animation as an image...

Thanks, buddy.

I am trying the tint, but somehow the simplicity of it is lost on me. Here's code where i use a picture of black, which is in the sketch/data folder, and attempt to reveal the white background through iteration;

PImage img;
int i = 0;

void setup() {
size(400, 400);
background(255);
img = loadImage("ff.jpg");
image(img, 0, 0);
}

void draw() {
   i = (i + 1) % 255;
   tint(255, i);
   //println(i);
}

sorry, if i misexplain, here is a better try;

i am hoping to use a layer, say a black picture, and use transparency as a means to reveal the somewhat complicated animation underneath that i have already coded.  like a fade to black in the movies.  essentially anything that will allow me to control the brightness of the entire sketch without having to rewrite all the previous code would be sweetness.  the code i posted is just a test, as the "program" i have written is too messy to post and it would be unclear what i was doing.

thanks for your patience.

Try a variation on what Noah suggested:  Just draw a black rect() over the whole screen, and adjust its opacity to reveal/hide to whatever degree you like.  So, to "fade in", start the rect() at full opacity, and decrease it slightly each frame.

You'd need to make the rect() the last thing in your draw() loop, so it draws "on top" of everything else.

nevermind, saw scott's post regarding someone else changing rect() opacity.  here it is again in case someone else is directed here;

   i = (i + 1) % 255;
   fill(255, 0, 0, i);
   rect(0, 0, 300, 300);