this question has come up sooo many times.. did you try a forum search?

ps. it's called a method in java (not a function)

edit: actually i can't find any of those old threads so i'll just go ahead and answer.

The simple answer is No, it cannot be done.
However there are ways around it. One is to make your method like this:

1. void myFunction(PGraphics p,int x, int y, int t_width, int t_height){
         p.beginDraw(); 
         p.rect(x, y, t_width, t_height);
         p.endDraw();
   }

Another is to create your own object that extends PGraphics and give that object your method however i don't have the time atm to write an example of this and im not sure how to get around the fact that PGraphics are initialized my createGraphics... so ignore this.

I couldn't find either (yeah 1 topic that was confusing and unclear).
Thx for the clear example.
For people who need it to be done for a class:

1. PGraphics pg;
   DoStuff ds;
   
   void setup() {
     size(200, 200);
     pg = createGraphics(200, 200, P2D);
     ds = new DoStuff();
   }
   
   void draw() {
     ds.doSomething(pg);
     image(pg, 0, 0);
   }
   
   class DoStuff {
     void DoStuff() {//constructor
     }
     void doSomething(PGraphics p) {
       p.beginDraw();
       p.rect(0, 0, 50, 50);
       p.endDraw();
     }
   }
   
   

Could someone go deeper into this?

Another is to create your own object that extends PGraphics and give that object your method however i don't have the time atm to write an example of this and im not sure how to get around the fact that PGraphics are initialized my createGraphics... so ignore this.

I'm intrested in other ways.
I dislike that i have to also set font, textsize and fill inside the class...

Check out the source:

http://processing.googlecode.com/svn/trunk/processing/core/src/processing/core/PGraphics.java

There's some documentation on sub-classing PGraphics which might be of use, but I'd be wary of doing this unless absolutely necessary.  What's the issue with having to set textsize etc. within the class?

And are you sure you don't want to store the PGraphic Object within the Class:

1. class Drawing {
2.   PGraphic p;
3.   // there's no return type on a constructor
   
4.   Drawing(int w, int h) {
5.     p = createGraphics(w, h, P2D);
6.   }
7.   void drawRect() {
8.     p.beginDraw();
9.           p.rect(0, 0, 50, 50);
10.     p.endDraw();
11.   }
12. }

TBH - I'm thinking out loud a bit here.  bjordal's solution seems like the way to go ;)

1. PGraphics pg = createGraphics(200, 200, P2D);
2. void setup(){
3.   noLoop();
4. }
5. void draw(){
6.   pg.beginDraw();
7.   myFunction(pg, 10, 10, 50, 50);
8.   pg.endDraw();
9. }
10. void myFunction(PGraphics pg, int x, int y, int t_width, int t_height){
11.   pg.rect(x, y, t_width, t_height);
12. }

What's the issue with having to set textsize etc. within the class?

I don't like to many options for the creation of a class.
This has also to do with things i want to make in the future, i want a certain logic of how i create things.
Maybe in the end i think it's better to have it inside the class, i don't know yet, kinda hard for me to make logic desicions like these.

And are you sure you don't want to store the PGraphic Object within the Class:

It does make more sense does it?

I don't like to many options for the creation of a class.

If you mean the number of parameters in the constructor; then you're right: it's best to keep these to a minimum.  But you can still set fonts, colours etc. in the class: just write a method that sets default values and call this from a constructor that takes the minimum number of parameters required.  You can then write overloaded constructors to allow fonts etc. to be set, should you need to, or better still methods to set these independently from the constructor...