import processing.opengl.*;

void setup() {
  size(200, 200, OPENGL);
}

void draw() {
  background(200);
  ortho(-1,1,-1,1,-10,10);
  resetMatrix();
  printMatrix();
  printProjection();
  println(screenX(0,0,0)+","+screenY(0,0,0));
  rectMode(CENTER);
  rect(0,0,1,1);
}