void scribe(String S) {fill(black); text(S,20,20); noFill();}
void scribe(String S, int i) {fill(black); text(S,20,20+i*20); noFill();}

void mousePressed() { if (mouse().isInWindow()) clickPolygon(); else ; } 
  
void keyPressed() {  
  if (key==' ') showHelpText=!showHelpText ; 
  if (key=='X') {String S=" "+"-####.tif"; saveFrame(S);};   ;
  if (key=='?') printIt=true;  // toggle debug mode
   };     

void showHelp() {
    fill(dblue); pushMatrix(); translate(20,20);
     text("PGS (PLANAR GEOMETRY SANDBOX) by Jarek Rossignac",0,0); translate(0,20);
     text("  ",0,0); translate(0,20);
     text("First click in the window to activate it ",0,0); translate(0,20);
     text("Press SPACE to show/hide this help text",0,0); translate(0,20);
     text("Click & drag points ",0,0); translate(0,20);
     text("  ",0,0); translate(0,20);
      text("Press 'X' top snap a picture (when running Processing, not in browser)",0,0); translate(0,20);
     text("'?' print debugging stuff (when running Processing, not in browser)   ",0,0); translate(0,20);
     popMatrix(); noFill();
   }