void squareCorridor() {
      noFill();
      strokeWeight(12);                              // Controls thickness of blue border
      stroke(color(0, 0, 31));
      rectMode(CENTER);                                  
      rect(convertXCoord(screenWidth - 1000), convertYCoord(550), xsize/calibrator.magx *15, ysize/calibrator.magy *15);
      
      fill(color(0, 0, 255));
      noStroke();
      rectMode(CENTER);
      rect(convertXCoord(screenWidth - 1000), convertYCoord(550), xsize/calibrator.magx *9, ysize/calibrator.magy *9);
}