press    'w'      save O-Table and V-Table to file
press    'c'      toggle circle/select mode

press    '+'      increase the circle size
press    '-'      decrease the circle size

press    'n'      move blue dot to next corner
press    'p'      move blue dot to previous corner
press    'o'      move blue dot to opposite corner, if it exist
press    'r'      move blue dot to right corner, if it exist
press    'l'      move blue dot to left corner, if it exist
press    '>'      move blue dot along the border
press    '<'      move blue dot along the border

press    'v'      toggle 2D/3D mode
press   ARROWS    rotate mesh in 3D mode
press BACKSPACE   To reset, return to one triangle
press   'ESC'     To exit
press    'h'      To show this help