NVIDIA Vertex Buffer Object demo

'p': toggle points.
'w': toggle wireframe.
'h'/'H': increase/decrease high frequency scaling factor.
'l'/'L': increase/decrease low frequency scaling factor.
'1'/'2': increase/decrease low frequency.
'3'/'4': increase/decrease high frequency.
'5'/'6': increase/decrease low frequency phase rate.
'7'/'8': increase/decrease high frequency phase rate.
't'/'T': increase/decrease mesh density.