def keyboard(key, x, y):
global R, ALT, AZ
global TERRAIN
if key == 'z' and R > 10.0:
R -= 1.0
elif key == 'Z' and R < 50.0:
R += 1.0
elif key == 'w' and ALT < 45.0:
ALT += 1.0
elif key == 's' and ALT > -45.0:
ALT -= 1.0
elif key == 'a' and AZ > -90.0:
AZ -= 1.0
elif key == 'd' and AZ < 90.0:
AZ += 1.0
elif key == 'r':
TERRAIN = midpoint_displace(32, 1.0)
altaz_to_cart()
glutPostRedisplay()
def setup():
global TERRAIN
glEnable(GL_DEPTH_TEST)
altaz_to_cart()
TERRAIN = midpoint_displace(32, 1.0)