class Satellite(Body):
def __init__(self, *args, **kwargs):
self.parent = kwargs.pop('parent')
self.orbit_speed = kwargs.pop('orbit_speed', 1)
# Semi-major axis and eccentricity defines orbit
distance = kwargs.pop('distance', 100)
eccentricity = kwargs.pop('eccentricity', 0)
# Inclination, longitude of ascending node, and argument of periapsis defines orbital plane
inclination = kwargs.pop('inclination', 0)
longitude = kwargs.pop('longitude', 0)
argument = kwargs.pop('argument', 0)
# Orbit calculation
self.orbit_id = None
self.orbit_cache = None
self.theta = 0
# OpenGL's z-axis is reversed
self.orbit = KeplerOrbit(distance, eccentricity, inclination, longitude, argument)
super(Satellite, self).__init__(*args, **kwargs)
def get_orbit(self):
# Cache key is the three orbital plane parameters and eccentricity
cache = (self.orbit.eccentricity, self.orbit.longitude, self.orbit.inclination, self.orbit.argument)
if self.orbit_cache == cache:
return self.orbit_id
if self.orbit_id is not None:
glDeleteLists(self.orbit_id, 1)
id = glGenLists(1)
glNewList(id, GL_COMPILE)
glBegin(GL_LINE_LOOP)
for theta in xrange(360):
x, z, y = self.orbit.orbit(theta)
glVertex3f(x, y, z)
glEnd()
glEndList()
self.orbit_id = id
self.orbit_cache = cache
return id
def update(self):
super(Body, self).update() # Notice how the parent class is skipped
if self.last_tick != self.world.tick:
self.last_tick = self.world.tick
pitch, yaw, roll = self.rotation
roll = (self.initial_roll + self.world.tick * self.rotation_angle) % 360
self.rotation = pitch, yaw, roll
self.parent.update()
px, py, pz = self.parent.location
self.theta = self.world.tick * self.orbit_speed % 360
x, z, y = self.orbit.orbit(self.theta)
self.location = (x + px, y + py, z + pz)
def __init__(self, *args, **kwargs):
self.parent = kwargs.pop('parent')
self.orbit_speed = kwargs.pop('orbit_speed', 1)
# Semi-major axis and eccentricity defines orbit
distance = kwargs.pop('distance', 100)
eccentricity = kwargs.pop('eccentricity', 0)
# Inclination, longitude of ascending node, and argument of periapsis defines orbital plane
inclination = kwargs.pop('inclination', 0)
longitude = kwargs.pop('longitude', 0)
argument = kwargs.pop('argument', 0)
# Orbit calculation
self.orbit_id = None
self.orbit_cache = None
self.theta = 0
# OpenGL's z-axis is reversed
self.orbit = KeplerOrbit(distance, eccentricity, inclination, longitude, argument)
super(Satellite, self).__init__(*args, **kwargs)
