def build_tile(params):
hparts, vparts, zoom, x, y = params
hparts_size = 24.0 / hparts
vparts_size = 180.0 / vparts
v1 = azalt_to_vector(0, 0)
v2 = azalt_to_vector(hparts_size, vparts_size)
min_distance = vector3_distance(v1, v2)
hour = ((x * hparts_size + hparts_size / 2.0) + 12) % 24
deg = 90 - y * vparts_size - vparts_size / 2.0
mid_v = azalt_to_vector(hour, deg)
tile_coords = get_tile_coords((hour, deg), zoom)
assert tile_coords == (x, y + vparts / 2), (tile_coords, (x, y + vparts / 2))
tile_id = "%s-%s-%s" % (zoom, x, y + vparts / 2)
tile_objects = []
for star in get_stars():
object_v = azalt_to_vector(star.ra, star.dec)
if vector3_distance(mid_v, object_v) <= min_distance:
obj = (star.id, star.ra, star.dec, star.mag)
# Some stars that are part of our constellations do not have
# B/F designation. Need to make sure they're shown at all zoom levels
if star.id in EXEMPTIONS and zoom >= EXEMPTIONS[star.id]:
tile_objects.append(obj)
continue
# Always show stars if they have a proper name or part of a constellation
# excluding Gliese designation
if star.bayer_flamsteed or star.proper_name:
tile_objects.append(obj)
continue
# All stars visible by zoom 7
if zoom >= 7:
tile_objects.append(obj)
continue
if star.mag <= 6 + (zoom - 5):
tile_objects.append(obj)
tile_objects.sort(key=lambda o: o[3], reverse=True)
print "Tile: %s Objects: %d" % (tile_id, len(tile_objects))
zpath = os.path.join("../indexes", str(zoom))
try:
os.mkdir(zpath)
except:
pass
f = open(os.path.join(zpath, "%s.dat"%tile_id), "wb")
try:
pickle.dump(tile_objects, f)
finally:
f.close()
def get_named_stars():
global NAMED_STARS
if not NAMED_STARS:
NAMED_STARS = [star for star in get_stars() if star.proper_name]
return NAMED_STARS