Celestia Forums

MLY_PER_AU = 149597870.7 / KM_PER_MICROLY

object_list = {}
object_list.n = 0

function append(list, obj)
list.n = list.n + 1
list[list.n] = obj
end

function fill_object_list(node)
append(object_list, node)
for i,v in ipairs(node:getchildren()) do
fill_object_list(v)
end
end

fill_object_list(celestia:find("Sol"))
distance_map = {}

function cmp_lt(obj1, obj2)
return distance_map[obj1] < distance_map[obj2]
end

function human_readable_dist(dist)
if dist > 0.1 * MLY_PER_AU then
return string.format("%4f au", dist/MLY_PER_AU)
else
return string.format("%4.1f km", dist*KM_PER_MICROLY)
end
end
while true do
obs = celestia:getobserver()
pos = obs:getposition()
for i,v in ipairs(object_list) do
distance_map[v] = pos:vectorto(v:getposition()):length()
end
table.sort(object_list, cmp_lt)
txt = ""
for i = 1, 10 do
txt = txt .. string.format("%i. %s (%s)\n", i, object_list[i]:name(), human_readable_dist(distance_map[object_list[i]]))
end
celestia:print(txt, 5, -1, 1, 2, -6)
wait(0.1)
end