random-stuff/computercraft/opus-trilaterator.lua

102 lines
3.1 KiB
Lua

-- TrilateratorGPS, modified a bit to track Opus SNMP pings instead now that GPS is anonymized
local filter = ...
local config = dofile "config.lua"
local modems = {}
for name, location in pairs(config.modems) do
modems[name] = peripheral.wrap(name)
modems[name].location = location
modems[name].open(999)
end
local function timestamp()
return os.date "!%X"
end
-- Trilateration code from GPS and modified slightly
local function trilaterate( A, B, C )
local a2b = B.position - A.position
local a2c = C.position - A.position
if math.abs( a2b:normalize():dot( a2c:normalize() ) ) > 0.999 then
return nil
end
local d = a2b:length()
local ex = a2b:normalize( )
local i = ex:dot( a2c )
local ey = (a2c - (ex * i)):normalize()
local j = ey:dot( a2c )
local ez = ex:cross( ey )
local r1 = A.distance
local r2 = B.distance
local r3 = C.distance
local x = (r1*r1 - r2*r2 + d*d) / (2*d)
local y = (r1*r1 - r3*r3 - x*x + (x-i)*(x-i) + j*j) / (2*j)
local result = A.position + (ex * x) + (ey * y)
local zSquared = r1*r1 - x*x - y*y
if zSquared > 0 then
local z = math.sqrt( zSquared )
local result1 = result + (ez * z)
local result2 = result - (ez * z)
local rounded1, rounded2 = result1:round( 0.01 ), result2:round( 0.01 )
if rounded1.x ~= rounded2.x or rounded1.y ~= rounded2.y or rounded1.z ~= rounded2.z then
return rounded1, rounded2
else
return rounded1
end
end
return result:round( 0.01 )
end
local function narrow( p1, p2, fix )
local dist1 = math.abs( (p1 - fix.position):length() - fix.distance )
local dist2 = math.abs( (p2 - fix.position):length() - fix.distance )
if math.abs(dist1 - dist2) < 0.01 then
return p1, p2
elseif dist1 < dist2 then
return p1:round( 0.01 )
else
return p2:round( 0.01 )
end
end
local monitor = peripheral.find "monitor"
if monitor then
monitor.setTextScale(0.5)
term.redirect(monitor)
end
print(timestamp(), "Initialized")
local fixes = {}
while true do
local _, modem, channel, reply_channel, message, distance = os.pullEvent "modem_message"
if distance then
if not fixes[reply_channel] then fixes[reply_channel] = {} end
local rc_fixes = fixes[reply_channel]
local recv_modem = modems[modem]
table.insert(rc_fixes, { position = vector.new(unpack(recv_modem.location)), distance = distance })
if #rc_fixes == 4 then
local p1, p2 = trilaterate(rc_fixes[1], rc_fixes[2], rc_fixes[3])
if p1 and p2 then
local pos = narrow(p1, p2, rc_fixes[4])
local status, label = "?", "?"
if type(message) == "table" then status = tostring(message.status) label = tostring(message.label) end
if (not filter) or (label:match(filter)) then
print(timestamp(), ("%05d %s (%.0f %.0f %.0f) %s"):format(reply_channel, label, pos.x, pos.y, pos.z, status))
end
end
fixes[reply_channel] = {}
end
end
end