sc3-rom-dump/rom/programs/gps.lua

99 lines
2.8 KiB
Lua

-- SPDX-FileCopyrightText: 2017 Daniel Ratcliffe
--
-- SPDX-License-Identifier: LicenseRef-CCPL
local function printUsage()
local programName = arg[0] or fs.getName(shell.getRunningProgram())
print("Usages:")
print(programName .. " host")
print(programName .. " host <x> <y> <z>")
print(programName .. " locate")
end
local tArgs = { ... }
if #tArgs < 1 then
printUsage()
return
end
local sCommand = tArgs[1]
if sCommand == "locate" then
-- "gps locate"
-- Just locate this computer (this will print the results)
gps.locate(2, true)
elseif sCommand == "host" then
-- "gps host"
-- Act as a GPS host
if pocket then
print("GPS Hosts must be stationary")
return
end
-- Find a modem
local sModemSide = nil
for _, sSide in ipairs(rs.getSides()) do
if peripheral.getType(sSide) == "modem" and peripheral.call(sSide, "isWireless") then
sModemSide = sSide
break
end
end
if sModemSide == nil then
print("No wireless modems found. 1 required.")
return
end
-- Determine position
local x, y, z
if #tArgs >= 4 then
-- Position is manually specified
x = tonumber(tArgs[2])
y = tonumber(tArgs[3])
z = tonumber(tArgs[4])
if x == nil or y == nil or z == nil then
printUsage()
return
end
print("Position is " .. x .. "," .. y .. "," .. z)
else
-- Position is to be determined using locate
x, y, z = gps.locate(2, true)
if x == nil then
print("Run \"gps host <x> <y> <z>\" to set position manually")
return
end
end
-- Open a channel
local modem = peripheral.wrap(sModemSide)
print("Opening channel on modem " .. sModemSide)
modem.open(gps.CHANNEL_GPS)
-- Serve requests indefinitely
local nServed = 0
while true do
local e, p1, p2, p3, p4, p5 = os.pullEvent("modem_message")
if e == "modem_message" then
-- We received a message from a modem
local sSide, sChannel, sReplyChannel, sMessage, nDistance = p1, p2, p3, p4, p5
if sSide == sModemSide and sChannel == gps.CHANNEL_GPS and sMessage == "PING" and nDistance then
-- We received a ping message on the GPS channel, send a response
modem.transmit(sReplyChannel, gps.CHANNEL_GPS, { x, y, z })
-- Print the number of requests handled
nServed = nServed + 1
if nServed > 1 then
local _, y = term.getCursorPos()
term.setCursorPos(1, y - 1)
end
print(nServed .. " GPS requests served")
end
end
end
else
-- "gps somethingelse"
-- Error
printUsage()
end