wooshings
143 lines
2.5 KiB
Lua
143 lines
2.5 KiB
Lua
local socket = require("socket")
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local network = {}
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local client
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-- Packet IDs
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network.MSG_KEY_PRESS = 1
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network.MSG_GAMESTATE = 2
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--------------------------------------------------
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-- Packing
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--------------------------------------------------
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local function packU16(n)
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return string.char(math.floor(n / 256) % 256, n % 256)
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end
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local function packU32(n)
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return string.char(math.floor(n / 16777216) % 256, math.floor(n / 65536) % 256, math.floor(n / 256) % 256, n % 256)
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end
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local function unpackU16(s)
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local b1, b2 = s:byte(1, 2)
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return b1 * 256 + b2
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end
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local function unpackU32(s)
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local b1, b2, b3, b4 = s:byte(1, 4)
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return b1 * 16777216 + b2 * 65536 + b3 * 256 + b4
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end
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--------------------------------------------------
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-- Connection
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--------------------------------------------------
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function network.connect(ip, port)
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client = assert(socket.tcp())
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client:settimeout(0)
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local ok, err = client:connect(ip, port)
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-- Non-blocking connect is expected
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if not ok and err ~= "timeout" then
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error(err)
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end
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print("Connecting...")
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end
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--------------------------------------------------
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-- Sending
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--------------------------------------------------
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function network.sendPacket(id, payload)
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if not client then
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return
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end
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payload = payload or ""
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local length = 2 + #payload
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local packet = packU32(length) .. packU16(id) .. payload
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client:send(packet)
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end
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function network.sendKey(key)
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network.sendPacket(network.MSG_KEY_PRESS, key)
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end
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--------------------------------------------------
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-- Packet handlers
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--------------------------------------------------
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network.handlers = {}
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function network.on(id, callback)
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network.handlers[id] = callback
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end
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--------------------------------------------------
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-- Receiving
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--------------------------------------------------
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local function receivePacket()
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local lenData, err = client:receive(4)
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if not lenData then
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return nil
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end
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local length = unpackU32(lenData)
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local idData = client:receive(2)
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if not idData then
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return nil
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end
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local msgID = unpackU16(idData)
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local payload = ""
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if length > 2 then
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payload = client:receive(length - 2)
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if not payload then
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return nil
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end
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end
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return msgID, payload
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end
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--------------------------------------------------
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-- Poll every frame
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--------------------------------------------------
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function network.update()
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if not client then
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return
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end
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while true do
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local id, payload = receivePacket()
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if not id then
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break
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end
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local handler = network.handlers[id]
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if handler then
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handler(payload)
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end
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end
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end
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return network
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