Love2D MP Client w/ colliders

--[[

    This is a testgame to test out multiplayer features.
    ~Piorjade
]]

local socket = require "socket"

local address, port = "localhost", 12345
local DEBUG

local entity
local updaterate = 0.03
local SPEED = 100

local world = {}
local t

local OBJECT_WIDTH, OBJECT_HEIGHT = 159, 159

local _print = print

function print(text)
    if DEBUG then
        _print(text)
    end
end

function love.load()
    udp = socket.udp()
    udp:settimeout(0)
    udp:setpeername(address, port)
    math.randomseed(os.time())
    entity = tostring(math.random(800, 9999))
    local dg = string.format("%s %s %d %d %s", entity, 'at', 320, 240, "Player")
    udp:send(dg)

    t = 0
end

function move(oldx, oldy, x, y)
    for each, object in pairs(world) do
        if each ~= entity and object.type == "metal_block" and ( (world[entity].x+x >= object.x and world[entity].x+x <= (object.x+OBJECT_WIDTH) ) or (world[entity].x+x+OBJECT_WIDTH >= object.x and world[entity].x+x+OBJECT_WIDTH <= (object.x+OBJECT_WIDTH) ) ) and ((world[entity].y+y >= object.y and world[entity].y+y <= (object.y+OBJECT_WIDTH)) or (world[entity].y+y+OBJECT_WIDTH >= object.y and world[entity].y+y+OBJECT_WIDTH <= (object.y+OBJECT_WIDTH))) then
            print("Collision with : "..tostring(each).." type: "..tostring(object.type))


            --Berechne wie viel von der Bewegung abgezogen werden muss, damit man so nah wie möglich an das objekt rankommt
            local diffx, diffy
            --Rechts
            if x > 0 then
                diffx = (world[entity].x+x+OBJECT_WIDTH+1) - (object.x)
            --links
            elseif x < 0 then
                diffx = (object.x+OBJECT_WIDTH+1) - (world[entity].x+x)
            else
                diffx = 0
            end

            --unten
            if y > 0 then
                diffy = (world[entity].y+y+OBJECT_WIDTH+1) - object.y
            --oben
            elseif y < 0 then
                diffy = (object.y+OBJECT_WIDTH+1) - (world[entity].y+y)
            else
                diffy = 0
            end

            print("Differenzen: diffx="..tostring(diffx).." y="..tostring(diffy))

            --Ausgleichen damit man nicht weiter zurückgeschoben wird als die bewegung ("Bounce" Effekt)
            if x > 0 then
                if x - diffx < 0 then
                    diffx = x
                end
            elseif x < 0 then
                if x + diffx > 0 then
                    diffx = -x
                end
            end

            if y > 0 then
                if y - diffy < 0 then
                    diffy = y
                end
            elseif y < 0 then
                if y + diffy > 0 then
                    diffy = -y
                end
            end



            --Falls es schon so nah wie möglich ist, wird aus der rechnung automatisch 0


            local newx, newy
            if x > 0 then
                newx = x-diffx
            else
                newx = x+diffx
            end

            if y > 0 then
                newy = y-diffy
            else
                newy = y+diffy
            end
            print("NEUE BEWEGUNG: x="..tostring(newx).." y="..tostring(newy))
            return newx, newy

        end
    end
    return x, y
end

function love.update(deltatime)
    t = t+deltatime

    if t > updaterate then
        local x, y = 0, 0
        if love.keyboard.isDown("up") then x, y = move(x, y, x, y-(SPEED*t)) end
        if love.keyboard.isDown("down") then x, y = move(x, y, x, y+(SPEED*t)) end
        if love.keyboard.isDown("left") then x, y = move(x, y, x-(SPEED*t), y) end
        if love.keyboard.isDown("right") then x, y = move(x, y, x+(SPEED*t), y) end
        local dg = string.format("%s %s %f %f", entity, "move", x, y)
        udp:send(dg)
        local dg = string.format("%s %s $", entity, "update")
        udp:send(dg)
        t = t-updaterate
    end

    repeat
        data, msg = udp:receive()
        if data then
            ent, cmd, parms = data:match("^(%S*) (%S*) (.*)")
            if cmd == "at" then
                local x, y, typ = parms:match("^(%-?[%d.e]*) (%-?[%d.e]*) (%S*)")
                assert(x and y and typ)
                x, y = tonumber(x), tonumber(y)
                world[ent] = {x=x, y=y, type = typ}
            else
                print("unrecognized command: ", cmd)
            end
        elseif msg ~= "timeout" then
            error("Network error: "..tostring(msg))
        end
    until not data

end

function love.draw()
    for k, v in pairs(world) do
        if v.type == "metal_block" then
            love.graphics.rectangle("fill", v.x, v.y, OBJECT_WIDTH, OBJECT_WIDTH)
        elseif v.type == "Player" then
            love.graphics.rectangle("line", v.x, v.y, OBJECT_WIDTH, OBJECT_WIDTH)
        end
    end
end