ComputerCraft Jump n' Run "Engine" (you are free to edit it)

--Main "Engine"
--Completely Written by Piorjade
--You a free to edit/extend the code for your own purposes...
--GET THE LEVELEDITOR HERE: pastebin get ESPY1FUz editor
--(Though I'm really shitty at programming)

--Variablen
_ver = 0.1
_verstr = "0.1"
lvlLocation = "/game/levels/"
lvlData = {}
currentLevel = ""
xPos = 1
yPos = 1

--Funktionen

function clear(bg, fg)
    term.setCursorPos(1,1)
    term.setBackgroundColor(bg)
    term.setTextColor(fg)
    term.clear()
end

function menu()
    clear(colors.black, colors.white)
    term.setCursorPos(24,6)
    term.setBackgroundColor(colors.lime)
    term.write("Start")
    term.setCursorPos(24,8)
    term.write("Exit")
    menu = true
    while menu do
        local event, button, x, y = os.pullEventRaw("mouse_click")
        if button == 1 and x >= 24 and x <= 28 and y == 6 then
            menu = false
            loadLevel("tutorial")
            break
        elseif button == 1 and x >= 24 and x <= 27 and y == 8 then
            clear(colors.black, colors.white)
            print("Thanks for playing!")
            break
        end
    end
end

function getLevelData(level)
    local file = fs.open(lvlLocation..level..".lvlDat","r")
    local inhalt = file.readAll()
    lvlData = textutils.unserialize(inhalt)
    file.close()
end

function drawEntities()
    term.setBackgroundColor(colors.blue)
    term.setTextColor(colors.black)
    xPos = tonumber(lvlData.spawnPosX)
    yPos = tonumber(lvlData.spawnPosY)
    term.setCursorPos(xPos, yPos)
    term.write("P")

    playing = true
    game()
end

function game()
    while playing do
        local event, key = os.pullEventRaw("key")
        if key == keys.left and xPos > 1 then
            local blocktrue = false
            for _, block in ipairs(lvlData.blocksX) do
                local x = tonumber(block)
                local y = tonumber(lvlData.blocksY[_])
                if xPos == x+1 and yPos == y then
                    blocktrue = true
                end
            end
            if blocktrue then

            else
                xPos = xPos-1
                gravity()
                redrawLvl()
            end
        elseif key == keys.right and xPos < 51 then
            local block = false
            for _,block in ipairs(lvlData.blocksX) do
                local x = tonumber(block)
                local y = tonumber(lvlData.blocksY[_])
                if xPos == x-1 and yPos == y then
                    blocktrue = true
                end
            end
            if blocktrue then

            else
                xPos = xPos+1
                gravity()
                redrawLvl()
            end
        end
    end
end

function gravity()
    for _, block in ipairs(lvlData.blocksX) do
        local x = tonumber(block)
        local y = tonumber(lvlData.blocksY[_])
        if xPos == x and yPos+1 == y then
            break
        elseif xPos == x and yPos+2 <= y then
            yPos = yPos+1
            gravity()
        end
    end
end

function redrawLvl()
    clear(colors.black, colors.white)
    lvl = paintutils.loadImage(lvlLocation..currentLevel..".lvl")
    paintutils.drawImage(lvl, 1, 1)
    term.setBackgroundColor(colors.blue)
    term.setTextColor(colors.black)
    term.setCursorPos(xPos, yPos)
    term.write("P")
end

function loadLevel(level)
    getLevelData(level)
    lvl = paintutils.loadImage(lvlLocation..level..".lvl")
    clear(colors.black, colors.white)
    paintutils.drawImage(lvl, 1, 1)
    currentLevel = level
    drawEntities()
end


--Code
local args = {...}

if #args < 1 then
    clear(colors.black, colors.white)
    menu()
elseif #args == 2 then
    if fs.exists(args[1]) and fs.exists(args[1]..args[2]..".lvl") then
        lvlLocation = args[1]
        currentLevel = args[2]
        loadLevel(args[2])
    else
        print("File does not exist. Please make sure")
        print("that you wrote it like this:")
        term.setTextColor(colors.yellow)
        print("thisfile <folder/to/the> <level>")
        term.setTextColor(colors.red)
        print("AND WITHOUT THE .lvl ENDING!")
        term.setTextColor(colors.white)
    end
else
    print("Too many arguments. Please make sure")
    print("that you wrote it like this:")
    term.setTextColor(colors.yellow)
    print("thisfile <folder/to/the> <level>")
    term.setTextColor(colors.red)
    print("AND WITHOUT THE .lvl ENDING!")
    term.setTextColor(colors.white)
end