Space Invaders

term.clear()

function split (inputstr, sep)
    if sep == nil then
            sep = "%s"
    end
    local t={}
    for str in string.gmatch(inputstr, "([^"..sep.."]+)") do
            table.insert(t, str)
    end
    return t
end

-- ^^^ DON'T TOUCH THIS FUTURE ME ^^^ ---

_rendertable = {}
_rendertable.aliens = {"1 1","2 1","3 1"}
_rendertable.structures = {"2 17","2 16","2 15","3 15","4 15","5 15","6 15","7 15","7 16","7 17",
"16 17","16 16","16 15","17 15","18 15","19 15","20 15","21 15","21 16","21 17",
"50 17","50 16","50 15","49 15","48 15","47 15","46 15","45 15","45 16","45 17",
"31 17","31 16","31 15","32 15","33 15","34 15","35 15","36 15","36 16","36 17",
} --Table that holds all X and Y coordinates for a singular pixel (Thanks prince :) )
_rendertable.playerpos = {"25 19","26 19","27 19"}
_rendertable.bulletpos = {}
playerpos = 26
alienpos = 2
alienleft = 0

function alienbody()
    while true do
        if alienpos == 50 then
            alienleft = 1
        elseif alienpos == 2 then
            alienleft = 0
        end
            alienpos = alienpos
            sleep(1)
        if _rendertable.aliens[1] ~= "0 0" and _rendertable.aliens[2] ~= "0 0" and _rendertable.aliens[3] ~= "0 0" and alienleft == 0 then
            alienpos = alienpos + 1
            _rendertable.aliens = {tostring(alienpos-1).." 1",tostring(alienpos).." 1",tostring(alienpos+1).." 1"}
        end
        if _rendertable.aliens[1] ~= "0 0" and _rendertable.aliens[2] ~= "0 0" and _rendertable.aliens[3] ~= "0 0" and alienleft == 1 then
            alienpos = alienpos - 1
            _rendertable.aliens = {tostring(alienpos-1).." 1",tostring(alienpos).." 1",tostring(alienpos+1).." 1"}
        end

        sleep()
    end
end

function playerbody()
    while true do
        playerpos = playerpos
        local event, key = os.pullEvent("key")
        if key == keys.d and playerpos <= 49 then
            playerpos = playerpos + 1
            _rendertable.playerpos = {tostring(playerpos-1).." 19",tostring(playerpos).." 19",tostring(playerpos+1).." 19"}
        end
        if key == keys.a and playerpos >= 3 then
            playerpos = playerpos - 1
            _rendertable.playerpos = {tostring(playerpos-1).." 19",tostring(playerpos).." 19",tostring(playerpos+1).." 19"}
        end
        if key == keys.space and textutils.serialise(_rendertable.bulletpos) == "{}" then
            table.insert(_rendertable.bulletpos,tostring(playerpos).." 18")
        end
        sleep()
    end
end

function bulletbody()
    while true do
        for x=1,#_rendertable.bulletpos do
            _rendertable.bulletpos = {tostring(tonumber(split(_rendertable.bulletpos[x]," ")[1])).." "..tostring(tonumber(split(_rendertable.bulletpos[x]," ")[2])-1)}
            for y=1,#_rendertable.structures do
                if _rendertable.structures[y] == _rendertable.bulletpos[x] then
                    _rendertable.bulletpos[x] = "0 0"
                    _rendertable.structures[y] = "0 0"
                    -- table.remove(_rendertable.bulletpos, x)
                    -- table.remove(_rendertable.structures, y)
                end
            end
            for y=1,#_rendertable.aliens do
                if _rendertable.aliens[y] == _rendertable.bulletpos[x] then
                    _rendertable.bulletpos[x] = "0 0"
                    _rendertable.aliens = {"0 0","0 0","0 0"}
                    -- table.remove(_rendertable.bulletpos, x)
                    -- table.remove(_rendertable.structures, y)
                end
            end
            if tonumber(split(_rendertable.bulletpos[x]," ")[2]) <= 0 then
                _rendertable.bulletpos = {}
            end
        end
        sleep(0.075)
    end
end

function render() --Function that will render (duh) everything in the _rendertable variable (WILL RUN FOREVER)
    while true do
        _rendertable = _rendertable
        _rendertable.playerpos = _rendertable.playerpos
        term.setBackgroundColor(colors.black)
        term.clear()
        -- print(#_rendertable.playerpos)
        if #_rendertable > 0 then
            for x=1,#_rendertable do
                paintutils.drawPixel(tonumber(split(_rendertable[x]," ")[1]),tonumber(split(_rendertable[x]," ")[2]),colors.white)
            end
        end
        if #_rendertable.structures > 0 then
            for x=1,#_rendertable.structures do
                paintutils.drawPixel(tonumber(split(_rendertable.structures[x]," ")[1]),tonumber(split(_rendertable.structures[x]," ")[2]),colors.white)
            end
        end
        if #_rendertable.playerpos > 0 then
            for x=1,#_rendertable.playerpos do
                paintutils.drawPixel(tonumber(split(_rendertable.playerpos[x]," ")[1]),tonumber(split(_rendertable.playerpos[x]," ")[2]),colors.white)
            end
        end
        if #_rendertable.bulletpos > 0 then
            for x=1,#_rendertable.bulletpos do
                paintutils.drawPixel(tonumber(split(_rendertable.bulletpos[x]," ")[1]),tonumber(split(_rendertable.bulletpos[x]," ")[2]),colors.white)
            end
        end
        if #_rendertable.aliens > 0 then
            for x=1,#_rendertable.aliens do
                paintutils.drawPixel(tonumber(split(_rendertable.aliens[x]," ")[1]),tonumber(split(_rendertable.aliens[x]," ")[2]),colors.white)
            end
        end
        sleep()
    end
end

function drawEntites01()
    parallel.waitForAll(playerbody,bulletbody)
end
function drawEntites02()
    parallel.waitForAll(drawEntites01,alienbody)
end

parallel.waitForAll(drawEntites02,render)