CC circle screensaver (actual circles)

--[[
 pastebin get rXQhBupz circle
 std ld circle-scr circle
 std pb rXQhBupz circle
--]]

local sizediv = 1
local bigno = 16
local yieldNotSleep = true

local tArg = {...}

if tArg[1] == "blittle" then
    sizediv = tArg[2] or sizediv
    bigno = tArg[3] or bigno
    if not fs.exists("blittle") then
        local prog = http.get("http://pastebin.com/raw/ujchRSnU")
        if not prog then
            error("Could not get BLittle API.")
        end
        local file = fs.open("blittle","w")
        file.write(prog.readAll())rXQhBupz
        file.close()
        print("Wrote to 'blittle'")
    end
else
    sizediv = tonumber(tArg[1]) or sizediv
    bigno = tonumber(tArg[2]) or bigno
end

if term.current().setTextScale then term.current().setTextScale(0.5) end

if (fs.exists("blittle") or blittle) and tArg[1] == "blittle" then
    os.loadAPI("blittle")
    local mon = blittle.createWindow()
    term.redirect(mon)
    scr_x, scr_y = term.getSize()
end

local scr_x, scr_y = term.getSize()
local mx,my = scr_x/2,scr_y/2

local exitOnMouse = true
local exitOnButton = true

local yield = function()
    os.queueEvent("yield")
    os.pullEvent("yield")
end

local grayOut = function(color)
    local c = _G.colors
    local grays = {
        [c.white] = c.white,
        [c.orange] = c.lightGray,
        [c.magenta] = c.lightGray,
        [c.lightBlue] = c.lightGray,
        [c.yellow] = c.white,
        [c.lime] = c.lightGray,
        [c.pink] = c.white,
        [c.gray] = c.gray,
        [c.lightGray] = c.lightGray,
        [c.cyan] = c.gray,
        [c.purple] = c.gray,
        [c.blue] = c.gray,
        [c.brown] = c.gray,
        [c.green] = c.gray,
        [c.red] = c.gray,
        [c.black] = c.black,
    }
    local newColor = grays[color] or 1
    return newColor
end

local CTB = function(_color) --Color To Blit
    local blitcolors = {
        [colors.white] = "0",
        [colors.orange] = "1",
        [colors.magenta] = "2",
        [colors.lightBlue] = "3",
        [colors.yellow] = "4",
        [colors.lime] = "5",
        [colors.pink] = "6",
        [colors.gray] = "7",
        [colors.lightGray] = "8",
        [colors.cyan] = "9",
        [colors.purple] = "a",
        [colors.blue] = "b",
        [colors.brown] = "c",
        [colors.green] = "d",
        [colors.red] = "e",
        [colors.black] = "f",
    }
    return blitcolors[_color]
end

local getColor = function(num)
    if term.isColor() then
        return 2^(math.floor(num)%16)
    else
        return grayOut(2^(math.floor(num)%16))
    end
end

local spaces = string.rep(" ", scr_x)
local render = function(dist,xshift,yshift)
    local lines = {}
    term.current().setVisible(false)
    for y = 1, scr_y do
        local line = {}
        for x = 1, scr_x do
            local thing = (math.sqrt((((x+xshift)-mx)^2)+(((y+yshift)-my)^2))+((dist/bigno)*(16*sizediv)))/sizediv
            line[x] = CTB(getColor(thing))
        end
        lines[y] = table.concat(line)
    end
    for y = 1, scr_y do
        term.setCursorPos(1,y)
        term.blit(spaces, spaces, lines[y])
    end
    term.current().setVisible(true)
end

local doAnimation = function()
    local mult = 0
    while true do
        for a = 1, bigno do
            render(a, (math.sin((a+(bigno*mult))/20)*(mx*0.8))+(math.cos((a+(bigno*mult))/30)*(mx/12)), ((math.cos((a+(bigno*mult))/20)*my)+(math.sin((a+(bigno*mult))/35)*(my/9))))
            if yieldNotSleep then
                yield()
            else
                sleep(0)
            end
        end
        mult = mult + 1
    end
end

local waitForInput= function()
    while true do
        local evt = os.pullEvent()
        if (evt == "char" and exitOnButton) or (evt == "mouse_click" and exitOnMouse) then
            return
        end
    end
end

parallel.waitForAny(waitForInput,doAnimation)
term.setBackgroundColor(colors.black)
term.clear()
term.setCursorPos(1,1)