Bresenham Circles in CC

-- Adapted from https://iq.opengenus.org/bresenhams-circle-drawing-algorithm/ to lua
-- going to use this for a few things soon:tm:

local function putpixel(x, y, color)
  term.setCursorPos(x, y)
  term.setBackgroundColor(color)
  io.write(' ')
end

local function displayBresenhamCircle(xc_, yc_, x, y)
  putpixel(xc_+x, yc_+y, colors.white);
  putpixel(xc_-x, yc_+y, colors.white);
  putpixel(xc_+x, yc_-y, colors.white);
  putpixel(xc_-x, yc_-y, colors.white);
  putpixel(xc_+y, yc_+x, colors.white);
  putpixel(xc_-y, yc_+x, colors.white);
  putpixel(xc_+y, yc_-x, colors.white);
  putpixel(xc_-y, yc_-x, colors.white);
end

local function drawBresenhamCircle(radius_, xc, yc)
  term.clear()
  local x = 0
  local y = radius_
  local decisionParameter = 3 - 2 * radius_
  displayBresenhamCircle(xc, yc, x, y)

  while y >= x do
    x = x + 1
    if decisionParameter > 0 then
      y = y - 1
      decisionParameter = decisionParameter + 4 * (x - y) + 10
    else
      decisionParameter = decisionParameter + 4 * x + 6
    end
    displayBresenhamCircle(xc, yc, x, y)
    os.sleep(0.1)
  end
end

local function readNum(out)
  io.write(out .. ": ")
  local got = tonumber(io.read())
  return type(got) == "number" and got or readNum(out)
end

drawBresenhamCircle(readNum("Radius of circle"), readNum("X pos of circle"), readNum("Y pos of circle"))
os.sleep(10)