Circle Animation

-- Circle Loading Animation, By Symmetryc

-- # Configuration # --
local back_color = colors.white
local dither_color = colors.lightBlue
local dither_char = "#"
local dither_len = 10
local solid_color = colors.lightBlue
local solid_len = dither_len * 3
local speed = 7
local radius = 10
local thickness = 2
local size_x, size_y = term.getSize()
local center_x, center_y = size_x / 2, size_y / 2
local y_comp = 2 / 3
local text = "<Loading Text>"
local text_color = colors.cyan
local text_back = back_color
local text_x, text_y = center_x - #text / 2, center_y

-- # Code # --
local x, y, n
local sin, cos = math.sin, math.cos
local pi = math.pi
local up = math.ceil
local draw_pixel = function(back, text, char, from, to)
    term.setBackgroundColor(back)
    term.setTextColor(text)
    for i = from, to do
        n = pi * i / 180
        for j = radius, radius + thickness do
            x = center_x + j * sin(n)
            y = center_y + j * y_comp * cos(n)
            term.setCursorPos(up(x > center_x and x - 1 or x), up(y))
            term.write(char)
        end
    end
end

term.setBackgroundColor(back_color)
term.clear()
term.setCursorPos(up(text_x), up(text_y))
term.setTextColor(text_color)
term.setBackgroundColor(text_back)
term.write(text)
local inc
while true do
    for i = 1, 360, speed do
        draw_pixel(back_color, back_color, " ", i - speed, i)
        inc = i
        draw_pixel(back_color, dither_color, dither_char, inc + 1, inc + dither_len)
        inc = inc + dither_len
        draw_pixel(solid_color, solid_color, " ", inc + 1, inc + solid_len)
        inc = inc + solid_len
        draw_pixel(back_color, dither_color, dither_char, inc + 1, inc + dither_len)
        os.queueEvent("circle")
        os.pullEvent("circle")
    end
end