QuickAPI

--Define Variables
local component = require("component") --Require/Load Component API
local unicode = require("unicode") --Require/Load Unicode API
local gpu = component.gpu --Assign "gpu" as the handle for the gpu
local wres,hres = component.gpu.getResolution() --Assign wres,hres to the current width and height of the display.

--setPixel - Sets a pixel to a specific colour, and sets text
function setPixel(xpos,ypos,color,letter)
  if unicode.len(letter) <= 1 then
    gpu.setBackground(color)
    gpu.set(xpos,ypos,letter)
    gpu.setBackground(0x000000)
  else
    error("Too Long")
  end
end

--drawBar - Draws bar across the screen at the specified height
function drawBar(ypos,color)
  for i=1,wres do
    setPixel(i,ypos,color," ")
  end
end


--Script, Not API Function
drawBar(1,0x666666)
gpu.setForeground(0xff3300)
setPixel(wres-1,1,0x666666,●)
gpu.setForeground(0xff9933)
setPixel(wres-3,1,0x666666,●)
gpu.setForeground(0xffffff)