Glasses Power View

local glass = peripheral.wrap('bottom')
local power = peripheral.wrap('left')

-- Glasses
local startX = 20
local startY = 5

local powerID = 'IC2:fluidUuMatter'

function init()
  if ( checkErrors() ) then
    error('error found')
  end
  glassesLoop()
end

function glassesLoop()
  while true do
    glass.clear()

    -- Power
    local powerUsed = power.getEnergyStored()
    local powerMax = power.getMaxEnergyStored()
    local powerPercentage = ( ( powerUsed / powerMax ) * 100 )
    local text = 'POWER: ' .. round(powerPercentage, 2)

    addChargeProgress(startX+1, startY+1, powerID, nil, powerUsed, powerMax, 0.75, 0x7f7f7f, 0.5, 0x4B0082, 1, 0.25, 0.5, 3, text)

    glass.sync()
    sleep(1)
  end
end

function checkErrors()
  return false
end

function addChargeProgress(x, y, id, meta, amt, max_amt, n_a, s_rgb, s_a, rgb, a, tb_a, e_a, e_int, text)
    local w = getStringWidth(text) + 34
  local h = 18
  glass.addBox(x + 1, y + 1, w - 2, h - 2, rgb, a)
  local i = x + 1 + e_a
  while i <= x + w - 2 do
      glass.addBox(i, y + 1, 1, h - 2, 0x000000, e_a)
      i = i + e_int
  end
  glass.addBox(x + 1, y + 1, w - 2, 3, 0x000000, tb_a)
  glass.addBox(x + 1, y + h - 4, w - 2, 3, 0x000000, tb_a)
  glass.addBox(x, y, w, 1, s_rgb, s_a)
  glass.addBox(x, y + h - 1, w, 1, s_rgb, s_a)
  glass.addBox(x, y + 1, 1, h - 2, s_rgb, s_a)
  glass.addBox(x + w - 1, y + 1, 1, h - 2, s_rgb, s_a)
  local amt_prog = math.ceil(amt / max_amt * w - 2)
  glass.addBox(x + 1 + amt_prog, y + 1, w - 2 - amt_prog, h - 2, 0x000000, n_a)
  glass.addIcon(x + 1, y + 1, id, meta)
  glass.addText(x + 22, y + 5, text)
end

function getStringWidth(text)
  local w = 0
  local def = 5
  local w1 = "i!,.:;|"
  local w2 = "'l"
  local w3 = " t"
  local w4 = "*{}()\"<>f"
  local w6 = "~"
  for i = 1, string.len(text) do
      local c = string.sub(text, i, i)
      if string.find(w1, c) ~= nil then
          w = w + 1
      elseif string.find(w2, c) ~= nil then
          w = w + 2
      elseif string.find(w3, c) ~= nil then
          w = w + 3
      elseif string.find(w4, c) ~= nil then
          w = w + 4
      elseif string.find(w6, c) ~= nil then
          w = w + 6
      else
          w = w + 5
      end
      if i < string.len(text) - 1 then
          w = w + 1
      end
  end
  return w
end

function round(num, numDecimalPlaces)
  local mult = 10^(numDecimalPlaces or 0)
  return math.floor(num * mult + 0.5) / mult
end

init()