draw

local args = {...}

local downHeight = 80
local screen = peripheral.wrap(args[1])
screen.setTextScale(0.5)
screen.width, screen.height = screen.getSize()
screen.width = screen.width-1
screen.height = screen.height-1

local zc = string.byte("0")
local ac = string.byte("a")

local cindex = {}
cindex[zc] = colors.white
cindex[zc+1] = colors.orange
cindex[zc+2] = colors.magenta
cindex[zc+3] = colors.lightBlue
cindex[zc+4] = colors.yellow
cindex[zc+5] = colors.lime
cindex[zc+6] = colors.pink
cindex[zc+7] = colors.gray
cindex[zc+8] = colors.lightGray
cindex[zc+9] = colors.cyan
cindex[ac] = colors.purple
cindex[ac+1] = colors.blue
cindex[ac+2] = colors.brown
cindex[ac+3] = colors.green
cindex[ac+4] = colors.red
cindex[ac+5] = colors.black

local file = fs.open("/disk/images/"..args[2], "r")
local image = {}
image.width = tonumber(file.readLine())
image.height = tonumber(file.readLine())
image.data = file.readLine()
file.close()

function draw(sx, sy, iy)
  for j = 0, image.height-iy-1 do
    for i = 0, image.width-1 do
      local pixel = string.byte(image.data, (j+iy)*image.width+i+1)
      local color = cindex[pixel]
      paintutils.drawPixel(i+sx+2, j+sy+2, color)
    end
  end
end

local pane = #args >= 3 and args[3] or "down"

local sx = (screen.width-1-image.width)/2
local sy = nil
local iy = nil

if pane == "down" then
  sy = 0
  iy = image.height - downHeight
else
  sy = screen.height - image.height + downHeight
  iy = 0
end

term.redirect(screen)
term.setBackgroundColor(colors.black)
term.clear()
term.setCursorPos(1, 1)

draw(sx, sy, iy)

term.restore()