xtermcontrol 3.11

xterm -fa 'Default' -fs 1 -geometry 1000x1000 -e "lua5.4 tga.lua image.tga; sleep 500"`

local tga =
{
   IMAGE_TYPE_EMPTY = 0;
   IMAGE_TYPE_PALETTE = 1;
   IMAGE_TYPE_TRUECOLOR = 2;
   IMAGE_TYPE_MONOCHROME = 3;
   IMAGE_TYPE_PALETTE_RLE = 9;
   IMAGE_TYPE_TRUECOLOR_RLE = 10;
   IMAGE_TYPE_MONOCHROME_RLE = 11;
}
-------------------------------------------------------------------------------
local function tga_read_header(file_handler)
      local header = { colormap = { } }
      header.identificator_len,
      header.colormap_type    ,
      header.type             ,
      header.colormap.position,
      header.colormap.numelems,
      header.colormap.bitselem,
      header.pose_x           ,
      header.pose_y           ,
      header.width            ,
      header.height           ,
      header.bits             ,
      header.properties = ('BBBI2I2BI2I2I2I2BB'):unpack(header)
      header.channels = math.max(1,math.floor(image.bits / 8))
      return header
end
-------------------------------------------------------------------------------
local function tga_read_pallete(file_handler,header)

end
-------------------------------------------------------------------------------
local function tga_read_colormap(file_handler,header)

end
-------------------------------------------------------------------------------
local function tga_read_colordata(file_handler,header)

end
-------------------------------------------------------------------------------
local function tga_read_rle_colormap(file_handler,header)

end
-------------------------------------------------------------------------------
local function tga_read_rle_colordata(file_handler,header)

end
-------------------------------------------------------------------------------
function tga.load(filename)
    if type(filename) ~= 'string' then
       return nil,"[ERROR] Bad filename argument"
    end
    ---
    local file = io.open(filename,"rb")
    ---
    if io.type(file) ~= 'file' then
       return nil,"[ERROR] Failed open "..filename
    end
    ---
    local header = file:read(18)
    if type(header) ~= 'string' then
       return nil,"[ERROR] Failed read "..filename
    end
    ---
    local image = { colormap = { } }
    ---
    image.identificator_len,
    image.colormap_type    ,
    image.type             ,
    image.colormap.position,
    image.colormap.numelems,
    image.colormap.bitselem,
    image.pose_x           ,
    image.pose_y           ,
    image.width            ,
    image.height           ,
    image.bits             ,
    image.properties = ('BBBI2I2BI2I2I2I2BB'):unpack(header)
    image.channels = math.floor(image.bits / 8)
    ---
    image.data = {}
    ---
    if image.type == tga.IMAGE_TYPE_EMPTY then
       return image
    end
    ---
    if image.type == tga.IMAGE_TYPE_PALETTE then
       local colormap = { }
       local colormap_channels = image.colormap.bitselem / 8
       image.channels = colormap_channels
       local image_size = (image.height * image.width)
       local colormap_data = file:read(colormap_channels * image.colormap.numelems)
       ---
       if type(colormap_data) ~= 'string' then
          return nil,"[ERROR] Failed read colormap in "..filename
       end
       ---
       for i=1,#colormap_data, colormap_channels do
           if colormap_channels == 1 then
              colormap[#colormap+1] =
              {
                  (colormap_data:sub(i+0,i+0)):byte(),
              }
           elseif colormap_channels == 2 then
              colormap[#colormap+1] =
              {
                  (colormap_data:sub(i+0,i+0)):byte(),
                  (colormap_data:sub(i+1,i+1)):byte(),
              }
           elseif colormap_channels == 3 then
              colormap[#colormap+1] =
              {
                  (colormap_data:sub(i+0,i+0)):byte(),
                  (colormap_data:sub(i+1,i+1)):byte(),
                  (colormap_data:sub(i+2,i+2)):byte(),
              }
           elseif colormap_channels == 4 then
              colormap[#colormap+1] =
              {
                  (colormap_data:sub(i+0,i+0)):byte(),
                  (colormap_data:sub(i+1,i+1)):byte(),
                  (colormap_data:sub(i+2,i+2)):byte(),
                  (colormap_data:sub(i+3,i+3)):byte(),
              }
           end
       end
       ---
       local data = file:read(image_size)
       ---
       if type(data) ~= 'string' then
          return nil,"[ERROR] Failed read colorcodes in "..filename
       end
       ---
       for i=1,image_size do
           local color_code = data:sub(i,i):byte()+1
           --io.write(color_code,' ' )
           for j=1,colormap_channels do
               image.data[#image.data+1] = colormap[color_code][j]
               for p=1,image.channels-colormap_channels do
                   image.data[#image.data+1] = 0
               end
           end
       end
       return image
    end
    ---
    local image_size = (image.height * image.width) * (image.channels)
    local data = file:read(image_size)
    ---
    ---
    if type(data) ~= 'string' then
       return nil,"[ERROR] Failed read "..filename
    end
    ---
    file:close()
    ---
    image.data = {}
    for i=1,#data do
        image.data[i] = string.byte(data:sub(i,i))
    end

    return image
end

function tga.ascii_print(image,style)
    local c = 0
    for i=1,#image.data,image.channels do
        c = c + 1
        if style == 'rgb' then
           io.write('\27[48;2;',image.data[i+2],';',
                                image.data[i+1],';',
                                image.data[i+0],'m','   ','\27[0m')
        elseif style == 'ascii' then
           io.write(string.char((33 + (image.data[i+0] +
                                       image.data[i+1] +
                                       image.data[i+2] /3)) % 125))
        end

        if c % image.width == 0 then print() end
    end
end



local image,err = assert(tga.load(({...})[1]))

tga.ascii_print(image,'rgb')

print(
image.identificator_len,
image.colormap_type    ,
image.type             ,
image.colormap.position,
image.colormap.numelems,
image.colormap.bitselem,
image.pose_x ,
image.pose_y ,
image.width,
image.height,
image.bits,
image.properties)