CC Luminum Lamp Turtle Pixelart Painter Rednet Remote Computer Controller

-- CraftOS 1.7 BMP loader (no seek, no read(n), only read())
-- Supports 24-bit uncompressed BMP

local function read_byte(f)
    local b = f.read()
    if b == nil then error("Unexpected EOF while reading byte") end
    return b
end

local function skip(f, n)
    for i = 1, n do
        if f.read() == nil then error("Unexpected EOF while skipping") end
    end
end

local function readIntLE(f, n)
    local v = 0
    for i = 0, n-1 do
        local b = read_byte(f)
        v = v + (b * (256 ^ i))
    end
    return v
end

local function bmpToHexColorTable(path)
    local f = fs.open(path, "rb")
    if not f then error("File not found: " .. path) end

    -- BMP signature "BM"
    if read_byte(f) ~= 0x42 or read_byte(f) ~= 0x4D then
        error("Not a BMP file")
    end

    -- file size (4), reserved (4)
    skip(f, 8)

    -- pixel data offset
    local pixelOffset = readIntLE(f, 4)

    -- DIB header
    local dibSize = readIntLE(f, 4)
    local width   = readIntLE(f, 4)
    local heightS = readIntLE(f, 4)
    local height  = math.abs(heightS)

    local planes = readIntLE(f, 2)
    if planes ~= 1 then error("Unsupported color planes") end

    local bpp = readIntLE(f, 2)
    if bpp ~= 24 then error("Only 24-bit BMP supported") end

    -- Skip rest of DIB header
    skip(f, dibSize - 16)

    -- MANUAL SEEK → skip until pixelOffset
    local headerEnd = 14 + dibSize
    if pixelOffset < headerEnd then error("Invalid BMP offset") end
    skip(f, pixelOffset - headerEnd)

    -- Pixel reading
    local rowSize = width * 3
    local padding = (4 - (rowSize % 4)) % 4
    local colorTable = {}

    local yStart, yEnd, yStep
    if heightS < 0 then
        -- top-down
        yStart, yEnd, yStep = 0, height - 1, 1
    else
        -- bottom-up
        yStart, yEnd, yStep = height - 1, 0, -1
    end

    for y = yStart, yEnd, yStep do
        colorTable[y] = {}
        for x = 0, width - 1 do
            local b = read_byte(f)
            local g = read_byte(f)
            local r = read_byte(f)
            colorTable[y][x] = tonumber(string.format("0x%02X%02X%02X", r, g, b))
        end
        skip(f, padding)
    end

    f.close()
    return colorTable
end

--main

local filename = "pic.bmp"
local ok, tbl = pcall(bmpToHexColorTable, filename)
if not ok then
    print("Error reading BMP:", tbl)
    return
end

print("BMP loaded successfully.")

rednet.open("back")

local startID = 15676
local i = 0

local keys = {}
for y,_ in pairs(tbl) do table.insert(keys, y) end
table.sort(keys)

for _, y in ipairs(keys) do
    local row = tbl[y]
    local msg = "function c(col) local l=peripheral.wrap('bottom') l.setColor(col) turtle.forward() end"

    -- rows use numeric keys starting at 0
    for x, col in pairs(row) do
        msg = msg .. " c(" .. tostring(col) .. ")"
    end

    rednet.send(startID + i, msg)
    sleep(1)
    i = i + 1
end

print("Done sending.")