imageConverter

--[[

### Image processing code from fyvushfinkle ###

### HOW TO USE: ###

tArgs:
[1] = name of input file
[2] = name of output file
[3] = width of image being converted
[4] = height of image being converted

Example program use:
imgC shrek shrekC 64 64

]]

local tArgs = {...}

if tArgs[1] == nil then error("Missing input file name")
elseif tArgs[2] == nil then error("Missing output file name")
elseif tArgs[3] == nil then error("Missing image width")
elseif tArgs[4] == nil then error("Missing image height")
end

local file, err = fs.open(tArgs[1], "r")
assert(file, err)
--local file = fs.open("texture", "r")

local colorList = {
    size = { x = tArgs[3], y = tArgs[4] },
}

local W = tArgs[3] --16
local H = tArgs[4] --16

--pixelSize used for drawing to screen. Not needed for raw image processing
local pixelSize = tArgs[5] or 5

for y=1, H do
    for x=1, W do
        local r = file.readLine()
        local g = file.readLine()
        local b = file.readLine()
        local a = file.readLine()

        if a == nil then
            break
        end

        local rgb = 0

        if a ~= 0 then

            r = bit.blshift(r, 16)
            g = bit.blshift(g, 8)
            rgb = bit.bor(bit.bor(r, g), b)
        end

        colorList[y * W + x] = rgb
    end
end
file.close()

local file, err = fs.open(tArgs[2], "w")
assert(file, err)
file.write(textutils.serialize(colorList))
file.close()


--[[
for y = 1, H do
    for x = 1, W do
        local col = colorList[y * W + x]
        if col == nil then
            break
        end
        --print(string.format("%x", col))
        ar.fill(x * pixelSize, y * pixelSize, (x+1) * pixelSize, (y+1) * pixelSize, col)
        --os.sleep(0.1)
    end
end
]]