icondecode.py

import heatshrink2
import argparse
import io


def padded_hex(i, l):
    given_int = i
    given_len = l

    hex_result = hex(given_int)[2:]  # remove '0x' from beginning of str
    num_hex_chars = len(hex_result)
    extra_zeros = "0" * (given_len - num_hex_chars)  # may not get used..

    return (
        "0x" + hex_result
        if num_hex_chars == given_len
        else "?" * given_len
        if num_hex_chars > given_len
        else "0x" + extra_zeros + hex_result
        if num_hex_chars < given_len
        else None
    )


parser = argparse.ArgumentParser(description="Turn icon char arrays back into .xbm")

parser.add_argument("infile", metavar="i", help="Input file")
parser.add_argument("outfile", metavar="o", help="File to write to")
parser.add_argument(
    "Width",
    metavar="W",
    type=int,
    nargs="?",
    default="128",
    help="Width of the image. Find from meta.txt or directory name",
)
parser.add_argument(
    "Height",
    metavar="H",
    type=int,
    nargs="?",
    default="64",
    help="Height of the image. Find from meta.txt or directory name",
)
parser.add_argument(
    "Trim",
    metavar="T",
    type=int,
    nargs="?",
    default="8",
    help="Number of bytes off the start/header to trim. Multiples of 2 required.",
)
args = vars(parser.parse_args())

imageWidth = args["Width"]
imageHeight = args["Height"]
trimStart = args["Trim"]

with open(args["infile"], "rb") as f:
    output = f.read()
f = io.StringIO(output.decode().strip())

data = f.read().strip().replace(";", "").replace("{", "").replace("}", "")
data_str = data.replace(",", "").replace("0x", "")
data_bin = bytearray.fromhex(data_str[trimStart:])

data_decoded_str = heatshrink2.decompress(data_bin, window_sz2=8, lookahead_sz2=4)

b = list(data_decoded_str)

c = ", ".join(padded_hex(my_int, 2) for my_int in b)

width_out = "#define icon_width " + str(imageWidth) + "\n"
height_out = "#define icon_height " + str(imageHeight) + "\n"
bytes_out = "static unsigned char icon_bits[] = {" + str(c) + "};"

data = width_out + height_out + bytes_out

with open(args["outfile"], "w") as f:
    f.write(data)