Archipelago/worlds/soe/Patch.py

58 lines
2.0 KiB
Python

import bsdiff4
import yaml
from typing import Optional
import Utils
USHASH = '6e9c94511d04fac6e0a1e582c170be3a'
current_patch_version = 2
def read_rom(stream, strip_header=True) -> bytes:
"""Reads rom into bytearray and optionally strips off any smc header"""
data = stream.read()
if strip_header and len(data) % 0x400 == 0x200:
return data[0x200:]
return data
def generate_yaml(patch: bytes, metadata: Optional[dict] = None) -> bytes:
patch = yaml.dump({"meta": metadata,
"patch": patch,
"game": "Secret of Evermore",
# minimum version of patch system expected for patching to be successful
"compatible_version": 1,
"version": current_patch_version,
"base_checksum": USHASH})
return patch.encode(encoding="utf-8-sig")
def generate_patch(vanilla_file, randomized_file, metadata: Optional[dict] = None) -> bytes:
with open(vanilla_file, "rb") as f:
vanilla = read_rom(f)
with open(randomized_file, "rb") as f:
randomized = read_rom(f)
if metadata is None:
metadata = {}
patch = bsdiff4.diff(vanilla, randomized)
return generate_yaml(patch, metadata)
if __name__ == '__main__':
import argparse
import pathlib
import lzma
parser = argparse.ArgumentParser(description='Apply patch to Secret of Evermore.')
parser.add_argument('patch', type=pathlib.Path, help='path to .absoe file')
args = parser.parse_args()
with open(args.patch, "rb") as f:
data = Utils.parse_yaml(lzma.decompress(f.read()).decode("utf-8-sig"))
if data['game'] != 'Secret of Evermore':
raise RuntimeError('Patch is not for Secret of Evermore')
with open(Utils.get_options()['soe_options']['rom_file'], 'rb') as f:
vanilla_data = read_rom(f)
patched_data = bsdiff4.patch(vanilla_data, data["patch"])
with open(args.patch.parent / (args.patch.stem + '.sfc'), 'wb') as f:
f.write(patched_data)