cathedral_patch_font.py

#!/usr/bin/env python3
# Font patcher for this game: https://store.steampowered.com/app/1056180/Cathedral/

import gzip
import io
import json
import struct
import sys
from typing import Any, Dict, List, TypedDict, cast

import PIL.Image

FONT_RESOURCE_IDS = {
  "default": "RESOURCES\\FONT\\DEFAULT",
  "small-gui": "RESOURCES\\FONT\\SMALL-GUI",
}
SUPPLEMENTARY_FONT_PATHS = {
  "default": "default-ru.png",
  "small-gui": "small-gui-ru.png",
}
PATCHED_CHARACTERS = "абвгдеёжзийклмнопрстуфхцчшщъыьэюяАБВГДЕЁЖЗИЙКЛМНОПРСТУФХЦЧШЩЪЫЬЭЮЯ"


class MetadataAnimationTrack(TypedDict):
  start: int
  end: int
  fps: int


class MetadataAnimation(TypedDict):
  frameWidth: int
  frameHeight: int
  tracks: Dict[str, MetadataAnimationTrack]


class MetadataResource(TypedDict):
  key: str
  value: str


class MetadataLayout(TypedDict):
  x: int
  y: int
  width: int
  height: int


class Metadata(TypedDict):
  animations: Dict[str, MetadataAnimation]
  properties: Dict[str, Dict[str, object]]
  resources: List[MetadataResource]


MetadataAtlasLayout = Dict[str, MetadataLayout]


def main(argv: List[str]) -> int:
  pak_file_path = sys.argv[1]

  with gzip.GzipFile(pak_file_path, "rb") as pak_file:
    data_len: int
    (data_len,) = struct.unpack("<i", pak_file.read(4))
    metadata: Metadata = json.loads(pak_file.read(data_len).decode("utf8"))
    (data_len,) = struct.unpack("<i", pak_file.read(4))
    atlas_layout: MetadataAtlasLayout = json.loads(pak_file.read(data_len).decode("utf8"))
    atlas_data = pak_file.read()
    with PIL.Image.open(io.BytesIO(atlas_data), formats=["PNG"]) as orig_atlas_img:
      new_atlas_img = orig_atlas_img

      resources_to_files_mapping = {res["key"]: res["value"] for res in metadata["resources"]}

      additional_height = 0
      for font_name, resource_id in FONT_RESOURCE_IDS.items():
        font_sprite = atlas_layout[resources_to_files_mapping[resource_id]]
        additional_height = max(additional_height, font_sprite["height"])

      new_atlas_img = PIL.Image.new(
        cast(Any, orig_atlas_img.mode),
        (orig_atlas_img.width, orig_atlas_img.height + additional_height)
      )
      new_atlas_img.paste(orig_atlas_img, (0, 0))

      font_pos_x = 0
      font_pos_y = orig_atlas_img.height
      for font_name, resource_id in FONT_RESOURCE_IDS.items():
        font_sprite = atlas_layout[resources_to_files_mapping[resource_id]]
        font_animation = metadata["animations"][resource_id]

        with PIL.Image.open(SUPPLEMENTARY_FONT_PATHS[font_name], formats=["PNG"]) as suppl_img:
          expected_suppl_width = font_animation["frameWidth"] * len(PATCHED_CHARACTERS)
          expected_suppl_height = font_animation["frameHeight"]
          if suppl_img.width != expected_suppl_width or suppl_img.height != expected_suppl_height:
            raise Exception(
              f"Invalid dimensions of the supplementary font: {suppl_img.width}x{suppl_img.height}, must be: {expected_suppl_width}x{expected_suppl_height}"
            )

          orig_font_img = orig_atlas_img.crop((
            font_sprite["x"],
            font_sprite["y"],
            font_sprite["x"] + font_sprite["width"],
            font_sprite["y"] + font_sprite["height"],
          ))
          font_sprite["x"] = font_pos_x
          font_sprite["y"] = font_pos_y
          font_sprite["width"] = orig_font_img.width + suppl_img.width
          font_sprite["height"] = max(orig_font_img.height, suppl_img.height)
          font_pos_x += font_sprite["width"]

          new_atlas_img.paste(orig_font_img, (font_sprite["x"], font_sprite["y"]))
          new_atlas_img.paste(
            suppl_img, (font_sprite["x"] + orig_font_img.width, font_sprite["y"])
          )

          start_idx = orig_font_img.width // font_animation["frameWidth"]
          for char in PATCHED_CHARACTERS:
            font_animation["tracks"]["_0x" + char.encode("utf8").hex()] = (
              MetadataAnimationTrack(start=start_idx, end=start_idx, fps=1)
            )
            start_idx += 1

      if new_atlas_img is orig_atlas_img:
        new_atlas_img = orig_atlas_img.copy()

  with gzip.GzipFile(pak_file_path, "wb") as pak_file:
    data: bytes
    data = json.dumps(metadata).encode("utf8")
    pak_file.write(struct.pack("<i", len(data)))
    pak_file.write(data)
    data = json.dumps(atlas_layout).encode("utf8")
    pak_file.write(struct.pack("<i", len(data)))
    pak_file.write(data)
    data_io = io.BytesIO()
    new_atlas_img.save(data_io, format="PNG")
    pak_file.write(data_io.getvalue())

  return 0


if __name__ == "__main__":
  sys.exit(main(sys.argv))