unpack_flcg.py

import os
from pathlib import Path
import sys
from lib.kaitai_defs.flcg import Flcg
from glob import glob

TOOL_NAME = "Jyl's FLCG exporter"

DIR = "filesystem/DATA/files/STG_HI"
OUT_DIR = "out/STG_HI"


def unpack(in_path: str, out_dir: str):
    os.makedirs(out_dir, exist_ok=True)
    print(in_path)
    gcl: Flcg = Flcg.from_file(in_path)

    out_path = os.path.join(out_dir, Path(in_path).stem + ".obj")

    with open(out_path, "w") as f:
        f.write("# OBJ file\n")
        f.write(f"# Generated by {TOOL_NAME}\n")

        last_index = 0

        for i in range(gcl.num_areas):
            area = gcl.areas[i]
            f.write(f"o {area.name}_{i}\n")

            area = gcl.areas[i]

            for tri in area.data.col_mesh:
                f.write(vert_2_obj(tri.v0, area.origin))
                f.write(vert_2_obj(tri.v1, area.origin))
                f.write(vert_2_obj(tri.v2, area.origin))

            for ii in range(last_index, last_index + area.data.num_col_tris):
                f.write(f"f {ii * 3 + 1} {ii * 3 + 2} {ii * 3 + 3}\n")

            last_index += area.data.num_col_tris


def vert_2_obj(v: Flcg.FlVector, origin: Flcg.FlVector) -> str:
    """
    This bakes in object origin, because I don't think wavefront supports it.
    Coords are divided by 10 because the unit seems to be 10m.
    """
    x = (v.x + origin.x) * 0.1
    y = (v.y + origin.y) * 0.1
    z = (v.z + origin.z) * 0.1
    return f"v {x} {y} {z}\n"


if __name__ == "__main__":
    match len(sys.argv):
        case 2:
            in_path = sys.argv[1]
            out_path = os.path.join(".", Path(in_path).stem + "_extracted")
            unpack(in_path, out_path)

        case 3:
            in_path = sys.argv[1]
            out_path = sys.argv[2]
            unpack(in_path, out_path)

        case _:
            print(
                "Provide 1 or 2 args:\n    - input file path\n    - output dir path (optional)"
            )