""" A Pillow loader for .ftc and .ftu files (FTEX) Jerome Leclanche <jerome@leclan.ch> The contents of this file are hereby released in the public domain (CC0) Full text of the CC0 license: https://creativecommons.org/publicdomain/zero/1.0/ Independence War 2: Edge Of Chaos - Texture File Format - 16 October 2001 The textures used for 3D objects in Independence War 2: Edge Of Chaos are in a packed custom format called FTEX. This file format uses file extensions FTC and FTU. * FTC files are compressed textures (using standard texture compression). * FTU files are not compressed. Texture File Format The FTC and FTU texture files both use the same format, called. This has the following structure: {header} {format_directory} {data} Where: {header} = { u32:magic, u32:version, u32:width, u32:height, u32:mipmap_count, u32:format_count } * The "magic" number is "FTEX". * "width" and "height" are the dimensions of the texture. * "mipmap_count" is the number of mipmaps in the texture. * "format_count" is the number of texture formats (different versions of the same texture) in this file. {format_directory} = format_count * { u32:format, u32:where } The format value is 0 for DXT1 compressed textures and 1 for 24-bit RGB uncompressed textures. The texture data for a format starts at the position "where" in the file. Each set of texture data in the file has the following structure: {data} = format_count * { u32:mipmap_size, mipmap_size * { u8 } } * "mipmap_size" is the number of bytes in that mip level. For compressed textures this is the size of the texture data compressed with DXT1. For 24 bit uncompressed textures, this is 3 * width * height. Following this are the image bytes for that mipmap level. Note: All data is stored in little-Endian (Intel) byte order. """ import struct from io import BytesIO from PIL import Image, ImageFile from PIL.DdsImagePlugin import _dxt1 MAGIC = b"FTEX" FORMAT_DXT1 = 0 FORMAT_UNCOMPRESSED = 1 class FtexImageFile(ImageFile.ImageFile): format = "FTEX" format_description = "Texture File Format (IW2:EOC)" def _open(self): magic = struct.unpack("<I", self.fp.read(4)) version = struct.unpack("<i", self.fp.read(4)) self.size = struct.unpack("<2i", self.fp.read(8)) mipmap_count, format_count = struct.unpack("<2i", self.fp.read(8)) self.mode = "RGB" # Only support single-format files. I don't know of any multi-format file. assert format_count == 1 format, where = struct.unpack("<2i", self.fp.read(8)) self.fp.seek(where) mipmap_size, = struct.unpack("<i", self.fp.read(4)) data = self.fp.read(mipmap_size) if format == FORMAT_DXT1: data = _dxt1(BytesIO(data), self.width, self.height) self.tile = [("raw", (0, 0) + self.size, 0, ('RGBX', 0, 1))] elif format == FORMAT_UNCOMPRESSED: self.tile = [("raw", (0, 0) + self.size, 0, ('RGB', 0, 1))] else: raise ValueError("Invalid texture compression format: %r" % (format)) self.fp.close() self.fp = BytesIO(data) def load_seek(self, pos): pass def _validate(prefix): return prefix[:4] == MAGIC Image.register_open(FtexImageFile.format, FtexImageFile, _validate) Image.register_extension(FtexImageFile.format, ".ftc") Image.register_extension(FtexImageFile.format, ".ftu")