94 lines
3.2 KiB
Python
94 lines
3.2 KiB
Python
"""
|
|
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. 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 . import Image, ImageFile
|
|
|
|
|
|
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:
|
|
self.mode = "RGBA"
|
|
self.tile = [("bcn", (0, 0) + self.size, 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_extensions(FtexImageFile.format, [".ftc", ".ftu"])
|