|
|
- """
- 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"])
|
