Add a loader for the FTEX format from Independence War 2: Edge of Chaos

PIL/FtexImagePlugin.py

@@ -0,0 +1,97 @@
+"""
+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")

PIL/__init__.py

@@ -56,4 +56,6 @@ _plugins = ['BmpImagePlugin',
             'WmfImagePlugin',
             'XbmImagePlugin',
             'XpmImagePlugin',
-            'XVThumbImagePlugin']
+            'XVThumbImagePlugin',
+            'FtexImagePlugin',
+            ]