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- """
- A Pillow loader for .dds files (S3TC-compressed aka DXTC)
- Jerome Leclanche <jerome@leclan.ch>
-
- Documentation:
- https://web.archive.org/web/20170802060935/http://oss.sgi.com/projects/ogl-sample/registry/EXT/texture_compression_s3tc.txt
-
- 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/
- """
-
- import struct
- from io import BytesIO
- from . import Image, ImageFile
-
-
- # Magic ("DDS ")
- DDS_MAGIC = 0x20534444
-
- # DDS flags
- DDSD_CAPS = 0x1
- DDSD_HEIGHT = 0x2
- DDSD_WIDTH = 0x4
- DDSD_PITCH = 0x8
- DDSD_PIXELFORMAT = 0x1000
- DDSD_MIPMAPCOUNT = 0x20000
- DDSD_LINEARSIZE = 0x80000
- DDSD_DEPTH = 0x800000
-
- # DDS caps
- DDSCAPS_COMPLEX = 0x8
- DDSCAPS_TEXTURE = 0x1000
- DDSCAPS_MIPMAP = 0x400000
-
- DDSCAPS2_CUBEMAP = 0x200
- DDSCAPS2_CUBEMAP_POSITIVEX = 0x400
- DDSCAPS2_CUBEMAP_NEGATIVEX = 0x800
- DDSCAPS2_CUBEMAP_POSITIVEY = 0x1000
- DDSCAPS2_CUBEMAP_NEGATIVEY = 0x2000
- DDSCAPS2_CUBEMAP_POSITIVEZ = 0x4000
- DDSCAPS2_CUBEMAP_NEGATIVEZ = 0x8000
- DDSCAPS2_VOLUME = 0x200000
-
- # Pixel Format
- DDPF_ALPHAPIXELS = 0x1
- DDPF_ALPHA = 0x2
- DDPF_FOURCC = 0x4
- DDPF_PALETTEINDEXED8 = 0x20
- DDPF_RGB = 0x40
- DDPF_LUMINANCE = 0x20000
-
-
- # dds.h
-
- DDS_FOURCC = DDPF_FOURCC
- DDS_RGB = DDPF_RGB
- DDS_RGBA = DDPF_RGB | DDPF_ALPHAPIXELS
- DDS_LUMINANCE = DDPF_LUMINANCE
- DDS_LUMINANCEA = DDPF_LUMINANCE | DDPF_ALPHAPIXELS
- DDS_ALPHA = DDPF_ALPHA
- DDS_PAL8 = DDPF_PALETTEINDEXED8
-
- DDS_HEADER_FLAGS_TEXTURE = (DDSD_CAPS | DDSD_HEIGHT | DDSD_WIDTH |
- DDSD_PIXELFORMAT)
- DDS_HEADER_FLAGS_MIPMAP = DDSD_MIPMAPCOUNT
- DDS_HEADER_FLAGS_VOLUME = DDSD_DEPTH
- DDS_HEADER_FLAGS_PITCH = DDSD_PITCH
- DDS_HEADER_FLAGS_LINEARSIZE = DDSD_LINEARSIZE
-
- DDS_HEIGHT = DDSD_HEIGHT
- DDS_WIDTH = DDSD_WIDTH
-
- DDS_SURFACE_FLAGS_TEXTURE = DDSCAPS_TEXTURE
- DDS_SURFACE_FLAGS_MIPMAP = DDSCAPS_COMPLEX | DDSCAPS_MIPMAP
- DDS_SURFACE_FLAGS_CUBEMAP = DDSCAPS_COMPLEX
-
- DDS_CUBEMAP_POSITIVEX = DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_POSITIVEX
- DDS_CUBEMAP_NEGATIVEX = DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_NEGATIVEX
- DDS_CUBEMAP_POSITIVEY = DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_POSITIVEY
- DDS_CUBEMAP_NEGATIVEY = DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_NEGATIVEY
- DDS_CUBEMAP_POSITIVEZ = DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_POSITIVEZ
- DDS_CUBEMAP_NEGATIVEZ = DDSCAPS2_CUBEMAP | DDSCAPS2_CUBEMAP_NEGATIVEZ
-
-
- # DXT1
- DXT1_FOURCC = 0x31545844
-
- # DXT3
- DXT3_FOURCC = 0x33545844
-
- # DXT5
- DXT5_FOURCC = 0x35545844
-
-
- # dxgiformat.h
-
- DXGI_FORMAT_BC7_TYPELESS = 97
- DXGI_FORMAT_BC7_UNORM = 98
- DXGI_FORMAT_BC7_UNORM_SRGB = 99
-
-
- class DdsImageFile(ImageFile.ImageFile):
- format = "DDS"
- format_description = "DirectDraw Surface"
-
- def _open(self):
- magic, header_size = struct.unpack("<II", self.fp.read(8))
- if header_size != 124:
- raise IOError("Unsupported header size %r" % (header_size))
- header_bytes = self.fp.read(header_size - 4)
- if len(header_bytes) != 120:
- raise IOError("Incomplete header: %s bytes" % len(header_bytes))
- header = BytesIO(header_bytes)
-
- flags, height, width = struct.unpack("<3I", header.read(12))
- self._size = (width, height)
- self.mode = "RGBA"
-
- pitch, depth, mipmaps = struct.unpack("<3I", header.read(12))
- reserved = struct.unpack("<11I", header.read(44))
-
- # pixel format
- pfsize, pfflags = struct.unpack("<2I", header.read(8))
- fourcc = header.read(4)
- bitcount, rmask, gmask, bmask, amask = struct.unpack("<5I",
- header.read(20))
-
- data_start = header_size + 4
- n = 0
- if fourcc == b"DXT1":
- self.pixel_format = "DXT1"
- n = 1
- elif fourcc == b"DXT3":
- self.pixel_format = "DXT3"
- n = 2
- elif fourcc == b"DXT5":
- self.pixel_format = "DXT5"
- n = 3
- elif fourcc == b"DX10":
- data_start += 20
- # ignoring flags which pertain to volume textures and cubemaps
- dxt10 = BytesIO(self.fp.read(20))
- dxgi_format, dimension = struct.unpack("<II", dxt10.read(8))
- if dxgi_format in (DXGI_FORMAT_BC7_TYPELESS,
- DXGI_FORMAT_BC7_UNORM):
- self.pixel_format = "BC7"
- n = 7
- elif dxgi_format == DXGI_FORMAT_BC7_UNORM_SRGB:
- self.pixel_format = "BC7"
- self.im_info["gamma"] = 1/2.2
- n = 7
- else:
- raise NotImplementedError("Unimplemented DXGI format %d" %
- (dxgi_format))
- else:
- raise NotImplementedError("Unimplemented pixel format %r" %
- (fourcc))
-
- self.tile = [
- ("bcn", (0, 0) + self.size, data_start, (n))
- ]
-
- def load_seek(self, pos):
- pass
-
-
- def _validate(prefix):
- return prefix[:4] == b"DDS "
-
-
- Image.register_open(DdsImageFile.format, DdsImageFile, _validate)
- Image.register_extension(DdsImageFile.format, ".dds")
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