"""
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
from ._binary import o32le as o32
# 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_R8G8B8A8_TYPELESS = 27
DXGI_FORMAT_R8G8B8A8_UNORM = 28
DXGI_FORMAT_R8G8B8A8_UNORM_SRGB = 29
DXGI_FORMAT_BC5_TYPELESS = 82
DXGI_FORMAT_BC5_UNORM = 83
DXGI_FORMAT_BC5_SNORM = 84
DXGI_FORMAT_BC6H_UF16 = 95
DXGI_FORMAT_BC6H_SF16 = 96
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):
if not _accept(self.fp.read(4)):
raise SyntaxError("not a DDS file")
(header_size,) = struct.unpack("<I", self.fp.read(4))
if header_size != 124:
raise OSError(f"Unsupported header size {repr(header_size)}")
header_bytes = self.fp.read(header_size - 4)
if len(header_bytes) != 120:
raise OSError(f"Incomplete header: {len(header_bytes)} 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))
struct.unpack("<11I", header.read(44)) # reserved
# pixel format
pfsize, pfflags = struct.unpack("<2I", header.read(8))
fourcc = header.read(4)
(bitcount,) = struct.unpack("<I", header.read(4))
masks = struct.unpack("<4I", header.read(16))
if pfflags & DDPF_RGB:
# Texture contains uncompressed RGB data
masks = {mask: ["R", "G", "B", "A"][i] for i, mask in enumerate(masks)}
rawmode = ""
if bitcount == 32:
rawmode += masks[0xFF000000]
else:
self.mode = "RGB"
rawmode += masks[0xFF0000] + masks[0xFF00] + masks[0xFF]
self.tile = [("raw", (0, 0) + self.size, 0, (rawmode[::-1], 0, 1))]
else:
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"ATI1":
self.pixel_format = "BC4"
n = 4
self.mode = "L"
elif fourcc == b"ATI2":
self.pixel_format = "BC5"
n = 5
self.mode = "RGB"
elif fourcc == b"BC5S":
self.pixel_format = "BC5S"
n = 5
self.mode = "RGB"
elif fourcc == b"DX10":
data_start += 20
# ignoring flags which pertain to volume textures and cubemaps
(dxgi_format,) = struct.unpack("<I", self.fp.read(4))
self.fp.read(16)
if dxgi_format in (DXGI_FORMAT_BC5_TYPELESS, DXGI_FORMAT_BC5_UNORM):
self.pixel_format = "BC5"
n = 5
self.mode = "RGB"
elif dxgi_format == DXGI_FORMAT_BC5_SNORM:
self.pixel_format = "BC5S"
n = 5
self.mode = "RGB"
elif dxgi_format == DXGI_FORMAT_BC6H_UF16:
self.pixel_format = "BC6H"
n = 6
self.mode = "RGB"
elif dxgi_format == DXGI_FORMAT_BC6H_SF16:
self.pixel_format = "BC6HS"
n = 6
self.mode = "RGB"
elif 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.info["gamma"] = 1 / 2.2
n = 7
elif dxgi_format in (
DXGI_FORMAT_R8G8B8A8_TYPELESS,
DXGI_FORMAT_R8G8B8A8_UNORM,
DXGI_FORMAT_R8G8B8A8_UNORM_SRGB,
):
self.tile = [("raw", (0, 0) + self.size, 0, ("RGBA", 0, 1))]
if dxgi_format == DXGI_FORMAT_R8G8B8A8_UNORM_SRGB:
self.info["gamma"] = 1 / 2.2
return
else:
raise NotImplementedError(
f"Unimplemented DXGI format {dxgi_format}"
)
else:
raise NotImplementedError(f"Unimplemented pixel format {repr(fourcc)}")
self.tile = [
("bcn", (0, 0) + self.size, data_start, (n, self.pixel_format))
]
def load_seek(self, pos):
pass
def _save(im, fp, filename):
if im.mode not in ("RGB", "RGBA"):
raise OSError(f"cannot write mode {im.mode} as DDS")
fp.write(
o32(DDS_MAGIC)
+ o32(124) # header size
+ o32(
DDSD_CAPS | DDSD_HEIGHT | DDSD_WIDTH | DDSD_PITCH | DDSD_PIXELFORMAT
) # flags
+ o32(im.height)
+ o32(im.width)
+ o32((im.width * (32 if im.mode == "RGBA" else 24) + 7) // 8) # pitch
+ o32(0) # depth
+ o32(0) # mipmaps
+ o32(0) * 11 # reserved
+ o32(32) # pfsize
+ o32(DDS_RGBA if im.mode == "RGBA" else DDPF_RGB) # pfflags
+ o32(0) # fourcc
+ o32(32 if im.mode == "RGBA" else 24) # bitcount
+ o32(0xFF0000) # rbitmask
+ o32(0xFF00) # gbitmask
+ o32(0xFF) # bbitmask
+ o32(0xFF000000 if im.mode == "RGBA" else 0) # abitmask
+ o32(DDSCAPS_TEXTURE) # dwCaps
+ o32(0) # dwCaps2
+ o32(0) # dwCaps3
+ o32(0) # dwCaps4
+ o32(0) # dwReserved2
)
if im.mode == "RGBA":
r, g, b, a = im.split()
im = Image.merge("RGBA", (a, r, g, b))
ImageFile._save(im, fp, [("raw", (0, 0) + im.size, 0, (im.mode[::-1], 0, 1))])
def _accept(prefix):
return prefix[:4] == b"DDS "
Image.register_open(DdsImageFile.format, DdsImageFile, _accept)
Image.register_save(DdsImageFile.format, _save)
Image.register_extension(DdsImageFile.format, ".dds")
