sigilplugins/imagecrunch/PIL/DdsImagePlugin.py
2019-08-03 00:49:15 -07:00

172 lines
4.9 KiB
Python

"""
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")