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Source code for kivy.lib.ddsfile

'''
DDS File library
================

This library can be used to parse and save DDS
(`DirectDraw Surface <https://en.wikipedia.org/wiki/DirectDraw_Surface>`)
files.

The initial version was written by::

    Alexey Borzenkov (snaury@gmail.com)

All the initial work credits go to him! Thank you :)

This version uses structs instead of ctypes.


DDS Format
----------

::

    [DDS ][SurfaceDesc][Data]

    [SurfaceDesc]:: (everything is uint32)
        Size
        Flags
        Height
        Width
        PitchOrLinearSize
        Depth
        MipmapCount
        Reserved1 * 11
        [PixelFormat]::
            Size
            Flags
            FourCC
            RGBBitCount
            RBitMask
            GBitMask
            BBitMask
            ABitMask
        [Caps]::
            Caps1
            Caps2
            Reserved1 * 2
        Reserverd2

.. warning::

    This is an external library and Kivy does not provide any support for it.
    It might change in the future and we advise you don't rely on it in your
    code.

'''
# flake8: noqa

from struct import pack, unpack, calcsize

# DDSURFACEDESC2 dwFlags
DDSD_CAPS                  = 0x00000001
DDSD_HEIGHT                = 0x00000002
DDSD_WIDTH                 = 0x00000004
DDSD_PITCH                 = 0x00000008
DDSD_PIXELFORMAT           = 0x00001000
DDSD_MIPMAPCOUNT           = 0x00020000
DDSD_LINEARSIZE            = 0x00080000
DDSD_DEPTH                 = 0x00800000

# DDPIXELFORMAT dwFlags
DDPF_ALPHAPIXELS           = 0x00000001
DDPF_FOURCC                = 0x00000004
DDPF_RGB                   = 0x00000040
DDPF_LUMINANCE             = 0x00020000

# DDSCAPS2 dwCaps1
DDSCAPS_COMPLEX            = 0x00000008
DDSCAPS_TEXTURE            = 0x00001000
DDSCAPS_MIPMAP             = 0x00400000

# DDSCAPS2 dwCaps2
DDSCAPS2_CUBEMAP           = 0x00000200
DDSCAPS2_CUBEMAP_POSITIVEX = 0x00000400
DDSCAPS2_CUBEMAP_NEGATIVEX = 0x00000800
DDSCAPS2_CUBEMAP_POSITIVEY = 0x00001000
DDSCAPS2_CUBEMAP_NEGATIVEY = 0x00002000
DDSCAPS2_CUBEMAP_POSITIVEZ = 0x00004000
DDSCAPS2_CUBEMAP_NEGATIVEZ = 0x00008000
DDSCAPS2_VOLUME            = 0x00200000

# Common FOURCC codes
DDS_DXTN = 0x00545844
DDS_DXT1 = 0x31545844
DDS_DXT2 = 0x32545844
DDS_DXT3 = 0x33545844
DDS_DXT4 = 0x34545844
DDS_DXT5 = 0x35545844

def dxt_to_str(dxt):
    if dxt == DDS_DXT1:
        return 's3tc_dxt1'
    elif dxt == DDS_DXT2:
        return 's3tc_dxt2'
    elif dxt == DDS_DXT3:
        return 's3tc_dxt3'
    elif dxt == DDS_DXT4:
        return 's3tc_dxt4'
    elif dxt == DDS_DXT5:
        return 's3tc_dxt5'
    elif dxt == 0:
        return 'rgba'
    elif dxt == 1:
        return 'alpha'
    elif dxt == 2:
        return 'luminance'
    elif dxt == 3:
        return 'luminance_alpha'

def str_to_dxt(dxt):
    if dxt == 's3tc_dxt1':
        return DDS_DXT1
    if dxt == 's3tc_dxt2':
        return DDS_DXT2
    if dxt == 's3tc_dxt3':
        return DDS_DXT3
    if dxt == 's3tc_dxt4':
        return DDS_DXT4
    if dxt == 's3tc_dxt5':
        return DDS_DXT5
    if dxt == 'rgba':
        return 0
    if dxt == 'alpha':
        return 1
    if dxt == 'luminance':
        return 2
    if dxt == 'luminance_alpha':
        return 3

def align_value(val, b):
    return val + (-val % b)

def check_flags(val, fl):
    return (val & fl) == fl

def dxt_size(w, h, dxt):
    w = max(1, w // 4)
    h = max(1, h // 4)
    if dxt == DDS_DXT1:
        return w * h * 8
    elif dxt in (DDS_DXT2, DDS_DXT3, DDS_DXT4, DDS_DXT5):
        return w * h * 16
    return -1

[docs]class QueryDict(dict): def __getattr__(self, attr): try: return self.__getitem__(attr) except KeyError: try: return super(QueryDict, self).__getattr__(attr) except AttributeError: raise KeyError(attr) def __setattr__(self, attr, value): self.__setitem__(attr, value)
[docs]class DDSException(Exception): pass
class DDSFile(object): fields = ( ('size', 0), ('flags', 1), ('height', 2), ('width', 3), ('pitchOrLinearSize', 4), ('depth', 5), ('mipmapCount', 6), ('pf_size', 18), ('pf_flags', 19), ('pf_fourcc', 20), ('pf_rgbBitCount', 21), ('pf_rBitMask', 22), ('pf_gBitMask', 23), ('pf_bBitMask', 24), ('pf_aBitMask', 25), ('caps1', 26), ('caps2', 27)) def __init__(self, filename=None): super(DDSFile, self).__init__() self._dxt = 0 self._fmt = None self.meta = meta = QueryDict() self.count = 0 self.images = [] self.images_size = [] for field, index in DDSFile.fields: meta[field] = 0 if filename: self.load(filename) def load(self, filename): self.filename = filename with open(filename, 'rb') as fd: data = fd.read() # ensure magic magic_header = data[:4] if isinstance(magic_header, bytes): magic_header = magic_header.decode() if data[:4] != 'DDS ': raise DDSException('Invalid magic header') # read header fmt = 'I' * 31 fmt_size = calcsize(fmt) pf_size = calcsize('I' * 8) header, data = data[4:4+fmt_size], data[4+fmt_size:] if len(header) != fmt_size: raise DDSException('Truncated header in') # depack header = unpack(fmt, header) meta = self.meta for name, index in DDSFile.fields: meta[name] = header[index] # check header validity if meta.size != fmt_size: raise DDSException('Invalid header size (%d instead of %d)' % (meta.size, fmt_size)) if meta.pf_size != pf_size: raise DDSException('Invalid pixelformat size (%d instead of %d)' % (meta.pf_size, pf_size)) if not check_flags(meta.flags, DDSD_CAPS | DDSD_PIXELFORMAT | DDSD_WIDTH | DDSD_HEIGHT): raise DDSException('Not enough flags') if not check_flags(meta.caps1, DDSCAPS_TEXTURE): raise DDSException('Not a DDS texture') self.count = 1 if check_flags(meta.flags, DDSD_MIPMAPCOUNT): if not check_flags(meta.caps1, DDSCAPS_COMPLEX | DDSCAPS_MIPMAP): raise DDSException('Invalid mipmap without flags') self.count = meta.mipmapCount hasrgb = check_flags(meta.pf_flags, DDPF_RGB) hasalpha = check_flags(meta.pf_flags, DDPF_ALPHAPIXELS) hasluminance = check_flags(meta.pf_flags, DDPF_LUMINANCE) bpp = None dxt = block = pitch = 0 if hasrgb or hasalpha or hasluminance: bpp = meta.pf_rgbBitCount if hasrgb and hasluminance: raise DDSException('File have RGB and Luminance') if hasrgb: dxt = 0 elif hasalpha and not hasluminance: dxt = 1 elif hasluminance and not hasalpha: dxt = 2 elif hasalpha and hasluminance: dxt = 3 elif check_flags(meta.pf_flags, DDPF_FOURCC): dxt = meta.pf_fourcc if dxt not in (DDS_DXT1, DDS_DXT2, DDS_DXT3, DDS_DXT4, DDS_DXT5): raise DDSException('Unsupported FOURCC') else: raise DDSException('Unsupported format specified') if bpp: block = align_value(bpp, 8) // 8 pitch = align_value(block * meta.width, 4) if check_flags(meta.flags, DDSD_LINEARSIZE): if dxt in (0, 1, 2, 3): size = pitch * meta.height else: size = dxt_size(meta.width, meta.height, dxt) w = meta.width h = meta.height images = self.images images_size = self.images_size for i in range(self.count): if dxt in (0, 1, 2, 3): size = align_value(block * w, 4) * h else: size = dxt_size(w, h, dxt) image, data = data[:size], data[size:] if len(image) < size: raise DDSException('Truncated image for mipmap %d' % i) images_size.append((w, h)) images.append(image) if w == 1 and h == 1: break w = max(1, w // 2) h = max(1, h // 2) if len(images) == 0: raise DDSException('No images available') if len(images) < self.count: raise DDSException('Not enough images') self._dxt = dxt def save(self, filename): if len(self.images) == 0: raise DDSException('No images to save') fields = dict(DDSFile.fields) fields_keys = list(fields.keys()) fields_index = list(fields.values()) mget = self.meta.get header = [] for idx in range(31): if idx in fields_index: value = mget(fields_keys[fields_index.index(idx)], 0) else: value = 0 header.append(value) with open(filename, 'wb') as fd: fd.write('DDS ') fd.write(pack('I' * 31, *header)) for image in self.images: fd.write(image) def add_image(self, level, bpp, fmt, width, height, data): assert(bpp == 32) assert(fmt in ('rgb', 'rgba', 'dxt1', 'dxt2', 'dxt3', 'dxt4', 'dxt5')) assert(width > 0) assert(height > 0) assert(level >= 0) meta = self.meta images = self.images if len(images) == 0: assert(level == 0) # first image, set defaults ! for k in meta.keys(): meta[k] = 0 self._fmt = fmt meta.size = calcsize('I' * 31) meta.pf_size = calcsize('I' * 8) meta.pf_flags = 0 meta.flags = DDSD_CAPS | DDSD_PIXELFORMAT | DDSD_WIDTH | DDSD_HEIGHT meta.width = width meta.height = height meta.caps1 = DDSCAPS_TEXTURE meta.flags |= DDSD_LINEARSIZE meta.pitchOrLinearSize = len(data) meta.pf_rgbBitCount = 32 meta.pf_rBitMask = 0x00ff0000 meta.pf_gBitMask = 0x0000ff00 meta.pf_bBitMask = 0x000000ff meta.pf_aBitMask = 0xff000000 if fmt in ('rgb', 'rgba'): assert(True) assert(bpp == 32) meta.pf_flags |= DDPF_RGB meta.pf_rgbBitCount = 32 meta.pf_rBitMask = 0x00ff0000 meta.pf_gBitMask = 0x0000ff00 meta.pf_bBitMask = 0x000000ff meta.pf_aBitMask = 0x00000000 if fmt == 'rgba': meta.pf_flags |= DDPF_ALPHAPIXELS meta.pf_aBitMask = 0xff000000 else: meta.pf_flags |= DDPF_FOURCC if fmt == 'dxt1': meta.pf_fourcc = DDS_DXT1 elif fmt == 'dxt2': meta.pf_fourcc = DDS_DXT2 elif fmt == 'dxt3': meta.pf_fourcc = DDS_DXT3 elif fmt == 'dxt4': meta.pf_fourcc = DDS_DXT4 elif fmt == 'dxt5': meta.pf_fourcc = DDS_DXT5 images.append(data) else: assert(level == len(images)) assert(fmt == self._fmt) images.append(data) meta.flags |= DDSD_MIPMAPCOUNT meta.caps1 |= DDSCAPS_COMPLEX | DDSCAPS_MIPMAP meta.mipmapCount = len(images) def __repr__(self): return '<DDSFile filename=%r size=%r dxt=%r len(images)=%r>' % ( self.filename, self.size, self.dxt, len(self.images)) def _get_size(self): meta = self.meta return meta.width, meta.height def _set_size(self, size): self.meta.update({'width': size[0], 'height': size[1]}) size = property(_get_size, _set_size) def _get_dxt(self): return dxt_to_str(self._dxt) def _set_dxt(self, dxt): self._dxt = str_to_dxt(dxt) dxt = property(_get_dxt, _set_dxt) if __name__ == '__main__': import sys if len(sys.argv) == 1: print('Usage: python ddsfile.py <file1> <file2> ...') sys.exit(0) for filename in sys.argv[1:]: print('=== Loading', filename) try: dds = DDSFile(filename=filename) print(dds) dds.save('bleh.dds') except IOError as e: print('ERR>', e) except DDSException as e: print('DDS>', e)