# # Copyright 2009 VMware, Inc. # Copyright 2014 Intel Corporation # All Rights Reserved. # # Permission is hereby granted, free of charge, to any person obtaining a # copy of this software and associated documentation files (the # "Software"), to deal in the Software without restriction, including # without limitation the rights to use, copy, modify, merge, publish, # distribute, sub license, and/or sell copies of the Software, and to # permit persons to whom the Software is furnished to do so, subject to # the following conditions: # # The above copyright notice and this permission notice (including the # next paragraph) shall be included in all copies or substantial portions # of the Software. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS # OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. # IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR # ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, # TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE # SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. import sys VOID = 'x' UNSIGNED = 'u' SIGNED = 's' FLOAT = 'f' ARRAY = 'array' PACKED = 'packed' OTHER = 'other' RGB = 'rgb' SRGB = 'srgb' YUV = 'yuv' ZS = 'zs' VERY_LARGE = 99999999999999999999999 class Channel: """Describes a color channel.""" def __init__(self, type, norm, size): self.type = type self.norm = norm self.size = size self.sign = type in (SIGNED, FLOAT) self.name = None # Set when the channels are added to the format self.shift = -1 # Set when the channels are added to the format self.index = -1 # Set when the channels are added to the format def __str__(self): s = str(self.type) if self.norm: s += 'n' s += str(self.size) return s def __eq__(self, other): return self.type == other.type and self.norm == other.norm and self.size == other.size def max(self): """Returns the maximum representable number.""" if self.type == FLOAT: return VERY_LARGE if self.norm: return 1 if self.type == UNSIGNED: return (1 << self.size) - 1 if self.type == SIGNED: return (1 << (self.size - 1)) - 1 assert False def min(self): """Returns the minimum representable number.""" if self.type == FLOAT: return -VERY_LARGE if self.type == UNSIGNED: return 0 if self.norm: return -1 if self.type == SIGNED: return -(1 << (self.size - 1)) assert False def one(self): """Returns the value that represents 1.0f.""" if self.type == UNSIGNED: return (1 << self.size) - 1 if self.type == SIGNED: return (1 << (self.size - 1)) - 1 else: return 1 def datatype(self): """Returns the datatype corresponding to a channel type and size""" return _get_datatype(self.type, self.size) class Swizzle: """Describes a swizzle operation. A Swizzle is a mapping from one set of channels in one format to the channels in another. Each channel in the destination format is associated with one of the following constants: * SWIZZLE_X: The first channel in the source format * SWIZZLE_Y: The second channel in the source format * SWIZZLE_Z: The third channel in the source format * SWIZZLE_W: The fourth channel in the source format * SWIZZLE_ZERO: The numeric constant 0 * SWIZZLE_ONE: THe numeric constant 1 * SWIZZLE_NONE: No data available for this channel Sometimes a Swizzle is represented by a 4-character string. In this case, the source channels are represented by the characters "x", "y", "z", and "w"; the numeric constants are represented as "0" and "1"; and no mapping is represented by "_". For instance, the map from luminance-alpha to rgba is given by "xxxy" because each of the three rgb channels maps to the first luminance-alpha channel and the alpha channel maps to second luminance-alpha channel. The mapping from bgr to rgba is given by "zyx1" because the first three colors are reversed and alpha is always 1. """ __identity_str = 'xyzw01_' SWIZZLE_X = 0 SWIZZLE_Y = 1 SWIZZLE_Z = 2 SWIZZLE_W = 3 SWIZZLE_ZERO = 4 SWIZZLE_ONE = 5 SWIZZLE_NONE = 6 def __init__(self, swizzle): """Creates a Swizzle object from a string or array.""" if isinstance(swizzle, str): swizzle = [Swizzle.__identity_str.index(c) for c in swizzle] else: swizzle = list(swizzle) for s in swizzle: assert isinstance(s, int) and 0 <= s and s <= Swizzle.SWIZZLE_NONE assert len(swizzle) <= 4 self.__list = swizzle + [Swizzle.SWIZZLE_NONE] * (4 - len(swizzle)) assert len(self.__list) == 4 def __iter__(self): """Returns an iterator that iterates over this Swizzle. The values that the iterator produces are described by the SWIZZLE_* constants. """ return self.__list.__iter__() def __str__(self): """Returns a string representation of this Swizzle.""" return ''.join(Swizzle.__identity_str[i] for i in self.__list) def __getitem__(self, idx): """Returns the SWIZZLE_* constant for the given destination channel. Valid values for the destination channel include any of the SWIZZLE_* constants or any of the following single-character strings: "x", "y", "z", "w", "r", "g", "b", "a", "z" "s". """ if isinstance(idx, int): assert idx >= Swizzle.SWIZZLE_X and idx <= Swizzle.SWIZZLE_NONE if idx <= Swizzle.SWIZZLE_W: return self.__list.__getitem__(idx) else: return idx elif isinstance(idx, str): if idx in 'xyzw': idx = 'xyzw'.find(idx) elif idx in 'rgba': idx = 'rgba'.find(idx) elif idx in 'zs': idx = 'zs'.find(idx) else: assert False return self.__list.__getitem__(idx) else: assert False def __mul__(self, other): """Returns the composition of this Swizzle with another Swizzle. The resulting swizzle is such that, for any valid input to __getitem__, (a * b)[i] = a[b[i]]. """ assert isinstance(other, Swizzle) return Swizzle(self[x] for x in other) def inverse(self): """Returns a pseudo-inverse of this swizzle. Since swizzling isn't necisaraly a bijection, a Swizzle can never be truely inverted. However, the swizzle returned is *almost* the inverse of this swizzle in the sense that, for each i in range(3), a[a.inverse()[i]] is either i or SWIZZLE_NONE. If swizzle is just a permutation with no channels added or removed, then this function returns the actual inverse. This "pseudo-inverse" idea can be demonstrated by mapping from luminance-alpha to rgba that is given by "xxxy". To get from rgba to lumanence-alpha, we use Swizzle("xxxy").inverse() or "xw__". This maps the first component in the lumanence-alpha texture is the red component of the rgba image and the second to the alpha component, exactly as you would expect. """ rev = [Swizzle.SWIZZLE_NONE] * 4 for i in range(4): for j in range(4): if self.__list[j] == i and rev[i] == Swizzle.SWIZZLE_NONE: rev[i] = j return Swizzle(rev) class Format: """Describes a pixel format.""" def __init__(self, name, layout, block_width, block_height, block_depth, channels, swizzle, colorspace): """Constructs a Format from some metadata and a list of channels. The channel objects must be unique to this Format and should not be re-used to construct another Format. This is because certain channel information such as shift, offset, and the channel name are set when the Format is created and are calculated based on the entire list of channels. Arguments: name -- Name of the format such as 'MESA_FORMAT_A8R8G8B8' layout -- One of 'array', 'packed' 'other', or a compressed layout block_width -- The block width if the format is compressed, 1 otherwise block_height -- The block height if the format is compressed, 1 otherwise block_depth -- The block depth if the format is compressed, 1 otherwise channels -- A list of Channel objects swizzle -- A Swizzle from this format to rgba colorspace -- one of 'rgb', 'srgb', 'yuv', or 'zs' """ self.name = name self.layout = layout self.block_width = block_width self.block_height = block_height self.block_depth = block_depth self.channels = channels assert isinstance(swizzle, Swizzle) self.swizzle = swizzle self.name = name assert colorspace in (RGB, SRGB, YUV, ZS) self.colorspace = colorspace # Name the channels chan_names = ['']*4 if self.colorspace in (RGB, SRGB): for (i, s) in enumerate(swizzle): if s < 4: chan_names[s] += 'rgba'[i] elif colorspace == ZS: for (i, s) in enumerate(swizzle): if s < 4: chan_names[s] += 'zs'[i] else: chan_names = ['x', 'y', 'z', 'w'] for c, name in zip(self.channels, chan_names): assert c.name is None if name == 'rgb': c.name = 'l' elif name == 'rgba': c.name = 'i' elif name == '': c.name = 'x' else: c.name = name # Set indices and offsets if self.layout == PACKED: shift = 0 for channel in self.channels: assert channel.shift == -1 channel.shift = shift shift += channel.size for idx, channel in enumerate(self.channels): assert channel.index == -1 channel.index = idx else: pass # Shift means nothing here def __str__(self): return self.name def short_name(self): """Returns a short name for a format. The short name should be suitable to be used as suffix in function names. """ name = self.name if name.startswith('MESA_FORMAT_'): name = name[len('MESA_FORMAT_'):] name = name.lower() return name def block_size(self): """Returns the block size (in bits) of the format.""" size = 0 for channel in self.channels: size += channel.size return size def num_channels(self): """Returns the number of channels in the format.""" nr_channels = 0 for channel in self.channels: if channel.size: nr_channels += 1 return nr_channels def array_element(self): """Returns a non-void channel if this format is an array, otherwise None. If the returned channel is not None, then this format can be considered to be an array of num_channels() channels identical to the returned channel. """ if self.layout == ARRAY: return self.channels[0] elif self.layout == PACKED: ref_channel = self.channels[0] if ref_channel.type == VOID: ref_channel = self.channels[1] for channel in self.channels: if channel.size == 0 or channel.type == VOID: continue if channel.size != ref_channel.size or channel.size % 8 != 0: return None if channel.type != ref_channel.type: return None if channel.norm != ref_channel.norm: return None return ref_channel else: return None def is_array(self): """Returns true if this format can be considered an array format. This function will return true if self.layout == 'array'. However, some formats, such as MESA_FORMAT_A8G8B8R8, can be considered as array formats even though they are technically packed. """ return self.array_element() != None def is_compressed(self): """Returns true if this is a compressed format.""" return self.block_width != 1 or self.block_height != 1 or self.block_depth != 1 def is_int(self): """Returns true if this format is an integer format. See also: is_norm() """ if self.layout not in (ARRAY, PACKED): return False for channel in self.channels: if channel.type not in (VOID, UNSIGNED, SIGNED): return False return True def is_float(self): """Returns true if this format is an floating-point format.""" if self.layout not in (ARRAY, PACKED): return False for channel in self.channels: if channel.type not in (VOID, FLOAT): return False return True def channel_type(self): """Returns the type of the channels in this format.""" _type = VOID for c in self.channels: if c.type == VOID: continue if _type == VOID: _type = c.type assert c.type == _type return _type def channel_size(self): """Returns the size (in bits) of the channels in this format. This function should only be called if all of the channels have the same size. This is always the case if is_array() returns true. """ size = None for c in self.channels: if c.type == VOID: continue if size is None: size = c.size assert c.size == size return size def max_channel_size(self): """Returns the size of the largest channel.""" size = 0 for c in self.channels: if c.type == VOID: continue size = max(size, c.size) return size def is_normalized(self): """Returns true if this format is normalized. While only integer formats can be normalized, not all integer formats are normalized. Normalized integer formats are those where the integer value is re-interpreted as a fixed point value in the range [0, 1]. """ norm = None for c in self.channels: if c.type == VOID: continue if norm is None: norm = c.norm assert c.norm == norm return norm def has_channel(self, name): """Returns true if this format has the given channel.""" if self.is_compressed(): # Compressed formats are a bit tricky because the list of channels # contains a single channel of type void. Since we don't have any # channel information there, we pull it from the swizzle. if str(self.swizzle) == 'xxxx': return name == 'i' elif str(self.swizzle)[0:3] in ('xxx', 'yyy'): if name == 'l': return True elif name == 'a': return self.swizzle['a'] <= Swizzle.SWIZZLE_W else: return False elif name in 'rgba': return self.swizzle[name] <= Swizzle.SWIZZLE_W else: return False else: for channel in self.channels: if channel.name == name: return True return False def get_channel(self, name): """Returns the channel with the given name if it exists.""" for channel in self.channels: if channel.name == name: return channel return None def datatype(self): """Returns the datatype corresponding to a format's channel type and size""" if self.layout == PACKED: if self.block_size() == 8: return 'uint8_t' if self.block_size() == 16: return 'uint16_t' if self.block_size() == 32: return 'uint32_t' else: assert False else: return _get_datatype(self.channel_type(), self.channel_size()) def _get_datatype(type, size): if type == FLOAT: if size == 32: return 'float' elif size == 16: return 'uint16_t' else: assert False elif type == UNSIGNED: if size <= 8: return 'uint8_t' elif size <= 16: return 'uint16_t' elif size <= 32: return 'uint32_t' else: assert False elif type == SIGNED: if size <= 8: return 'int8_t' elif size <= 16: return 'int16_t' elif size <= 32: return 'int32_t' else: assert False else: assert False def _parse_channels(fields, layout, colorspace, swizzle): channels = [] for field in fields: if not field: continue type = field[0] if field[0] else 'x' if field[1] == 'n': norm = True size = int(field[2:]) else: norm = False size = int(field[1:]) channel = Channel(type, norm, size) channels.append(channel) return channels def parse(filename): """Parse a format description in CSV format. This function parses the given CSV file and returns an iterable of channels.""" with open(filename) as stream: for line in stream: try: comment = line.index('#') except ValueError: pass else: line = line[:comment] line = line.strip() if not line: continue fields = [field.strip() for field in line.split(',')] name = fields[0] layout = fields[1] block_width = int(fields[2]) block_height = int(fields[3]) block_depth = int(fields[4]) colorspace = fields[10] try: swizzle = Swizzle(fields[9]) except: sys.exit("error parsing swizzle for format " + name) channels = _parse_channels(fields[5:9], layout, colorspace, swizzle) yield Format(name, layout, block_width, block_height, block_depth, channels, swizzle, colorspace)