PLAIN = 'plain'
+RGB = 'rgb'
+SRGB = 'srgb'
+YUV = 'yuv'
+ZS = 'zs'
+
def is_pot(x):
- return (x & (x - 1)) == 0;
+ return (x & (x - 1)) == 0
+
+
+VERY_LARGE = 99999999999999999999999
class Channel:
'''Describe the channel of a color channel.'''
- def __init__(self, type, norm, size):
+ def __init__(self, type, norm, size, name = ''):
self.type = type
self.norm = norm
self.size = size
self.sign = type in (SIGNED, FIXED, FLOAT)
+ self.name = name
def __str__(self):
s = str(self.type)
def __eq__(self, other):
return self.type == other.type and self.norm == other.norm and self.size == other.size
+ def max(self):
+ '''Maximum representable number.'''
+ if self.type == FLOAT:
+ return VERY_LARGE
+ if self.type == FIXED:
+ return (1 << (self.size/2)) - 1
+ 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):
+ '''Minimum representable number.'''
+ if self.type == FLOAT:
+ return -VERY_LARGE
+ if self.type == FIXED:
+ return -(1 << (self.size/2))
+ if self.type == UNSIGNED:
+ return 0
+ if self.norm:
+ return -1
+ if self.type == SIGNED:
+ return -(1 << (self.size - 1))
+ assert False
+
class Format:
'''Describe a pixel format.'''
return nr_channels
def is_array(self):
+ if self.layout != PLAIN:
+ return False
ref_channel = self.channels[0]
for channel in self.channels[1:]:
if channel.size and (channel.size != ref_channel.size or channel.size % 8):
return True
def is_mixed(self):
+ if self.layout != PLAIN:
+ return False
ref_channel = self.channels[0]
+ if ref_channel.type == VOID:
+ ref_channel = self.channels[1]
for channel in self.channels[1:]:
if channel.type != VOID:
if channel.type != ref_channel.type:
return is_pot(self.block_size())
def is_int(self):
+ if self.layout != PLAIN:
+ return False
for channel in self.channels:
if channel.type not in (VOID, UNSIGNED, SIGNED):
return False
return True
def is_float(self):
+ if self.layout != PLAIN:
+ return False
for channel in self.channels:
if channel.type not in (VOID, FLOAT):
return False
return True
+ def is_bitmask(self):
+ if self.layout != PLAIN:
+ return False
+ if self.block_size() not in (8, 16, 32):
+ return False
+ for channel in self.channels:
+ if channel.type not in (VOID, UNSIGNED, SIGNED):
+ return False
+ return True
+
+ def inv_swizzles(self):
+ '''Return an array[4] of inverse swizzle terms'''
+ inv_swizzle = [None]*4
+ for i in range(4):
+ swizzle = self.swizzles[i]
+ if swizzle < 4:
+ inv_swizzle[swizzle] = i
+ return inv_swizzle
+
def stride(self):
return self.block_size()/8
line = line.strip()
if not line:
continue
+
fields = [field.strip() for field in line.split(',')]
+
name = fields[0]
layout = fields[1]
block_width, block_height = map(int, fields[2:4])
+
+ swizzles = [_swizzle_parse_map[swizzle] for swizzle in fields[8]]
+ colorspace = fields[9]
+
+ if layout == PLAIN:
+ names = ['']*4
+ if colorspace in (RGB, SRGB):
+ for i in range(4):
+ swizzle = swizzles[i]
+ if swizzle < 4:
+ names[swizzle] += 'rgba'[i]
+ elif colorspace == ZS:
+ for i in range(4):
+ swizzle = swizzles[i]
+ if swizzle < 4:
+ names[swizzle] += 'zs'[i]
+ else:
+ assert False
+ for i in range(4):
+ if names[i] == '':
+ names[i] = 'x'
+ else:
+ names = ['x', 'y', 'z', 'w']
+
channels = []
- for field in fields[4:8]:
+ for i in range(0, 4):
+ field = fields[4 + i]
if field:
type = _type_parse_map[field[0]]
if field[1] == 'n':
type = VOID
norm = False
size = 0
- channel = Channel(type, norm, size)
+ channel = Channel(type, norm, size, names[i])
channels.append(channel)
- swizzles = [_swizzle_parse_map[swizzle] for swizzle in fields[8]]
- colorspace = fields[9]
- formats.append(Format(name, layout, block_width, block_height, channels, swizzles, colorspace))
+
+ format = Format(name, layout, block_width, block_height, channels, swizzles, colorspace)
+ formats.append(format)
return formats