src/gallium/auxiliary/util/u_format_parse.py

   1 #!/usr/bin/env python
   2
   3 '''
   4 /**************************************************************************
   5  *
   6  * Copyright 2009 VMware, Inc.
   7  * All Rights Reserved.
   8  *
   9  * Permission is hereby granted, free of charge, to any person obtaining a
  10  * copy of this software and associated documentation files (the
  11  * "Software"), to deal in the Software without restriction, including
  12  * without limitation the rights to use, copy, modify, merge, publish,
  13  * distribute, sub license, and/or sell copies of the Software, and to
  14  * permit persons to whom the Software is furnished to do so, subject to
  15  * the following conditions:
  16  *
  17  * The above copyright notice and this permission notice (including the
  18  * next paragraph) shall be included in all copies or substantial portions
  19  * of the Software.
  20  *
  21  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  22  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  24  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  25  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  26  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  27  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28  *
  29  **************************************************************************/
  30 '''
  31
  32
  33 VOID, UNSIGNED, SIGNED, FIXED, FLOAT = range(5)
  34
  35 SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_W, SWIZZLE_0, SWIZZLE_1, SWIZZLE_NONE, = range(7)
  36
  37 PLAIN = 'plain'
  38
  39 RGB = 'rgb'
  40 SRGB = 'srgb'
  41 YUV = 'yuv'
  42 ZS = 'zs'
  43
  44
  45 def is_pot(x):
  46    return (x & (x - 1)) == 0;
  47
  48
  49 VERY_LARGE = 99999999999999999999999
  50
  51
  52 class Channel:
  53     '''Describe the channel of a color channel.'''
  54
  55     def __init__(self, type, norm, size, name = ''):
  56         self.type = type
  57         self.norm = norm
  58         self.size = size
  59         self.sign = type in (SIGNED, FIXED, FLOAT)
  60         self.name = name
  61
  62     def __str__(self):
  63         s = str(self.type)
  64         if self.norm:
  65             s += 'n'
  66         s += str(self.size)
  67         return s
  68
  69     def __eq__(self, other):
  70         return self.type == other.type and self.norm == other.norm and self.size == other.size
  71
  72     def max(self):
  73         '''Maximum representable number.'''
  74         if self.type == FLOAT:
  75             return VERY_LARGE
  76         if self.norm:
  77             return 1
  78         if self.type == UNSIGNED:
  79             return (1 << self.size) - 1
  80         if self.type == SIGNED:
  81             return (1 << (self.size - 1)) - 1
  82         assert False
  83
  84     def min(self):
  85         '''Minimum representable number.'''
  86         if self.type == FLOAT:
  87             return -VERY_LARGE
  88         if self.type == UNSIGNED:
  89             return 0
  90         if self.norm:
  91             return -1
  92         if self.type == SIGNED:
  93             return -(1 << (self.size - 1))
  94         assert False
  95
  96
  97 class Format:
  98     '''Describe a pixel format.'''
  99
 100     def __init__(self, name, layout, block_width, block_height, channels, swizzles, colorspace):
 101         self.name = name
 102         self.layout = layout
 103         self.block_width = block_width
 104         self.block_height = block_height
 105         self.channels = channels
 106         self.swizzles = swizzles
 107         self.name = name
 108         self.colorspace = colorspace
 109
 110     def __str__(self):
 111         return self.name
 112
 113     def short_name(self):
 114         '''Make up a short norm for a format, suitable to be used as suffix in
 115         function names.'''
 116
 117         name = self.name
 118         if name.startswith('PIPE_FORMAT_'):
 119             name = name[len('PIPE_FORMAT_'):]
 120         name = name.lower()
 121         return name
 122
 123     def block_size(self):
 124         size = 0
 125         for channel in self.channels:
 126             size += channel.size
 127         return size
 128
 129     def nr_channels(self):
 130         nr_channels = 0
 131         for channel in self.channels:
 132             if channel.size:
 133                 nr_channels += 1
 134         return nr_channels
 135
 136     def is_array(self):
 137         ref_channel = self.channels[0]
 138         for channel in self.channels[1:]:
 139             if channel.size and (channel.size != ref_channel.size or channel.size % 8):
 140                 return False
 141         return True
 142
 143     def is_mixed(self):
 144         ref_channel = self.channels[0]
 145         if ref_channel.type == VOID:
 146            ref_channel = self.channels[1]
 147         for channel in self.channels[1:]:
 148             if channel.type != VOID:
 149                 if channel.type != ref_channel.type:
 150                     return True
 151                 if channel.norm != ref_channel.norm:
 152                     return True
 153         return False
 154
 155     def is_pot(self):
 156         return is_pot(self.block_size())
 157
 158     def is_int(self):
 159         for channel in self.channels:
 160             if channel.type not in (VOID, UNSIGNED, SIGNED):
 161                 return False
 162         return True
 163
 164     def is_float(self):
 165         for channel in self.channels:
 166             if channel.type not in (VOID, FLOAT):
 167                 return False
 168         return True
 169
 170     def is_bitmask(self):
 171         if self.block_size() not in (8, 16, 32):
 172             return False
 173         for channel in self.channels:
 174             if channel.type not in (VOID, UNSIGNED, SIGNED):
 175                 return False
 176         return True
 177
 178     def inv_swizzles(self):
 179         '''Return an array[4] of inverse swizzle terms'''
 180         inv_swizzle = [None]*4
 181         for i in range(4):
 182             swizzle = self.swizzles[i]
 183             if swizzle < 4:
 184                 inv_swizzle[swizzle] = i
 185         return inv_swizzle
 186
 187     def stride(self):
 188         return self.block_size()/8
 189
 190
 191 _type_parse_map = {
 192     '':  VOID,
 193     'x': VOID,
 194     'u': UNSIGNED,
 195     's': SIGNED,
 196     'h': FIXED,
 197     'f': FLOAT,
 198 }
 199
 200 _swizzle_parse_map = {
 201     'x': SWIZZLE_X,
 202     'y': SWIZZLE_Y,
 203     'z': SWIZZLE_Z,
 204     'w': SWIZZLE_W,
 205     '0': SWIZZLE_0,
 206     '1': SWIZZLE_1,
 207     '_': SWIZZLE_NONE,
 208 }
 209
 210 def parse(filename):
 211     '''Parse the format descrition in CSV format in terms of the
 212     Channel and Format classes above.'''
 213
 214     stream = open(filename)
 215     formats = []
 216     for line in stream:
 217         try:
 218             comment = line.index('#')
 219         except ValueError:
 220             pass
 221         else:
 222             line = line[:comment]
 223         line = line.strip()
 224         if not line:
 225             continue
 226
 227         fields = [field.strip() for field in line.split(',')]
 228
 229         name = fields[0]
 230         layout = fields[1]
 231         block_width, block_height = map(int, fields[2:4])
 232
 233         swizzles = [_swizzle_parse_map[swizzle] for swizzle in fields[8]]
 234         colorspace = fields[9]
 235
 236         if layout == PLAIN:
 237             names = ['']*4
 238             if colorspace in (RGB, SRGB):
 239                 for i in range(4):
 240                     swizzle = swizzles[i]
 241                     if swizzle < 4:
 242                         names[swizzle] += 'rgba'[i]
 243             elif colorspace == ZS:
 244                 for i in range(4):
 245                     swizzle = swizzles[i]
 246                     if swizzle < 4:
 247                         names[swizzle] += 'zs'[i]
 248             else:
 249                 assert False
 250             for i in range(4):
 251                 if names[i] == '':
 252                     names[i] = 'x'
 253         else:
 254             names = ['x', 'y', 'z', 'w']
 255
 256         channels = []
 257         for i in range(0, 4):
 258             field = fields[4 + i]
 259             if field:
 260                 type = _type_parse_map[field[0]]
 261                 if field[1] == 'n':
 262                     norm = True
 263                     size = int(field[2:])
 264                 else:
 265                     norm = False
 266                     size = int(field[1:])
 267             else:
 268                 type = VOID
 269                 norm = False
 270                 size = 0
 271             channel = Channel(type, norm, size, names[i])
 272             channels.append(channel)
 273
 274         format = Format(name, layout, block_width, block_height, channels, swizzles, colorspace)
 275         formats.append(format)
 276     return formats
 277