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.type == FIXED:
  77             return (1 << (self.size/2)) - 1
  78         if self.norm:
  79             return 1
  80         if self.type == UNSIGNED:
  81             return (1 << self.size) - 1
  82         if self.type == SIGNED:
  83             return (1 << (self.size - 1)) - 1
  84         assert False
  85
  86     def min(self):
  87         '''Minimum representable number.'''
  88         if self.type == FLOAT:
  89             return -VERY_LARGE
  90         if self.type == FIXED:
  91             return -(1 << (self.size/2))
  92         if self.type == UNSIGNED:
  93             return 0
  94         if self.norm:
  95             return -1
  96         if self.type == SIGNED:
  97             return -(1 << (self.size - 1))
  98         assert False
  99
 100
 101 class Format:
 102     '''Describe a pixel format.'''
 103
 104     def __init__(self, name, layout, block_width, block_height, channels, swizzles, colorspace):
 105         self.name = name
 106         self.layout = layout
 107         self.block_width = block_width
 108         self.block_height = block_height
 109         self.channels = channels
 110         self.swizzles = swizzles
 111         self.name = name
 112         self.colorspace = colorspace
 113
 114     def __str__(self):
 115         return self.name
 116
 117     def short_name(self):
 118         '''Make up a short norm for a format, suitable to be used as suffix in
 119         function names.'''
 120
 121         name = self.name
 122         if name.startswith('PIPE_FORMAT_'):
 123             name = name[len('PIPE_FORMAT_'):]
 124         name = name.lower()
 125         return name
 126
 127     def block_size(self):
 128         size = 0
 129         for channel in self.channels:
 130             size += channel.size
 131         return size
 132
 133     def nr_channels(self):
 134         nr_channels = 0
 135         for channel in self.channels:
 136             if channel.size:
 137                 nr_channels += 1
 138         return nr_channels
 139
 140     def is_array(self):
 141         if self.layout != PLAIN:
 142             return False
 143         ref_channel = self.channels[0]
 144         for channel in self.channels[1:]:
 145             if channel.size and (channel.size != ref_channel.size or channel.size % 8):
 146                 return False
 147         return True
 148
 149     def is_mixed(self):
 150         if self.layout != PLAIN:
 151             return False
 152         ref_channel = self.channels[0]
 153         if ref_channel.type == VOID:
 154            ref_channel = self.channels[1]
 155         for channel in self.channels[1:]:
 156             if channel.type != VOID:
 157                 if channel.type != ref_channel.type:
 158                     return True
 159                 if channel.norm != ref_channel.norm:
 160                     return True
 161         return False
 162
 163     def is_pot(self):
 164         return is_pot(self.block_size())
 165
 166     def is_int(self):
 167         if self.layout != PLAIN:
 168             return False
 169         for channel in self.channels:
 170             if channel.type not in (VOID, UNSIGNED, SIGNED):
 171                 return False
 172         return True
 173
 174     def is_float(self):
 175         if self.layout != PLAIN:
 176             return False
 177         for channel in self.channels:
 178             if channel.type not in (VOID, FLOAT):
 179                 return False
 180         return True
 181
 182     def is_bitmask(self):
 183         if self.layout != PLAIN:
 184             return False
 185         if self.block_size() not in (8, 16, 32):
 186             return False
 187         for channel in self.channels:
 188             if channel.type not in (VOID, UNSIGNED, SIGNED):
 189                 return False
 190         return True
 191
 192     def inv_swizzles(self):
 193         '''Return an array[4] of inverse swizzle terms'''
 194         inv_swizzle = [None]*4
 195         for i in range(4):
 196             swizzle = self.swizzles[i]
 197             if swizzle < 4:
 198                 inv_swizzle[swizzle] = i
 199         return inv_swizzle
 200
 201     def stride(self):
 202         return self.block_size()/8
 203
 204
 205 _type_parse_map = {
 206     '':  VOID,
 207     'x': VOID,
 208     'u': UNSIGNED,
 209     's': SIGNED,
 210     'h': FIXED,
 211     'f': FLOAT,
 212 }
 213
 214 _swizzle_parse_map = {
 215     'x': SWIZZLE_X,
 216     'y': SWIZZLE_Y,
 217     'z': SWIZZLE_Z,
 218     'w': SWIZZLE_W,
 219     '0': SWIZZLE_0,
 220     '1': SWIZZLE_1,
 221     '_': SWIZZLE_NONE,
 222 }
 223
 224 def parse(filename):
 225     '''Parse the format descrition in CSV format in terms of the
 226     Channel and Format classes above.'''
 227
 228     stream = open(filename)
 229     formats = []
 230     for line in stream:
 231         try:
 232             comment = line.index('#')
 233         except ValueError:
 234             pass
 235         else:
 236             line = line[:comment]
 237         line = line.strip()
 238         if not line:
 239             continue
 240
 241         fields = [field.strip() for field in line.split(',')]
 242
 243         name = fields[0]
 244         layout = fields[1]
 245         block_width, block_height = map(int, fields[2:4])
 246
 247         swizzles = [_swizzle_parse_map[swizzle] for swizzle in fields[8]]
 248         colorspace = fields[9]
 249
 250         if layout == PLAIN:
 251             names = ['']*4
 252             if colorspace in (RGB, SRGB):
 253                 for i in range(4):
 254                     swizzle = swizzles[i]
 255                     if swizzle < 4:
 256                         names[swizzle] += 'rgba'[i]
 257             elif colorspace == ZS:
 258                 for i in range(4):
 259                     swizzle = swizzles[i]
 260                     if swizzle < 4:
 261                         names[swizzle] += 'zs'[i]
 262             else:
 263                 assert False
 264             for i in range(4):
 265                 if names[i] == '':
 266                     names[i] = 'x'
 267         else:
 268             names = ['x', 'y', 'z', 'w']
 269
 270         channels = []
 271         for i in range(0, 4):
 272             field = fields[4 + i]
 273             if field:
 274                 type = _type_parse_map[field[0]]
 275                 if field[1] == 'n':
 276                     norm = True
 277                     size = int(field[2:])
 278                 else:
 279                     norm = False
 280                     size = int(field[1:])
 281             else:
 282                 type = VOID
 283                 norm = False
 284                 size = 0
 285             channel = Channel(type, norm, size, names[i])
 286             channels.append(channel)
 287
 288         format = Format(name, layout, block_width, block_height, channels, swizzles, colorspace)
 289         formats.append(format)
 290     return formats
 291