src/gallium/auxiliary/util/u_format_pack.py

   1 #!/usr/bin/env python
   2
   3 '''
   4 /**************************************************************************
   5  *
   6  * Copyright 2009-2010 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  * @file
  33  * Pixel format packing and unpacking functions.
  34  *
  35  * @author Jose Fonseca <jfonseca@vmware.com>
  36  */
  37 '''
  38
  39
  40 from u_format_parse import *
  41
  42
  43 def generate_format_type(format):
  44     '''Generate a structure that describes the format.'''
  45
  46     assert format.layout == PLAIN
  47
  48     print 'union util_format_%s {' % format.short_name()
  49
  50     if format.block_size() in (8, 16, 32, 64):
  51         print '   uint%u_t value;' % (format.block_size(),)
  52
  53     use_bitfields = False
  54     for channel in format.channels:
  55         if channel.size % 8 or not is_pot(channel.size):
  56             use_bitfields = True
  57
  58     print '   struct {'
  59     for channel in format.channels:
  60         if use_bitfields:
  61             if channel.type == VOID:
  62                 if channel.size:
  63                     print '      unsigned %s:%u;' % (channel.name, channel.size)
  64             elif channel.type == UNSIGNED:
  65                 print '      unsigned %s:%u;' % (channel.name, channel.size)
  66             elif channel.type in (SIGNED, FIXED):
  67                 print '      int %s:%u;' % (channel.name, channel.size)
  68             elif channel.type == FLOAT:
  69                 if channel.size == 64:
  70                     print '      double %s;' % (channel.name)
  71                 elif channel.size == 32:
  72                     print '      float %s;' % (channel.name)
  73                 else:
  74                     print '      unsigned %s:%u;' % (channel.name, channel.size)
  75             else:
  76                 assert 0
  77         else:
  78             assert channel.size % 8 == 0 and is_pot(channel.size)
  79             if channel.type == VOID:
  80                 if channel.size:
  81                     print '      uint%u_t %s;' % (channel.size, channel.name)
  82             elif channel.type == UNSIGNED:
  83                 print '      uint%u_t %s;' % (channel.size, channel.name)
  84             elif channel.type in (SIGNED, FIXED):
  85                 print '      int%u_t %s;' % (channel.size, channel.name)
  86             elif channel.type == FLOAT:
  87                 if channel.size == 64:
  88                     print '      double %s;' % (channel.name)
  89                 elif channel.size == 32:
  90                     print '      float %s;' % (channel.name)
  91                 elif channel.size == 16:
  92                     print '      uint16_t %s;' % (channel.name)
  93                 else:
  94                     assert 0
  95             else:
  96                 assert 0
  97     print '   } chan;'
  98     print '};'
  99     print
 100
 101
 102 def bswap_format(format):
 103     '''Generate a structure that describes the format.'''
 104
 105     if format.is_bitmask() and not format.is_array() and format.block_size() > 8:
 106         print '#ifdef PIPE_ARCH_BIG_ENDIAN'
 107         print '   pixel.value = util_bswap%u(pixel.value);' % format.block_size()
 108         print '#endif'
 109
 110
 111 def is_format_supported(format):
 112     '''Determines whether we actually have the plumbing necessary to generate the
 113     to read/write to/from this format.'''
 114
 115     # FIXME: Ideally we would support any format combination here.
 116
 117     if format.layout != PLAIN:
 118         return False
 119
 120     for i in range(4):
 121         channel = format.channels[i]
 122         if channel.type not in (VOID, UNSIGNED, SIGNED, FLOAT, FIXED):
 123             return False
 124         if channel.type == FLOAT and channel.size not in (16, 32, 64):
 125             return False
 126
 127     return True
 128
 129
 130 def native_type(format):
 131     '''Get the native appropriate for a format.'''
 132
 133     if format.layout == PLAIN:
 134         if not format.is_array():
 135             # For arithmetic pixel formats return the integer type that matches the whole pixel
 136             return 'uint%u_t' % format.block_size()
 137         else:
 138             # For array pixel formats return the integer type that matches the color channel
 139             channel = format.channels[0]
 140             if channel.type in (UNSIGNED, VOID):
 141                 return 'uint%u_t' % channel.size
 142             elif channel.type in (SIGNED, FIXED):
 143                 return 'int%u_t' % channel.size
 144             elif channel.type == FLOAT:
 145                 if channel.size == 16:
 146                     return 'uint16_t'
 147                 elif channel.size == 32:
 148                     return 'float'
 149                 elif channel.size == 64:
 150                     return 'double'
 151                 else:
 152                     assert False
 153             else:
 154                 assert False
 155     else:
 156         assert False
 157
 158
 159 def intermediate_native_type(bits, sign):
 160     '''Find a native type adequate to hold intermediate results of the request bit size.'''
 161
 162     bytes = 4 # don't use anything smaller than 32bits
 163     while bytes * 8 < bits:
 164         bytes *= 2
 165     bits = bytes*8
 166
 167     if sign:
 168         return 'int%u_t' % bits
 169     else:
 170         return 'uint%u_t' % bits
 171
 172
 173 def get_one_shift(type):
 174     '''Get the number of the bit that matches unity for this type.'''
 175     if type.type == 'FLOAT':
 176         assert False
 177     if not type.norm:
 178         return 0
 179     if type.type == UNSIGNED:
 180         return type.size
 181     if type.type == SIGNED:
 182         return type.size - 1
 183     if type.type == FIXED:
 184         return type.size / 2
 185     assert False
 186
 187
 188 def value_to_native(type, value):
 189     '''Get the value of unity for this type.'''
 190     if type.type == FLOAT:
 191         return value
 192     if type.type == FIXED:
 193         return int(value * (1 << (type.size/2)))
 194     if not type.norm:
 195         return int(value)
 196     if type.type == UNSIGNED:
 197         return int(value * ((1 << type.size) - 1))
 198     if type.type == SIGNED:
 199         return int(value * ((1 << (type.size - 1)) - 1))
 200     assert False
 201
 202
 203 def native_to_constant(type, value):
 204     '''Get the value of unity for this type.'''
 205     if type.type == FLOAT:
 206         if type.size <= 32:
 207             return "%ff" % value
 208         else:
 209             return "%ff" % value
 210     else:
 211         return str(int(value))
 212
 213
 214 def get_one(type):
 215     '''Get the value of unity for this type.'''
 216     return value_to_native(type, 1)
 217
 218
 219 def clamp_expr(src_channel, dst_channel, dst_native_type, value):
 220     '''Generate the expression to clamp the value in the source type to the
 221     destination type range.'''
 222
 223     if src_channel == dst_channel:
 224         return value
 225
 226     src_min = src_channel.min()
 227     src_max = src_channel.max()
 228     dst_min = dst_channel.min()
 229     dst_max = dst_channel.max()
 230
 231     # Translate the destination range to the src native value
 232     dst_min_native = value_to_native(src_channel, dst_min)
 233     dst_max_native = value_to_native(src_channel, dst_max)
 234
 235     if src_min < dst_min and src_max > dst_max:
 236         return 'CLAMP(%s, %s, %s)' % (value, dst_min_native, dst_max_native)
 237
 238     if src_max > dst_max:
 239         return 'MIN2(%s, %s)' % (value, dst_max_native)
 240
 241     if src_min < dst_min:
 242         return 'MAX2(%s, %s)' % (value, dst_min_native)
 243
 244     return value
 245
 246
 247 def conversion_expr(src_channel,
 248                     dst_channel, dst_native_type,
 249                     value,
 250                     clamp=True,
 251                     src_colorspace = RGB,
 252                     dst_colorspace = RGB):
 253     '''Generate the expression to convert a value between two types.'''
 254
 255     if src_colorspace != dst_colorspace:
 256         if src_colorspace == SRGB:
 257             assert src_channel.type == UNSIGNED
 258             assert src_channel.norm
 259             assert src_channel.size == 8
 260             assert dst_colorspace == RGB
 261             if dst_channel.type == FLOAT:
 262                 return 'util_format_srgb_8unorm_to_linear_float(%s)' % value
 263             else:
 264                 assert dst_channel.type == UNSIGNED
 265                 assert dst_channel.norm
 266                 assert dst_channel.size == 8
 267                 return 'util_format_srgb_to_linear_8unorm(%s)' % value
 268         elif dst_colorspace == SRGB:
 269             assert dst_channel.type == UNSIGNED
 270             assert dst_channel.norm
 271             assert dst_channel.size == 8
 272             assert src_colorspace == RGB
 273             if src_channel.type == FLOAT:
 274                 return 'util_format_linear_float_to_srgb_8unorm(%s)' % value
 275             else:
 276                 assert src_channel.type == UNSIGNED
 277                 assert src_channel.norm
 278                 assert src_channel.size == 8
 279                 return 'util_format_linear_to_srgb_8unorm(%s)' % value
 280         elif src_colorspace == ZS:
 281             pass
 282         elif dst_colorspace == ZS:
 283             pass
 284         else:
 285             assert 0
 286
 287     if src_channel == dst_channel:
 288         return value
 289
 290     src_type = src_channel.type
 291     src_size = src_channel.size
 292     src_norm = src_channel.norm
 293
 294     # Promote half to float
 295     if src_type == FLOAT and src_size == 16:
 296         value = 'util_half_to_float(%s)' % value
 297         src_size = 32
 298
 299     # Special case for float <-> ubytes for more accurate results
 300     # Done before clamping since these functions already take care of that
 301     if src_type == UNSIGNED and src_norm and src_size == 8 and dst_channel.type == FLOAT and dst_channel.size == 32:
 302         return 'ubyte_to_float(%s)' % value
 303     if src_type == FLOAT and src_size == 32 and dst_channel.type == UNSIGNED and dst_channel.norm and dst_channel.size == 8:
 304         return 'float_to_ubyte(%s)' % value
 305
 306     if clamp:
 307         if dst_channel.type != FLOAT or src_type != FLOAT:
 308             value = clamp_expr(src_channel, dst_channel, dst_native_type, value)
 309
 310     if src_type in (SIGNED, UNSIGNED) and dst_channel.type in (SIGNED, UNSIGNED):
 311         if not src_norm and not dst_channel.norm:
 312             # neither is normalized -- just cast
 313             return '(%s)%s' % (dst_native_type, value)
 314
 315         src_one = get_one(src_channel)
 316         dst_one = get_one(dst_channel)
 317
 318         if src_one > dst_one and src_norm and dst_channel.norm:
 319             # We can just bitshift
 320             src_shift = get_one_shift(src_channel)
 321             dst_shift = get_one_shift(dst_channel)
 322             value = '(%s >> %s)' % (value, src_shift - dst_shift)
 323         else:
 324             # We need to rescale using an intermediate type big enough to hold the multiplication of both
 325             tmp_native_type = intermediate_native_type(src_size + dst_channel.size, src_channel.sign and dst_channel.sign)
 326             value = '((%s)%s)' % (tmp_native_type, value)
 327             value = '(%s * 0x%x / 0x%x)' % (value, dst_one, src_one)
 328         value = '(%s)%s' % (dst_native_type, value)
 329         return value
 330
 331     # Promote to either float or double
 332     if src_type != FLOAT:
 333         if src_norm or src_type == FIXED:
 334             one = get_one(src_channel)
 335             if src_size <= 23:
 336                 value = '(%s * (1.0f/0x%x))' % (value, one)
 337                 if dst_channel.size <= 32:
 338                     value = '(float)%s' % value
 339                 src_size = 32
 340             else:
 341                 # bigger than single precision mantissa, use double
 342                 value = '(%s * (1.0/0x%x))' % (value, one)
 343                 src_size = 64
 344             src_norm = False
 345         else:
 346             if src_size <= 23 or dst_channel.size <= 32:
 347                 value = '(float)%s' % value
 348                 src_size = 32
 349             else:
 350                 # bigger than single precision mantissa, use double
 351                 value = '(double)%s' % value
 352                 src_size = 64
 353         src_type = FLOAT
 354
 355     # Convert double or float to non-float
 356     if dst_channel.type != FLOAT:
 357         if dst_channel.norm or dst_channel.type == FIXED:
 358             dst_one = get_one(dst_channel)
 359             if dst_channel.size <= 23:
 360                 value = '(%s * 0x%x)' % (value, dst_one)
 361             else:
 362                 # bigger than single precision mantissa, use double
 363                 value = '(%s * (double)0x%x)' % (value, dst_one)
 364         value = '(%s)%s' % (dst_native_type, value)
 365     else:
 366         # Cast double to float when converting to either half or float
 367         if dst_channel.size <= 32 and src_size > 32:
 368             value = '(float)%s' % value
 369             src_size = 32
 370
 371         if dst_channel.size == 16:
 372             value = 'util_float_to_half(%s)' % value
 373         elif dst_channel.size == 64 and src_size < 64:
 374             value = '(double)%s' % value
 375
 376     return value
 377
 378
 379 def generate_unpack_kernel(format, dst_channel, dst_native_type):
 380
 381     if not is_format_supported(format):
 382         return
 383
 384     assert format.layout == PLAIN
 385
 386     src_native_type = native_type(format)
 387
 388     if format.is_bitmask():
 389         depth = format.block_size()
 390         print '         uint%u_t value = *(const uint%u_t *)src;' % (depth, depth)
 391
 392         # Declare the intermediate variables
 393         for i in range(format.nr_channels()):
 394             src_channel = format.channels[i]
 395             if src_channel.type == UNSIGNED:
 396                 print '         uint%u_t %s;' % (depth, src_channel.name)
 397             elif src_channel.type == SIGNED:
 398                 print '         int%u_t %s;' % (depth, src_channel.name)
 399
 400         if depth > 8:
 401             print '#ifdef PIPE_ARCH_BIG_ENDIAN'
 402             print '         value = util_bswap%u(value);' % depth
 403             print '#endif'
 404
 405         # Compute the intermediate unshifted values
 406         shift = 0
 407         for i in range(format.nr_channels()):
 408             src_channel = format.channels[i]
 409             value = 'value'
 410             if src_channel.type == UNSIGNED:
 411                 if shift:
 412                     value = '%s >> %u' % (value, shift)
 413                 if shift + src_channel.size < depth:
 414                     value = '(%s) & 0x%x' % (value, (1 << src_channel.size) - 1)
 415             elif src_channel.type == SIGNED:
 416                 if shift + src_channel.size < depth:
 417                     # Align the sign bit
 418                     lshift = depth - (shift + src_channel.size)
 419                     value = '%s << %u' % (value, lshift)
 420                 # Cast to signed
 421                 value = '(int%u_t)(%s) ' % (depth, value)
 422                 if src_channel.size < depth:
 423                     # Align the LSB bit
 424                     rshift = depth - src_channel.size
 425                     value = '(%s) >> %u' % (value, rshift)
 426             else:
 427                 value = None
 428
 429             if value is not None:
 430                 print '         %s = %s;' % (src_channel.name, value)
 431
 432             shift += src_channel.size
 433
 434         # Convert, swizzle, and store final values
 435         for i in range(4):
 436             swizzle = format.swizzles[i]
 437             if swizzle < 4:
 438                 src_channel = format.channels[swizzle]
 439                 src_colorspace = format.colorspace
 440                 if src_colorspace == SRGB and i == 3:
 441                     # Alpha channel is linear
 442                     src_colorspace = RGB
 443                 value = src_channel.name
 444                 value = conversion_expr(src_channel,
 445                                         dst_channel, dst_native_type,
 446                                         value,
 447                                         src_colorspace = src_colorspace)
 448             elif swizzle == SWIZZLE_0:
 449                 value = '0'
 450             elif swizzle == SWIZZLE_1:
 451                 value = get_one(dst_channel)
 452             elif swizzle == SWIZZLE_NONE:
 453                 value = '0'
 454             else:
 455                 assert False
 456             print '         dst[%u] = %s; /* %s */' % (i, value, 'rgba'[i])
 457
 458     else:
 459         print '         union util_format_%s pixel;' % format.short_name()
 460         print '         memcpy(&pixel, src, sizeof pixel);'
 461         bswap_format(format)
 462
 463         for i in range(4):
 464             swizzle = format.swizzles[i]
 465             if swizzle < 4:
 466                 src_channel = format.channels[swizzle]
 467                 src_colorspace = format.colorspace
 468                 if src_colorspace == SRGB and i == 3:
 469                     # Alpha channel is linear
 470                     src_colorspace = RGB
 471                 value = 'pixel.chan.%s' % src_channel.name
 472                 value = conversion_expr(src_channel,
 473                                         dst_channel, dst_native_type,
 474                                         value,
 475                                         src_colorspace = src_colorspace)
 476             elif swizzle == SWIZZLE_0:
 477                 value = '0'
 478             elif swizzle == SWIZZLE_1:
 479                 value = get_one(dst_channel)
 480             elif swizzle == SWIZZLE_NONE:
 481                 value = '0'
 482             else:
 483                 assert False
 484             print '         dst[%u] = %s; /* %s */' % (i, value, 'rgba'[i])
 485
 486
 487 def generate_pack_kernel(format, src_channel, src_native_type):
 488
 489     if not is_format_supported(format):
 490         return
 491
 492     dst_native_type = native_type(format)
 493
 494     assert format.layout == PLAIN
 495
 496     inv_swizzle = format.inv_swizzles()
 497
 498     if format.is_bitmask():
 499         depth = format.block_size()
 500         print '         uint%u_t value = 0;' % depth
 501
 502         shift = 0
 503         for i in range(4):
 504             dst_channel = format.channels[i]
 505             if inv_swizzle[i] is not None:
 506                 value ='src[%u]' % inv_swizzle[i]
 507                 dst_colorspace = format.colorspace
 508                 if dst_colorspace == SRGB and inv_swizzle[i] == 3:
 509                     # Alpha channel is linear
 510                     dst_colorspace = RGB
 511                 value = conversion_expr(src_channel,
 512                                         dst_channel, dst_native_type,
 513                                         value,
 514                                         dst_colorspace = dst_colorspace)
 515                 if dst_channel.type in (UNSIGNED, SIGNED):
 516                     if shift + dst_channel.size < depth:
 517                         value = '(%s) & 0x%x' % (value, (1 << dst_channel.size) - 1)
 518                     if shift:
 519                         value = '(%s) << %u' % (value, shift)
 520                     if dst_channel.type == SIGNED:
 521                         # Cast to unsigned
 522                         value = '(uint%u_t)(%s) ' % (depth, value)
 523                 else:
 524                     value = None
 525                 if value is not None:
 526                     print '         value |= %s;' % (value)
 527
 528             shift += dst_channel.size
 529
 530         if depth > 8:
 531             print '#ifdef PIPE_ARCH_BIG_ENDIAN'
 532             print '         value = util_bswap%u(value);' % depth
 533             print '#endif'
 534
 535         print '         *(uint%u_t *)dst = value;' % depth
 536
 537     else:
 538         print '         union util_format_%s pixel;' % format.short_name()
 539
 540         for i in range(4):
 541             dst_channel = format.channels[i]
 542             width = dst_channel.size
 543             if inv_swizzle[i] is None:
 544                 continue
 545             dst_colorspace = format.colorspace
 546             if dst_colorspace == SRGB and inv_swizzle[i] == 3:
 547                 # Alpha channel is linear
 548                 dst_colorspace = RGB
 549             value ='src[%u]' % inv_swizzle[i]
 550             value = conversion_expr(src_channel,
 551                                     dst_channel, dst_native_type,
 552                                     value,
 553                                     dst_colorspace = dst_colorspace)
 554             print '         pixel.chan.%s = %s;' % (dst_channel.name, value)
 555
 556         bswap_format(format)
 557         print '         memcpy(dst, &pixel, sizeof pixel);'
 558
 559
 560 def generate_format_unpack(format, dst_channel, dst_native_type, dst_suffix):
 561     '''Generate the function to unpack pixels from a particular format'''
 562
 563     name = format.short_name()
 564
 565     print 'static INLINE void'
 566     print 'util_format_%s_unpack_%s(%s *dst_row, unsigned dst_stride, const uint8_t *src_row, unsigned src_stride, unsigned width, unsigned height)' % (name, dst_suffix, dst_native_type)
 567     print '{'
 568
 569     if is_format_supported(format):
 570         print '   unsigned x, y;'
 571         print '   for(y = 0; y < height; y += %u) {' % (format.block_height,)
 572         print '      %s *dst = dst_row;' % (dst_native_type)
 573         print '      const uint8_t *src = src_row;'
 574         print '      for(x = 0; x < width; x += %u) {' % (format.block_width,)
 575
 576         generate_unpack_kernel(format, dst_channel, dst_native_type)
 577
 578         print '         src += %u;' % (format.block_size() / 8,)
 579         print '         dst += 4;'
 580         print '      }'
 581         print '      src_row += src_stride;'
 582         print '      dst_row += dst_stride/sizeof(*dst_row);'
 583         print '   }'
 584
 585     print '}'
 586     print
 587
 588
 589 def generate_format_pack(format, src_channel, src_native_type, src_suffix):
 590     '''Generate the function to pack pixels to a particular format'''
 591
 592     name = format.short_name()
 593
 594     print 'static INLINE void'
 595     print 'util_format_%s_pack_%s(uint8_t *dst_row, unsigned dst_stride, const %s *src_row, unsigned src_stride, unsigned width, unsigned height)' % (name, src_suffix, src_native_type)
 596     print '{'
 597
 598     if is_format_supported(format):
 599         print '   unsigned x, y;'
 600         print '   for(y = 0; y < height; y += %u) {' % (format.block_height,)
 601         print '      const %s *src = src_row;' % (src_native_type)
 602         print '      uint8_t *dst = dst_row;'
 603         print '      for(x = 0; x < width; x += %u) {' % (format.block_width,)
 604
 605         generate_pack_kernel(format, src_channel, src_native_type)
 606
 607         print '         src += 4;'
 608         print '         dst += %u;' % (format.block_size() / 8,)
 609         print '      }'
 610         print '      dst_row += dst_stride;'
 611         print '      src_row += src_stride/sizeof(*src_row);'
 612         print '   }'
 613
 614     print '}'
 615     print
 616
 617
 618 def generate_format_fetch(format, dst_channel, dst_native_type, dst_suffix):
 619     '''Generate the function to unpack pixels from a particular format'''
 620
 621     name = format.short_name()
 622
 623     print 'static INLINE void'
 624     print 'util_format_%s_fetch_%s(%s *dst, const uint8_t *src, unsigned i, unsigned j)' % (name, dst_suffix, dst_native_type)
 625     print '{'
 626
 627     if is_format_supported(format):
 628         generate_unpack_kernel(format, dst_channel, dst_native_type)
 629
 630     print '}'
 631     print
 632
 633
 634 def is_format_hand_written(format):
 635     return format.layout in ('s3tc', 'rgtc', 'subsampled', 'other') or format.colorspace == ZS
 636
 637
 638 def generate(formats):
 639     print
 640     print '#include "pipe/p_compiler.h"'
 641     print '#include "u_math.h"'
 642     print '#include "u_half.h"'
 643     print '#include "u_format.h"'
 644     print '#include "u_format_other.h"'
 645     print '#include "u_format_srgb.h"'
 646     print '#include "u_format_yuv.h"'
 647     print '#include "u_format_zs.h"'
 648     print
 649
 650     for format in formats:
 651         if not is_format_hand_written(format):
 652
 653             if is_format_supported(format):
 654                 generate_format_type(format)
 655
 656             channel = Channel(FLOAT, False, 32)
 657             native_type = 'float'
 658             suffix = 'rgba_float'
 659
 660             generate_format_unpack(format, channel, native_type, suffix)
 661             generate_format_pack(format, channel, native_type, suffix)
 662             generate_format_fetch(format, channel, native_type, suffix)
 663
 664             channel = Channel(UNSIGNED, True, 8)
 665             native_type = 'uint8_t'
 666             suffix = 'rgba_8unorm'
 667
 668             generate_format_unpack(format, channel, native_type, suffix)
 669             generate_format_pack(format, channel, native_type, suffix)
 670