src/mesa/main/format_fallback.py

   1 COPYRIGHT = """\
   2 /*
   3  * Copyright 2017 Google
   4  *
   5  * Permission is hereby granted, free of charge, to any person obtaining a
   6  * copy of this software and associated documentation files (the
   7  * "Software"), to deal in the Software without restriction, including
   8  * without limitation the rights to use, copy, modify, merge, publish,
   9  * distribute, sub license, and/or sell copies of the Software, and to
  10  * permit persons to whom the Software is furnished to do so, subject to
  11  * the following conditions:
  12  *
  13  * The above copyright notice and this permission notice (including the
  14  * next paragraph) shall be included in all copies or substantial portions
  15  * of the Software.
  16  *
  17  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  18  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  19  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
  20  * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
  21  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  22  * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  23  * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  24  */
  25 """
  26
  27 # stdlib
  28 import argparse
  29 from sys import stdout
  30 from mako.template import Template
  31
  32 # local
  33 import format_parser
  34
  35 def parse_args():
  36     p = argparse.ArgumentParser()
  37     p.add_argument("csv")
  38     p.add_argument("out")
  39     return p.parse_args()
  40
  41 def get_unorm_to_srgb_map(formats):
  42     names = set(fmt.name for fmt in formats)
  43
  44     for fmt in formats:
  45         if fmt.colorspace != 'srgb':
  46             continue;
  47
  48         replacements = [
  49             ('SRGB', 'RGB'),
  50             ('SRGB', 'UNORM'),
  51             ('SRGB8_ALPHA8', 'RGBA'),
  52             ('SRGB8_ALPHA8', 'RGBA8'),
  53             ('SRGB_ALPHA_UNORM', 'RGBA_UNORM'),
  54         ]
  55         found_unorm_name = False
  56         for rep in replacements:
  57             if fmt.name.find(rep[0]) == -1:
  58                 continue
  59
  60             unorm_name = fmt.name.replace(rep[0], rep[1])
  61             if unorm_name in names:
  62                 yield unorm_name, fmt.name
  63                 found_unorm_name = True
  64                 break
  65
  66         # Every sRGB format MUST have a UNORM equivalent
  67         assert found_unorm_name
  68
  69 def get_rgbx_to_rgba_map(formats):
  70     names = set(fmt.name for fmt in formats)
  71
  72     for fmt in formats:
  73         if not fmt.has_channel('r') or not fmt.has_channel('x'):
  74             continue
  75
  76         # The condition above will still let MESA_FORMAT_R9G9B9E5_FLOAT
  77         # through.  We need to ensure it actually has an X in the name.
  78         if not 'X' in fmt.name:
  79             continue
  80
  81         rgbx_name = fmt.name
  82         rgba_name = rgbx_name.replace("X", "A")
  83         if rgba_name not in names:
  84             continue;
  85
  86         yield rgbx_name, rgba_name
  87
  88 TEMPLATE = Template(COPYRIGHT + """
  89 #include "formats.h"
  90
  91 /**
  92  * For an sRGB format, return the corresponding linear color space format.
  93  * For non-sRGB formats, return the format as-is.
  94  */
  95 mesa_format
  96 _mesa_get_srgb_format_linear(mesa_format format)
  97 {
  98    switch (format) {
  99 %for unorm, srgb in unorm_to_srgb_map:
 100    case ${srgb}:
 101       return ${unorm};
 102 %endfor
 103    default:
 104       return format;
 105    }
 106 }
 107
 108 /**
 109  * If the format has an alpha channel, and there exists a non-alpha
 110  * variant of the format with an identical bit layout, then return
 111  * the non-alpha format. Otherwise return the original format.
 112  *
 113  * Examples:
 114  *    Fallback exists:
 115  *       MESA_FORMAT_R8G8B8X8_UNORM -> MESA_FORMAT_R8G8B8A8_UNORM
 116  *       MESA_FORMAT_RGBX_UNORM16 -> MESA_FORMAT_RGBA_UNORM16
 117  *
 118  *    No fallback:
 119  *       MESA_FORMAT_R8G8B8A8_UNORM -> MESA_FORMAT_R8G8B8A8_UNORM
 120  *       MESA_FORMAT_Z_FLOAT32 -> MESA_FORMAT_Z_FLOAT32
 121  */
 122 mesa_format
 123 _mesa_format_fallback_rgbx_to_rgba(mesa_format format)
 124 {
 125    switch (format) {
 126 %for rgbx, rgba in rgbx_to_rgba_map:
 127    case ${rgbx}:
 128       return ${rgba};
 129 %endfor
 130    default:
 131       return format;
 132    }
 133 }
 134 """);
 135
 136 def main():
 137     pargs = parse_args()
 138
 139     formats = list(format_parser.parse(pargs.csv))
 140
 141     template_env = {
 142         'unorm_to_srgb_map': list(get_unorm_to_srgb_map(formats)),
 143         'rgbx_to_rgba_map': list(get_rgbx_to_rgba_map(formats)),
 144     }
 145
 146     with open(pargs.out, 'w') as f:
 147         f.write(TEMPLATE.render(**template_env))
 148
 149 if __name__ == "__main__":
 150     main()