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_rgbx_to_rgba_map(formats):
  42     names = {fmt.name for fmt in formats}
  43
  44     for fmt in formats:
  45         if not fmt.has_channel('r') or not fmt.has_channel('x'):
  46             continue
  47
  48         # The condition above will still let MESA_FORMAT_R9G9B9E5_FLOAT
  49         # through.  We need to ensure it actually has an X in the name.
  50         if not 'X' in fmt.name:
  51             continue
  52
  53         rgbx_name = fmt.name
  54         rgba_name = rgbx_name.replace("X", "A")
  55         if rgba_name not in names:
  56             continue;
  57
  58         yield rgbx_name, rgba_name
  59
  60 TEMPLATE = Template(COPYRIGHT + """
  61 #include "formats.h"
  62
  63 /**
  64  * If the format has an alpha channel, and there exists a non-alpha
  65  * variant of the format with an identical bit layout, then return
  66  * the non-alpha format. Otherwise return the original format.
  67  *
  68  * Examples:
  69  *    Fallback exists:
  70  *       MESA_FORMAT_R8G8B8X8_UNORM -> MESA_FORMAT_R8G8B8A8_UNORM
  71  *       MESA_FORMAT_RGBX_UNORM16 -> MESA_FORMAT_RGBA_UNORM16
  72  *
  73  *    No fallback:
  74  *       MESA_FORMAT_R8G8B8A8_UNORM -> MESA_FORMAT_R8G8B8A8_UNORM
  75  *       MESA_FORMAT_Z_FLOAT32 -> MESA_FORMAT_Z_FLOAT32
  76  */
  77 mesa_format
  78 _mesa_format_fallback_rgbx_to_rgba(mesa_format format)
  79 {
  80    switch (format) {
  81 %for rgbx, rgba in rgbx_to_rgba_map:
  82    case ${rgbx}:
  83       return ${rgba};
  84 %endfor
  85    default:
  86       return format;
  87    }
  88 }
  89 """);
  90
  91 def main():
  92     pargs = parse_args()
  93
  94     formats = list(format_parser.parse(pargs.csv))
  95
  96     template_env = {
  97         'rgbx_to_rgba_map': list(get_rgbx_to_rgba_map(formats)),
  98     }
  99
 100     with open(pargs.out, 'w') as f:
 101         f.write(TEMPLATE.render(**template_env))
 102
 103 if __name__ == "__main__":
 104     main()