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      1 #!/usr/bin/env python
      2 
      3 CopyRight = '''
      4 /**************************************************************************
      5  *
      6  * Copyright 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  * SRGB translation.
     34  *
     35  * @author Brian Paul <brianp (at] vmware.com>
     36  * @author Michal Krol <michal (at] vmware.com>
     37  * @author Jose Fonseca <jfonseca (at] vmware.com>
     38  */
     39 '''
     40 
     41 
     42 import math
     43 
     44 
     45 def srgb_to_linear(x):
     46     if x <= 0.04045:
     47         return x / 12.92
     48     else:
     49         return math.pow((x + 0.055) / 1.055, 2.4)
     50 
     51 
     52 def linear_to_srgb(x):
     53     if x >= 0.0031308:
     54         return 1.055 * math.pow(x, 0.41666) - 0.055
     55     else:
     56         return 12.92 * x
     57 
     58 def generate_srgb_tables():
     59     print 'const float'
     60     print 'util_format_srgb_8unorm_to_linear_float_table[256] = {'
     61     for j in range(0, 256, 4):
     62         print '   ',
     63         for i in range(j, j + 4):
     64             print '%.7e,' % (srgb_to_linear(i / 255.0),),
     65         print
     66     print '};'
     67     print
     68     print 'const uint8_t'
     69     print 'util_format_srgb_to_linear_8unorm_table[256] = {'
     70     for j in range(0, 256, 16):
     71         print '   ',
     72         for i in range(j, j + 16):
     73             print '%3u,' % (int(srgb_to_linear(i / 255.0) * 255.0 + 0.5),),
     74         print
     75     print '};'
     76     print
     77     print 'const uint8_t'
     78     print 'util_format_linear_to_srgb_8unorm_table[256] = {'
     79     for j in range(0, 256, 16):
     80         print '   ',
     81         for i in range(j, j + 16):
     82             print '%3u,' % (int(linear_to_srgb(i / 255.0) * 255.0 + 0.5),),
     83         print
     84     print '};'
     85     print
     86 
     87 
     88 def main():
     89     print '/* This file is autogenerated by u_format_srgb.py. Do not edit directly. */'
     90     print
     91     # This will print the copyright message on the top of this file
     92     print CopyRight.strip()
     93     print
     94     print '#include "u_format_srgb.h"'
     95     print
     96     generate_srgb_tables()    
     97 
     98 
     99 if __name__ == '__main__':
    100     main()
    101