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#!/usr/bin/env python
'''
/**************************************************************************
*
* Copyright 2010 VMware, Inc.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sub license, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial portions
* of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
* IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
* ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
**************************************************************************/
/**
* @file
* SRGB translation.
*
* @author Brian Paul <brianp@vmware.com>
* @author Michal Krol <michal@vmware.com>
* @author Jose Fonseca <jfonseca@vmware.com>
*/
'''
import math
def srgb_to_linear(x):
if x <= 0.04045:
return x / 12.92
else:
return math.pow((x + 0.055) / 1.055, 2.4)
def linear_to_srgb(x):
if x >= 0.0031308:
return 1.055 * math.pow(x, 0.41666) - 0.055
else:
return 12.92 * x
def generate_srgb_tables():
print 'const float'
print 'util_format_srgb_8unorm_to_linear_float_table[256] = {'
for j in range(0, 256, 4):
print ' ',
for i in range(j, j + 4):
print '%.7e,' % (srgb_to_linear(i / 255.0),),
print
print '};'
print
print 'const uint8_t'
print 'util_format_srgb_to_linear_8unorm_table[256] = {'
for j in range(0, 256, 16):
print ' ',
for i in range(j, j + 16):
print '%3u,' % (int(srgb_to_linear(i / 255.0) * 255.0 + 0.5),),
print
print '};'
print
print 'const uint8_t'
print 'util_format_linear_to_srgb_8unorm_table[256] = {'
for j in range(0, 256, 16):
print ' ',
for i in range(j, j + 16):
print '%3u,' % (int(linear_to_srgb(i / 255.0) * 255.0 + 0.5),),
print
print '};'
print
def main():
print '/* This file is autogenerated by u_format_srgb.py. Do not edit directly. */'
print
# This will print the copyright message on the top of this file
print __doc__.strip()
print
print '#include "u_format_srgb.h"'
print
generate_srgb_tables()
if __name__ == '__main__':
main()
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