/src/FreeImage/Source/OpenEXR/IlmImf/b44ExpLogTable.cpp
https://bitbucket.org/cabalistic/ogredeps/ · C++ · 136 lines · 62 code · 22 blank · 52 comment · 13 complexity · 38f2c2bc9d3aec05b0bd8c2c858ef1c6 MD5 · raw file
- ///////////////////////////////////////////////////////////////////////////
- //
- // Copyright (c) 2006, Industrial Light & Magic, a division of Lucas
- // Digital Ltd. LLC
- //
- // All rights reserved.
- //
- // Redistribution and use in source and binary forms, with or without
- // modification, are permitted provided that the following conditions are
- // met:
- // * Redistributions of source code must retain the above copyright
- // notice, this list of conditions and the following disclaimer.
- // * Redistributions in binary form must reproduce the above
- // copyright notice, this list of conditions and the following disclaimer
- // in the documentation and/or other materials provided with the
- // distribution.
- // * Neither the name of Industrial Light & Magic nor the names of
- // its contributors may be used to endorse or promote products derived
- // from this software without specific prior written permission.
- //
- // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- //
- ///////////////////////////////////////////////////////////////////////////
- //---------------------------------------------------------------------------
- //
- // b44ExpLogTable
- //
- // A program to generate lookup tables for
- //
- // y = exp (x / 8)
- //
- // and
- // x = 8 * log (x);
- //
- // where x and y are 16-bit floating-point numbers
- //
- // The tables are used by class B44Compressor.
- //
- //---------------------------------------------------------------------------
- #include <half.h>
- #include <math.h>
- #include <iostream>
- #include <iomanip>
- using namespace std;
- //---------------------------------------------
- // Main - prints the half-to-float lookup table
- //---------------------------------------------
- int
- main ()
- {
- #ifndef HAVE_IOS_BASE
- cout.setf (ios::hex, ios::basefield);
- #else
- cout.setf (ios_base::hex, ios_base::basefield);
- #endif
- cout << "//\n"
- "// This is an automatically generated file.\n"
- "// Do not edit.\n"
- "//\n\n";
- const int iMax = (1 << 16);
- cout << "const unsigned short expTable[] =\n"
- "{\n"
- " ";
- for (int i = 0; i < iMax; i++)
- {
- half h;
- h.setBits (i);
- if (!h.isFinite())
- h = 0;
- else if (h >= 8 * log (HALF_MAX))
- h = HALF_MAX;
- else
- h = exp (h / 8);
- cout << "0x" << setfill ('0') << setw (4) << h.bits() << ", ";
- if (i % 8 == 7)
- {
- cout << "\n";
- if (i < iMax - 1)
- cout << " ";
- }
- }
- cout << "};\n\n";
- cout << "const unsigned short logTable[] =\n"
- "{\n"
- " ";
- for (int i = 0; i < iMax; i++)
- {
- half h;
- h.setBits (i);
- if (!h.isFinite() || h < 0)
- h = 0;
- else
- h = 8 * log (h);
- cout << "0x" << setfill ('0') << setw (4) << h.bits() << ", ";
- if (i % 8 == 7)
- {
- cout << "\n";
- if (i < iMax - 1)
- cout << " ";
- }
- }
- cout << "};\n";
- return 0;
- }