/src/FreeImage/Source/OpenEXR/Half/eLut.cpp
https://bitbucket.org/cabalistic/ogredeps/ · C++ · 114 lines · 45 code · 18 blank · 51 comment · 7 complexity · 982a90d0eba60fd6ab9d771c559b296a MD5 · raw file
- ///////////////////////////////////////////////////////////////////////////
- //
- // Copyright (c) 2002, 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.
- //
- ///////////////////////////////////////////////////////////////////////////
- #include <iostream>
- #include <iomanip>
- using namespace std;
- //-----------------------------------------------------
- // Compute a lookup table for float-to-half conversion.
- //
- // When indexed with the combined sign and exponent of
- // a float, the table either returns the combined sign
- // and exponent of the corresponding half, or zero if
- // the corresponding half may not be normalized (zero,
- // denormalized, overflow).
- //-----------------------------------------------------
- void
- initELut (unsigned short eLut[])
- {
- for (int i = 0; i < 0x100; i++)
- {
- int e = (i & 0x0ff) - (127 - 15);
- if (e <= 0 || e >= 30)
- {
- //
- // Special case
- //
- eLut[i] = 0;
- eLut[i | 0x100] = 0;
- }
- else
- {
- //
- // Common case - normalized half, no exponent overflow possible
- //
- eLut[i] = (e << 10);
- eLut[i | 0x100] = ((e << 10) | 0x8000);
- }
- }
- }
- //------------------------------------------------------------
- // Main - prints the sign-and-exponent conversion lookup table
- //------------------------------------------------------------
- int
- main ()
- {
- const int tableSize = 1 << 9;
- unsigned short eLut[tableSize];
- initELut (eLut);
- cout << "//\n"
- "// This is an automatically generated file.\n"
- "// Do not edit.\n"
- "//\n\n";
- cout << "{\n ";
- for (int i = 0; i < tableSize; i++)
- {
- cout << setw (5) << eLut[i] << ", ";
- if (i % 8 == 7)
- {
- cout << "\n";
- if (i < tableSize - 1)
- cout << " ";
- }
- }
- cout << "};\n";
- return 0;
- }