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/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
/** \file
* \ingroup imbdds
*/
/*
* This file is based on a similar file from the NVIDIA texture tools
* (http://nvidia-texture-tools.googlecode.com/)
*
* Original license from NVIDIA follows.
*/
// Copyright NVIDIA Corporation 2007 -- Ignacio Castano <icastano@nvidia.com>
//
// 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, sublicense, 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 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
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
// HOLDERS 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.
#pragma once
#include "Common.h"
namespace PixelFormat {
// Convert component \a c having \a inbits to the returned value having \a outbits.
inline uint convert(uint c, uint inbits, uint outbits)
{
if (inbits == 0) {
return 0;
}
else if (inbits >= outbits) {
// truncate
return c >> (inbits - outbits);
}
else {
// bitexpand
return (c << (outbits - inbits)) | convert(c, inbits, outbits - inbits);
}
}
// Get pixel component shift and size given its mask.
inline void maskShiftAndSize(uint mask, uint *shift, uint *size)
{
if (!mask) {
*shift = 0;
*size = 0;
return;
}
*shift = 0;
while ((mask & 1) == 0) {
++(*shift);
mask >>= 1;
}
*size = 0;
while ((mask & 1) == 1) {
++(*size);
mask >>= 1;
}
}
inline float quantizeCeil(float f, int inbits, int outbits)
{
// uint i = f * (float(1 << inbits) - 1);
// i = convert(i, inbits, outbits);
// float result = float(i) / (float(1 << outbits) - 1);
// nvCheck(result >= f);
float result;
int offset = 0;
do {
uint i = offset + uint(f * (float(1 << inbits) - 1));
i = convert(i, inbits, outbits);
result = float(i) / (float(1 << outbits) - 1);
offset++;
} while (result < f);
return result;
}
#if 0
inline float quantizeRound(float f, int bits)
{
float scale = float(1 << bits);
return fround(f * scale) / scale;
}
inline float quantizeFloor(float f, int bits)
{
float scale = float(1 << bits);
return floor(f * scale) / scale;
}
#endif
} // namespace PixelFormat
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