///////////////////////////////////////////////////////////////////////////
//
// 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
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///////////////////////////////////////////////////////////////////////////
#ifndef INCLUDED_IMF_LUT_H
#define INCLUDED_IMF_LUT_H
//-----------------------------------------------------------------------------
//
// Lookup tables for efficient application
// of half --> half functions to pixel data,
// and some commonly applied functions.
//
//-----------------------------------------------------------------------------
#include <ImfRgbaFile.h>
#include <ImfFrameBuffer.h>
#include "ImathBox.h"
#include "halfFunction.h"
namespace Imf {
//
// Lookup table for individual half channels.
//
class HalfLut
{
public:
//------------
// Constructor
//------------
template <class Function>
HalfLut (Function f);
//----------------------------------------------------------------------
// Apply the table to data[0], data[stride] ... data[(nData-1) * stride]
//----------------------------------------------------------------------
void apply (half *data,
int nData,
int stride = 1) const;
//---------------------------------------------------------------
// Apply the table to a frame buffer slice (see ImfFrameBuffer.h)
//---------------------------------------------------------------
void apply (const Slice &data,
const Imath::Box2i &dataWindow) const;
private:
halfFunction <half> _lut;
};
//
// Lookup table for combined RGBA data.
//
class RgbaLut
{
public:
//------------
// Constructor
//------------
template <class Function>
RgbaLut (Function f, RgbaChannels chn = WRITE_RGB);
//----------------------------------------------------------------------
// Apply the table to data[0], data[stride] ... data[(nData-1) * stride]
//----------------------------------------------------------------------
void apply (Rgba *data,
int nData,
int stride = 1) const;
//-----------------------------------------------------------------------
// Apply the table to a frame buffer (see RgbaOutpuFile.setFrameBuffer())
//-----------------------------------------------------------------------
void apply (Rgba *base,
int xStride,
int yStride,
const Imath::Box2i &dataWindow) const;
private:
halfFunction <half> _lut;
RgbaChannels _chn;
};
//
// 12bit log rounding reduces data to 20 stops with 200 steps per stop.
// That makes 4000 numbers. An extra 96 just come along for the ride.
// Zero explicitly remains zero. The first non-zero half will map to 1
// in the 0-4095 12log space. A nice power of two number is placed at
// the center [2000] and that number is near 0.18.
//
half round12log (half x);
//
// Round to n-bit precision (n should be between 0 and 10).
// After rounding, the significand's 10-n least significant
// bits will be zero.
//
struct roundNBit
{
roundNBit (int n): n(n) {}
half operator () (half x) {return x.round(n);}
int n;
};
//
// Template definitions
//
template <class Function>
HalfLut::HalfLut (Function f):
_lut(f, -HALF_MAX, HALF_MAX, half (0),
half::posInf(), half::negInf(), half::qNan())
{
// empty
}
template <class Function>
RgbaLut::RgbaLut (Function f, RgbaChannels chn):
_lut(f, -HALF_MAX, HALF_MAX, half (0),
half::posInf(), half::negInf(), half::qNan()),
_chn(chn)
{
// empty
}
} // namespace Imf
#endif