source: NonGTP/OpenEXR/include/IlmImf/ImfLut.h @ 855

Revision 855, 5.0 KB checked in by igarcia, 19 years ago (diff)
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[855]1///////////////////////////////////////////////////////////////////////////
2//
3// Copyright (c) 2002, Industrial Light & Magic, a division of Lucas
4// Digital Ltd. LLC
5//
6// All rights reserved.
7//
8// Redistribution and use in source and binary forms, with or without
9// modification, are permitted provided that the following conditions are
10// met:
11// *       Redistributions of source code must retain the above copyright
12// notice, this list of conditions and the following disclaimer.
13// *       Redistributions in binary form must reproduce the above
14// copyright notice, this list of conditions and the following disclaimer
15// in the documentation and/or other materials provided with the
16// distribution.
17// *       Neither the name of Industrial Light & Magic nor the names of
18// its contributors may be used to endorse or promote products derived
19// from this software without specific prior written permission.
20//
21// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32//
33///////////////////////////////////////////////////////////////////////////
34
35
36
37#ifndef INCLUDED_IMF_LUT_H
38#define INCLUDED_IMF_LUT_H
39
40//-----------------------------------------------------------------------------
41//
42//      Lookup tables for efficient application
43//      of half --> half functions to pixel data,
44//      and some commonly applied functions.
45//
46//-----------------------------------------------------------------------------
47
48#include <ImfRgbaFile.h>
49#include <ImfFrameBuffer.h>
50#include <ImathBox.h>
51#include <halfFunction.h>
52
53namespace Imf {
54
55//
56// Lookup table for individual half channels.
57//
58
59class HalfLut
60{
61  public:
62
63    //------------
64    // Constructor
65    //------------
66
67    template <class Function>
68    HalfLut (Function f);
69
70
71    //----------------------------------------------------------------------
72    // Apply the table to data[0], data[stride] ... data[(nData-1) * stride]
73    //----------------------------------------------------------------------
74
75    void apply (half *data,
76                int nData,
77                int stride = 1) const;
78
79
80    //---------------------------------------------------------------
81    // Apply the table to a frame buffer slice (see ImfFrameBuffer.h)
82    //---------------------------------------------------------------
83
84    void apply (const Slice &data,
85                const Imath::Box2i &dataWindow) const;
86
87  private:
88
89    halfFunction <half> _lut;
90};
91
92
93//
94// Lookup table for combined RGBA data.
95//
96
97class RgbaLut
98{
99  public:
100
101    //------------
102    // Constructor
103    //------------
104
105    template <class Function>
106    RgbaLut (Function f, RgbaChannels chn = WRITE_RGB);
107
108
109    //----------------------------------------------------------------------
110    // Apply the table to data[0], data[stride] ... data[(nData-1) * stride]
111    //----------------------------------------------------------------------
112
113    void apply (Rgba *data,
114                int nData,
115                int stride = 1) const;
116
117
118    //-----------------------------------------------------------------------
119    // Apply the table to a frame buffer (see RgbaOutpuFile.setFrameBuffer())
120    //-----------------------------------------------------------------------
121
122    void apply (Rgba *base,
123                int xStride,
124                int yStride,
125                const Imath::Box2i &dataWindow) const;
126
127  private:
128
129    halfFunction <half> _lut;
130    RgbaChannels        _chn;
131};
132
133
134//
135// 12bit log rounding reduces data to 20 stops with 200 steps per stop.
136// That makes 4000 numbers.  An extra 96 just come along for the ride.
137// Zero explicitly remains zero.  The first non-zero half will map to 1
138// in the 0-4095 12log space.  A nice power of two number is placed at
139// the center [2000] and that number is near 0.18.
140//
141
142half round12log (half x);
143
144
145//
146// Round to n-bit precision (n should be between 0 and 10).
147// After rounding, the significand's 10-n least significant
148// bits will be zero.
149//
150
151struct roundNBit
152{
153    roundNBit (int n): n(n) {}
154    half operator () (half x) {return x.round(n);}
155    int n;
156};
157
158
159//
160// Template definitions
161//
162
163
164template <class Function>
165HalfLut::HalfLut (Function f):
166    _lut(f, -HALF_MAX, HALF_MAX, half (0),
167         half::posInf(), half::negInf(), half::qNan())
168{
169    // empty
170}
171
172
173template <class Function>
174RgbaLut::RgbaLut (Function f, RgbaChannels chn):
175    _lut(f, -HALF_MAX, HALF_MAX, half (0),
176         half::posInf(), half::negInf(), half::qNan()),
177    _chn(chn)
178{
179    // empty
180}
181
182
183} // namespace Imf
184
185#endif
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