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:
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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.
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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
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24// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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32//
33///////////////////////////////////////////////////////////////////////////
34
35
36
37//-----------------------------------------------------------------------------
38//
39//	Lookup tables for efficient application
40//	of half --> half functions to pixel data,
41//	and some commonly applied functions.
42//
43//-----------------------------------------------------------------------------
44
45#include <ImfLut.h>
46#include <math.h>
47#include <assert.h>
48
49namespace Imf {
50
51
52void
53HalfLut::apply (half *data, int nData, int stride) const
54{
55    while (nData)
56    {
57	*data = _lut (*data);
58	data += stride;
59	nData -= 1;
60    }
61}
62
63
64void
65HalfLut::apply (const Slice &data, const Imath::Box2i &dataWindow) const
66{
67    assert (data.type == HALF);
68    assert (dataWindow.min.x % data.xSampling == 0);
69    assert (dataWindow.min.y % data.ySampling == 0);
70    assert ((dataWindow.max.x - dataWindow.min.x + 1) % data.xSampling == 0);
71    assert ((dataWindow.max.y - dataWindow.min.y + 1) % data.ySampling == 0);
72
73    char *base = data.base + data.yStride *
74		 (dataWindow.min.y / data.ySampling);
75
76    for (int y = dataWindow.min.y;
77	 y <= dataWindow.max.y;
78	 y += data.ySampling)
79    {
80	char *pixel = base + data.xStride *
81		      (dataWindow.min.x / data.xSampling);
82
83	for (int x = dataWindow.min.x;
84	     x <= dataWindow.max.x;
85	     x += data.xSampling)
86	{
87	    *(half *)pixel = _lut (*(half *)pixel);
88	    pixel += data.xStride;
89	}
90
91	base += data.yStride;
92    }
93}
94
95
96void
97RgbaLut::apply (Rgba *data, int nData, int stride) const
98{
99    while (nData)
100    {
101	if (_chn & WRITE_R)
102	    data->r = _lut (data->r);
103
104	if (_chn & WRITE_G)
105	    data->g = _lut (data->g);
106
107	if (_chn & WRITE_B)
108	    data->b = _lut (data->b);
109
110	if (_chn & WRITE_A)
111	    data->a = _lut (data->a);
112
113	data += stride;
114	nData -= 1;
115    }
116}
117
118
119void
120RgbaLut::apply (Rgba *base,
121		int xStride, int yStride,
122		const Imath::Box2i &dataWindow) const
123{
124    base += dataWindow.min.y * yStride;
125
126    for (int y = dataWindow.min.y; y <= dataWindow.max.y; ++y)
127    {
128	Rgba *pixel = base + dataWindow.min.x * xStride;
129
130	for (int x = dataWindow.min.x; x <= dataWindow.max.x; ++x)
131	{
132	    if (_chn & WRITE_R)
133		pixel->r = _lut (pixel->r);
134
135	    if (_chn & WRITE_G)
136		pixel->g = _lut (pixel->g);
137
138	    if (_chn & WRITE_B)
139		pixel->b = _lut (pixel->b);
140
141	    if (_chn & WRITE_A)
142		pixel->a = _lut (pixel->a);
143
144	    pixel += xStride;
145	}
146
147	base += yStride;
148    }
149}
150
151
152half
153round12log (half x)
154{
155    const float middleval = pow (2.0, -2.5);
156    int int12log;
157
158    if (x <= 0)
159    {
160	return 0;
161    }
162    else
163    {
164	int12log = int (2000.5 + 200.0 * log (x / middleval) / log (2.0));
165
166	if (int12log > 4095)
167	    int12log = 4095;
168
169	if (int12log < 1)
170	    int12log = 1;
171    }
172
173    return middleval * pow (2.0, (int12log - 2000.0) / 200.0);
174}
175
176} // namespace Imf
177