|
1
|
|
/*
|
|
2
|
|
RawSpeed - RAW file decoder.
|
|
3
|
|
|
|
4
|
|
Copyright (C) 2018 Stefan Löffler
|
|
5
|
|
Copyright (C) 2018 Roman Lebedev
|
|
6
|
|
|
|
7
|
|
This library is free software; you can redistribute it and/or
|
|
8
|
|
modify it under the terms of the GNU Lesser General Public
|
|
9
|
|
License as published by the Free Software Foundation; either
|
|
10
|
|
version 2 of the License, or (at your option) any later version.
|
|
11
|
|
|
|
12
|
|
This library is distributed in the hope that it will be useful,
|
|
13
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
14
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
15
|
|
Lesser General Public License for more details.
|
|
16
|
|
|
|
17
|
|
You should have received a copy of the GNU Lesser General Public
|
|
18
|
|
License along with this library; if not, write to the Free Software
|
|
19
|
|
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
20
|
|
*/
|
|
21
|
|
|
|
22
|
|
#pragma once
|
|
23
|
|
|
|
24
|
|
#include "common/Common.h" // for clampBits
|
|
25
|
|
#include <algorithm> // for generate_n
|
|
26
|
|
#include <cassert> // for assert
|
|
27
|
|
#include <functional> // for function
|
|
28
|
|
#include <iterator> // for back_inserter
|
|
29
|
|
#include <type_traits> // for enable_if, is_convertible
|
|
30
|
|
#include <vector> // for vector
|
|
31
|
|
|
|
32
|
|
namespace rawspeed {
|
|
33
|
|
|
|
34
|
|
template <typename T, int TableBitWidth> class SimpleLUT final {
|
|
35
|
|
public:
|
|
36
|
|
using value_type = T;
|
|
37
|
|
|
|
38
|
1
|
SimpleLUT() = default;
|
|
39
|
|
|
|
40
|
|
private:
|
|
41
|
|
std::vector<value_type> table;
|
|
42
|
|
|
|
43
|
|
public:
|
|
44
|
|
template <typename F,
|
|
45
|
|
typename = std::enable_if<std::is_convertible<
|
|
46
|
|
F, std::function<value_type(
|
|
47
|
|
typename decltype(table)::size_type,
|
|
48
|
|
typename decltype(table)::size_type)>>::value>>
|
|
49
|
1
|
explicit SimpleLUT(F&& f) {
|
|
50
|
1
|
const auto fullTableSize = 1U << TableBitWidth;
|
|
51
|
1
|
table.reserve(fullTableSize);
|
|
52
|
1
|
std::generate_n(std::back_inserter(table), fullTableSize,
|
|
53
|
1
|
[&f, table = &table]() {
|
|
54
|
|
// which row [0..fullTableSize) are we filling?
|
|
55
|
1
|
const auto i = table->size();
|
|
56
|
1
|
return f(i, fullTableSize);
|
|
57
|
|
});
|
|
58
|
0
|
assert(table.size() == fullTableSize);
|
|
59
|
|
}
|
|
60
|
|
|
|
61
|
1
|
inline value_type operator[](int x) const {
|
|
62
|
1
|
unsigned clampedX = clampBits(x, TableBitWidth);
|
|
63
|
1
|
return table[clampedX];
|
|
64
|
|
}
|
|
65
|
|
};
|
|
66
|
|
|
|
67
|
|
} // namespace rawspeed
|
LebedevRI