png++: packed_pixel.hpp Source File

png++ 0.2.10

packed_pixel.hpp
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1 /*
2 * Copyright (C) 2007,2008 Alex Shulgin
3 *
4 * This file is part of png++ the C++ wrapper for libpng. PNG++ is free
5 * software; the exact copying conditions are as follows:
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright notice,
11 * this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * 3. The name of the author may not be used to endorse or promote products
18 * derived from this software without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
23 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
25 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31 #ifndef PNGPP_PACKED_PIXEL_HPP_INCLUDED
32 #define PNGPP_PACKED_PIXEL_HPP_INCLUDED
33
34 #include "types.hpp"
35
36 namespace png
37 {
38
39 namespace detail
40 {
41 template< int bits > class allowed_bit_depth;
42
43 template<> class allowed_bit_depth< 1 > {};
44 template<> class allowed_bit_depth< 2 > {};
45 template<> class allowed_bit_depth< 4 > {};
46 } // namespace detail
47
53 template< int bits >
54 class packed_pixel
55 : detail::allowed_bit_depth< bits >
56 {
57 public:
58 packed_pixel(byte value = 0)
59 : m_value(value & get_bit_mask())
60 {
61 }
62
63 operator byte() const
64 {
65 return m_value;
66 }
67
68 static int get_bit_depth()
69 {
70 return bits;
71 }
72
73 static byte get_bit_mask()
74 {
75 return (1 << bits) - 1;
76 }
77
78 private:
79 byte m_value;
80 };
81
82 } // namespace png
83
84 #endif // PNGPP_PACKED_PIXEL_HPP_INCLUDED
types.hpp
png::packed_pixel
The packed pixel class template.
Definition: packed_pixel.hpp:54
png::byte
png_byte byte
Definition: types.hpp:39
png::packed_pixel::get_bit_depth
static int get_bit_depth()
Definition: packed_pixel.hpp:68
png::detail::allowed_bit_depth
Definition: packed_pixel.hpp:41
png
Definition: color.hpp:36
png::packed_pixel::get_bit_mask
static byte get_bit_mask()
Definition: packed_pixel.hpp:73
png::packed_pixel::packed_pixel
packed_pixel(byte value=0)
Definition: packed_pixel.hpp:58