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_GA_PIXEL_HPP_INCLUDED
32 #define PNGPP_GA_PIXEL_HPP_INCLUDED
33 
34 #include <limits>
35 
36 #include "types.hpp"
37 #include "pixel_traits.hpp"
38 
39 namespace png
40 {
41 
42     /**
43      * \brief Basic Gray+Alpha pixel type.
44      */
45     template< typename T >
46     struct basic_ga_pixel
47     {
48         typedef pixel_traits< basic_ga_pixel< T > > traits;
49 
50         /**
51          * \brief Constructs basic_ga_pixel object from \a value and
52          * \a alpha components passed as parameters.  Alpha defaults
53          * to full opacity.
54          */
basic_ga_pixelpng::basic_ga_pixel55         basic_ga_pixel(T value = 0, T alpha = traits::get_alpha_filler())
56             : value(value), alpha(alpha)
57         {
58         }
59 
60         T value;
61         T alpha;
62     };
63 
64     /**
65      * \brief The 8-bit Gray+Alpha pixel type.
66      */
67     typedef basic_ga_pixel< byte > ga_pixel;
68 
69     /**
70      * \brief The 16-bit Gray+Alpha pixel type.
71      */
72     typedef basic_ga_pixel< uint_16 > ga_pixel_16;
73 
74     /**
75      * \brief Pixel traits specialization for basic_ga_pixel.
76      */
77     template< typename T >
78     struct pixel_traits< basic_ga_pixel< T > >
79         : basic_pixel_traits< basic_ga_pixel< T >, T, color_type_ga >,
80           basic_alpha_pixel_traits< T >
81     {
82     };
83 
84 } // namespace png
85 
86 #endif // PNGPP_GA_PIXEL_HPP_INCLUDED
87