png++  0.2.9
packed_pixel.hpp
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1 /*
2  * Copyright (C) 2007,2008 Alex Shulgin
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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 >
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
The packed pixel class template.
Definition: packed_pixel.hpp:54
png_byte byte
Definition: types.hpp:39
static int get_bit_depth()
Definition: packed_pixel.hpp:68
Definition: packed_pixel.hpp:41
Definition: color.hpp:36
static byte get_bit_mask()
Definition: packed_pixel.hpp:73
packed_pixel(byte value=0)
Definition: packed_pixel.hpp:58