00001 /* 00002 * Copyright (C) 2007,2008 Alex Shulgin 00003 * 00004 * This file is part of png++ the C++ wrapper for libpng. PNG++ is free 00005 * software; the exact copying conditions are as follows: 00006 * 00007 * Redistribution and use in source and binary forms, with or without 00008 * modification, are permitted provided that the following conditions are met: 00009 * 00010 * 1. Redistributions of source code must retain the above copyright notice, 00011 * this list of conditions and the following disclaimer. 00012 * 00013 * 2. Redistributions in binary form must reproduce the above copyright 00014 * notice, this list of conditions and the following disclaimer in the 00015 * documentation and/or other materials provided with the distribution. 00016 * 00017 * 3. The name of the author may not be used to endorse or promote products 00018 * derived from this software without specific prior written permission. 00019 * 00020 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 00021 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 00022 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN 00023 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 00024 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED 00025 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 00026 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF 00027 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 00028 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 00029 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 00030 */ 00031 #ifndef PNGPP_PACKED_PIXEL_HPP_INCLUDED 00032 #define PNGPP_PACKED_PIXEL_HPP_INCLUDED 00033 00034 #include "types.hpp" 00035 00036 namespace png 00037 { 00038 00039 namespace detail 00040 { 00041 template< size_t bits > class allowed_bit_depth; 00042 00043 template<> class allowed_bit_depth< 1 > {}; 00044 template<> class allowed_bit_depth< 2 > {}; 00045 template<> class allowed_bit_depth< 4 > {}; 00046 } // namespace detail 00047 00053 template< size_t bits > 00054 class packed_pixel 00055 : detail::allowed_bit_depth< bits > 00056 { 00057 public: 00058 packed_pixel(byte value = 0) 00059 : m_value(value & get_bit_mask()) 00060 { 00061 } 00062 00063 operator byte() const 00064 { 00065 return m_value; 00066 } 00067 00068 static size_t const get_bit_depth() 00069 { 00070 return bits; 00071 } 00072 00073 static byte const get_bit_mask() 00074 { 00075 return (1 << bits) - 1; 00076 } 00077 00078 private: 00079 byte m_value; 00080 }; 00081 00082 } // namespace png 00083 00084 #endif // PNGPP_PACKED_PIXEL_HPP_INCLUDED
1.7.1