png++
0.2.9
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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_GENERATOR_HPP_INCLUDED 00032 #define PNGPP_GENERATOR_HPP_INCLUDED 00033 00034 #include <cassert> 00035 #include <stdexcept> 00036 #include <iostream> 00037 #include <ostream> 00038 00039 #include "config.hpp" 00040 #include "error.hpp" 00041 #include "streaming_base.hpp" 00042 #include "writer.hpp" 00043 00044 namespace png 00045 { 00046 00112 template< typename pixel, 00113 class pixgen, 00114 class info_holder = def_image_info_holder, 00115 bool interlacing_supported = false > 00116 class generator 00117 : public streaming_base< pixel, info_holder > 00118 { 00119 public: 00128 template< typename ostream > 00129 void write(ostream& stream) 00130 { 00131 writer< ostream > wr(stream); 00132 wr.set_image_info(this->get_info()); 00133 wr.write_info(); 00134 00135 #if __BYTE_ORDER == __LITTLE_ENDIAN 00136 if (pixel_traits< pixel >::get_bit_depth() == 16) 00137 { 00138 #ifdef PNG_WRITE_SWAP_SUPPORTED 00139 wr.set_swap(); 00140 #else 00141 throw error("Cannot write 16-bit image: recompile with PNG_WRITE_SWAP_SUPPORTED."); 00142 #endif 00143 } 00144 #endif 00145 00146 size_t pass_count; 00147 if (this->get_info().get_interlace_type() != interlace_none) 00148 { 00149 #ifdef PNG_WRITE_INTERLACING_SUPPORTED 00150 if (interlacing_supported) 00151 { 00152 pass_count = wr.set_interlace_handling(); 00153 } 00154 else 00155 { 00156 throw std::logic_error("Cannot write interlaced image: generator does not support it."); 00157 } 00158 #else 00159 throw error("Cannot write interlaced image: interlace handling disabled."); 00160 #endif 00161 } 00162 else 00163 { 00164 pass_count = 1; 00165 } 00166 pixgen* pixel_gen = static_cast< pixgen* >(this); 00167 for (size_t pass = 0; pass < pass_count; ++pass) 00168 { 00169 pixel_gen->reset(pass); 00170 00171 for (uint_32 pos = 0; pos < this->get_info().get_height(); ++pos) 00172 { 00173 wr.write_row(pixel_gen->get_next_row(pos)); 00174 } 00175 } 00176 00177 wr.write_end_info(); 00178 } 00179 00180 protected: 00181 typedef streaming_base< pixel, info_holder > base; 00182 00187 explicit generator(image_info& info) 00188 : base(info) 00189 { 00190 } 00191 00196 generator(size_t width, size_t height) 00197 : base(width, height) 00198 { 00199 } 00200 }; 00201 00202 } // namespace png 00203 00204 #endif // PNGPP_GENERATOR_HPP_INCLUDED