mapnik/include/mapnik/miniz_png.hpp
2013-07-30 12:32:32 -04:00

84 lines
2.8 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2012 Artem Pavlenko
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*****************************************************************************/
#ifndef MAPNIK_MINIZ_PNG_HPP
#define MAPNIK_MINIZ_PNG_HPP
// mapnik
#include <mapnik/palette.hpp>
// stl
#include <vector>
#include <iostream>
#include <stdexcept>
/* miniz.c porting issues:
- duplicate symbols in python bindings require moving miniz.c include to just cpp file
- due to http://code.google.com/p/miniz/issues/detail?id=7
- avoiding including miniz.c here requires fwd declaring the two structs below
- being able to fwd declare requires removing typedef from struct declarations in miniz.c
- being able to fwd declare also requires using pointers to structs
- if updated, need to apply c++11 fix: https://github.com/mapnik/mapnik/issues/1967
*/
// TODO: try using #define MINIZ_HEADER_FILE_ONLY
struct tdefl_output_buffer;
struct tdefl_compressor;
namespace mapnik { namespace MiniZ {
using mapnik::rgb;
class PNGWriter {
public:
PNGWriter(int level, int strategy);
~PNGWriter();
private:
inline void writeUInt32BE(unsigned char *target, unsigned int value);
size_t startChunk(const unsigned char header[], size_t length);
void finishChunk(size_t start);
public:
void writeIHDR(unsigned int width, unsigned int height, unsigned char pixel_depth);
void writePLTE(std::vector<rgb> const& palette);
void writetRNS(std::vector<unsigned> const& alpha);
template<typename T>
void writeIDAT(T const& image);
template<typename T>
void writeIDATStripAlpha(T const& image);
void writeIEND();
void toStream(std::ostream& stream);
private:
tdefl_compressor *compressor;
tdefl_output_buffer *buffer;
static const unsigned char preamble[];
static const unsigned char IHDR_tpl[];
static const unsigned char PLTE_tpl[];
static const unsigned char tRNS_tpl[];
static const unsigned char IDAT_tpl[];
static const unsigned char IEND_tpl[];
};
}}
#endif // MAPNIK_MINIZ_PNG_HPP