mapnik/include/mapnik/image_reader.hpp
Dane Springmeyer 8bb77bce92 image readers: ability to check if image has alpha before full read
Conflicts:
	src/webp_reader.cpp
2014-06-16 09:52:26 -07:00

78 lines
2.4 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2011 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_IMAGE_READER_HPP
#define MAPNIK_IMAGE_READER_HPP
// mapnik
#include <mapnik/image_data.hpp>
#include <mapnik/config.hpp>
#include <mapnik/noncopyable.hpp>
#include <mapnik/factory.hpp>
// boost
#include <boost/optional.hpp>
// stl
#include <stdexcept>
#include <string>
namespace mapnik
{
class image_reader_exception : public std::exception
{
private:
std::string message_;
public:
image_reader_exception(std::string const& message)
: message_(message) {}
~image_reader_exception() throw() {}
virtual const char* what() const throw()
{
return message_.c_str();
}
};
struct MAPNIK_DECL image_reader : private mapnik::noncopyable
{
virtual unsigned width() const=0;
virtual unsigned height() const=0;
virtual bool has_alpha() const=0;
virtual bool premultiplied_alpha() const=0;
virtual void read(unsigned x,unsigned y,image_data_32& image)=0;
virtual ~image_reader() {}
};
template <typename...Args>
bool register_image_reader(std::string const& type, image_reader* (* fun)(Args...))
{
return factory<image_reader,std::string, Args...>::instance().register_product(type, fun);
}
MAPNIK_DECL image_reader* get_image_reader(std::string const& file,std::string const& type);
MAPNIK_DECL image_reader* get_image_reader(std::string const& file);
MAPNIK_DECL image_reader* get_image_reader(char const* data, size_t size);
}
#endif // MAPNIK_IMAGE_READER_HPP