mapnik/include/mapnik/image_reader.hpp
artemp 77e585895f + add premultiplied_alpha method to image_reader
* tiff - TIFFTAG_EXTRASAMPLES
  * png  - non-premultiplied alpha (http://www.libpng.org/pub/png/spec/1.1/PNG-Rationale.html)
  * jpeg - no-alpha channel, ensure pre-multiplied model
2012-09-28 16:37:21 +01:00

67 lines
2 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>
// 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
{
virtual unsigned width() const=0;
virtual unsigned height() const=0;
virtual bool premultiplied_alpha() const=0;
virtual void read(unsigned x,unsigned y,image_data_32& image)=0;
virtual ~image_reader() {}
};
bool register_image_reader(std::string const& type,image_reader* (*)(std::string const&));
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);
}
#endif // MAPNIK_IMAGE_READER_HPP