mapnik/include/mapnik/image_view_null.hpp
2017-05-05 13:02:01 +02:00

65 lines
2.4 KiB
C++

/*****************************************************************************
*
* This file is part of Mapnik (c++ mapping toolkit)
*
* Copyright (C) 2017 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_VIEW_NULL_HPP
#define MAPNIK_IMAGE_VIEW_NULL_HPP
#include <mapnik/image_view.hpp>
//stl
#include <stdexcept>
namespace mapnik {
template <>
class MAPNIK_DECL image_view<image_null>
{
public:
using pixel_type = image_null::pixel_type;
static const image_dtype dtype = image_null::dtype;
image_view() {}
~image_view() {};
image_view(image_view<image_null> const&) {}
image_view<image_null> & operator=(image_view<image_null> const&) { return *this; }
bool operator==(image_view<image_null> const&) const { return true; }
bool operator<(image_view<image_null> const&) const { return false; }
std::size_t x() const { return 0; }
std::size_t y() const { return 0; }
std::size_t width() const { return 0; }
std::size_t height() const { return 0; }
pixel_type operator() (std::size_t, std::size_t) const { throw std::runtime_error("Can not get from a null image view"); }
std::size_t size() const { return 0; }
std::size_t row_size() const { return 0; }
const pixel_type* get_row(std::size_t) const { return nullptr; }
const pixel_type* get_row(std::size_t, std::size_t) const { return nullptr; }
bool get_premultiplied() const { return false; }
double get_offset() const { return 0.0; }
double get_scaling() const { return 1.0; }
image_dtype get_dtype() const { return dtype; }
};
} // end ns
#endif // MAPNIK_IMAGE_VIEW_NULL_HPP