mapnik/include/mapnik/image_view.hpp
2012-07-12 20:00:02 +01:00

110 lines
2.7 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_VIEW_HPP
#define MAPNIK_IMAGE_VIEW_HPP
namespace mapnik {
template <typename T>
class image_view
{
public:
typedef typename T::pixel_type pixel_type;
image_view(unsigned x, unsigned y, unsigned width, unsigned height, T const& data)
: x_(x),
y_(y),
width_(width),
height_(height),
data_(data)
{
if (x_ >= data_.width()) x_=data_.width()-1;
if (y_ >= data_.height()) x_=data_.height()-1;
if (x_ + width_ > data_.width()) width_= data_.width() - x_;
if (y_ + height_ > data_.height()) height_= data_.height() - y_;
}
~image_view() {}
image_view(image_view<T> const& rhs)
: x_(rhs.x_),
y_(rhs.y_),
width_(rhs.width_),
height_(rhs.height_),
data_(rhs.data_) {}
image_view<T> & operator=(image_view<T> const& rhs)
{
if (&rhs==this) return *this;
x_ = rhs.x_;
y_ = rhs.y_;
width_ = rhs.width_;
height_ = rhs.height_;
data_ = rhs.data_;
return *this;
}
inline unsigned x() const
{
return x_;
}
inline unsigned y() const
{
return y_;
}
inline unsigned width() const
{
return width_;
}
inline unsigned height() const
{
return height_;
}
inline const pixel_type* getRow(unsigned row) const
{
return data_.getRow(row + y_) + x_;
}
inline T& data()
{
return data_;
}
inline T const& data() const
{
return data_;
}
private:
unsigned x_;
unsigned y_;
unsigned width_;
unsigned height_;
T const& data_;
};
}
#endif // MAPNIK_IMAGE_VIEW_HPP