simgear/simgear/math/SGRect.hxx

// Class representing a rectangular region
//
// Copyright (C) 2012  Thomas Geymayer <tomgey@gmail.com>
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU Library General Public
// License as published by the Free Software Foundation; either
// version 2 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
// Library General Public License for more details.
//
// You should have received a copy of the GNU Library 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 SG_RECT_HXX_
#define SG_RECT_HXX_

#include "SGLimits.hxx"
#include "SGVec2.hxx"

template<typename T>
class SGRect
{
  public:

    SGRect():
      _min(SGLimits<T>::max(), SGLimits<T>::max()),
      _max(-SGLimits<T>::max(), -SGLimits<T>::max())
    {

    }

    explicit SGRect(const SGVec2<T>& pt):
      _min(pt),
      _max(pt)
    {

    }

    SGRect(T x, T y):
      _min(x, y),
      _max(x, y)
    {

    }

    SGRect(const SGVec2<T>& min, const SGVec2<T>& max):
      _min(min),
      _max(max)
    {

    }

    SGRect(T x, T y, T w, T h):
      _min(x, y),
      _max(x + w, y + h)
    {

    }

    template<typename S>
    explicit SGRect(const SGRect<S>& rect):
      _min(rect.getMin()),
      _max(rect.getMax())
    {

    }

    void setMin(const SGVec2<T>& min) { _min = min; }
    const SGVec2<T>& getMin() const { return _min; }

    void setMax(const SGVec2<T>& max) { _max = max; }
    const SGVec2<T>& getMax() const { return _max; }

    void set(T x, T y, T w, T h)
    {
      _min.x() = x;
      _min.y() = y;
      _max.x() = x + w;
      _max.y() = y + h;
    }

    T x() const { return _min.x(); }
    T y() const { return _min.y(); }
    T width() const { return _max.x() - _min.x(); }
    T height() const { return _max.y() - _min.y(); }
    SGVec2<T> const& pos() const { return _min; }
    SGVec2<T> size() const { return SGVec2<T>(width(), height()); }

    void setX(T x) { T w = width(); _min.x() = x; _max.x() = x + w; }
    void setY(T y) { T h = height(); _min.y() = y; _max.y() = y + h; }
    void setWidth(T w) { _max.x() = _min.x() + w; }
    void setHeight(T h) { _max.y() = _min.y() + h; }
    void setPos(const SGVec2<T>& p) { setX(p.x()); setY(p.y()); }
    void setSize(const SGVec2<T>& s) { setWidth(s.x()); setHeight(s.y()); }

    T l() const { return _min.x(); }
    T r() const { return _max.x(); }
    T t() const { return _min.y(); }
    T b() const { return _max.y(); }

    T& l() { return _min.x(); }
    T& r() { return _max.x(); }
    T& t() { return _min.y(); }
    T& b() { return _max.y(); }

    void setLeft(T l) { _min.x() = l; }
    void setRight(T r) { _max.x() = r; }
    void setTop(T t) { _min.y() = t; }
    void setBottom(T b) { _max.y() = b; }

    /**
     * Expand rectangle to include the given position
     */
    void expandBy(T x, T y)
    {
      if( x < _min.x() ) _min.x() = x;
      if( x > _max.x() ) _max.x() = x;

      if( y < _min.y() ) _min.y() = y;
      if( y > _max.y() ) _max.y() = y;
    }

    /**
     * Move rect by vector
     */
    SGRect& operator+=(const SGVec2<T>& offset)
    {
      _min += offset;
      _max += offset;
      return *this;
    }

    /**
     * Move rect by vector in inverse direction
     */
    SGRect& operator-=(const SGVec2<T>& offset)
    {
      _min -= offset;
      _max -= offset;
      return *this;
    }

    bool operator==(const SGRect<T>& rhs) const
    {
      return _min == rhs._min
          && _max == rhs._max;
    }

    bool operator!=(const SGRect<T>& rhs) const
    {
      return !(*this == rhs);
    }

    bool contains(T x, T y) const
    {
      return _min.x() <= x && x <= _max.x()
          && _min.y() <= y && y <= _max.y();
    }

    bool contains(T x, T y, T margin) const
    {
      return (_min.x() - margin) <= x && x <= (_max.x() + margin)
          && (_min.y() - margin) <= y && y <= (_max.y() + margin);
    }

  private:
    SGVec2<T> _min,
              _max;
};

template<typename T>
inline SGRect<T> operator+(SGRect<T> rect, const SGVec2<T>& offset)
{
  return rect += offset;
}

template<typename T>
inline SGRect<T> operator+(const SGVec2<T>& offset, SGRect<T> rect)
{
  return rect += offset;
}

template<typename T>
inline SGRect<T> operator-(SGRect<T> rect, const SGVec2<T>& offset)
{
  return rect -= offset;
}

template<typename T>
inline SGRect<T> operator-(const SGVec2<T>& offset, SGRect<T> rect)
{
  return rect -= offset;
}

template<typename char_type, typename traits_type, typename T>
inline
std::basic_ostream<char_type, traits_type>&
operator<<(std::basic_ostream<char_type, traits_type>& s, const SGRect<T>& rect)
{ return s << "min = " << rect.getMin() << ", max = " << rect.getMax(); }

typedef SGRect<int> SGRecti;
typedef SGRect<float> SGRectf;
typedef SGRect<double> SGRectd;

#endif /* SG_RECT_HXX_ */