irrlicht/include/rect.h

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// Copyright (C) 2002-2012 Nikolaus Gebhardt
// This file is part of the "Irrlicht Engine".
// For conditions of distribution and use, see copyright notice in irrlicht.h
#pragma once
#include "irrTypes.h"
#include "dimension2d.h"
#include "position2d.h"
namespace irr
{
namespace core
{
//! Rectangle template.
/** Mostly used by 2D GUI elements and for 2D drawing methods.
It has 2 positions instead of position and dimension and a fast
method for collision detection with other rectangles and points.
Coordinates are (0,0) for top-left corner, and increasing to the right
and to the bottom.
*/
template <class T>
class rect
{
public:
//! Default constructor creating empty rectangle at (0,0)
constexpr rect() : UpperLeftCorner(0,0), LowerRightCorner(0,0) {}
//! Constructor with two corners
constexpr rect(T x, T y, T x2, T y2)
: UpperLeftCorner(x,y), LowerRightCorner(x2,y2) {}
//! Constructor with two corners
constexpr rect(const position2d<T>& upperLeft, const position2d<T>& lowerRight)
: UpperLeftCorner(upperLeft), LowerRightCorner(lowerRight) {}
//! Constructor with upper left corner and dimension
template <class U>
constexpr rect(const position2d<T>& pos, const dimension2d<U>& size)
: UpperLeftCorner(pos), LowerRightCorner(pos.X + size.Width, pos.Y + size.Height) {}
//! Constructor with upper left at 0,0 and lower right using dimension
template <class U>
explicit constexpr rect(const dimension2d<U>& size)
: UpperLeftCorner(0,0), LowerRightCorner(size.Width, size.Height) {}
//! move right by given numbers
rect<T> operator+(const position2d<T>& pos) const
{
rect<T> ret(*this);
return ret+=pos;
}
//! move right by given numbers
rect<T>& operator+=(const position2d<T>& pos)
{
UpperLeftCorner += pos;
LowerRightCorner += pos;
return *this;
}
//! move left by given numbers
rect<T> operator-(const position2d<T>& pos) const
{
rect<T> ret(*this);
return ret-=pos;
}
//! move left by given numbers
rect<T>& operator-=(const position2d<T>& pos)
{
UpperLeftCorner -= pos;
LowerRightCorner -= pos;
return *this;
}
//! equality operator
constexpr bool operator==(const rect<T>& other) const
{
return (UpperLeftCorner == other.UpperLeftCorner &&
LowerRightCorner == other.LowerRightCorner);
}
//! inequality operator
constexpr bool operator!=(const rect<T>& other) const
{
return (UpperLeftCorner != other.UpperLeftCorner ||
LowerRightCorner != other.LowerRightCorner);
}
//! compares size of rectangles
bool operator<(const rect<T>& other) const
{
return getArea() < other.getArea();
}
//! Returns size of rectangle
T getArea() const
{
return getWidth() * getHeight();
}
//! Returns if a 2d point is within this rectangle.
/** \param pos Position to test if it lies within this rectangle.
\return True if the position is within the rectangle, false if not. */
bool isPointInside(const position2d<T>& pos) const
{
return (UpperLeftCorner.X <= pos.X &&
UpperLeftCorner.Y <= pos.Y &&
LowerRightCorner.X >= pos.X &&
LowerRightCorner.Y >= pos.Y);
}
//! Check if the rectangle collides with another rectangle.
/** \param other Rectangle to test collision with
\return True if the rectangles collide. */
bool isRectCollided(const rect<T>& other) const
{
return (LowerRightCorner.Y > other.UpperLeftCorner.Y &&
UpperLeftCorner.Y < other.LowerRightCorner.Y &&
LowerRightCorner.X > other.UpperLeftCorner.X &&
UpperLeftCorner.X < other.LowerRightCorner.X);
}
//! Clips this rectangle with another one.
/** \param other Rectangle to clip with */
void clipAgainst(const rect<T>& other)
{
if (other.LowerRightCorner.X < LowerRightCorner.X)
LowerRightCorner.X = other.LowerRightCorner.X;
if (other.LowerRightCorner.Y < LowerRightCorner.Y)
LowerRightCorner.Y = other.LowerRightCorner.Y;
if (other.UpperLeftCorner.X > LowerRightCorner.X)
LowerRightCorner.X = other.UpperLeftCorner.X;
if (other.UpperLeftCorner.Y > LowerRightCorner.Y)
LowerRightCorner.Y = other.UpperLeftCorner.Y;
if (other.LowerRightCorner.X < UpperLeftCorner.X)
UpperLeftCorner.X = other.LowerRightCorner.X;
if (other.LowerRightCorner.Y < UpperLeftCorner.Y)
UpperLeftCorner.Y = other.LowerRightCorner.Y;
if (other.UpperLeftCorner.X > UpperLeftCorner.X)
UpperLeftCorner.X = other.UpperLeftCorner.X;
if (other.UpperLeftCorner.Y > UpperLeftCorner.Y)
UpperLeftCorner.Y = other.UpperLeftCorner.Y;
}
//! Moves this rectangle to fit inside another one.
/** \return True on success, false if not possible */
bool constrainTo(const rect<T>& other)
{
if (other.getWidth() < getWidth() || other.getHeight() < getHeight())
return false;
T diff = other.LowerRightCorner.X - LowerRightCorner.X;
if (diff < 0)
{
LowerRightCorner.X += diff;
UpperLeftCorner.X += diff;
}
diff = other.LowerRightCorner.Y - LowerRightCorner.Y;
if (diff < 0)
{
LowerRightCorner.Y += diff;
UpperLeftCorner.Y += diff;
}
diff = UpperLeftCorner.X - other.UpperLeftCorner.X;
if (diff < 0)
{
UpperLeftCorner.X -= diff;
LowerRightCorner.X -= diff;
}
diff = UpperLeftCorner.Y - other.UpperLeftCorner.Y;
if (diff < 0)
{
UpperLeftCorner.Y -= diff;
LowerRightCorner.Y -= diff;
}
return true;
}
//! Get width of rectangle.
T getWidth() const
{
return LowerRightCorner.X - UpperLeftCorner.X;
}
//! Get height of rectangle.
T getHeight() const
{
return LowerRightCorner.Y - UpperLeftCorner.Y;
}
//! If the lower right corner of the rect is smaller then the upper left, the points are swapped.
void repair()
{
if (LowerRightCorner.X < UpperLeftCorner.X)
{
T t = LowerRightCorner.X;
LowerRightCorner.X = UpperLeftCorner.X;
UpperLeftCorner.X = t;
}
if (LowerRightCorner.Y < UpperLeftCorner.Y)
{
T t = LowerRightCorner.Y;
LowerRightCorner.Y = UpperLeftCorner.Y;
UpperLeftCorner.Y = t;
}
}
//! Returns if the rect is valid to draw.
/** It would be invalid if the UpperLeftCorner is lower or more
right than the LowerRightCorner. */
bool isValid() const
{
return ((LowerRightCorner.X >= UpperLeftCorner.X) &&
(LowerRightCorner.Y >= UpperLeftCorner.Y));
}
//! Get the center of the rectangle
position2d<T> getCenter() const
{
return position2d<T>(
(UpperLeftCorner.X + LowerRightCorner.X) / 2,
(UpperLeftCorner.Y + LowerRightCorner.Y) / 2);
}
//! Get the dimensions of the rectangle
dimension2d<T> getSize() const
{
return dimension2d<T>(getWidth(), getHeight());
}
//! Adds a point to the rectangle
/** Causes the rectangle to grow bigger if point is outside of
the box
\param p Point to add to the box. */
void addInternalPoint(const position2d<T>& p)
{
addInternalPoint(p.X, p.Y);
}
//! Adds a point to the bounding rectangle
/** Causes the rectangle to grow bigger if point is outside of
the box
\param x X-Coordinate of the point to add to this box.
\param y Y-Coordinate of the point to add to this box. */
void addInternalPoint(T x, T y)
{
if (x>LowerRightCorner.X)
LowerRightCorner.X = x;
if (y>LowerRightCorner.Y)
LowerRightCorner.Y = y;
if (x<UpperLeftCorner.X)
UpperLeftCorner.X = x;
if (y<UpperLeftCorner.Y)
UpperLeftCorner.Y = y;
}
//! Upper left corner
position2d<T> UpperLeftCorner;
//! Lower right corner
position2d<T> LowerRightCorner;
};
//! Rectangle with float values
typedef rect<f32> rectf;
//! Rectangle with int values
typedef rect<s32> recti;
} // end namespace core
} // end namespace irr