genode/repos/os/include/util/geometry.h
2014-08-11 15:55:31 +02:00

201 lines
4.9 KiB
C++

/*
* \brief Geometric primitives
* \author Norman Feske
* \date 2006-08-05
*/
/*
* Copyright (C) 2006-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _INCLUDE__UTIL__GEOMETRY_H_
#define _INCLUDE__UTIL__GEOMETRY_H_
#include <util/misc_math.h>
#include <base/stdint.h>
namespace Genode {
template <typename CT = int> class Point;
template <typename DT = unsigned> class Area;
template <typename CT = int, typename DT = unsigned> class Rect;
}
/**
* \param CT coordinate type
*/
template <typename CT>
class Genode::Point
{
private:
CT _x, _y;
public:
Point(CT x, CT y): _x(x), _y(y) { }
Point(): _x(0), _y(0) { }
int x() const { return _x; }
int y() const { return _y; }
/**
* Operator for adding points
*/
Point operator + (Point const &p) const { return Point(_x + p.x(), _y + p.y()); }
/**
* Operator for subtracting points
*/
Point operator - (Point const &p) const { return Point(_x - p.x(), _y - p.y()); }
/**
* Operator for testing non-equality of two points
*/
bool operator != (Point const &p) const { return p.x() != _x || p.y() != _y; }
/**
* Operator for testing equality of two points
*/
bool operator == (Point const &p) const { return p.x() == _x && p.y() == _y; }
};
/**
* \param DT distance type
*/
template <typename DT>
class Genode::Area
{
private:
DT _w, _h;
public:
Area(DT w, DT h): _w(w), _h(h) { }
Area(): _w(0), _h(0) { }
DT w() const { return _w; }
DT h() const { return _h; }
bool valid() const { return _w > 0 && _h > 0; }
size_t count() const { return _w*_h; }
/**
* Operator for testing non-equality of two areas
*/
bool operator != (Area const &a) const { return a.w() != _w || a.h() != _h; }
/**
* Operator for testing equality of two areas
*/
bool operator == (Area const &a) const { return a.w() == _w && a.h() == _h; }
};
/**
* Rectangle
*
* A valid rectangle consists of two points wheras point 2 has higher or equal
* coordinates than point 1. All other cases are threated as invalid
* rectangles.
*
* \param CT coordinate type
* \param DT distance type
*/
template <typename CT, typename DT>
class Genode::Rect
{
private:
Point<CT> _p1, _p2;
public:
/**
* Constructors
*/
Rect(Point<CT> p1, Point<CT> p2): _p1(p1), _p2(p2) { }
Rect(Point<CT> p, Area<DT> a)
: _p1(p), _p2(p.x() + a.w() - 1, p.y() + a.h() - 1) { }
Rect() : /* invalid */ _p1(1, 1), _p2(0, 0) { }
/**
* Accessors
*/
CT x1() const { return _p1.x(); }
CT y1() const { return _p1.y(); }
CT x2() const { return _p2.x(); }
CT y2() const { return _p2.y(); }
DT w() const { return _p2.x() - _p1.x() + 1; }
DT h() const { return _p2.y() - _p1.y() + 1; }
Point<CT> p1() const { return _p1; }
Point<CT> p2() const { return _p2; }
Area<DT> area() const { return Area<DT>(w(), h()); }
/**
* Return true if rectangle area is greater than zero
*/
bool valid() const { return _p1.x() <= _p2.x() && _p1.y() <= _p2.y(); }
/**
* Return true if area fits in rectangle
*/
bool fits(Area<DT> area) const { return w() >= area.w() && h() >= area.h(); }
/**
* Return true if the specified point lies within the rectangle
*/
bool contains(Point<CT> p) const {
return p.x() >= x1() && p.x() <= x2() && p.y() >= y1() && p.y() <= y2(); }
/**
* Create new rectangle by intersecting two rectangles
*/
static Rect intersect(Rect r1, Rect r2) {
return Rect(Point<CT>(max(r1.x1(), r2.x1()), max(r1.y1(), r2.y1())),
Point<CT>(min(r1.x2(), r2.x2()), min(r1.y2(), r2.y2()))); }
/**
* Compute compounding rectangle of two rectangles
*/
static Rect compound(Rect r1, Rect r2) {
return Rect(Point<CT>(min(r1.x1(), r2.x1()), min(r1.y1(), r2.y1())),
Point<CT>(max(r1.x2(), r2.x2()), max(r1.y2(), r2.y2()))); }
/**
* Cut out rectangle from rectangle
*
* \param r rectangle to cut out
*
* In the worst case (if we cut a hole into the rectangle) we get
* four valid resulting rectangles.
*/
void cut(Rect r, Rect *top, Rect *left, Rect *right, Rect *bottom) const
{
/* limit the cut-out area to the actual rectangle */
r = intersect(r, *this);
*top = Rect(Point<CT>(x1(), y1()), Point<CT>(x2(), r.y1() - 1));
*left = Rect(Point<CT>(x1(), r.y1()), Point<CT>(r.x1() - 1, r.y2()));
*right = Rect(Point<CT>(r.x2() + 1, r.y1()), Point<CT>(x2(), r.y2()));
*bottom = Rect(Point<CT>(x1(), r.y2() + 1), Point<CT>(x2(), y2()));
}
/**
* Return position of an area when centered within the rectangle
*/
Point<CT> center(Area<DT> area) const {
return Point<CT>(((CT)w() - (CT)area.w())/2,
((CT)h() - (CT)area.h())/2) + p1(); }
};
#endif /* _INCLUDE__UTIL__GEOMETRY_H_ */