genode/os/include/nitpicker_gfx/geometry.h
2013-01-15 10:18:12 +01:00

162 lines
3.7 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__NITPICKER_GFX__GEOMETRY_H_
#define _INCLUDE__NITPICKER_GFX__GEOMETRY_H_
#include "miscmath.h"
class Point
{
private:
int _x, _y;
public:
Point(int x, int 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 p) { return Point(_x + p.x(), _y + p.y()); }
/**
* Operator for subtracting points
*/
Point operator - (Point p) { return Point(_x - p.x(), _y - p.y()); }
/**
* Operator for testing non-equality of two points
*/
bool operator != (Point p) { return p.x() != _x || p.y() != _y; }
};
class Area
{
private:
int _w, _h;
public:
Area(int w, int h): _w(w), _h(h) { }
Area(): _w(0), _h(0) { }
int w() const { return _w; }
int h() const { return _h; }
bool valid() const { return _w > 0 && _h > 0; }
int num_pixels() const { return _w*_h; }
};
/*
* 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.
*/
class Rect
{
private:
Point _p1, _p2;
public:
/**
* Constructors
*/
Rect(Point p1, Point p2): _p1(p1), _p2(p2) { }
Rect(Point p, Area a):
_p1(p), _p2(p.x() + a.w() - 1, p.y() + a.h() - 1) { }
Rect() { }
/**
* Assign new coordinates
*/
void rect(Rect r) { _p1 = r.p1(); _p2 = r.p2(); }
/**
* Accessors
*/
int x1() const { return _p1.x(); }
int y1() const { return _p1.y(); }
int x2() const { return _p2.x(); }
int y2() const { return _p2.y(); }
int w() const { return _p2.x() - _p1.x() + 1; }
int h() const { return _p2.y() - _p1.y() + 1; }
Point p1() const { return _p1; }
Point p2() const { return _p2; }
Area area() const { return Area(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 area) const { return w() >= area.w() && h() >= area.h(); }
/**
* Create new rectangle by intersecting two rectangles
*/
static Rect intersect(Rect r1, Rect r2) {
return Rect(Point(max(r1.x1(), r2.x1()), max(r1.y1(), r2.y1())),
Point(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(min(r1.x1(), r2.x1()), min(r1.y1(), r2.y1())),
Point(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)
{
/* limit the cut-out area to the actual rectangle */
r = intersect(r, *this);
*top = Rect(Point(x1(), y1()), Point(x2(), r.y1() - 1));
*left = Rect(Point(x1(), r.y1()), Point(r.x1() - 1, r.y2()));
*right = Rect(Point(r.x2() + 1, r.y1()), Point(x2(), r.y2()));
*bottom = Rect(Point(x1(), r.y2() + 1), Point(x2(), y2()));
}
/**
* Return position of an area when centered within the rectangle
*/
Point center(Area area) {
return Point((w() - area.w())/2, (h() - area.h())/2) + p1(); }
};
#endif /* _INCLUDE__NITPICKER_GFX__GEOMETRY_H_ */