QGpCoreTools::Line2D Class Reference

#include <Line2D.h>

List of all members.

Public Member Functions
Point2D	intersect (const Line2D &o, bool &ok) const
	Line2D (double c=0.0)
	Line2D (double b, double c)
	Line2D (double x1, double y1, double az)
	Line2D (const Line2D &o)
	~Line2D ()
Protected Attributes
double	_a
double	_b
double	_c

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Constructor & Destructor Documentation

QGpCoreTools::Line2D::Line2D

(

double

c = 0.0

)

Construct a vertical line (parallel to y axis) crossing at (c, 0)

line equation is a * y + b * x=c (with a=0 and b=1).

References _a, _b, _c, and TRACE.

{
  TRACE;
  _a=0;
  _b=1;
  _c=c;
}

QGpCoreTools::Line2D::Line2D	(	double	b,
		double	c
	)

Construct any line except vertical ones.

line equation is a * y + b * x=c (with a=1)

References _a, _b, _c, and TRACE.

{
  TRACE;
  _a=1;
  _b=b;
  _c=c;
}

QGpCoreTools::Line2D::Line2D	(	double	x1,
		double	y1,
		double	az
	)

Construct any line passing by point ( x1, y1) and with azimuth az (counted clockwize from North).

line equation is a * y + b * x=c

References _a, _b, _c, QGpCoreTools::tan(), and TRACE.

{
  TRACE;
  if(az==0) {
    _a=0;
    _b=1;
    _c=x1;
  } else {
    _a=1;
    _b=-::tan(0.5 * M_PI - az);
    _c=y1 + _b * x1;
  }
}

QGpCoreTools::Line2D::Line2D

(

const Line2D &

o

)

Copy constructor

References _a, _b, and _c.

{
  _a=o._a;
  _b=o._b;
  _c=o._c;
}

QGpCoreTools::Line2D::~Line2D

(

)

[inline]

{}

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Member Function Documentation

Point2D QGpCoreTools::Line2D::intersect	(	const Line2D &	o,
		bool &	ok
	)		const

Returns interstection between this line and line o. If no intersection is found, ok is set to false.

References _a, _b, _c, QGpCoreTools::Point2D::setX(), QGpCoreTools::Point2D::setY(), TRACE, and QGpCoreTools::Point2D::x().

Referenced by QGpCoreTools::PointLocate::position().

{
  TRACE;
  Point2D inter(0, 0);
  if(_a==o._a && _b==o._b) {
    // Either no intersection or infinity of intersections
    ok=false;
  } else if(_a==0) { // this is vertical
    inter.setX(_c); // _b is 1
    inter.setY(o._c - o._b * inter.x()); // o._a is 1
    ok=true;
  } else if(o._a==0) { // o is vertical
    inter.setX(o._c); // o._b is 1
    inter.setY(_c - _b * inter.x()); // _a is 1
    ok=true;
  } else { // _a and o._a are 1
    inter.setX((_c - o._c)/(_b - o._b));
    inter.setY(_c - _b * inter.x());
    ok=true;
  }
  return inter;
}

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Member Data Documentation

double QGpCoreTools::Line2D::_a [protected]

Referenced by intersect(), and Line2D().

double QGpCoreTools::Line2D::_b [protected]

Referenced by intersect(), and Line2D().

double QGpCoreTools::Line2D::_c [protected]

Referenced by intersect(), and Line2D().

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The documentation for this class was generated from the following files:

• QGpCoreTools/Line2D.h
• QGpCoreTools/Line2D.cpp