Ellipse< T > Class Template Reference

Equations to calculate the shape of an ellipse and to calculate points on the edge of the ellipse and to see if points are inside or outside. More...

#include <gin_geometry.h>

Public Member Functions
	Ellipse (T x_, T y_, T a_, T b_)
	Creates a ellipse with a given centre and width / height.
	Ellipse (T a_, T b_)
	Creates an ellipse centred at (0,0) with the specified width and height.
bool	isPointOn (Point< T > pt, T accuracy=0.00001)
	Checks if a point lies on the ellipse boundary.
bool	isPointOutside (Point< T > pt)
	Checks if a point lies outside the ellipse.
bool	isPointInside (Point< T > pt)
	Checks if a point lies inside the ellipse.
Point< T >	pointAtAngle (T angle)
	Calculates the point on the ellipse at the specified angle.

Public Attributes
T	x = 0
T	y = 0
	Centre coordinates of the ellipse.
T	a = 0
T	b = 0
	Semi-major and semi-minor axes (half width and height)

Detailed Description

template<typename T>
class Ellipse< T >

Equations to calculate the shape of an ellipse and to calculate points on the edge of the ellipse and to see if points are inside or outside.

Constructor & Destructor Documentation

Ellipse() [1/2]

template<typename T >

Ellipse< T >::Ellipse	(	T	x_,
		T	y_,
		T	a_,
		T	b_
	)

Creates a ellipse with a given centre and width / height.

Ellipse() [2/2]

template<typename T >

Ellipse< T >::Ellipse	(	T	a_,
		T	b_
	)

Creates an ellipse centred at (0,0) with the specified width and height.

Parameters

a_	Half the width of the ellipse (semi-major axis if a > b)
b_	Half the height of the ellipse (semi-minor axis if b < a)

Member Function Documentation

isPointOn()

template<typename T >

bool Ellipse< T >::isPointOn	(	Point< T >	pt,
		T	accuracy = 0.00001
	)

Checks if a point lies on the ellipse boundary.

Parameters

pt	The point to test
accuracy	Tolerance for the test (default: 0.00001)

Returns

true if the point is on the ellipse within the given accuracy

References Ellipse< T >::a, Ellipse< T >::b, Point< T >::getX(), Point< T >::getY(), square, Ellipse< T >::x, Point< T >::x, Ellipse< T >::y, and Point< T >::y.

isPointOutside()

template<typename T >

bool Ellipse< T >::isPointOutside

(

Point< T >

pt

)

Checks if a point lies outside the ellipse.

Parameters

pt	The point to test

Returns

true if the point is outside the ellipse

References Ellipse< T >::a, Ellipse< T >::b, Point< T >::getX(), Point< T >::getY(), square, Ellipse< T >::x, Point< T >::x, Ellipse< T >::y, and Point< T >::y.

isPointInside()

template<typename T >

bool Ellipse< T >::isPointInside

(

Point< T >

pt

)

Checks if a point lies inside the ellipse.

Parameters

pt	The point to test

Returns

true if the point is inside the ellipse

References Ellipse< T >::a, Ellipse< T >::b, Point< T >::getX(), Point< T >::getY(), square, Ellipse< T >::x, Point< T >::x, Ellipse< T >::y, and Point< T >::y.

pointAtAngle()

template<typename T >

Point< T > Ellipse< T >::pointAtAngle

(

T

angle

)

Calculates the point on the ellipse at the specified angle.

The angle is measured from the positive x-axis, going counter-clockwise.

Parameters

angle

The angle in radians

Returns

The point on the ellipse at that angle

References Ellipse< T >::a, Ellipse< T >::b, square, Ellipse< T >::x, and Ellipse< T >::y.

Member Data Documentation

x

template<typename T >

T Ellipse< T >::x = 0

Referenced by Ellipse< T >::isPointInside(), Ellipse< T >::isPointOn(), Ellipse< T >::isPointOutside(), and Ellipse< T >::pointAtAngle().

y

template<typename T >

T Ellipse< T >::y = 0

Centre coordinates of the ellipse.

Referenced by Ellipse< T >::isPointInside(), Ellipse< T >::isPointOn(), Ellipse< T >::isPointOutside(), and Ellipse< T >::pointAtAngle().

a

template<typename T >

T Ellipse< T >::a = 0

Referenced by Ellipse< T >::isPointInside(), Ellipse< T >::isPointOn(), Ellipse< T >::isPointOutside(), and Ellipse< T >::pointAtAngle().

b

template<typename T >

T Ellipse< T >::b = 0

Semi-major and semi-minor axes (half width and height)

Referenced by Ellipse< T >::isPointInside(), Ellipse< T >::isPointOn(), Ellipse< T >::isPointOutside(), and Ellipse< T >::pointAtAngle().

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

• gin_geometry.h