ON_Triangle Class Reference

#include <opennurbs_line.h>

Public Member Functions
	ON_Triangle ()=default
	ON_Triangle (const ON_3dPoint vertices[3])
	ON_Triangle (const ON_3dPoint &a, const ON_3dPoint &b, const ON_3dPoint &c)
	ON_Triangle (double x)
	ON_Triangle (const ON_Triangle &tri)=default
	~ON_Triangle ()=default
double	Area () const
ON_BoundingBox	BoundingBox () const
	Get Triangles 3d axis aligned bounding box. More...
bool	ClosestPointTo (const ON_3dPoint &test_point, double *s1, double *s2) const
	Find the point on the triangle that is closest to the test_point. More...
ON_3dPoint	ClosestPointTo (const ON_3dPoint &test_point) const
	Find the point on the triangle that is closest to the test_point. More...
void	Create (const ON_3dPoint vertices[3])
	Create a Triangle from three points. More...
void	Create (const ON_3dPoint &a, const ON_3dPoint &b, const ON_3dPoint &c)
	Create a Triangle from three points. More...
double	DistanceTo (const ON_3dPoint &test_point) const
	Find the point on the triangle that is closest to the test_point. More...
ON_Line	Edge (int i) const
bool	GetBoundingBox (ON_BoundingBox &bbox, int bGrowBox=false) const
	Get line's 3d axis aligned bounding box or the union of the input box with the object's bounding box. More...
bool	GetTightBoundingBox (ON_BoundingBox &tight_bbox, bool bGrowBox=false, const ON_Xform *xform=nullptr) const
	Get tight bounding box with respect to a given frame More...
bool	IsDegenerate (double tol=ON_ZERO_TOLERANCE) const
bool	IsValid () const
ON_3dVector	Normal () const
	operator const ON_3dPoint * () const
	operator ON_3dPoint * ()
ON_Triangle &	operator= (const ON_Triangle &tri)=default
ON_3dPoint &	operator[] (int)
	Triangle[i] = Triangle.m_V[i]. More...
const ON_3dPoint &	operator[] (int) const
ON_PlaneEquation	PlaneEquation () const
ON_3dPoint	PointAt (double s1, double s2) const
	Evaluate point on triangle. More...
void	Reverse (int i)
	Reverse endpoints of Edge[i]. More...
bool	Rotate (double sin_angle, double cos_angle, const ON_3dVector &axis_of_rotation, const ON_3dPoint &center_of_rotation)
	rotate line about a point and axis More...
bool	Rotate (double angle_in_radians, const ON_3dVector &axis_of_rotation, const ON_3dPoint &center_of_rotation)
bool	Transform (const ON_Xform &xform)
bool	Translate (const ON_3dVector &delta)
ON_3dVector	UnitNormal () const

Public Attributes
ON_3dPoint	m_V [3]

Static Public Attributes
static const ON_Triangle	NanTriangle
static const ON_Triangle	UnsetTriangle
static const ON_Triangle	ZeroTriangle

Constructor & Destructor Documentation

ON_Triangle() [1/5]

ON_Triangle::ON_Triangle ( )

default

ON_Triangle() [2/5]

ON_Triangle::ON_Triangle

(

const ON_3dPoint

vertices[3]

)

ON_Triangle() [3/5]

ON_Triangle::ON_Triangle	(	const ON_3dPoint &	a,
		const ON_3dPoint &	b,
		const ON_3dPoint &	c
	)

ON_Triangle() [4/5]

ON_Triangle::ON_Triangle

(

double

x

)

ON_Triangle() [5/5]

ON_Triangle::ON_Triangle ( const ON_Triangle &  tri )

default

~ON_Triangle()

ON_Triangle::~ON_Triangle ( )

default

Member Function Documentation

Area()

double ON_Triangle::Area

(

)

const

Returns

Area of triangle

BoundingBox()

ON_BoundingBox ON_Triangle::BoundingBox

(

)

const

Get Triangles 3d axis aligned bounding box.

Returns

3d bounding box.

ClosestPointTo() [1/2]

bool ON_Triangle::ClosestPointTo	(	const ON_3dPoint &	test_point,
		double *	s1,
		double *	s2
	)		const

Find the point on the triangle that is closest to the test_point.

Parameters

test_point

[in] s1, s2 - [out] PointAt( *s1, *s2) is the point on the triangle closest to test_point.

Returns

true if successful.

ClosestPointTo() [2/2]

ON_3dPoint ON_Triangle::ClosestPointTo

(

const ON_3dPoint &

test_point

)

const

Find the point on the triangle that is closest to the test_point.

Parameters

test_point

[in]

Returns

The point on the line that is closest to test_point.

Create() [1/2]

void ON_Triangle::Create

(

const ON_3dPoint

vertices[3]

)

Create a Triangle from three points.

Parameters

vertices

[in] vertices

Create() [2/2]

void ON_Triangle::Create	(	const ON_3dPoint &	a,
		const ON_3dPoint &	b,
		const ON_3dPoint &	c
	)

Create a Triangle from three points.

TODODOC: a,b,c - [in] vertices

DistanceTo()

double ON_Triangle::DistanceTo

(

const ON_3dPoint &

test_point

)

const

Find the point on the triangle that is closest to the test_point.

Parameters

test_point

[in]

Returns

distance from the point on triangle that is closest to test_point.

See also

ON_3dPoint::DistanceTo, ON_Line::ClosestPointTo

Edge()

ON_Line ON_Triangle::Edge

(

int

i

)

const

Returns

Edge opposite m_V[i] Specifically, ON_Line( m_V[(i+1)%3 ], m_V[(i+2)%3 ] )

GetBoundingBox()

bool ON_Triangle::GetBoundingBox	(	ON_BoundingBox &	bbox,
		int	bGrowBox = false
	)		const

Get line's 3d axis aligned bounding box or the union of the input box with the object's bounding box.

Parameters

bbox	[in/out] 3d axis aligned bounding box
bGrowBox	[in] (default=false) If true, then the union of the input bbox and the object's bounding box is returned in bbox. If false, the object's bounding box is returned in bbox.

Returns

true if object has bounding box and calculation was successful.

GetTightBoundingBox()

bool ON_Triangle::GetTightBoundingBox	(	ON_BoundingBox &	tight_bbox,
		bool	bGrowBox = false,
		const ON_Xform *	xform = nullptr
	)		const

Get tight bounding box with respect to a given frame

Parameters

tight_bbox	[in/out] tight bounding box
bGrowBox	[in] (default=false) If true and the input tight_bbox is valid, then returned tight_bbox is the union of the input tight_bbox and the line's tight bounding box.
xform	[in] (default=nullptr) If not nullptr, the tight bounding box of the transformed triangle is calculated. The triangle is not modified.

Returns

True if a valid tight_bbox is returned.

IsDegenerate()

bool ON_Triangle::IsDegenerate

(

double

tol = ON_ZERO_TOLERANCE

)

const

Returns

true if Area()< tol Note: Recall Area = .5* base * height. So this degeneracy tests for a combination long enough and high enough.

See also

ON_Triangle::Area()

IsValid()

bool ON_Triangle::IsValid

(

)

const

Returns

True if m_V[i].IsValid() for all i

Normal()

ON_3dVector ON_Triangle::Normal

(

)

const

Returns

N = ( b-a) X ( c-a) where a,b,c are the verticies

See also

ON_Triangle UnitNormal()

operator const ON_3dPoint *()

ON_Triangle::operator const ON_3dPoint *

(

)

const

operator ON_3dPoint *()

ON_Triangle::operator ON_3dPoint *

(

)

operator=()

ON_Triangle& ON_Triangle::operator= ( const ON_Triangle &  tri )

default

operator[]() [1/2]

ON_3dPoint& ON_Triangle::operator[]

(

int

)

Triangle[i] = Triangle.m_V[i].

operator[]() [2/2]

const ON_3dPoint& ON_Triangle::operator[]

(

int

)

const

PlaneEquation()

ON_PlaneEquation ON_Triangle::PlaneEquation

(

)

const

Returns

Plane containing Triangle with normal given by UnitNormal(). Notes: Ensure !IsDegenerate() to gaurentee meaningful result

PointAt()

ON_3dPoint ON_Triangle::PointAt	(	double	s1,
		double	s2
	)		const

Evaluate point on triangle.

TODODOC: s1, s2 - [in] evaluation parameter.

Returns

(1-s1-s2)* m_V[0] + s1*m_V[1] + s2*m_V[2] Notes: Point is in the triangle iff s1>=0, s2>=0 and s1 + s2<=1. Other values produce points on the plane of the triangle.

Reverse()

void ON_Triangle::Reverse

(

int

i

)

Reverse endpoints of Edge[i].

Rotate() [1/2]

bool ON_Triangle::Rotate	(	double	sin_angle,
		double	cos_angle,
		const ON_3dVector &	axis_of_rotation,
		const ON_3dPoint &	center_of_rotation
	)

rotate line about a point and axis

Rotate() [2/2]

bool ON_Triangle::Rotate	(	double	angle_in_radians,
		const ON_3dVector &	axis_of_rotation,
		const ON_3dPoint &	center_of_rotation
	)

Transform()

bool ON_Triangle::Transform

(

const ON_Xform &

xform

)

Translate()

bool ON_Triangle::Translate

(

const ON_3dVector &

delta

)

UnitNormal()

ON_3dVector ON_Triangle::UnitNormal

(

)

const

Returns

Normal().Unitize() Notes: Ensure !IsDegenerate() to gaurentee that UnitNormal().Length()==1 and the result is not just a bunch of noise. Can return zero vector in some degenerate cases.

Member Data Documentation

m_V

ON_3dPoint ON_Triangle::m_V[3]

NanTriangle

const ON_Triangle ON_Triangle::NanTriangle

static

UnsetTriangle

const ON_Triangle ON_Triangle::UnsetTriangle

static

ZeroTriangle

const ON_Triangle ON_Triangle::ZeroTriangle

static