axom::primal::Octahedron< T, NDIMS > Class Template Reference

Represents an octahedral geometric shape defined by six points. More...

#include </home/docs/checkouts/readthedocs.org/user_builds/axom/checkouts/v0.7.0/src/axom/primal/geometry/Octahedron.hpp>

Public Types
enum	{ NUM_OCT_VERTS = 6 }
using	PointType = Point< T, NDIMS >
using	VectorType = Vector< T, NDIMS >

Public Member Functions
AXOM_HOST_DEVICE	Octahedron ()
	Default constructor. Creates a degenerate octahedron. More...
AXOM_HOST_DEVICE	Octahedron (const PointType &p, const PointType &q, const PointType &r, const PointType &s, const PointType &t, const PointType &u)
	Creates an octahedron from the 6 points p,q,r,s,t,u. More...
AXOM_HOST_DEVICE PointType &	operator[] (int idx)
	Index operator to get the i^th vertex. More...
AXOM_HOST_DEVICE const PointType &	operator[] (int idx) const
	Index operator to get the i^th vertex. More...
AXOM_HOST_DEVICE bool	equals (const Octahedron &other, double eps=1.e-24) const
	Test if this Octahedron is equal to another, within a tolerance. More...
std::ostream &	print (std::ostream &os) const
	Simple formatted print of an octahedron instance. More...

Detailed Description

template<typename T, int NDIMS = 3>
class axom::primal::Octahedron< T, NDIMS >

Represents an octahedral geometric shape defined by six points.

Template Parameters

T	the coordinate type, e.g., double, float, etc.
NDIMS	the number of spatial dimensions

There are six vertices in the octahedron, labelled P through U as the constructor's arguments. They are accessible using the square-brackets operator, with P being index 0, Q index 1, through U as index 5.

Imagine a regular octahedron with two parallel triangles, top and bottom— the end-caps, as it were. If you look "down", normal to the end-cap triangles, you will see that the vertices of the top triangle protrude beyond the edges of the bottom triangle (and vice versa). Here's a diagram showing just the end-cap triangles, omitting the other edges for clarity.

*
*         P
*         /\
*    Q -------- U
*      \      /
*      /\    /\
*    R --\  /-- T
*         \/
*         S
*
* 

Now imagine looking from the side, edge-on to the end-caps. If you unroll the "side-wall" triangles, you get a triangle strip. Here's another diagram showing just the triangle strip, with the same points labeled. Points P and Q are repeated so we can show all eight faces.

*
*        Q --- S --- U --- Q
*       / \   / \   / \   /
*      /   \ /   \ /   \ /
*     P --- R --- T --- P
*
* 

Member Typedef Documentation

PointType

template<typename T, int NDIMS = 3>

using axom::primal::Octahedron< T, NDIMS >::PointType = Point<T, NDIMS>

VectorType

template<typename T, int NDIMS = 3>

using axom::primal::Octahedron< T, NDIMS >::VectorType = Vector<T, NDIMS>

Member Enumeration Documentation

anonymous enum

template<typename T, int NDIMS = 3>

anonymous enum

Enumerator
NUM_OCT_VERTS

Constructor & Destructor Documentation

Octahedron() [1/2]

template<typename T, int NDIMS = 3>

AXOM_HOST_DEVICE axom::primal::Octahedron< T, NDIMS >::Octahedron ( )

inline

Default constructor. Creates a degenerate octahedron.

References AXOM_HOST_DEVICE.

Octahedron() [2/2]

template<typename T, int NDIMS = 3>

AXOM_HOST_DEVICE axom::primal::Octahedron< T, NDIMS >::Octahedron ( const PointType &  p, const PointType &  q, const PointType &  r, const PointType &  s, const PointType &  t, const PointType &  u  )

inline

Creates an octahedron from the 6 points p,q,r,s,t,u.

Parameters

[in]	Point	corresponding to vertex p of the octahedron.
[in]	Point	corresponding to vertex q of the octahedron.
[in]	Point	corresponding to vertex r of the octahedron.
[in]	Point	corresponding to vertex s of the octahedron.
[in]	Point	corresponding to vertex t of the octahedron.
[in]	Point	corresponding to vertex u of the octahedron.

p is opposite s, q is opposite t, r is opposite u.

Member Function Documentation

operator[]() [1/2]

template<typename T, int NDIMS = 3>

AXOM_HOST_DEVICE PointType& axom::primal::Octahedron< T, NDIMS >::operator[] ( int  idx )

inline

Index operator to get the i^th vertex.

Parameters

idx	The index of the desired vertex

Precondition

idx is 0, 1, 2, 3, 4, or 5

References axom::primal::Octahedron< T, NDIMS >::NUM_OCT_VERTS, and SLIC_ASSERT.

operator[]() [2/2]

template<typename T, int NDIMS = 3>

AXOM_HOST_DEVICE const PointType& axom::primal::Octahedron< T, NDIMS >::operator[] ( int  idx ) const

inline

Index operator to get the i^th vertex.

Parameters

idx	The index of the desired vertex

Precondition

idx is 0, 1, 2, 3, 4, or 5

References AXOM_HOST_DEVICE, axom::primal::Octahedron< T, NDIMS >::NUM_OCT_VERTS, and SLIC_ASSERT.

equals()

template<typename T, int NDIMS = 3>

AXOM_HOST_DEVICE bool axom::primal::Octahedron< T, NDIMS >::equals ( const Octahedron< T, NDIMS > &  other, double  eps = 1.e-24  ) const

inline

Test if this Octahedron is equal to another, within a tolerance.

References axom::primal::Octahedron< T, NDIMS >::NUM_OCT_VERTS, and axom::primal::squared_distance().

print()

template<typename T, int NDIMS = 3>

std::ostream& axom::primal::Octahedron< T, NDIMS >::print ( std::ostream &  os ) const

inline

Simple formatted print of an octahedron instance.

Parameters

os	The output stream to write to

Returns

A reference to the modified ostream

References axom::primal::Octahedron< T, NDIMS >::NUM_OCT_VERTS.

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

• /home/docs/checkouts/readthedocs.org/user_builds/axom/checkouts/v0.7.0/src/axom/primal/geometry/Octahedron.hpp