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# csPoly3D Class Reference
[Geometry utilities]

The following class represents a general 3D polygon. More...

`#include <csgeom/poly3d.h>`

Inheritance diagram for csPoly3D:

[legend]
List of all members.

## Public Member Functions
size_t | AddVertex (float x, float y, float z)
| Add a vertex (3D) to the polygon.
size_t | AddVertex (const csVector3 &v)
| Add a vertex (3D) to the polygon.
int | Classify (const csPlane3 &pl) const
| Classify this polygon with regards to a plane.
int | ClassifyAxis (int axis, float where) const
| Same as Classify() but for a given axis plane.
int | ClassifyX (float x) const
| Same as Classify() but for X plane only.
int | ClassifyY (float y) const
| Same as Classify() but for Y plane only.
int | ClassifyZ (float z) const
| Same as Classify() but for Z plane only.
int | ComputeMainNormalAxis () const
| Calculate the main axis of the normal.
csVector3 | ComputeNormal () const
| Compute the normal of this polygon.
csPlane3 | ComputePlane () const
| Compute the plane of this polygon.
| csPoly3D (const csPoly3D &copy)
| Copy constructor.
| csPoly3D (size_t start_size=10)
| Make a new empty polygon.
void | CutToPlane (const csPlane3 &split_plane)
| Cut this polygon with a plane and only keep the front side.
float | GetArea () const
| Calculate the area of this polygon.
csVector3 | GetCenter () const
| Compute and get the central vertex of this polygon.
const csVector3 * | GetFirst () const
| Get the first vertex.
const csVector3 * | GetLast () const
| Get the last vertex.
const csVector3 * | GetVertex (size_t i) const
| Get the specified vertex.
size_t | GetVertexCount () const
| Get the number of vertices.
csVector3 * | GetVertices ()
| Get the array with all vertices.
const csVector3 * | GetVertices () const
| Get the array with all vertices.
bool | In (const csVector3 &v) const
| Test if this vector is inside the polygon.
int | IsAxisAligned (float &where, float epsilon=SMALL_EPSILON) const
| Test if this polygon is axis aligned and return the axis (one of CS_AXIS_ constants).
void | MakeEmpty ()
| Initialize the polygon to empty.
void | MakeRoom (size_t new_max)
| Make room for at least the specified number of vertices.
const csVector3 & | operator[] (size_t i) const
| Get the specified vertex.
csVector3 & | operator[] (size_t i)
| Get the specified vertex.
bool | ProjectAxisPlane (const csVector3 &point, int plane_nr, float plane_pos, csPoly2D *poly2d) const
| Project this polygon onto an axis-aligned plane as seen from some point in space.
bool | ProjectXPlane (const csVector3 &point, float plane_x, csPoly2D *poly2d) const
| Project this polygon onto a X plane as seen from some point in space.
bool | ProjectYPlane (const csVector3 &point, float plane_y, csPoly2D *poly2d) const
| Project this polygon onto a Y plane as seen from some point in space.
bool | ProjectZPlane (const csVector3 &point, float plane_z, csPoly2D *poly2d) const
| Project this polygon onto a Z plane as seen from some point in space.
void | SetVertexCount (size_t n)
| Set the number of vertices.
void | SetVertices (csVector3 const *v, size_t num)
| Set all polygon vertices at once.
void | SplitWithPlane (csPoly3D &front, csPoly3D &back, const csPlane3 &split_plane) const
| Split this polygon with the given plane (A,B,C,D).
void | SplitWithPlaneX (csPoly3D &front, csPoly3D &back, float x) const
| Split this polygon to the x-plane.
void | SplitWithPlaneY (csPoly3D &front, csPoly3D &back, float y) const
| Split this polygon to the y-plane.
void | SplitWithPlaneZ (csPoly3D &front, csPoly3D &back, float z) const
| Split this polygon to the z-plane.
virtual | ~csPoly3D ()
| Destructor.
## Static Public Member Functions
static int | Classify (const csPlane3 &pl, const csVector3 *vertices, size_t num_vertices)
| Static function to classify a polygon with regards to a plane.
static csVector3 | ComputeNormal (int *poly, size_t num, csVector3 *vertices)
| Compute the normal of an indexed polygon.
static csVector3 | ComputeNormal (const csArray< csVector3 > &poly)
| Compute the normal of a polygon.
static csVector3 | ComputeNormal (const csVector3 *vertices, size_t num)
| Compute the normal of a polygon.
static csPlane3 | ComputePlane (int *poly, size_t num, csVector3 *vertices)
| Compute the plane of an indexed polygon.
static csPlane3 | ComputePlane (const csArray< csVector3 > &poly)
| Compute the plane of a polygon.
static csPlane3 | ComputePlane (const csVector3 *vertices, size_t num)
| Compute the plane of a polygon.
static bool | In (csVector3 *poly, size_t num_poly, const csVector3 &v)
| Test if a vector is inside the given polygon.
## Protected Attributes
csDirtyAccessArray< csVector3 > | vertices
| The 3D vertices.

## Detailed Description

The following class represents a general 3D polygon.

Definition at line 53 of file poly3d.h.

## Constructor & Destructor Documentation

csPoly3D::csPoly3D | ( | size_t | start_size = `10` | ) |

Make a new empty polygon.

csPoly3D::csPoly3D | ( | const csPoly3D & | copy | ) |

Copy constructor.

virtual csPoly3D::~csPoly3D | ( |  | ) | `[virtual]`

Destructor.

## Member Function Documentation

size_t csPoly3D::AddVertex | ( | float | x,
|  | float | y,
|  | float | z |
| ) |  |  |

Add a vertex (3D) to the polygon.

Return index of added vertex.

size_t csPoly3D::AddVertex | ( | const csVector3 & | v | ) | `[inline]`

Add a vertex (3D) to the polygon.

Return index of added vertex.

Definition at line 163 of file poly3d.h.

References csVector3::x, csVector3::y, and csVector3::z.

int csPoly3D::Classify | ( | const csPlane3 & | pl | ) | const`[inline]`

Classify this polygon with regards to a plane.

If this poly is on same plane it returns CS_POL_SAME_PLANE. If this poly is completely in front of the given plane it returnes CS_POL_FRONT. If this poly is completely back of the given plane it returnes CS_POL_BACK. Otherwise it returns CS_POL_SPLIT_NEEDED.

Definition at line 249 of file poly3d.h.

static int csPoly3D::Classify | ( | const csPlane3 & | pl,
|  | const csVector3 * | vertices,
|  | size_t | num_vertices |
| ) |  |  | `[static]`

Static function to classify a polygon with regards to a plane.

If this poly is on same plane it returns CS_POL_SAME_PLANE. If this poly is completely in front of the given plane it returnes CS_POL_FRONT. If this poly is completely back of the given plane it returnes CS_POL_BACK. Otherwise it returns CS_POL_SPLIT_NEEDED.

int csPoly3D::ClassifyAxis | ( | int | axis,
|  | float | where |
| ) |  |  | const`[inline]`

Same as Classify() but for a given axis plane.

Definition at line 264 of file poly3d.h.

References CS_AXIS_X, CS_AXIS_Y, and CS_AXIS_Z.

int csPoly3D::ClassifyX | ( | float | x | ) | const

Same as Classify() but for X plane only.

int csPoly3D::ClassifyY | ( | float | y | ) | const

Same as Classify() but for Y plane only.

int csPoly3D::ClassifyZ | ( | float | z | ) | const

Same as Classify() but for Z plane only.

int csPoly3D::ComputeMainNormalAxis | ( |  | ) | const

Calculate the main axis of the normal.

Returns one of the CS_AXIS_ constants;

csVector3 csPoly3D::ComputeNormal | ( |  | ) | const`[inline]`

Compute the normal of this polygon.

Definition at line 316 of file poly3d.h.

static csVector3 csPoly3D::ComputeNormal | ( | int * | poly,
|  | size_t | num,
|  | csVector3 * | vertices |
| ) |  |  | `[static]`

Compute the normal of an indexed polygon.

static csVector3 csPoly3D::ComputeNormal | ( | const csArray< csVector3 > & | poly | ) | `[static]`

Compute the normal of a polygon.

static csVector3 csPoly3D::ComputeNormal | ( | const csVector3 * | vertices,
|  | size_t | num |
| ) |  |  | `[static]`

Compute the normal of a polygon.

csPlane3 csPoly3D::ComputePlane | ( |  | ) | const`[inline]`

Compute the plane of this polygon.

Definition at line 331 of file poly3d.h.

static csPlane3 csPoly3D::ComputePlane | ( | int * | poly,
|  | size_t | num,
|  | csVector3 * | vertices |
| ) |  |  | `[static]`

Compute the plane of an indexed polygon.

static csPlane3 csPoly3D::ComputePlane | ( | const csArray< csVector3 > & | poly | ) | `[static]`

Compute the plane of a polygon.

static csPlane3 csPoly3D::ComputePlane | ( | const csVector3 * | vertices,
|  | size_t | num |
| ) |  |  | `[static]`

Compute the plane of a polygon.

void csPoly3D::CutToPlane | ( | const csPlane3 & | split_plane | ) |

Cut this polygon with a plane and only keep the front side.

float csPoly3D::GetArea | ( |  | ) | const

Calculate the area of this polygon.

csVector3 csPoly3D::GetCenter | ( |  | ) | const

Compute and get the central vertex of this polygon.

const csVector3* csPoly3D::GetFirst | ( |  | ) | const`[inline]`

Get the first vertex.

Definition at line 119 of file poly3d.h.

const csVector3* csPoly3D::GetLast | ( |  | ) | const`[inline]`

Get the last vertex.

Definition at line 128 of file poly3d.h.

const csVector3* csPoly3D::GetVertex | ( | size_t | i | ) | const`[inline]`

Get the specified vertex.

Definition at line 94 of file poly3d.h.

size_t csPoly3D::GetVertexCount | ( |  | ) | const`[inline]`

Get the number of vertices.

Definition at line 79 of file poly3d.h.

csVector3* csPoly3D::GetVertices | ( |  | ) | `[inline]`

Get the array with all vertices.

Definition at line 89 of file poly3d.h.

const csVector3* csPoly3D::GetVertices | ( |  | ) | const`[inline]`

Get the array with all vertices.

Definition at line 84 of file poly3d.h.

static bool csPoly3D::In | ( | csVector3 * | poly,
|  | size_t | num_poly,
|  | const csVector3 & | v |
| ) |  |  | `[static]`

Test if a vector is inside the given polygon.

bool csPoly3D::In | ( | const csVector3 & | v | ) | const

Test if this vector is inside the polygon.

int csPoly3D::IsAxisAligned | ( | float & | where,
|  | float | epsilon = `SMALL_EPSILON` |
| ) |  |  | const

Test if this polygon is axis aligned and return the axis (one of CS_AXIS_ constants).

The location of the axis is returned in 'where'. Returns CS_AXIS_NONE if the polygon is not axis aligned. The epsilon will be used to test if two coordinates are close.

void csPoly3D::MakeEmpty | ( |  | ) |

Initialize the polygon to empty.

void csPoly3D::MakeRoom | ( | size_t | new_max | ) |

Make room for at least the specified number of vertices.

const csVector3& csPoly3D::operator[] | ( | size_t | i | ) | const`[inline]`

Get the specified vertex.

Definition at line 111 of file poly3d.h.

csVector3& csPoly3D::operator[] | ( | size_t | i | ) | `[inline]`

Get the specified vertex.

Definition at line 103 of file poly3d.h.

bool csPoly3D::ProjectAxisPlane | ( | const csVector3 & | point,
|  | int | plane_nr,
|  | float | plane_pos,
|  | csPoly2D * | poly2d |
| ) |  |  | const`[inline]`

Project this polygon onto an axis-aligned plane as seen from some point in space.

Fills the given 2D polygon with the projection on the plane. This function assumes that there actually is a projection. Plane_nr is 0 for the X plane, 1 for Y, and 2 for Z. Or one of the CS_AXIX_ constants.

Definition at line 220 of file poly3d.h.

References CS_AXIS_X, CS_AXIS_Y, and CS_AXIS_Z.

bool csPoly3D::ProjectXPlane | ( | const csVector3 & | point,
|  | float | plane_x,
|  | csPoly2D * | poly2d |
| ) |  |  | const

Project this polygon onto a X plane as seen from some point in space.

Fills the given 2D polygon with the projection on the plane. This function assumes that there actually is a projection. If the polygon to project comes on the same plane as 'point' then it will return false (no valid projection).

bool csPoly3D::ProjectYPlane | ( | const csVector3 & | point,
|  | float | plane_y,
|  | csPoly2D * | poly2d |
| ) |  |  | const

Project this polygon onto a Y plane as seen from some point in space.

Fills the given 2D polygon with the projection on the plane. This function assumes that there actually is a projection. If the polygon to project comes on the same plane as 'point' then it will return false (no valid projection).

bool csPoly3D::ProjectZPlane | ( | const csVector3 & | point,
|  | float | plane_z,
|  | csPoly2D * | poly2d |
| ) |  |  | const

Project this polygon onto a Z plane as seen from some point in space.

Fills the given 2D polygon with the projection on the plane. This function assumes that there actually is a projection. If the polygon to project comes on the same plane as 'point' then it will return false (no valid projection).

void csPoly3D::SetVertexCount | ( | size_t | n | ) | `[inline]`

Set the number of vertices.

Definition at line 153 of file poly3d.h.

void csPoly3D::SetVertices | ( | csVector3 const * | v,
|  | size_t | num |
| ) |  |  | `[inline]`

Set all polygon vertices at once.

Copies the array.

Definition at line 177 of file poly3d.h.

void csPoly3D::SplitWithPlane | ( | csPoly3D & | front,
|  | csPoly3D & | back,
|  | const csPlane3 & | split_plane |
| ) |  |  | const

Split this polygon with the given plane (A,B,C,D).

void csPoly3D::SplitWithPlaneX | ( | csPoly3D & | front,
|  | csPoly3D & | back,
|  | float | x |
| ) |  |  | const

Split this polygon to the x-plane.

void csPoly3D::SplitWithPlaneY | ( | csPoly3D & | front,
|  | csPoly3D & | back,
|  | float | y |
| ) |  |  | const

Split this polygon to the y-plane.

void csPoly3D::SplitWithPlaneZ | ( | csPoly3D & | front,
|  | csPoly3D & | back,
|  | float | z |
| ) |  |  | const

Split this polygon to the z-plane.

## Member Data Documentation

csDirtyAccessArray<csVector3> csPoly3D::vertices`[protected]`

The 3D vertices.

Definition at line 57 of file poly3d.h.

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

- csgeom/poly3d.h