CrystalSpace

Public API Reference

csFrustum Class Reference
[Geometry utilities]

A general frustum. More...

#include <csgeom/frustum.h>

Inheritance diagram for csFrustum:

List of all members.

Public Member Functions

void AddVertex (const csVector3 &v)
 Add a vertex to the frustum polygon.
void ClipPolyToPlane (csPlane3 *plane)
 Clip the polygon of this frustum to the postive side of an arbitrary plane (which should be specified relative to the origin of the frustum).
void ClipToPlane (csVector3 &v1, csVector3 &v2)
 Clip this frustum to the positive side of a plane formed by the origin of this frustum, and the two given vertices.
bool Contains (const csVector3 &point)
 Check if a point (given relative to the origin of the frustum) is inside the frustum.
 csFrustum (const csFrustum &copy)
 Copy constructor.
 csFrustum (const csVector3 &o, size_t num_verts, csPlane3 *backp=0)
 Create a frustum given a number of vertices and a backplane.
 csFrustum (const csVector3 &o, csVector3 *verts, size_t num_verts, csPlane3 *backp=0)
 Create a frustum given a polygon and a backplane.
 csFrustum (const csVector3 &o)
 Create a new empty frustum.
csPlane3GetBackPlane () const
 Get the back plane.
const csVector3GetOrigin () const
 Get the origin of this frustum.
csVector3GetOrigin ()
 Get the origin of this frustum.
const csVector3GetVertex (size_t idx) const
 Get a vertex.
csVector3GetVertex (size_t idx)
 Get a vertex.
size_t GetVertexCount () const
 Get the number of vertices.
csVector3GetVertices () const
 Get the array of vertices.
bool Intersect (csSegment3 &segment)
 Intersect a segment with the frustum.
csPtr< csFrustumIntersect (csVector3 *poly, size_t num) const
 Intersect a convex polygon with this volume.
csPtr< csFrustumIntersect (const csFrustum &other) const
 Intersect with another frustum.
bool IsEmpty () const
 Return true if frustum is empty.
bool IsInfinite () const
 Return true if frustum is infinite.
bool IsMirrored () const
 Is this frustum mirrored?
bool IsWide () const
 Return true if frustum is infinitely wide but it can still have a back plane.
void MakeEmpty ()
 Make the frustum empty.
void MakeInfinite ()
 Make the frustum infinite (i.e.
const csFrustumoperator= (const csFrustum &other)
 Assignment operator.
void RemoveBackPlane ()
 Remove the back plane of this frustum.
void SetBackPlane (const csPlane3 &plane)
 Set the back plane of this frustum.
void SetMirrored (bool m)
 Enable/disable mirroring.
void SetOrigin (const csVector3 &o)
 Set the origin of this frustum.
void Transform (csTransform *trans)
 Apply a transformation to this frustum.

Static Public Member Functions

static int BatchClassify (csVector3 *frustum, csVector3 *frustumNormals, size_t num_frust, csVector3 *poly, size_t num_poly)
 This is like the above version except that it takes a vector of precalculated frustum plane normals.
static int Classify (csVector3 *frustum, size_t num_frust, csVector3 *poly, size_t num_poly)
 Check if a polygon intersects with the frustum (i.e.
static void ClipToPlane (csVector3 *vertices, size_t &num_vertices, csClipInfo *clipinfo, const csPlane3 &plane)
 Clip a frustum (defined from 0,0,0 origin) to the given plane.
static void ClipToPlane (csVector3 *vertices, size_t &num_vertices, csClipInfo *clipinfo, const csVector3 &v1, const csVector3 &v2)
 Clip a frustum (defined from 0,0,0 origin) to the given plane (defined as 0-v1-v2).
static bool Contains (csVector3 *frustum, size_t num_frust, const csPlane3 &plane, const csVector3 &point)
 Check if a point is inside a frustum.
static bool Contains (csVector3 *frustum, size_t num_frust, const csVector3 &point)
 Check if a point is inside a frustum.
static csPtr< csFrustumIntersect (const csVector3 &frust_origin, csVector3 *frust, size_t num_frust, const csVector3 &v1, const csVector3 &v2, const csVector3 &v3)
 Intersect a triangle with this volume.
static csPtr< csFrustumIntersect (const csVector3 &frust_origin, csVector3 *frust, size_t num_frust, csVector3 *poly, size_t num)
 Intersect a convex polygon with this volume.

Detailed Description

A general frustum.

This consist of a center point (origin), a frustum polygon in 3D space (relative to center point) and a plane. The planes which go through the center and every edge of the polygon form the frustum. The plane is the back plane of the frustum. It is also possible to have an infinite frustum in which case the polygon will be 0 (not specified). The back plane can also be 0.

Definition at line 157 of file frustum.h.


Constructor & Destructor Documentation

csFrustum::csFrustum ( const csVector3 o  )  [inline]

Create a new empty frustum.

Definition at line 201 of file frustum.h.

csFrustum::csFrustum ( const csVector3 o,
csVector3 verts,
size_t  num_verts,
csPlane3 backp = 0 
)

Create a frustum given a polygon and a backplane.

The polygon is given relative to the origin 'o'. If the given polygon is 0 then we create an empty frustum.

csFrustum::csFrustum ( const csVector3 o,
size_t  num_verts,
csPlane3 backp = 0 
)

Create a frustum given a number of vertices and a backplane.

The vertices are not initialized but space is reserved for them. The polygon is given relative to the origin 'o'.

csFrustum::csFrustum ( const csFrustum copy  ) 

Copy constructor.


Member Function Documentation

void csFrustum::AddVertex ( const csVector3 v  ) 

Add a vertex to the frustum polygon.

static int csFrustum::BatchClassify ( csVector3 frustum,
csVector3 frustumNormals,
size_t  num_frust,
csVector3 poly,
size_t  num_poly 
) [static]

This is like the above version except that it takes a vector of precalculated frustum plane normals.

Use this if you have to classify a batch of polygons against the same frustum.

static int csFrustum::Classify ( csVector3 frustum,
size_t  num_frust,
csVector3 poly,
size_t  num_poly 
) [static]

Check if a polygon intersects with the frustum (i.e.

is visible in the frustum). Returns one of CS_FRUST_OUTSIDE etc. values. Frustum and polygon should be given relative to (0,0,0).

void csFrustum::ClipPolyToPlane ( csPlane3 plane  ) 

Clip the polygon of this frustum to the postive side of an arbitrary plane (which should be specified relative to the origin of the frustum).

Note that this clips the polygon which forms the frustum. It does not clip the frustum itself.

static void csFrustum::ClipToPlane ( csVector3 vertices,
size_t &  num_vertices,
csClipInfo clipinfo,
const csPlane3 plane 
) [static]

Clip a frustum (defined from 0,0,0 origin) to the given plane.

This routine will also fill an array of clipinfo so that you can use this information to correctly interpolate information related to the vertex (like texture mapping coordinates). Note that clipinfo needs to be preinitialized correctly with CS_CLIPINFO_ORIGINAL instances and correct indices.

static void csFrustum::ClipToPlane ( csVector3 vertices,
size_t &  num_vertices,
csClipInfo clipinfo,
const csVector3 v1,
const csVector3 v2 
) [static]

Clip a frustum (defined from 0,0,0 origin) to the given plane (defined as 0-v1-v2).

This routine will also fill an array of clipinfo so that you can use this information to correctly interpolate information related to the vertex (like texture mapping coordinates). Note that clipinfo needs to be preinitialized correctly with CS_CLIPINFO_ORIGINAL instances and correct indices.

void csFrustum::ClipToPlane ( csVector3 v1,
csVector3 v2 
)

Clip this frustum to the positive side of a plane formed by the origin of this frustum, and the two given vertices.

'v1' and 'v2' are given relative to that origin.

static bool csFrustum::Contains ( csVector3 frustum,
size_t  num_frust,
const csPlane3 plane,
const csVector3 point 
) [static]

Check if a point is inside a frustum.

The point and frustum are relative to (0,0,0). This function also checks if point is in front of given plane.

static bool csFrustum::Contains ( csVector3 frustum,
size_t  num_frust,
const csVector3 point 
) [static]

Check if a point is inside a frustum.

The point and frustum are relative to (0,0,0). Note that this function does not work correctly if the point is in the other direction from the average direction of the frustum.

bool csFrustum::Contains ( const csVector3 point  ) 

Check if a point (given relative to the origin of the frustum) is inside the frustum.

csPlane3* csFrustum::GetBackPlane (  )  const [inline]

Get the back plane.

Definition at line 261 of file frustum.h.

const csVector3& csFrustum::GetOrigin (  )  const [inline]

Get the origin of this frustum.

Definition at line 238 of file frustum.h.

csVector3& csFrustum::GetOrigin (  )  [inline]

Get the origin of this frustum.

Definition at line 235 of file frustum.h.

const csVector3& csFrustum::GetVertex ( size_t  idx  )  const [inline]

Get a vertex.

Definition at line 290 of file frustum.h.

csVector3& csFrustum::GetVertex ( size_t  idx  )  [inline]

Get a vertex.

Definition at line 281 of file frustum.h.

size_t csFrustum::GetVertexCount (  )  const [inline]

Get the number of vertices.

Definition at line 276 of file frustum.h.

csVector3* csFrustum::GetVertices (  )  const [inline]

Get the array of vertices.

Definition at line 299 of file frustum.h.

bool csFrustum::Intersect ( csSegment3 segment  ) 

Intersect a segment with the frustum.

Returns:
True if the segment is inside the frustum at any point. The segment will be updated to be the part within the frustum
static csPtr<csFrustum> csFrustum::Intersect ( const csVector3 frust_origin,
csVector3 frust,
size_t  num_frust,
const csVector3 v1,
const csVector3 v2,
const csVector3 v3 
) [static]

Intersect a triangle with this volume.

The triangle is given relative to the center point (origin) of this frustum.

Returns a new frustum which exactly covers the intersection of the triangle with the frustum (i.e. the smallest frustum which is part of this frustum and which 'sees' exactly the same of the given polygon as this frustum).

This function returns 0 if there is no intersection.

Note that the frustum polygon of the returned csFrustum is guaranteed to be coplanar with the given triangle.

static csPtr<csFrustum> csFrustum::Intersect ( const csVector3 frust_origin,
csVector3 frust,
size_t  num_frust,
csVector3 poly,
size_t  num 
) [static]

Intersect a convex polygon with this volume.

The convex polygon is given relative to the center point (origin) of this frustum.

Returns a new frustum which exactly covers the intersection of the polygon with the frustum (i.e. the smallest frustum which is part of this frustum and which 'sees' exactly the same of the given polygon as this frustum).

This function returns 0 if there is no intersection.

Note that the frustum polygon of the returned csFrustum is guaranteed to be coplanar with the given polygon.

csPtr<csFrustum> csFrustum::Intersect ( csVector3 poly,
size_t  num 
) const

Intersect a convex polygon with this volume.

The convex polygon is given relative to the center point (origin) of this frustum.

Returns a new frustum which exactly covers the intersection of the polygon with the frustum (i.e. the smallest frustum which is part of this frustum and which 'sees' exactly the same of the given polygon as this frustum).

This function returns 0 if there is no intersection.

Note that the frustum polygon of the returned csFrustum is guaranteed to be coplanar with the given polygon.

csPtr<csFrustum> csFrustum::Intersect ( const csFrustum other  )  const

Intersect with another frustum.

The other frustum must have the same origin as this one. Otherwise the result is undefined.

Returns:
The new frustum. If there is no intersection then 0 is returned.
bool csFrustum::IsEmpty (  )  const [inline]

Return true if frustum is empty.

Definition at line 468 of file frustum.h.

bool csFrustum::IsInfinite (  )  const [inline]

Return true if frustum is infinite.

Definition at line 471 of file frustum.h.

bool csFrustum::IsMirrored (  )  const [inline]

Is this frustum mirrored?

Definition at line 248 of file frustum.h.

bool csFrustum::IsWide (  )  const [inline]

Return true if frustum is infinitely wide but it can still have a back plane.

Definition at line 477 of file frustum.h.

void csFrustum::MakeEmpty (  ) 

Make the frustum empty.

void csFrustum::MakeInfinite (  ) 

Make the frustum infinite (i.e.

clear the polygon and the back plane).

const csFrustum& csFrustum::operator= ( const csFrustum other  ) 

Assignment operator.

void csFrustum::RemoveBackPlane (  ) 

Remove the back plane of this frustum.

void csFrustum::SetBackPlane ( const csPlane3 plane  ) 

Set the back plane of this frustum.

The given plane is copied to this structure and can thus be reused/freed later. The plane should be specified relative to the origin point.

void csFrustum::SetMirrored ( bool  m  )  [inline]

Enable/disable mirroring.

If mirroring is enabled this means that the frustum polygon is given in anti-clockwise order.

Definition at line 245 of file frustum.h.

void csFrustum::SetOrigin ( const csVector3 o  )  [inline]

Set the origin of this frustum.

Definition at line 232 of file frustum.h.

void csFrustum::Transform ( csTransform trans  ) 

Apply a transformation to this frustum.


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

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