This class implements an array of 3D triangles. More...

#include <CTriangleArray.h>

Inheritance diagram for chai3d::cTriangleArray:

Public Member Functions
	cTriangleArray (cVertexArrayPtr a_vertexArray)

	~cTriangleArray ()

void	clear ()
	Clear all triangles from array. More...

virtual unsigned int	getNumVerticesPerElement ()
	This method returns the number of vertices that compose a triangle. More...

cTriangleArrayPtr	copy ()
	This method copies all triangle data and returns a new triangle array. More...

void	compress ()
	This method removes all non allocated triangles. More...

int	newTriangle (const unsigned int a_vertexIndex0, const unsigned int a_vertexIndex1, const unsigned int a_vertexIndex2)

void	removeTriangle (const unsigned int a_triangleIndex)

void	setVertices (const unsigned int a_triangleIndex, const unsigned int a_vertexIndex0, const unsigned int a_vertexIndex1, const unsigned int a_vertexIndex2)

void	setVertexIndex0 (const unsigned int a_triangleIndex, const unsigned int a_vertexIndex0)

unsigned int	getVertexIndex0 (const unsigned int a_triangleIndex) const

void	setVertexIndex1 (const unsigned int a_triangleIndex, const unsigned int a_vertexIndex1)

unsigned int	getVertexIndex1 (const unsigned int a_triangleIndex) const

void	setVertexIndex2 (const unsigned int a_triangleIndex, const unsigned int a_vertexIndex2)

unsigned int	getVertexIndex2 (const unsigned int a_triangleIndex) const

virtual unsigned int	getVertexIndex (const unsigned int a_elementIndex, const unsigned int a_vertexNumber) const

cVector3d	getTexCoordAtPosition (const unsigned int a_triangleIndex, const cVector3d &a_localPos)

void	flip (const unsigned int a_triangleIndex)

void	computeBTN ()

void	renderInitialize ()

void	renderFinalize ()

virtual bool	computeCollision (const unsigned int a_elementIndex, cGenericObject *a_object, cVector3d &a_segmentPointA, cVector3d &a_segmentPointB, cCollisionRecorder &a_recorder, cCollisionSettings &a_settings) const
	This method checks if the given line segment intersects a selected triangle from this array. More...

double	computeArea (const unsigned int a_triangleIndex)

cVector3d	computeNormal (const unsigned int a_triangleIndex, const bool a_applyNormalToVertices)

Public Member Functions inherited from chai3d::cGenericArray
	cGenericArray (cVertexArrayPtr a_vertexArray)

	~cGenericArray ()

virtual unsigned int	getNumElements ()
	This method returns the number of allocated elements. More...

void	compress ()
	This method removes non used elements. This compresses the array. More...

bool	getAllocated (const unsigned int a_index) const

cVector3d	getTexCoordAtPosition (const unsigned int a_elementIndex, const cVector3d &a_localPos)

virtual void	render ()
	This method render the OpenGL vertex buffer object. More...

Static Public Member Functions
static cTriangleArrayPtr	create (cVertexArrayPtr a_vertexArray)
	Shared cTriangleArray allocator. More...

Static Public Member Functions inherited from chai3d::cGenericArray
static cGenericArrayPtr	create (cVertexArrayPtr a_vertexArray)
	Shared cGenericArray allocator. More...

Additional Inherited Members
Public Attributes inherited from chai3d::cGenericArray
cVertexArrayPtr	m_vertices
	Vertex array that contains all vertices used to describe the elements of this array. More...

std::vector< unsigned int >	m_indices
	Element indices to vertices. More...

std::vector< bool >	m_allocated
	Element allocation flags. More...

bool	m_flagMarkForUpdate
	If true then element data has been modified. More...

bool	m_flagMarkForResize
	If true then element array size has changed. More...

GLuint	m_elementBuffer
	OpenGL Buffer for storing elements. More...

Protected Attributes inherited from chai3d::cGenericArray
std::list< unsigned int >	m_freeElements
	List of free elements. More...

Detailed Description

cTriangleArray defines an array of triangles, typically bound to a mesh for describing its geometry.
A triangle array is created by first passing a reference to an array of vertices (cVertexArray) from which the triangles are composed.
Every triangle is described by a set of three vertex indices. The indices point to the vertices, or points, that describe the shape of the triangle.
For graphic rendering purposes and memory efficiency, triangles are stored in large arrays. The number of allocated triangles in an array can be retrieved by call getNumElements().
New triangles can be added or removed by calling newTriangle() and removeTriangle(). respectively.
When a triangle is removed from the array, the vertex indices are set to zero and the triangle index number is added to a list of free triangles for future allocation. Triangles are therefore never removed from memory, but become a point until they are converted to an active triangle again.
To avoid accumulating large numbers of free triangles, it is possible to compress the array by calling compress(). This method removes all non used triangles from memory.

Constructor & Destructor Documentation

chai3d::cTriangleArray::cTriangleArray ( cVertexArrayPtr a_vertexArray )

inline

Constructor of cTriangleArray.

Parameters

a_vertexArray Array of vertices used to describe the triangles.

chai3d::cTriangleArray::~cTriangleArray ( )

inline

Destructor of cTriangleArray.

Member Function Documentation

void chai3d::cTriangleArray::clear ( )

inlinevirtual

Reimplemented from chai3d::cGenericArray.

static cTriangleArrayPtr chai3d::cTriangleArray::create ( cVertexArrayPtr a_vertexArray )

inlinestatic

virtual unsigned int chai3d::cTriangleArray::getNumVerticesPerElement ( )

inlinevirtual

Reimplemented from chai3d::cGenericArray.

cTriangleArrayPtr chai3d::cTriangleArray::copy ( )

This method copies all allocated triangles. Please note that this method does copy triangles that were previously deallocated.

Returns: New triangle array.

void chai3d::cTriangleArray::compress ( )

This method compressed the triangle array by removing all non allocated triangles. If many triangles are unused, this method can effectively reduce the memory footprint allocated by the array.
IMPORTANT:
After calling this method, it is important to immediately update any collision detector as the collision tree may try to access triangles that no longer exist.

int chai3d::cTriangleArray::newTriangle	(	const unsigned int	a_vertexIndex0,
		const unsigned int	a_vertexIndex1,
		const unsigned int	a_vertexIndex2
	)

inline

This method creates a new triangle.

Parameters

a_vertexIndex0	index of vertex 0.
a_vertexIndex1	index of vertex 1.
a_vertexIndex2	index of vertex 2.

Returns: Index number of new triangle.

void chai3d::cTriangleArray::removeTriangle ( const unsigned int a_triangleIndex )

inline

This method deallocates a selected triangle from the array. The three vertices of the triangle are set to zero, and the triangle is added to the free list for future allocation.

Parameters

a_triangleIndex Index of selected triangle.

void chai3d::cTriangleArray::setVertices	(	const unsigned int	a_triangleIndex,
		const unsigned int	a_vertexIndex0,
		const unsigned int	a_vertexIndex1,
		const unsigned int	a_vertexIndex2
	)

inline

This method set the vertices of a selected triangle by passing their index numbers.

Parameters

a_triangleIndex	Index of selected triangle.
a_vertexIndex0	Index of vertex 0.
a_vertexIndex1	Index of vertex 1.
a_vertexIndex2	Index of vertex 2.

void chai3d::cTriangleArray::setVertexIndex0	(	const unsigned int	a_triangleIndex,
		const unsigned int	a_vertexIndex0
	)

inline

This method sets vertex 0 of a selected triangle by passing their index numbers.

Parameters

a_triangleIndex	Index of triangle.
a_vertexIndex0	Index of vertex 0.

unsigned int chai3d::cTriangleArray::getVertexIndex0 ( const unsigned int a_triangleIndex ) const

inline

This method returns the index of vertex 0 of a selected triangle.

Parameters

a_triangleIndex Index of triangle.

Returns: Index to vertex 0.

void chai3d::cTriangleArray::setVertexIndex1	(	const unsigned int	a_triangleIndex,
		const unsigned int	a_vertexIndex1
	)

inline

This method sets vertex 1 of a selected triangle by passing their index numbers.

Parameters

a_triangleIndex	Index of triangle.
a_vertexIndex1	Index of vertex 1.

unsigned int chai3d::cTriangleArray::getVertexIndex1 ( const unsigned int a_triangleIndex ) const

inline

This method returns the index of vertex 1 of a selected triangle.

Parameters

a_triangleIndex Index of selected triangle.

Returns: Index to vertex 1.

void chai3d::cTriangleArray::setVertexIndex2	(	const unsigned int	a_triangleIndex,
		const unsigned int	a_vertexIndex2
	)

inline

This method sets vertex 2 of a selected triangle by passing their index numbers.

Parameters

a_triangleIndex	Index of triangle.
a_vertexIndex2	Index of vertex 2.

unsigned int chai3d::cTriangleArray::getVertexIndex2 ( const unsigned int a_triangleIndex ) const

inline

This method returns the index of vertex 2 of a selected triangle.

Parameters

a_triangleIndex Index of triangle.

Returns: Index to vertex 2.

virtual unsigned int chai3d::cTriangleArray::getVertexIndex	(	const unsigned int	a_elementIndex,
		const unsigned int	a_vertexNumber
	)		const

inlinevirtual

This method returns the index number of a selected vertex for a selected triangle. In the case of a triangle a_vertexNumber takes either 0, 1 or 2.

Parameters

a_elementIndex	Index number of selected triangle.
a_vertexNumber	Vertex number.

Returns: Index number of the requested vertex.

Reimplemented from chai3d::cGenericArray.

cVector3d chai3d::cTriangleArray::getTexCoordAtPosition	(	const unsigned int	a_triangleIndex,
		const cVector3d &	a_localPos
	)

inline

This method returns the texture coordinate at the nearest point on the triangle from an input location.

Parameters

a_triangleIndex	Index number of selected triangle.
a_localPos	Local point on triangle.

Returns: Interpolated texture coordinate at desired location.

void chai3d::cTriangleArray::flip ( const unsigned int a_triangleIndex )

inline

This method flips the vertices of the triangle.

Parameters

a_triangleIndex Index number of selected triangle.

void chai3d::cTriangleArray::computeBTN ( )

inline

This method computes the normal matrix vectors for all triangles.

void chai3d::cTriangleArray::renderInitialize ( )

inline

This method renders the OpenGL vertex buffer object.

void chai3d::cTriangleArray::renderFinalize ( )

inline

This method finalizes rendering the OpenGL vertex buffer object.

bool chai3d::cTriangleArray::computeCollision	(	const unsigned int	a_elementIndex,
		cGenericObject *	a_object,
		cVector3d &	a_segmentPointA,
		cVector3d &	a_segmentPointB,
		cCollisionRecorder &	a_recorder,
		cCollisionSettings &	a_settings
	)		const

virtual

This method checks if the given line segment intersects a selected a triangle from this array.
If a collision occurs, the collision point is reported in the collision recorder.

Parameters

a_elementIndex	Triangle index number.
a_object	Pointer to the object on which collision detection is being performed.
a_segmentPointA	Point from where collision ray starts (in local frame).
a_segmentPointB	Direction vector of collision ray (in local frame).
a_recorder	Stores collision events
a_settings	Collision detector settings.

Returns: true if a collision occurred, otherwise false.

Reimplemented from chai3d::cGenericArray.

double chai3d::cTriangleArray::computeArea ( const unsigned int a_triangleIndex )

inline

This method computes and returns the area for a selected triangle.

Returns: Area for selected triangle.

cVector3d chai3d::cTriangleArray::computeNormal	(	const unsigned int	a_triangleIndex,
		const bool	a_applyNormalToVertices
	)

inline

This method computes the surface normal of a triangle and if requested, updates the normal of each of the three vertices.

Parameters

a_triangleIndex	Index number of selected triangle.
a_applyNormalToVertices	If true, then update normal of each vertex.

Returns: Computed surface normal for selected triangle.

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

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation