Defines a polygonal shape consisting of triangles. More...

#include <cadex/ModelData/IndexedTriangleSet.hxx>

Inherits cadex::ModelData::PolyShape.

Public Types
typedef Geom::Point	VertexType

typedef Geom::Vector	NormalType

typedef std::vector< VertexType >	VertexVecType

typedef std::vector< NormalType >	NormalVecType

typedef std::vector< int >	IndexVecType

Public Member Functions
	IndexedTriangleSet ()
	Constructor.

bool	AddTriangles (const VertexVecType &theVertices, const IndexVecType &theVertexIndices)
	Adds triangles.

bool	AddTriangles (const VertexVecType &theVertices, const IndexVecType &theVertexIndices, const NormalVecType &theNormals, const IndexVecType &theNormalIndices)
	Adds triangles.

bool	AddTriangles (const IndexedTriangleSet &theTriangleSet)
	Adds triangles from theTriangleSet.

const VertexType &	Vertex (int theIndex) const
	Returns a vertex.

size_t	NumberOfVertices () const
	Returns a number of vertices.

bool	HasNormals () const
	Returns true if the triangle set has explicitly defined normals.

const NormalType &	Normal (int theIndex) const
	Returns a normal.

size_t	NumberOfNormals () const
	Returns a number of normals.

const VertexType &	TriangleVertex (size_t theTriangleIndex, size_t theVertexSlot) const
	Returns a vertex of a triangle.

int	TriangleVertexIndex (size_t theTriangleIndex, size_t theVertexSlot) const
	Returns a vertex index in a triangle.

const NormalType &	TriangleVertexNormal (size_t theTriangleIndex, size_t theVertexSlot) const
	Returns a normal at vertex in a triangle.

int	TriangleVertexNormalIndex (size_t theTriangleIndex, size_t theVertexSlot) const
	Returns a normal index for vertex in a triangle.

NormalType	TriangleNormal (size_t theTriangleIndex) const
	Returns a normal of a triangle.

size_t	NumberOfTriangles () const
	Returns a number of triangles.

Static Public Member Functions
static bool	CompareType (const BaseObject &theObject)

Detailed Description

Defines a polygonal shape consisting of triangles.

Triangles are defined via array of unique vertices and triplets of indices in this array. This is to describe connectivity and to reduce data required to describe a triangle set.

The triangle set can optionally contain normals which are defined per each vertex. Normals also use indexing in the same manner as vertices.

A triangle set can be constructed using AddTriangles(), supplying unique vertices and indices describing triangles, for instance:

//vertices
IndexedTriangleSet::VertexVecType aVertices = {
    { 0., 0., 0. },
    { 1., 0., 0. },
    { 1., 1., 0. },
    { 0., 1., 1. }
};
 
//triangles (vertex indices)
IndexedTriangleSet::IndexVecType aVertexIndices = {
    0, 1, 2,
    0, 2, 3
};
 
//normals
IndexedTriangleSet::NormalVecType aNormals = {
    { 0.,  0., 1. }, //to triangle #0: {0, 1, 2}
    { 1., -1., 1. }, //to triangle #1: {0, 2, 3}
};
 
//normal indices
IndexedTriangleSet::IndexVecType aNormalIndices = {
    0, 0, 0,
    1, 1, 1
};
 
ModelData::IndexedTriangleSet aTriangleSet;
aTriangleSet.AddTriangles (aVertices, aVertexIndices, aNormals, aNormalIndices);

The user must ensure data consistency so that the number of normals is equal to number of added vertices. Otherwise, triangles won't be added.

Data can be queried using the rank number of triangle and a vertex slot (0 to 2), for instance:

size_t n = aTriangleSet.NumberOfTriangles();
for (size_t i = 0; i < n; ++i) {
    cout << "Triangle " << i << ":" << endl;
    for (int j = 0; j < 3; ++j) {
        const auto& aV = aTS.TriangleVertex (i, j);
        const auto& aN = aTS.TriangleVertexNormal (i, j);
    }
}

Coordinate and normal indices into respective arrays of unique values can be queried using TriangleVertexIndex() and TriangleVertexNormalIndex() respectively.

Constructor & Destructor Documentation

◆ IndexedTriangleSet()

cadex::ModelData::IndexedTriangleSet::IndexedTriangleSet ( )

inline

Constructor.

Creates not initialized object, for which IsNull() returns true.

Member Function Documentation

◆ AddTriangles() [1/2]

bool cadex::ModelData::IndexedTriangleSet::AddTriangles	(	const VertexVecType &	theVertices,
		const IndexVecType &	theVertexIndices )

Adds triangles.

The number of values in theVertexIndices must be a multiple of three, since each triplet defines a triangle.

Returns true if the triangles were successfully added and false otherwise.

◆ AddTriangles() [2/2]

bool cadex::ModelData::IndexedTriangleSet::AddTriangles	(	const VertexVecType &	theVertices,
		const IndexVecType &	theVertexIndices,
		const NormalVecType &	theNormals,
		const IndexVecType &	theNormalIndices )

Adds triangles.

The number of values in theVertexIndices and theNormalIndices must be the same and a multiple of three, since each triple defines a vertex and vertex normal of a triangle, respectively.

Returns true if the triangles were successfully added and false otherwise.

◆ HasNormals()

bool cadex::ModelData::IndexedTriangleSet::HasNormals ( ) const

Returns true if the triangle set has explicitly defined normals.

See also: NumberOfNormals().

◆ Normal()

const IndexedTriangleSet::NormalType & cadex::ModelData::IndexedTriangleSet::Normal ( int theIndex ) const

Returns a normal.

theIndex must be in the range [0, NumberOfNormals()-1]. Otherwise the result is undefined.

◆ TriangleNormal()

IndexedTriangleSet::NormalType cadex::ModelData::IndexedTriangleSet::TriangleNormal ( size_t theTriangleIndex ) const

Returns a normal of a triangle.

theTriangleIndex must be in the range [0, NumberOfTriangles()-1]. Otherwise the result is undefined.

The normal is calculated on the fly based on the vertices of the triangle.

In case of a degenerate triangle the zero vector will be returned.

◆ TriangleVertex()

const IndexedTriangleSet::VertexType & cadex::ModelData::IndexedTriangleSet::TriangleVertex	(	size_t	theTriangleIndex,
		size_t	theVertexSlot ) const

Returns a vertex of a triangle.

theTriangleIndex must be in the range [0, NumberOfTriangles()-1]. Otherwise the result is undefined. theVertexSlot must be in the range [0, 2]. Otherwise the result is undefined.

See also: TriangleVertexIndex().

◆ TriangleVertexIndex()

int cadex::ModelData::IndexedTriangleSet::TriangleVertexIndex	(	size_t	theTriangleIndex,
		size_t	theVertexSlot ) const

Returns a vertex index in a triangle.

theTriangleIndex must be in the range [0, NumberOfTriangles()-1]. theVertexSlot must be in the range [0, 2].

If the vertex index was not found -1 will be returned.

See also: TriangleVertex().

◆ TriangleVertexNormal()

const IndexedTriangleSet::NormalType & cadex::ModelData::IndexedTriangleSet::TriangleVertexNormal	(	size_t	theTriangleIndex,
		size_t	theVertexSlot ) const

Returns a normal at vertex in a triangle.

theTriangleIndex must be in the range [0, NumberOfTriangles()-1]. Otherwise the result is undefined. theVertexSlot must be in the range [0, 2]. Otherwise the result is undefined.

See also: TriangleVertexNormalIndex().

◆ TriangleVertexNormalIndex()

int cadex::ModelData::IndexedTriangleSet::TriangleVertexNormalIndex	(	size_t	theTriangleIndex,
		size_t	theVertexSlot ) const

Returns a normal index for vertex in a triangle.

theTriangleIndex must be in the range [0, NumberOfTriangles()-1]. theVertexSlot must be in the range [0, 2].

If the normal index was not found -1 will be returned.

See also: TriangleVertexNormal().

◆ Vertex()

const IndexedTriangleSet::VertexType & cadex::ModelData::IndexedTriangleSet::Vertex ( int theIndex ) const

Returns a vertex.

theIndex must be in the range [0, NumberOfVertices()-1]. Otherwise the result is undefined.

Public Types

Public Member Functions

Static Public Member Functions