eng::VisitorComputeNormals Class Reference

Visitor to compute normal vectors on polygons and vertexs. More...

#include <eng_graph_draw.hh>

Inheritance diagram for eng::VisitorComputeNormals:

List of all members.

Public Member Functions
	VisitorComputeNormals (Graph &graph, NormalsNode &normalsNode, const LocalVertexs &localVertexs)
	~VisitorComputeNormals ()
void	Begin (void)
void	End (void)
Private Member Functions
template<typename VIXS>
void	ComputeAndTotalNormal (const Nix nix, const VIXS &vixs)
void	Visit (PolygonNode &node)
Private Attributes
const LocalVertexs &	mLocalVertexs
NormalVertexs &	mPolygonNormals
NormalVertexs &	mVertexNormals

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Detailed Description

Visitor to compute normal vectors on polygons and vertexs.

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Constructor & Destructor Documentation

eng::VisitorComputeNormals::VisitorComputeNormals	(	Graph &	graph,
		NormalsNode &	normalsNode,
		const LocalVertexs &	localVertexs
	)

eng::VisitorComputeNormals::~VisitorComputeNormals

(

)

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Member Function Documentation

void eng::VisitorComputeNormals::Begin

(

void

)

[inline]

void eng::VisitorComputeNormals::End

(

void

)

[virtual]

Called at end of traversal. mVertexNormals now contains totals of vectors. The final step in averaging normal vectors is to normalize them. A mathematical property of vectors (OpenGL red book) is that adding vectors then normalizing the sum results in a normalized average. Normalize( v1 + v2 + v3 ) = Normalize( (v1 + v2 + v3) / 3.0 )

Reimplemented from eng::Visitor.

template<typename VIXS>

void eng::VisitorComputeNormals::ComputeAndTotalNormal	(	const Nix	nix,
		const VIXS &	vixs
	)			[inline, private]

Compute normal vector on this polygon. Along the way, for the goal of averaging normal vectors of polygons adjacent to a vertex, add this normal vector to a total, to be later divided to produce an average.

A mathematical propery of vectors (OpenGL red book) is that adding vectors then normalizing the sum results in a normalized average. Normalize( v1 + v2 + v3 ) = Normalize( (v1 + v2 + v3) / 3.0 ) VisitorComputeNormals uses this property since it doesn't know how many vectors there will be (divisor unknown).

void eng::VisitorComputeNormals::Visit

(

PolygonNode &

node

)

[inline, private, virtual]

Reimplemented from eng::Visitor.

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Member Data Documentation

const LocalVertexs& eng::VisitorComputeNormals::mLocalVertexs [private]

NormalVertexs& eng::VisitorComputeNormals::mPolygonNormals [private]

NormalVertexs& eng::VisitorComputeNormals::mVertexNormals [private]

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

• eng_graph_draw.hh
• eng_graph_draw.cc

Palomino 3D Engine documents generated by doxygen 1.5.3 on Fri Nov 23 11:26:21 2007