mirror of https://github.com/axmolengine/axmol.git
70 lines
2.4 KiB
C
70 lines
2.4 KiB
C
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#ifndef POLARDECOMPOSITION_H
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#define POLARDECOMPOSITION_H
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#include "btMatrix3x3.h"
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/**
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* This class is used to compute the polar decomposition of a matrix. In
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* general, the polar decomposition factorizes a matrix, A, into two parts: a
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* unitary matrix (U) and a positive, semi-definite Hermitian matrix (H).
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* However, in this particular implementation the original matrix, A, is
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* required to be a square 3x3 matrix with real elements. This means that U will
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* be an orthogonal matrix and H with be a positive-definite, symmetric matrix.
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*/
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class btPolarDecomposition
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{
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public:
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/**
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* Creates an instance with optional parameters.
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*
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* @param tolerance - the tolerance used to determine convergence of the
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* algorithm
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* @param maxIterations - the maximum number of iterations used to achieve
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* convergence
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*/
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btPolarDecomposition(btScalar tolerance = btScalar(0.0001),
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unsigned int maxIterations = 16);
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/**
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* Decomposes a matrix into orthogonal and symmetric, positive-definite
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* parts. If the number of iterations returned by this function is equal to
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* the maximum number of iterations, the algorithm has failed to converge.
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*
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* @param a - the original matrix
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* @param u - the resulting orthogonal matrix
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* @param h - the resulting symmetric matrix
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*
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* @return the number of iterations performed by the algorithm.
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*/
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unsigned int decompose(const btMatrix3x3& a, btMatrix3x3& u, btMatrix3x3& h) const;
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/**
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* Returns the maximum number of iterations that this algorithm will perform
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* to achieve convergence.
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*
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* @return maximum number of iterations
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*/
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unsigned int maxIterations() const;
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private:
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btScalar m_tolerance;
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unsigned int m_maxIterations;
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};
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/**
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* This functions decomposes the matrix 'a' into two parts: an orthogonal matrix
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* 'u' and a symmetric, positive-definite matrix 'h'. If the number of
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* iterations returned by this function is equal to
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* btPolarDecomposition::DEFAULT_MAX_ITERATIONS, the algorithm has failed to
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* converge.
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*
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* @param a - the original matrix
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* @param u - the resulting orthogonal matrix
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* @param h - the resulting symmetric matrix
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*
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* @return the number of iterations performed by the algorithm.
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*/
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unsigned int polarDecompose(const btMatrix3x3& a, btMatrix3x3& u, btMatrix3x3& h);
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#endif // POLARDECOMPOSITION_H
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