0.9.5/api/a00079_source.html

 #ifndef GLM_GTX_matrix_query

 #define GLM_GTX_matrix_query


 // Dependency:

 #include "../glm.hpp"

 #include "../gtx/vector_query.hpp"

 #include <limits>


 #if(defined(GLM_MESSAGES) && !defined(GLM_EXT_INCLUDED))

 #       pragma message("GLM: GLM_GTX_matrix_query extension included")

 #endif


 namespace glm

 {


         template<typename T, precision P>

         bool isNull(detail::tmat2x2<T, P> const & m, T const & epsilon);


         template<typename T, precision P>

         bool isNull(detail::tmat3x3<T, P> const & m, T const & epsilon);


         template<typename T, precision P>

         bool isNull(detail::tmat4x4<T, P> const & m, T const & epsilon);


         template<typename T, precision P, template <typename, precision> class matType>

         bool isIdentity(matType<T, P> const & m, T const & epsilon);


         template<typename T, precision P>

         bool isNormalized(detail::tmat2x2<T, P> const & m, T const & epsilon);


         template<typename T, precision P>

         bool isNormalized(detail::tmat3x3<T, P> const & m, T const & epsilon);


         template<typename T, precision P>

         bool isNormalized(detail::tmat4x4<T, P> const & m, T const & epsilon);


         template<typename T, precision P, template <typename, precision> class matType>

         bool isOrthogonal(matType<T, P> const & m, T const & epsilon);


 }//namespace glm


 #include "matrix_query.inl"


 #endif//GLM_GTX_matrix_query

glm::epsilon
GLM_FUNC_DECL genType epsilon()
Return the epsilon constant for floating point types.

glm::isOrthogonal
bool isOrthogonal(matType< T, P > const &m, T const &epsilon)
Return whether a matrix is an orthonormalized matrix.

glm::isNormalized
bool isNormalized(detail::tmat2x2< T, P > const &m, T const &epsilon)
Return whether a matrix is a normalized matrix.

glm::isNull
bool isNull(detail::tmat2x2< T, P > const &m, T const &epsilon)
Return whether a matrix a null matrix.

glm::isIdentity
bool isIdentity(matType< T, P > const &m, T const &epsilon)
Return whether a matrix is an identity matrix.