added determinant() to util/Matrix module

git-svn-id: svn://anubis/fart/trunk@10 7f9b0f55-74a9-4bce-be96-3c2cd072584d
This commit is contained in:
Josh Holtrop 2009-01-20 00:12:06 +00:00
parent f63a1b8c3c
commit aec4a17e45
2 changed files with 34 additions and 0 deletions

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@ -14,6 +14,39 @@ Matrix Matrix::identity()
return res; return res;
} }
double Matrix::determinant()
{
return m_matrix[0][0]*m_matrix[1][1]*m_matrix[2][2]*m_matrix[3][3]
+ m_matrix[0][0]*m_matrix[1][2]*m_matrix[2][3]*m_matrix[3][1]
+ m_matrix[0][0]*m_matrix[1][3]*m_matrix[2][1]*m_matrix[3][2]
+ m_matrix[0][1]*m_matrix[1][0]*m_matrix[2][3]*m_matrix[3][2]
+ m_matrix[0][1]*m_matrix[1][2]*m_matrix[2][0]*m_matrix[3][3]
+ m_matrix[0][1]*m_matrix[1][3]*m_matrix[2][2]*m_matrix[3][0]
+ m_matrix[0][2]*m_matrix[1][0]*m_matrix[2][1]*m_matrix[3][3]
+ m_matrix[0][2]*m_matrix[1][1]*m_matrix[2][3]*m_matrix[3][0]
+ m_matrix[0][2]*m_matrix[1][3]*m_matrix[2][0]*m_matrix[3][1]
+ m_matrix[0][3]*m_matrix[1][0]*m_matrix[2][2]*m_matrix[3][1]
+ m_matrix[0][3]*m_matrix[1][1]*m_matrix[2][0]*m_matrix[3][2]
+ m_matrix[0][3]*m_matrix[1][2]*m_matrix[2][1]*m_matrix[3][0]
- m_matrix[0][0]*m_matrix[1][1]*m_matrix[2][3]*m_matrix[3][2]
- m_matrix[0][0]*m_matrix[1][2]*m_matrix[2][1]*m_matrix[3][3]
- m_matrix[0][0]*m_matrix[1][3]*m_matrix[2][2]*m_matrix[3][1]
- m_matrix[0][1]*m_matrix[1][0]*m_matrix[2][2]*m_matrix[3][3]
- m_matrix[0][1]*m_matrix[1][2]*m_matrix[2][3]*m_matrix[3][0]
- m_matrix[0][1]*m_matrix[1][3]*m_matrix[2][0]*m_matrix[3][2]
- m_matrix[0][2]*m_matrix[1][0]*m_matrix[2][3]*m_matrix[3][1]
- m_matrix[0][2]*m_matrix[1][1]*m_matrix[2][0]*m_matrix[3][3]
- m_matrix[0][2]*m_matrix[1][3]*m_matrix[2][1]*m_matrix[3][0]
- m_matrix[0][3]*m_matrix[1][0]*m_matrix[2][1]*m_matrix[3][2]
- m_matrix[0][3]*m_matrix[1][1]*m_matrix[2][2]*m_matrix[3][0]
- m_matrix[0][3]*m_matrix[1][2]*m_matrix[2][0]*m_matrix[3][1];
}
Matrix operator*(const Matrix & m1, const Matrix & m2) Matrix operator*(const Matrix & m1, const Matrix & m2)
{ {
Matrix res; Matrix res;

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@ -11,6 +11,7 @@ class Matrix
Matrix_row_t & operator[](int idx) { return m_matrix[idx]; } Matrix_row_t & operator[](int idx) { return m_matrix[idx]; }
const Matrix_row_t & operator[](int idx) const { return m_matrix[idx]; } const Matrix_row_t & operator[](int idx) const { return m_matrix[idx]; }
static Matrix identity(); static Matrix identity();
double determinant();
protected: protected:
double m_matrix[4][4]; double m_matrix[4][4];