78 lines
2.6 KiB
C++
78 lines
2.6 KiB
C++
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#include "Matrix.h"
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Matrix Matrix::identity()
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{
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Matrix res;
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for (int i = 0; i < 4; i++)
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{
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for (int j = 0; j < 4; j++)
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{
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res[i][j] = i == j ? 1.0 : 0.0;
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}
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}
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return res;
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}
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double Matrix::determinant()
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{
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return m_matrix[0][0]*m_matrix[1][1]*m_matrix[2][2]*m_matrix[3][3]
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+ m_matrix[0][0]*m_matrix[1][2]*m_matrix[2][3]*m_matrix[3][1]
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+ m_matrix[0][0]*m_matrix[1][3]*m_matrix[2][1]*m_matrix[3][2]
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+ m_matrix[0][1]*m_matrix[1][0]*m_matrix[2][3]*m_matrix[3][2]
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+ m_matrix[0][1]*m_matrix[1][2]*m_matrix[2][0]*m_matrix[3][3]
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+ m_matrix[0][1]*m_matrix[1][3]*m_matrix[2][2]*m_matrix[3][0]
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+ m_matrix[0][2]*m_matrix[1][0]*m_matrix[2][1]*m_matrix[3][3]
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+ m_matrix[0][2]*m_matrix[1][1]*m_matrix[2][3]*m_matrix[3][0]
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+ m_matrix[0][2]*m_matrix[1][3]*m_matrix[2][0]*m_matrix[3][1]
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+ m_matrix[0][3]*m_matrix[1][0]*m_matrix[2][2]*m_matrix[3][1]
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+ m_matrix[0][3]*m_matrix[1][1]*m_matrix[2][0]*m_matrix[3][2]
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+ m_matrix[0][3]*m_matrix[1][2]*m_matrix[2][1]*m_matrix[3][0]
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- m_matrix[0][0]*m_matrix[1][1]*m_matrix[2][3]*m_matrix[3][2]
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- m_matrix[0][0]*m_matrix[1][2]*m_matrix[2][1]*m_matrix[3][3]
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- m_matrix[0][0]*m_matrix[1][3]*m_matrix[2][2]*m_matrix[3][1]
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- m_matrix[0][1]*m_matrix[1][0]*m_matrix[2][2]*m_matrix[3][3]
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- m_matrix[0][1]*m_matrix[1][2]*m_matrix[2][3]*m_matrix[3][0]
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- m_matrix[0][1]*m_matrix[1][3]*m_matrix[2][0]*m_matrix[3][2]
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- m_matrix[0][2]*m_matrix[1][0]*m_matrix[2][3]*m_matrix[3][1]
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- m_matrix[0][2]*m_matrix[1][1]*m_matrix[2][0]*m_matrix[3][3]
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- m_matrix[0][2]*m_matrix[1][3]*m_matrix[2][1]*m_matrix[3][0]
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- m_matrix[0][3]*m_matrix[1][0]*m_matrix[2][1]*m_matrix[3][2]
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- m_matrix[0][3]*m_matrix[1][1]*m_matrix[2][2]*m_matrix[3][0]
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- m_matrix[0][3]*m_matrix[1][2]*m_matrix[2][0]*m_matrix[3][1];
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}
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Matrix operator*(const Matrix & m1, const Matrix & m2)
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{
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Matrix res;
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for (int i = 0; i < 4; i++)
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{
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for (int j = 0; j < 4; j++)
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{
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res[i][j] = m1[i][0] * m2[0][j]
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+ m1[i][1] * m2[1][j]
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+ m1[i][2] * m2[2][j]
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+ m1[i][3] * m2[3][j];
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}
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}
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return res;
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}
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Vector operator*(const Matrix & m, const Vector & v)
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{
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Vector res;
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for (int i = 0; i < 4; i++)
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{
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res[i] = m[i][0] * v[0]
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+ m[i][1] * v[1]
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+ m[i][2] * v[2]
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+ m[i][3]; /* v[3] is implicitly 1.0 */
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}
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return res;
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}
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