Types:

Matrix33;

A 3x3 Matrix.

typedef struct{
    float x[3][3];
} Matrix33;

void Matrix33_Add(const Matrix33* m1, const Matrix33* m2, Matrix33* res);

This function adds matrix m1 to matrix m2 returning the result in res.

Returns: nothing.

void Matrix33_Copy(const Matrix33* m, Matrix33* c);

This function returns a copy of matrix m in c.

Returns: nothing.

void Matrix33_ExtractFromXForm3d(const geXForm3d* xform, Matrix33* m);

This function extracts the upper left 3x3 sections of the geXForm3d xform and copies it to m.  I guess this would represent the non-translational transformation.

Returns: nothing.

void Matrix33_GetTranspose(const Matrix33* m, Matrix33* t);

This function transposes matrix m returning the result in t.

Returns: nothing.

void Matrix33_GetInverse(const Matrix33* m, Matrix33* inv);

This function inverts matrix m returning the result in t.

Returns:nothing.

void Matrix33_MakeCrossProductMatrix33(const geVec3d* v, Matrix33* m);

This function can be used to create a matrix from a vector to help calculate the cross product of two vectors.  As an example, if you wanted the cross product of the vectors A and B (A x B), this could be calculated as Matrix33_MakeCrossProductMatrix33(A,temp); Matrix33_MultiplyVec3d(temp, B, result) where result is the result.

Returns: nothing.

void Matrix33_Multiply(const Matrix33* m1, const Matrix33* m2, Matrix33* res);

This function multiplies matrices m1 and m2 returning the result in res.

Returns: nothing.

void Matrix33_MultiplyScalar(float s, const Matrix33* m, Matrix33* res);

This function multiplies the matrix m by the scalar float s returning the result in res.

Returns: nothing.

void Matrix33_MultiplyVec3d(const Matrix33* m, const geVec3d* v, geVec3d* res);

This function multiplies the matrix m by the geVec3d v returning the resulting geVec3d in res.

Returns: nothing.

void Matrix33_SetIdentity(Matrix33* m);

This function sets the matrix m to the identity matrix.

Returns: nothing.

void Matrix33_Subtract(const Matrix33* m1, const Matrix33* m2, Matrix33* res);

This function subtracts matrix m2 from matrix m1 returning the result in res.

Returns: nothing.