4 typedef struct mat3x3 {
8 mat3x3 make_mat3x3(float a11, float a12, float a13,
9 float a21, float a22, float a23,
10 float a31, float a32, float a33);
11 mat3x3 mat3x3_product(mat3x3 m1, mat3x3 m2);
12 mat3x3 mat3x3_product2(mat3x3 m1, mat3x3 m2, mat3x3 m3);
13 mat3x3 trans_mat(float x, float y);
14 mat3x3 rot_mat(float angle);
15 mat3x3 scale_mat(float factor);