orthonormal by taby

1

// direction should already be normalized vector_3 z_calc(dir_x, dir_y, dir_z); vector_3 axis; if (fabsf(z_calc.x) <= fabsf(z_calc.y) && fabsf(z_calc.x) <= fabsf(z_calc.z))     axis.set(1, 0, 0); else if (fabsf(z_calc.y) <= fabsf(z_calc.x) && fabsf(z_calc.y) <= fabsf(z_calc.z))     axis.set(0, 1, 0); else     axis.set(0, 0, 1); vector_3 x_calc = z_calc.cross(axis); x_calc.normalize(); vector_3 y_calc = z_calc.cross(x_calc); float m[16]; m[0] = x_calc.x; m[1] = x_calc.y; m[2] = x_calc.z; m[3] = 0.0f; m[4] = y_calc.x; m[5] = y_calc.y; m[6] = y_calc.z; m[7] = 0.0f; m[8] = z_calc.x; m[9] = z_calc.y; m[10] = z_calc.z; m[11] = 0.0f; m[12] = 0.0f; m[13] = 0.0f; m[14] = 0.0f; m[15] = 1.0f; glMultMatrixf(m);