public static extern void FT_Outline_Transform(IntPtr outline, ref FT_Matrix matrix);
public static extern FT_Error FT_Matrix_Invert(ref FT_Matrix matrix);
public static extern void FT_Matrix_Multiply(ref FT_Matrix a, ref FT_Matrix b);
public static extern void FT_Vector_Transform(ref FT_Vector vec, ref FT_Matrix matrix);
public static extern FT_Error FT_Glyph_Transform(IntPtr glyph, ref FT_Matrix matrix, ref FT_Vector delta);
public static extern FT_Error FT_Get_SubGlyph_Info(IntPtr glyph, uint sub_index, out int p_index, out uint p_flags, out int p_arg1, out int p_arg2, out FT_Matrix p_transform);