You can create a mousetrap of the native source type through the mousetrap_create or mousetrap_create_with_id API functions by specifying MT_NATIVE as the source_type parameter.
The source_flags parameter is unused for native sources.
The source parameter for native sources is a zero-based 2 element unsigned int array, the first element is the width of the mousetrap to be created, the second element is the height of the mousetrap to be created.