Function ncvisual_from_rgba 

pub unsafe extern "C" fn ncvisual_from_rgba(
    rgba: *const c_void,
    rows: c_int,
    rowstride: c_int,
    cols: c_int,
) -> *mut ncvisual

Prepare an ncvisual, and its underlying plane, based off RGBA content in memory at ‘rgba’. ‘rgba’ is laid out as ‘rows’ lines, each of which is ‘rowstride’ bytes in length. Each line has ‘cols’ 32-bit 8bpc RGBA pixels followed by possible padding (there will be ‘rowstride’ - ‘cols’ * 4 bytes of padding). The total size of ‘rgba’ is thus (‘rows’ * ‘rowstride’) bytes, of which (‘rows’ * ‘cols’ * 4) bytes are actual non-padding data. It is an error if any argument is not positive, if ‘rowstride’ is not a multiple of 4, or if ‘rowstride’ is less than ‘cols’ * 4.