Function cvCreateSeq

deps/opencv/modules/core/src/datastructs.cpp:365–397

Create empty sequence: */

/* Create empty sequence: */
CV_IMPL CvSeq *
cvCreateSeq( int seq_flags, size_t header_size, size_t elem_size, CvMemStorage* storage )
{
    CvSeq *seq = 0;

    if( !storage )
        CV_Error( CV_StsNullPtr, "" );
    if( header_size < sizeof( CvSeq ) || elem_size <= 0 )
        CV_Error( CV_StsBadSize, "" );

    /* allocate sequence header */
    seq = (CvSeq*)cvMemStorageAlloc( storage, header_size );
    memset( seq, 0, header_size );

    seq->header_size = (int)header_size;
    seq->flags = (seq_flags & ~CV_MAGIC_MASK) | CV_SEQ_MAGIC_VAL;
    {
        int elemtype = CV_MAT_TYPE(seq_flags);
        int typesize = CV_ELEM_SIZE(elemtype);

        if( elemtype != CV_SEQ_ELTYPE_GENERIC && elemtype != CV_USRTYPE1 &&
            typesize != 0 && typesize != (int)elem_size )
            CV_Error( CV_StsBadSize,
            "Specified element size doesn't match to the size of the specified element type "
            "(try to use 0 for element type)" );
    }
    seq->elem_size = (int)elem_size;
    seq->storage = storage;

    cvSetSeqBlockSize( seq, (int)((1 << 10)/elem_size) );

    return seq;
}


/* adjusts <delta_elems> field of sequence. It determines how much the sequence