Function cvSeqPopMulti

deps/opencv/modules/core/src/datastructs.cpp:1516–1582

Remove several elements from the end of sequence: */

/* Remove several elements from the end of sequence: */
CV_IMPL void
cvSeqPopMulti( CvSeq *seq, void *_elements, int count, int front )
{
    char *elements = (char *) _elements;

    if( !seq )
        CV_Error( CV_StsNullPtr, "NULL sequence pointer" );
    if( count < 0 )
        CV_Error( CV_StsBadSize, "number of removed elements is negative" );

    count = MIN( count, seq->total );

    if( !front )
    {
        if( elements )
            elements += count * seq->elem_size;

        while( count > 0 )
        {
            int delta = seq->first->prev->count;

            delta = MIN( delta, count );
            assert( delta > 0 );

            seq->first->prev->count -= delta;
            seq->total -= delta;
            count -= delta;
            delta *= seq->elem_size;
            seq->ptr -= delta;

            if( elements )
            {
                elements -= delta;
                memcpy( elements, seq->ptr, delta );
            }

            if( seq->first->prev->count == 0 )
                icvFreeSeqBlock( seq, 0 );
        }
    }
    else
    {
        while( count > 0 )
        {
            int delta = seq->first->count;

            delta = MIN( delta, count );
            assert( delta > 0 );

            seq->first->count -= delta;
            seq->total -= delta;
            count -= delta;
            seq->first->start_index += delta;
            delta *= seq->elem_size;

            if( elements )
            {
                memcpy( elements, seq->first->data, delta );