Function cvSeqPushMulti

deps/opencv/modules/core/src/datastructs.cpp:1447–1512

Add several elements to the beginning or end of a sequence: */

/* Add several elements to the beginning or end of a sequence: */
CV_IMPL void
cvSeqPushMulti( CvSeq *seq, const 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" );

    int elem_size = seq->elem_size;

    if( !front )
    {
        while( count > 0 )
        {
            int delta = (int)((seq->block_max - seq->ptr) / elem_size);

            delta = MIN( delta, count );
            if( delta > 0 )
            {
                seq->first->prev->count += delta;
                seq->total += delta;
                count -= delta;
                delta *= elem_size;
                if( elements )
                {
                    memcpy( seq->ptr, elements, delta );
                    elements += delta;
                }
                seq->ptr += delta;
            }

            if( count > 0 )
                icvGrowSeq( seq, 0 );
        }
    }
    else
    {
        CvSeqBlock* block = seq->first;

        while( count > 0 )
        {
            int delta;

            if( !block || block->start_index == 0 )
            {
                icvGrowSeq( seq, 1 );

                block = seq->first;
                assert( block->start_index > 0 );
            }

            delta = MIN( block->start_index, count );
            count -= delta;
            block->start_index -= delta;
            block->count += delta;
            seq->total += delta;