Function icvAdjustRect

deps/opencv/modules/imgproc/src/samplers.cpp:80–135

static const void*
icvAdjustRect( const void* srcptr, int src_step, int pix_size,
               CvSize src_size, CvSize win_size,
               CvPoint ip, CvRect* pRect )
{
    CvRect rect;
    const char* src = (const char*)srcptr;

    if( ip.x >= 0 )
    {
        src += ip.x*pix_size;
        rect.x = 0;
    }
    else
    {
        rect.x = -ip.x;
        if( rect.x > win_size.width )
            rect.x = win_size.width;
    }

    if( ip.x < src_size.width - win_size.width )
        rect.width = win_size.width;
    else
    {
        rect.width = src_size.width - ip.x - 1;
        if( rect.width < 0 )
        {
            src += rect.width*pix_size;
            rect.width = 0;
        }
        assert( rect.width <= win_size.width );
    }

    if( ip.y >= 0 )
    {
        src += ip.y * src_step;
        rect.y = 0;
    }
    else
        rect.y = -ip.y;

    if( ip.y < src_size.height - win_size.height )
        rect.height = win_size.height;
    else
    {
        rect.height = src_size.height - ip.y - 1;
        if( rect.height < 0 )
        {
            src += rect.height*src_step;
            rect.height = 0;
        }
    }

    *pRect = rect;
    return src - rect.x*pix_size;
}