/*****************************************************************************
*                                                                            *
*   GETSYMBOLOFFSET.SPL  Copyright (C) 2011 DSP Development Corporation      *
*                               All Rights Reserved                          *
*                                                                            *
*   Author:      Randy Race                                                  *
*                                                                            *
*   Synopsis:    Returns the starting point of a symbol plot                 *
*                                                                            *
*   Revisions:   31 Jan 2011  RRR  Creation                                  *
*                                                                            *
*****************************************************************************/

#include 

#if @HELP_GETSYMBOLOFFSET

    GETSYMBOLOFFSET

    Purpose: Returns the start sample for a symbol plot.

    Syntax:  GETSYMBOLOFFSET(series, item)

              series - Optional, a series. Defaults to current window

                item - Optional, an integer. The series number if the 
                       target is a Window with more than one series.
                       Defaults to 1.

    Returns: An integer, the symbol starting sample number.

    Example:
             W1: 1..20;setsym(14);setsymbolinterval(5);setsymboloffset(3)

             symoff = getsymboloffset(w1)

             W1 contains a 20 point series where a circle is used as a 
             symbol plotted every 5 points starting a the 3rd point

             symoff == 3           

    Remarks:
             The SYMBOLOFFSET only takes effect if SYMBOLINTERVAL > 1.

    See Also:
             Getsymbol
             Getsymbolinterval
             Getsymbolsize
             Setsymbol
             Setsymbolinterval
             Setsymboloffset
             Setsymbolsize
#endif



/* get symbol offset */
getsymboloffset(ser, item, member)
{
        local s, offset;
        
        (s, item, member) = getsymboloffset_parse_args(ser, item, member);

        if (isscalar(s))
        {
                if (s == 0)
                {
                        /* current window */
                        offset = (length > 0) ? getsymbol(2, item, member) : 0;

                        return(offset);
                }
                else
                {
                        s = castwindow(s);
                }
        }

        /* return offset */
        offset = (length(s) > 0) ? getsymbol(s, 2, item, member) : 0;

        return(offset);

}


/* parse args */
getsymboloffset_parse_args(s, item, member)
{
        local winnum = 0;

        if (argc < 3)
        {
                if (argc < 2)
                {
                        if (argc < 1) s = refwindow(w0);
                        item = -1;
                }
                member = -1;
        }

        if (isscalar(s))
        {
                member = item;
                item   = s;
                winnum = 0;
        }
        else if (iswindow(s))
        {
                winnum = getwnum(s);
        }
        else if (isarray(s))
        {
                winnum = refseries(s);
        }

        if (member < 0) member = 1;
        if (item < 0)   item   = 1;
        
        return(winnum, item, member);
}