/*****************************************************************************
*                                                                            *
*   RTSPIN.SPL   Copyright (C) 2000 DSP Development Corporation              *
*                               All Rights Reserved                          *
*                                                                            *
*   Author:      Randy Race                                                  *
*                                                                            *
*   Synopsis:    Spins a 3D plot in real time                                *
*                                                                            *
*   Revisions:   16 May 2000  RRR  Creation                                  *
*                                                                            *
*****************************************************************************/

#include 

#if @HELP_RTSPIN

    RTSPIN

    Purpose: Spins a 3D plot in Real Time

    Syntax:  RTSPIN(win, inc)

             win - an optional Window that contains a 3D plot,
                   defaults to the current Window

             inc - an optional integer, spin increment in degrees,
                   defaults to 3 degrees. If inc == 0, the current
                   rtspin is terminated.



    Returns: Nothing

    Example:
             W1: XYZ(gsin(100,.01,4),gcos(100,.01,4),0..0.01..0.99)

             Scalesoff
             rtspin


             Spins the spiral 3 degrees in each direction. Because the
             spin routine is automatically executed in the background,
             DADiSP is still responsive to user input while the plot
             spins.

    Example:
             W1: XYZ(gsin(100,.01,4),gcos(100,.01,4),0..0.01..0.99)

             Scalesoff
             rtspin(w1, 8)

             Same as above except the spin increment is 8 degrees.


    Remarks:
             Use RTSPIN(0) to terminate the real time spin.

             RTSPIN automatically adds itself to the real time task list
             using RTTINIT. Currently, only one RTSPIN function is active
             per real time session.


    See Also:
             Rotate3d
             Rttinit
             Rttterm
             Spin
             XYZ

#endif

/* spin a 3D Window in real time */
rtspin(w, inc)
{
        local x, y, z;

        if (argc < 2)
        {
                inc = 3;
                
                if (argc < 1)
                {
                        if (not(addrtspin(w0, inc))) remrtspin();
                        
                        return;
                }
                else if (iswindow(w))
                {
                        /* add to real time list if necessary */
                        if (addrtspin(w, inc)) return;
                }
                else if (isscalar(w))
                {
                        if (w == 0)
                        {
                                remrtspin();
                                return();
                        }
                        else
                        {
                                if (addrtspin(w0, w)) return;
                        }
                }
        }
        else if (iswindow(w))
        {
                /* add to real time list if necessary */
                if (addrtspin(w, inc)) return;
        }

        if (isscalar(w))
        {
                /* remove from realtime list */
                remrtspin();
        }
        else if (_is3d(w))
        {
                x = getrotate3d(w, 1);
                y = getrotate3d(w, 2);
                z = getrotate3d(w, 3);

                rotate3d(w, x + inc, y + inc, z + inc);
                
                if (getwnum != castint(strwin(w))) plotmode(w, 1);
        }
        
        return;
}


/* add spin to real time task list */
addrtspin(w, inc)
{
        local retval = 0;

        if (not(isvar("rtspin_on")) && _is3d(w))
        {
                if (argc < 2)
                {
                        if (iswindow(w))
                        {
                                eval(sprintf("rttinit('rtspin(%s)')", strwin(w)));
                                setvar("rtspin_on", 1);
                                retval = 1;
                        }
                }
                else if (iswindow(w))
                {
                        eval(sprintf("rttinit('rtspin(%s, %d)')", strwin(w), inc));
                        setvar("rtspin_on", 1);
                        retval = 1;
                }
        }
        
        return(retval);
}


/* remove all real time tasks */
remrtspin()
{
        rttterm(-1);
        delvar("rtspin_on");
}