Developer CD Series 1998 May: Tool Chest/Dev.CD May 98 TC.toast/Tool Chest/Development Kits/HyperCard Related/APDA HyperCard Toolkits/CD Audio Toolkit 1.0/Source/CDDiscTime.c

C/C++ Source or Header | 1995-02-07 | 4.9 KB | 188 lines | [TEXT/MPS ]

/*
    CDDiscTime - An XFCN to report the time on disc
    ©Apple Computer, Inc. 1988
    All Rights Reserved.

    88/11/08    BL°B    First Version

    To compile and link this file using Macintosh Programmer's Workshop,

    C -q2 CDDiscTime.c
    link -sn Main=CDDiscTime -sn STDIO=CDDiscTime ∂
         -sn INTENV=CDDiscTime -rt XFCN=42 ∂
         -m CDDiscTime CDDiscTime.c.o "{CLibraries}"CRuntime.o ∂
         "{CLibraries}"StdCLib.o ∂
         -o HyperCommands

    This link directive puts the XCMD in the file "HyperCommands".
    Substitute the name of the stack you want it in.  To move XCMDs
    between stacks, use ResEdit.  They can be in an individual stack,
    the Home stack, the HyperCard application, or the System File.

*/

#include <cd.h>

/* prototype definitions for functions */
OSErr    ThisDisc(short, long *, long *, long *);
void    TimeDiff(long *, long *, long *, long, long, long, long, long, long);

/* **** WARNING:  DO NOT USE GLOBAL VARIABLES! **** */


/************************************************************************
 *
 *  Function:        CDDiscTime
 *
 *  Purpose:        return the time of this disc.
 *
 *  Returns:        either 0, or an error
 *                    if it's a negative number, it's an error
 *
 *  Side Effects:
 *
 *  Description:    We need one parameter:
 *                    1) the ioRefNum that we got from previously calling
 *                       CDOpen()
 *                    call the driver with a READTOC call to find out
 *                    the lead-out time.  The disc time is lead-out time
 *                    minus one block.
 *
 ************************************************************************/
pascal void
CDDiscTime(paramPtr)
XCmdBlockPtr    paramPtr;
{
    Str31    returnString;
    OSErr    result;
    short    ioRefNum;
    Handle    refHandle;
    long    discTime[3];    /* minute, second, block */

    /* Must be no parameters */
    if ((paramPtr->paramCount) != 0)
    {
        /* Report error in parameters by returning -1 */
        NumToStr(paramPtr, (long) -1, &returnString);
        paramPtr->returnValue = PasToZero(paramPtr, (StringPtr) &returnString);
        return;
    }

    /* Get the global ioRefNum and convert it. */
    refHandle = GetGlobal(paramPtr, GLOBALNAME);
    ioRefNum = atoi(*(refHandle));
    DisposHandle(refHandle);
    ioRefNum &= 0xFFFF;            /* remove vRefNum; not needed. */

    result = ThisDisc(ioRefNum, &discTime[0], &discTime[1], &discTime[2]);

    TimeDiff(&discTime[0], &discTime[1], &discTime[2],
            discTime[0], discTime[1], discTime[2], 0, 0, 1);        /* disc time is lead-out time minus 1 block */

    if (result == noErr)
    {
        /* convert each value to a string, concatenate, & return. */
        FormatString(&returnString, discTime, 3);
        paramPtr->returnValue = PasToZero(paramPtr, (StringPtr) &returnString);
    }
    else
    {
        /* We got an error. Convert result to string & return it as error */
        NumToStr(paramPtr, (long) result, &returnString);
        paramPtr->returnValue = PasToZero(paramPtr, (StringPtr) &returnString);
    }
}

/************************************************************************
 *
 *  Function:        ThisDisc
 *
 *  Purpose:        return total time on this disc
 *
 *  Returns:        OSErr
 *                    either noErr if everything was okay
 *                    or some parameter error from driver call.
 *
 *  Side Effects:
 *                    fills in totalMinute, totalSecond, totalBlock
 *
 *  Description:
 *                    call the driver ReadTOC call to get the appropriate
 *                    information.
 *
 ************************************************************************/
OSErr
ThisDisc(refNum, minute, second, block)
short    refNum;
long    *minute;
long    *second;
long    *block;
{
    CDParam    myPB;
    OSErr    result;

    myPB.ioCompletion = 0;
    myPB.ioNamePtr = (char *) 0;
    myPB.ioVRefNum = 1;
    myPB.ioCRefNum = refNum;
    myPB.csCode = READTOC;
    myPB.csParam[0] = 0;
    myPB.csParam[1] = 2;     /* request lead-out time */

    result = PBControl(&myPB, false);

    if (result == noErr)
    {
        *minute = (long) BCD2DECIMAL(myPB.csParam[0]);
        *second = (long) BCD2DECIMAL(myPB.csParam[1]);
        *block = (long) BCD2DECIMAL(myPB.csParam[2]);
    }
    return result;
}

/************************************************************************
 *
 *  Function:        TimeDiff
 *
 *  Purpose:        calculate difference between two times
 *
 *  Returns:        nothing
 *
 *  Side Effects:    fills rMinute, rSecond, rBlock
 *
 *  Description:    convert the absolute times designated by
 *                    {m1, s1, f1} and {m2, s2, f2} to absolute
 *                    blocks.  Subtract the second time from the
 *                    first.  Convert the result back to {m, s, f}
 *                    format.
 *
 ************************************************************************/
void
TimeDiff(rMinute, rSecond, rBlock, m1, s1, f1, m2, s2, f2)
long    *rMinute;
long    *rSecond;
long    *rBlock;
long    m1, s1, f1, m2, s2, f2;
{
    long    time1, time2;
    long    minute, second, block;

    time1 = f1 + (s1 * BLOCKSEC) + (m1 * BLOCKMIN);
    time2 = f2 + (s2 * BLOCKSEC) + (m2 * BLOCKMIN);

    time1 = time1 - time2;

    minute = time1 / BLOCKMIN;
    time1 = time1 - (minute * BLOCKMIN);

    second = time1 / BLOCKSEC;
    block = time1 - (second * BLOCKSEC);

    *rMinute = minute;
    *rSecond = second;
    *rBlock = block;
}

/* C routines for HyperCard callbacks */
#include <XCmdGlue.inc.c>