/*

    File:       CarbonSndPlayDB.c

    Description: Routines demonstrating how to create a function that works

                 much like the original SndPlayDoubleBuffer but is Carbon compatible

                 (which SndPlayDoubleBuffer isn't).

    Author:     Quinn, MC, ERA

    Version:    1.0.3

    Copyright:  © Copyright 1999-2002 Apple Computer, Inc. All rights reserved.

    Disclaimer: IMPORTANT:  This Apple software is supplied to you by Apple Computer, Inc.

                ("Apple") in consideration of your agreement to the following terms, and your

                use, installation, modification or redistribution of this Apple software

                constitutes acceptance of these terms.  If you do not agree with these terms,

                please do not use, install, modify or redistribute this Apple software.

                In consideration of your agreement to abide by the following terms, and subject

                to these terms, Apple grants you a personal, non-exclusive license, under AppleÕs

                copyrights in this original Apple software (the "Apple Software"), to use,

                reproduce, modify and redistribute the Apple Software, with or without

                modifications, in source and/or binary forms; provided that if you redistribute

                the Apple Software in its entirety and without modifications, you must retain

                this notice and the following text and disclaimers in all such redistributions of

                the Apple Software.  Neither the name, trademarks, service marks or logos of

                Apple Computer, Inc. may be used to endorse or promote products derived from the

                Apple Software without specific prior written permission from Apple.  Except as

                expressly stated in this notice, no other rights or licenses, express or implied,

                are granted by Apple herein, including but not limited to any patent rights that

                may be infringed by your derivative works or by other works in which the Apple

                Software may be incorporated.

                The Apple Software is provided by Apple on an "AS IS" basis.  APPLE MAKES NO

                WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION THE IMPLIED

                WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY AND FITNESS FOR A PARTICULAR

                PURPOSE, REGARDING THE APPLE SOFTWARE OR ITS USE AND OPERATION ALONE OR IN

                COMBINATION WITH YOUR PRODUCTS.

                IN NO EVENT SHALL APPLE BE LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR

                CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE

                GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

                ARISING IN ANY WAY OUT OF THE USE, REPRODUCTION, MODIFICATION AND/OR DISTRIBUTION

                OF THE APPLE SOFTWARE, HOWEVER CAUSED AND WHETHER UNDER THEORY OF CONTRACT, TORT

                (INCLUDING NEGLIGENCE), STRICT LIABILITY OR OTHERWISE, EVEN IF APPLE HAS BEEN

                ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    Change History (most recent first): <1> 6/12/02 Fixed OS X crashing bugs per radar 2944451 & 2894327

*/

/* Requirements for using this shim code:

    1) The sound channel's queue must be empty before you call CarbonSndPlayDoubleBuffer

    2) You cannot call MySndDoImmediate until CarbonSndPlayDoubleBuffer returns.  Be

       careful about calling MySndDoImmediate at interrupt time with a quietCmd.

*/

#define TARGET_API_MAC_CARBON 1

#ifdef __APPLE_CC__

    #include <Carbon/Carbon.h>

#else

    #include <Carbon.h>

#endif

#include "CarbonSndPlayDB.h"

#define DEBUG 0

#define kBufSize                    2048

// Structs

struct PerChanInfo {

    QElemPtr                        qLink;                      /* next queue entry */

    short                           qType;                      /* queue type = 0 */

    short                           stopping;

    #if DEBUG

        OSType                      magic;

    #endif

    SndCallBackUPP                  usersCallBack;

    SndDoubleBufferHeaderPtr        theParams;

    CmpSoundHeader                  soundHeader;

};

typedef struct PerChanInfo          PerChanInfo;

typedef struct PerChanInfo *        PerChanInfoPtr;

// Globals

    Boolean                         gNMRecBusy;

    NMRecPtr                        gNMRecPtr;

    QHdrPtr                         gFreeList;

    Ptr                             gSilenceTwos;

    Ptr                             gSilenceOnes;

static SndCallBackUPP               gCarbonSndPlayDoubleBufferCallBackUPP = nil;

static SndCallBackUPP               gCarbonSndPlayDoubleBufferCleanUpUPP = nil;

// Remember this routine could be called at interrupt time, so don't allocate or deallocate memory.

OSErr   MySndDoImmediate (SndChannelPtr chan, SndCommand * cmd) {

    PerChanInfoPtr                  perChanInfoPtr;

    // Is this being called on one of the sound channels we are manipulating?

    // If so, we need to pull our callback out of the way so that the user's commands run

    if (gCarbonSndPlayDoubleBufferCallBackUPP == chan->callBack) {

        if (quietCmd == cmd->cmd || flushCmd == cmd->cmd) {

            // We know that our callBackCmd is the first item in the queue if this is our channel

            perChanInfoPtr = (PerChanInfoPtr)(chan->queue[chan->qHead].param2);

            #if DEBUG

                if (perChanInfoPtr->magic != 'SANE') DebugStr("\pBAD in MySndDoImmediate");

            #endif

            perChanInfoPtr->stopping = true;

            Enqueue ((QElemPtr)perChanInfoPtr, gFreeList);

            if (! OTAtomicSetBit (&gNMRecBusy, 0)) {

                NMInstall (gNMRecPtr);

            }

            chan->callBack = perChanInfoPtr->usersCallBack;

        }

    }

    return (SndDoImmediate (chan, cmd));

}

// This must be called at task time.

OSErr   CarbonSndPlayDoubleBuffer (SndChannelPtr chan, SndDoubleBufferHeaderPtr theParams) {

    OSErr                           err;

    CompressionInfo                 compInfo;

    PerChanInfoPtr                  perChanInfoPtr;

    SndCommand                      playCmd;

    SndCommand                      callBack;

    if (nil == chan) {

        err = badChannel;

        goto exit;

    }

    if (nil == theParams) {

        err = paramErr;

        goto exit;

    }

    if (nil == gFreeList) {

        // This can't ever be disposed since we don't know when we might need to use it (at interrupt time)

        gFreeList = (QHdrPtr)NewPtrClear (sizeof (QHdr));

        err = MemError ();

        if (noErr != err) goto exit;

    }

    if (nil == gSilenceOnes) {

        short       i;

        // This can't ever be disposed since we don't know when we might need to use it (at interrupt time)

        gSilenceOnes = NewPtr (kBufSize);

        err = MemError ();

        if (noErr != err) goto exit;

        for (i = 0; i < kBufSize; i++)

             gSilenceOnes[i] = (char)0x80;

    }

    if (nil == gSilenceTwos) {

        // This can't ever be disposed since we don't know when we might need to use it (at interrupt time)

        gSilenceTwos = NewPtrClear (kBufSize);

        err = MemError ();

        if (noErr != err) goto exit;

    }

    if (nil == gNMRecPtr) {

        // This can't ever be disposed since we don't know when we might need to use it (at interrupt time)

        gNMRecPtr = (NMRecPtr)NewPtr (sizeof (NMRec));

        err = MemError ();

        if (noErr != err) goto exit;

        // Set up our NMProc info that will dispose of most (but not all) of our memory

        gNMRecPtr->qLink = nil;

        gNMRecPtr->qType = 8;

        gNMRecPtr->nmFlags = 0;

        gNMRecPtr->nmPrivate = 0;

        gNMRecPtr->nmReserved = 0;

        gNMRecPtr->nmMark = nil;

        gNMRecPtr->nmIcon = nil;

        gNMRecPtr->nmSound = nil;

        gNMRecPtr->nmStr = nil;

        #if TARGET_API_MAC_CARBON

            gNMRecPtr->nmResp = NewNMUPP(NMResponseProc);

        #else

            gNMRecPtr->nmResp = NewNMProc(NMResponseProc);

        #endif

        gNMRecPtr->nmRefCon = 0;

    }

    perChanInfoPtr = (PerChanInfoPtr)NewPtr (sizeof (PerChanInfo));

    err = MemError ();

    if (noErr != err) goto exit;

    // Init basic per channel information

    perChanInfoPtr->qLink = nil;

    perChanInfoPtr->qType = 0;              // not used

    perChanInfoPtr->stopping = 0;

    #if DEBUG

        perChanInfoPtr->magic = 'SANE';

    #endif

    perChanInfoPtr->theParams = theParams;

    // Have to remember the user's callback function from the sound because

    // we are going to overwrite it with our own callback function.

    perChanInfoPtr->usersCallBack = chan->callBack;

    // Set up the sound header for the bufferCmd that will be used to play

    // the buffers passed in by the SndPlayDoubleBuffer call.

    perChanInfoPtr->soundHeader.samplePtr = (Ptr)(theParams->dbhBufferPtr[0]->dbSoundData);

    perChanInfoPtr->soundHeader.numChannels = theParams->dbhNumChannels;

    perChanInfoPtr->soundHeader.sampleRate = theParams->dbhSampleRate;

    perChanInfoPtr->soundHeader.loopStart = 0;

    perChanInfoPtr->soundHeader.loopEnd = 0;

    perChanInfoPtr->soundHeader.encode = cmpSH;

    perChanInfoPtr->soundHeader.baseFrequency = kMiddleC;

    perChanInfoPtr->soundHeader.numFrames = (unsigned long)theParams->dbhBufferPtr[0]->dbNumFrames;

    //  perChanInfoPtr->soundHeader.AIFFSampleRate = 0;             // unused

    perChanInfoPtr->soundHeader.markerChunk = nil;

    perChanInfoPtr->soundHeader.futureUse2 = nil;

    perChanInfoPtr->soundHeader.stateVars = nil;

    perChanInfoPtr->soundHeader.leftOverSamples = nil;

    perChanInfoPtr->soundHeader.compressionID = theParams->dbhCompressionID;

    perChanInfoPtr->soundHeader.packetSize = (unsigned short)theParams->dbhPacketSize;

    perChanInfoPtr->soundHeader.snthID = 0;

    perChanInfoPtr->soundHeader.sampleSize = (unsigned short)theParams->dbhSampleSize;

    perChanInfoPtr->soundHeader.sampleArea[0] = 0;

    // Is the sound compressed?  If so, we need to treat theParams as a SndDoubleBufferHeader2Ptr.

    if (0 != theParams->dbhCompressionID) {

        // Sound is compressed

        err = GetCompressionInfo(theParams->dbhCompressionID,

                                ((SndDoubleBufferHeader2Ptr)theParams)->dbhFormat,

                                theParams->dbhNumChannels,

                                theParams->dbhSampleSize,

                                &compInfo);

        if (noErr != err) goto exitDispose;

        perChanInfoPtr->soundHeader.format = compInfo.format;

    } else {

        // Sound is not compressed

        perChanInfoPtr->soundHeader.format = kSoundNotCompressed;

    }

    playCmd.cmd = bufferCmd;

    playCmd.param1 = 0;                         // unused

    playCmd.param2 = (long)&perChanInfoPtr->soundHeader;

    callBack.cmd = callBackCmd;

    callBack.param1 = 0;                        // which buffer to fill, 0 buffer, 1, 0, ...

    callBack.param2 = (long)perChanInfoPtr;

    // Install our callback function pointer straight into the sound channel structure

    if (nil == gCarbonSndPlayDoubleBufferCallBackUPP) {

        #if TARGET_API_MAC_CARBON

            gCarbonSndPlayDoubleBufferCallBackUPP = NewSndCallBackUPP(CarbonSndPlayDoubleBufferCallBackProc);

        #else

            gCarbonSndPlayDoubleBufferCallBackUPP = NewSndCallBackProc(CarbonSndPlayDoubleBufferCallBackProc);

        #endif

    }

    chan->callBack = gCarbonSndPlayDoubleBufferCallBackUPP;

    if (nil == gCarbonSndPlayDoubleBufferCleanUpUPP) {

        #if TARGET_API_MAC_CARBON

            gCarbonSndPlayDoubleBufferCleanUpUPP = NewSndCallBackUPP(CarbonSndPlayDoubleBufferCleanUpProc);

        #else

            gCarbonSndPlayDoubleBufferCleanUpUPP = NewSndCallBackProc(CarbonSndPlayDoubleBufferCleanUpProc);

        #endif

    }

    err = SndDoCommand (chan, &playCmd, true);

    if (noErr != err) goto exitDispose;

    err = SndDoCommand (chan, &callBack, true);

    if (noErr != err) goto exitDispose;

exit:

    return err;

exitDispose:

    if (nil != perChanInfoPtr)

        DisposePtr ((Ptr)perChanInfoPtr);

    goto exit;

}

static pascal void  CarbonSndPlayDoubleBufferCleanUpProc (SndChannelPtr theChannel, SndCommand * theCallBackCmd) {

    PerChanInfoPtr                  perChanInfoPtr;

    perChanInfoPtr = (PerChanInfoPtr)(theCallBackCmd->param2);

    #if DEBUG

        if (perChanInfoPtr->magic != 'SANE') DebugStr("\pBAD in CarbonSndPlayDoubleBufferCleanUpProc");

    #endif

    // Put our per channel data on the free queue so we can clean up later

    Enqueue ((QElemPtr)perChanInfoPtr, gFreeList);

    // Have to put the user's callback proc back so they get called when the next buffer finishes

    theChannel->callBack = perChanInfoPtr->usersCallBack;

    // Have to install our Notification Manager routine so that we can clean up the gFreeList

    if (! OTAtomicSetBit (&gNMRecBusy, 0)) {

        NMInstall (gNMRecPtr);

    }

}

static pascal void  CarbonSndPlayDoubleBufferCallBackProc (SndChannelPtr theChannel, SndCommand * theCallBackCmd) {

    SndDoubleBufferHeaderPtr        theParams;

    SndDoubleBufferPtr              emptyBuf;

    SndDoubleBufferPtr              nextBuf;

    PerChanInfoPtr                  perChanInfoPtr;

    SndCommand                      playCmd;

    perChanInfoPtr = (PerChanInfoPtr)(theCallBackCmd->param2);

    #if DEBUG

        if (perChanInfoPtr->magic != 'SANE') DebugStr("\pBAD in CarbonSndPlayDoubleBufferCallBackProc");

    #endif

    if (true == perChanInfoPtr->stopping) goto exit;

    theParams = perChanInfoPtr->theParams;

    // The buffer that just played and needs to be filled

    emptyBuf = theParams->dbhBufferPtr[theCallBackCmd->param1];

    // Clear the ready flag

    emptyBuf->dbFlags ^= dbBufferReady;

    // This is the buffer to play now

    nextBuf = theParams->dbhBufferPtr[!theCallBackCmd->param1];

    // Check to see if it is ready, or if we have to wait a bit

    if (nextBuf->dbFlags & dbBufferReady) {

        perChanInfoPtr->soundHeader.numFrames = (unsigned long)nextBuf->dbNumFrames;

        perChanInfoPtr->soundHeader.samplePtr = (Ptr)(nextBuf->dbSoundData);

        // Flip the bit telling us which buffer is next

        theCallBackCmd->param1 = !theCallBackCmd->param1;

        // If this isn't the last buffer, call the user's fill routine

        if (!(nextBuf->dbFlags & dbLastBuffer)) {

            #if TARGET_API_MAC_CARBON

                // Declare a function pointer to the user's double back proc

                void (*doubleBackProc)(SndChannel*, SndDoubleBuffer*);

                // Call user's double back proc

                doubleBackProc = (void*)theParams->dbhDoubleBack;

                (*doubleBackProc) (theChannel, emptyBuf);

            #else

                CallSndDoubleBackProc (theParams->dbhDoubleBack, theChannel, emptyBuf);

            #endif

        } else {

            // Call our clean up proc when the last buffer finishes

            theChannel->callBack = gCarbonSndPlayDoubleBufferCleanUpUPP;

        }

    } else {

        // We have to wait for the buffer to become ready.

        // The real SndPlayDoubleBuffer would play a short bit of silence waiting for

        // the user to read the audio from disk, so that's what we do here.

        #if DEBUG

            DebugStr ("\p buffer is not ready!");

        #endif

        // Play a short section of silence so that we can check the ready flag again

        if (theParams->dbhSampleSize == 8) {

            perChanInfoPtr->soundHeader.numFrames = (UInt32)(kBufSize / theParams->dbhNumChannels);

            perChanInfoPtr->soundHeader.samplePtr = gSilenceOnes;

        } else {

            perChanInfoPtr->soundHeader.numFrames = (UInt32)(kBufSize / (theParams->dbhNumChannels * (theParams->dbhSampleSize / 8)));

            perChanInfoPtr->soundHeader.samplePtr = gSilenceTwos;

        }

    }

    // Insert our callback command

    InsertSndDoCommand (theChannel, theCallBackCmd);

    // Play the next buffer

    playCmd.cmd = bufferCmd;

    playCmd.param1 = 0;

    playCmd.param2 = (long)&(perChanInfoPtr->soundHeader);

    InsertSndDoCommand (theChannel, &playCmd);

exit:

    return;

}

static void InsertSndDoCommand (SndChannelPtr chan, SndCommand * newCmd) {

    if (-1 == chan->qHead) {

        chan->qHead = chan->qTail;

    }

    if (1 <= chan->qHead) {

        chan->qHead--;

    } else {

        // chan->qHead = chan->qTail;

        chan->qHead = chan->qLength-1; // Fix radar 2944451

    }

    chan->queue[chan->qHead] = *newCmd;

}

static pascal void NMResponseProc (NMRecPtr nmReqPtr) {

    PerChanInfoPtr                  perChanInfoPtr;

    OSErr                           err;

    NMRemove (nmReqPtr);

    gNMRecBusy = false;

    do {

        perChanInfoPtr = (PerChanInfoPtr)gFreeList->qHead;

        if (nil != perChanInfoPtr) {

            err = Dequeue ((QElemPtr)perChanInfoPtr, gFreeList);

            if (noErr == err) {

                DisposePtr ((Ptr)perChanInfoPtr);

            }

        }

    } while (nil != perChanInfoPtr && noErr == err);

}