Developer CD Series 2000 August: Tool Chest/Dev.CD Aug 00 TC Disk 2.toast/pc/sample code/quicktime/wired movies and sprites/qtwiredsprites/common files/imagecompressionutilities.c

Text File | 2000-06-23 | 23.9 KB | 803 lines

//////////
//
//    File:        ImageCompressionUtilities.c
//
//    Contains:    Image Compression Utilities.
//
//    Written by:    Peter Hoddie, Sean Allen, Chris Flick
//    Revised by:    Tim Monroe
//
//    Copyright:    © 1998 by Apple Computer, Inc., all rights reserved.
//
//    Change History (most recent first):
//
//       <4>         12/16/98    rtm        removed orphaned prototype for compressTransparentRLEwithHitTesting
//       <3>         05/28/98    rtm        added some typecasting to minimize MSDev compiler warnings
//       <2>         03/22/98    rtm        made changes to RecompressPictureFileWithTransparency, as per Chris' fixes
//       <1>         03/27/98    rtm        existing file
//
//////////


#ifndef __COLORPICKER__
#include <ColorPicker.h>
#endif

#ifndef __RESOURCES__
#include <Resources.h>
#endif

#ifndef __ENDIAN__
#include <Endian.h>
#endif

#ifndef _IMAGECOMPRESSIONUTILITIES_
#include "ImageCompressionUtilities.h"
#endif

pascal void extractStdPix( PixMap *src, Rect *srcRect, MatrixRecord *matrix, short mode, RgnHandle mask, PixMap *matte, Rect *matteRect, short flags );
static ImageDescriptionHandle createImageDescription( CodecType cType, PixMapHandle pixmap );
static void DrawPictureNoDither(PicHandle pic, const Rect *bounds);
static OSErr prepareFor16BitCompress(PicHandle *pic);

// We use the Animation compressor at 16 bit depth in these utilities
#define kCompressDepth    16

// Used for compressing QuickDraw pictures with transparency/hittesting

typedef struct {
    PicHandle    picture;
} PictureCompressProcData;

static pascal OSErr myPictureCompressDrawProc( short message, Rect * bounds, GWorldPtr drawingPort, OSType portType, void * refcon );


// Used for recompressing QuickTime compressed data with transparency/hittesting

typedef struct {
    ImageDescriptionHandle    imageDesc;
    Handle                    imageData;
} CompressedImageCompressProcData;


static pascal OSErr myImageCompressDrawProc( short message, Rect * bounds, GWorldPtr drawingPort, OSType portType, void * refcon );


// A few macros to help with error handling
#define        BailIf(a, e)         {if (a)     { err = e; goto bail; }}
#define        BailOSErr(a)         {if ((err = a) != noErr)    goto bail;}
#define        BailMemErr(a)        {a; if ((err = MemError()) != noErr) goto bail;}


// PICT to compressed image conversion

//    Given a QuickDraw picture, extract QuickTime compressed image data and description, if any.
//
//    It does this by creating a temporary CGrafPort, installing a QuickDraw bottleneck
//    routine for the StdPix call, and then drawing the picture. Since this routine will
//    be called whenever QuickTime compressed image data is encountered, it can
//    stash away any found compressed data and description. On DrawPicture's return, the
//    stashed data and description is retrieved and returned to the caller.
//
//    Worth noting in this utility is definition of the extractPictRecord. This is a
//    structure consisting of a CGrafPort structure followed by fields for a handle to
//    image data and an ImageDescription. This layout allows ExtractCompressData to open
//    a CGrafPort using the embedded CGrafPort field, and set this as the current port.
//    Then, in the StdPix routine extractStdPix, the current port can be retrieved and
//    cast to a pointer to an extractPictRecord to get access to the other fields.
//

typedef struct {
    CGrafPort tempPort;

    Handle data;
    ImageDescriptionHandle idh;
} extractPictRecord;


OSErr ExtractCompressData( PicHandle thePict, Handle *dataOut, ImageDescriptionHandle *idh )
{
    OSErr                err = noErr;
    extractPictRecord     state;
    CQDProcs             procs;
    GrafPtr             savePort;
    Rect                 bounds;

    if ( dataOut )
        *dataOut = nil;
    if ( idh )
        *idh = nil;

    GetPort( &savePort );

    OpenCPort( &state.tempPort );
    SetStdCProcs( &procs );
    procs.newProc1 = (UniversalProcPtr)NewStdPixProc(extractStdPix);
    state.tempPort.grafProcs = &procs;

    state.data = nil;
    state.idh = nil;

    MacSetPort( (GrafPtr)&state.tempPort );
    HidePen();

    bounds = (**thePict).picFrame;
    DrawPicture(thePict, &bounds);

    MacSetPort( savePort );
    CloseCPort( &state.tempPort );

    DisposeRoutineDescriptor( procs.newProc1 );

    *dataOut    = state.data;
    *idh        = state.idh;

    return err;
}

pascal void extractStdPix( PixMap *src, Rect *srcRect, MatrixRecord *matrix, short mode, RgnHandle mask, PixMap *matte, Rect *matteRect, short flags )
{
#if TARGET_OS_MAC
#pragma unused(srcRect,matrix,mode,mask,matte,matteRect,flags)
#endif
    extractPictRecord    *state;

    GetPort( (GrafPtr *)&state );

    if  ( state->idh == nil ) {
        ImageDescriptionHandle    desc;
        Ptr                     data;
        long                    bufferSize;

        if ( GetCompressedPixMapInfo(src, &desc, &data, &bufferSize, nil, nil) == noErr ) {
            state->idh = desc;
            HandToHand( (Handle *)&state->idh );
            PtrToHand( data, &state->data, bufferSize );
        }
    }
}


static ImageDescriptionHandle createImageDescription( CodecType cType, PixMapHandle pixmap )
{
    ImageDescriptionHandle    desc = nil;

    if ( ( desc = (ImageDescription **)NewHandleClear(sizeof(ImageDescription)) ) != nil ) {
        ImageDescription     *dp = *desc;
        Rect                bounds = (**pixmap).bounds;

        dp->idSize             = sizeof(ImageDescription);
        dp->cType             = cType;
        dp->spatialQuality     = codecNormalQuality;
        dp->width            = bounds.right - bounds.left;
        dp->height             = bounds.bottom - bounds.top;
        dp->hRes             = 72L << 16;
        dp->vRes             = 72L << 16;
        dp->dataSize         = ((**pixmap).rowBytes & 0x3fff) * dp->height;
        dp->depth             = (**pixmap).pixelSize;
        dp->clutID             = -1;

        if ( SetImageDescriptionCTable( desc, (**pixmap).pmTable ) ) {
            DisposeHandle( (Handle) desc );
            desc = nil;
        }
    }
    return desc;
}

pascal void noDitherBitsProc(const BitMap *srcBits, const Rect *srcRect, const Rect *dstRect, short mode, RgnHandle maskRgn);
pascal void noDitherBitsProc(const BitMap *srcBits, const Rect *srcRect, const Rect *dstRect, short mode, RgnHandle maskRgn)
{
    mode &= ~ditherCopy;
    StdBits(srcBits, srcRect, dstRect, mode, maskRgn);
}

//    DrawPictureNoDither is used to draw a QuickDraw picture but to turn convert any
//    use of ditherCopy graphics modes to graphics modes that don't use ditherCopy. It
//    only performs this with the stdbits bottleneck routine. Since ditherCopy is simply
//    ORed in with other graphics modes, the replaced bottleneck routine only needs to
//    AND off the ditherCopy flag.
void DrawPictureNoDither(PicHandle pic, const Rect *bounds)
{
    CQDProcs procs;
    GrafPtr savePort;
    CQDProcsPtr saveProcs;

    GetPort(&savePort);
    saveProcs = (CQDProcsPtr)savePort->grafProcs;
    SetStdCProcs( &procs );

    procs.bitsProc = (QDBitsUPP)NewQDBitsProc(noDitherBitsProc);
    savePort->grafProcs = (QDProcs *)&procs;

    DrawPicture(pic, bounds);

    savePort->grafProcs = (QDProcs *)saveProcs;

    DisposeRoutineDescriptor( procs.bitsProc );
}


//
// The following is a routine that can be used to clean up the colors in a picture
// before being compressed with the Animation compressor in 16-bits at codecNormal
// quality. The QuickTime Animation compressor can operate in both a lossless and
// lossy manner. This routine is meant to help when compressing in a lossy manner.
//
// By clean up, what's meant is the forcing of any colors that are sufficiently close
// to white to colors that are not as close. Since the Animation compressor will
// perform threshholding of the image's colors when codecNormal quality is specified,
// without this preprocessing, colors very close to white can be mapped to white
// in the compression. If white was chosen as the key color, pixels that are
// close to white could possibly become transparent as well.
//
// While not used by other routines in this file, prepareFor16BitCompress is provided
// as an example of how this might be done.
//
// Note that with codecLossless quality, there is no remapping of colors so this
// step is unnecessary.
//

#define kThreshold (255 - 16)

OSErr prepareFor16BitCompress(PicHandle *pic)
{
    OSErr err = noErr;
    PicHandle newPicture = nil;
    Rect r;
    GWorldPtr gw = nil;
    CGrafPtr savePort;
    GDHandle saveGD;
    short rowBytes;
    Ptr baseAddr;
    long w, h;
    PixMapHandle pm;

    GetGWorld(&savePort, &saveGD);

    r = (***pic).picFrame;
    MacOffsetRect(&r, (short)-r.left, (short)-r.top);

    err = NewGWorld(&gw, 32, &r, nil, nil, useTempMem);
    if (err) {
        err = NewGWorld(&gw, 32, &r, nil, nil, 0);
        if (err) goto bail;
    }

    pm = GetGWorldPixMap(gw);
    LockPixels(pm);
    SetGWorld(gw, nil);
    EraseRect(&r);

    DrawPicture(*pic, &r);

    baseAddr = GetPixBaseAddr(pm);
    rowBytes = (**pm).rowBytes & 0x3fff;
    for (h=0; h<r.bottom; h++) {
        long *pixelPtr = (long *)baseAddr;

        for (w=0; w<r.right; w++, pixelPtr++) {
            UInt8 r, g, b, a;
            long pixel = *pixelPtr;

            if ((pixel & 0x0ffffff) == 0x00ffffff)        // pure white
                continue;

            a = (pixel >> 24) & 0x0ff;
            r = (pixel >> 16) & 0x0ff;
            g = (pixel >>  8) & 0x0ff;
            b = (pixel >>  0) & 0x0ff;
            if ((r > kThreshold) && (g > kThreshold) && (b > kThreshold)) {
                r = g = b = kThreshold;
                *pixelPtr = (a << 24) | (kThreshold << 16) | (kThreshold << 8) | (kThreshold << 0);
            }
        }

        baseAddr += rowBytes;
    }

    newPicture = OpenPicture(&r);
    CopyBits((BitMap *)&gw->portPixMap, (BitMap *)&gw->portPixMap, &r, &r, ditherCopy, nil);
    ClosePicture();
    UnlockPixels(pm);

bail:
    if (gw)
        DisposeGWorld(gw);

    if (err == noErr) {
        if (newPicture) {
            KillPicture(*pic);
            *pic = newPicture;
        }
    }

    SetGWorld(savePort, saveGD);

    return err;
}


/*
    ---------------- Callback based routines for compressing with hittesting and transparency ----------------
 */

/*
    RecompressWithTransparencyFromProc

    This is a routine either called indirectly through RecompressCompressedImageWithTransparency,
    RecompressPictureWithTransparency, or RecompressPictureFileWithTransparency or called directly.
    It takes a callback procedure which is responsible for returning the dimensions of the
    area of some type of drawable entity and for actually drawing that entity.

        includeHitTesting        TRUE if hit testing data should be added to the compressed data
        keyColor                A RGBColor that should be used as the transparency color. Pass nil
                                if the image doesn't have transparent portions.
        hitTestRegion            A RgnHandle specifying an area that is to be used as the hit test
                                area. If you pass this, you must also set includeHitTesting to TRUE.
                                This is optional as the callback procedure can perform drawing
                                itself of the hit test area which is often suitable when both the
                                image and hit test area were painted in a drawing program.
        idh                        Returned ImageDescriptionHandle for the compressed image data
        imageData                Returned Handle to the compressed image data

 */
OSErr RecompressWithTransparencyFromProc( CompressDrawProc drawProc, void * drawProcRefcon,
                                                    Boolean includeHitTesting,
                                                    RGBColor *keyColor,
                                                    RgnHandle hitTestRegion,
                                                    ImageDescriptionHandle *idh, Handle * imageData )
{
    OSErr                         err = noErr;
    Rect                        bounds;
    CGrafPtr                    savePort;
    GDHandle                    saveDevice;
    GWorldPtr                    gwImage = nil;        // always used
    GWorldPtr                    gwPrev = nil;        // used if compressing with transparency (via keycolor)
    GWorldPtr                    gwMap = nil;        // used if compressing with hittesting data
    ImageDescriptionHandle        desc = nil;            // resulting image description
    ImageDescriptionHandle        gwMapDesc = nil;
    ImageSequence                seq = 0;            // compress sequence
    ImageSequenceDataSource        mapSource = 0L;
    Ptr                            data = nil;
    long                         dataSize;
    UInt8                         similarity;
    Boolean                        includeTransparency = false;
    RGBColor                    saveBackColor;

    GetGWorld( &savePort, &saveDevice );

    if( !drawProc || !idh || !imageData ){
        err = paramErr;
        goto bail;
    }

    // tell callback that it should initialize any storage it needs
    err = drawProc( kRecoProcInitMsg, nil, nil, 0, drawProcRefcon );
    if(err) goto bail;

    // determine bounds to use for compression
    err = drawProc( kRecoProcGetBoundsMsg, &bounds, nil, 0, drawProcRefcon );
    if(err) goto bail;

    err = QTNewGWorld(&gwImage, kCompressDepth, &bounds, nil, nil, kICMTempThenAppMemory);
    if(err) goto bail;

    if( keyColor ) {
        includeTransparency = true;
    }

    // Include hit testing? If so, we need a previous buffer and an 8-bit GWorld for the mask data
    if( includeHitTesting ) {
        err = QTNewGWorld(&gwPrev, kCompressDepth, &bounds, nil, nil, kICMTempThenAppMemory);
        if(err) goto bail;

        err = QTNewGWorld(&gwMap, 8, &bounds, nil, nil, kICMTempThenAppMemory);
        if(err) goto bail;
    }

    LockPixels( GetGWorldPixMap(gwImage) );

    if( gwPrev )
        LockPixels( GetGWorldPixMap(gwPrev) );

    if( gwMap )
        LockPixels( GetGWorldPixMap(gwMap) );

    if(gwPrev) {
        SetGWorld( gwPrev, nil );
        ClipRect( &bounds );

        GetBackColor( &saveBackColor );
        if( keyColor )
            RGBBackColor( keyColor );

            EraseRect( &bounds );

        RGBBackColor( &saveBackColor );
    }

    if( gwMap ) {
        SetGWorld( gwMap, nil );

        EraseRect( &bounds );            // paint background white

        err = drawProc( kRecoProcDrawMsg, &bounds, gwMap, kRecoProcHitTestingImageType, drawProcRefcon );
        if(err) goto bail;

        if( hitTestRegion ) {
            RGBColor blackRGB;

            blackRGB.red = blackRGB.green = blackRGB.blue = 0;

            RGBForeColor( &blackRGB );
            MacPaintRgn( hitTestRegion );
        }

        gwMapDesc = createImageDescription(kRawCodecType, GetGWorldPixMap(gwMap));
        err = MemError();
        if(err) goto bail;
    }

    SetGWorld( gwImage, nil );
    ClipRect( &bounds );
    EraseRect( &bounds );

    desc = (ImageDescriptionHandle) NewHandle(sizeof(ImageDescription));


    // NOTE: We pass codecLosslessQuality so that the key color if any is matched exactly. This avoids colors within
    // some threshhold different from the key color being taken as equivalent to the key color. Alternatively, we
    // could perform some threshhold processing on the source image's pixels and pass codecNormalQuality.
    if( includeHitTesting ) {
        // Allocate a compression sequence and add source data for hittest mask
        err = CompressSequenceBegin(&seq, GetGWorldPixMap(gwPrev), nil, nil, nil, kCompressDepth, kAnimationCodecType,
                                            anyCodec, codecLosslessQuality, codecLosslessQuality, 2, nil, 0, desc);

        // with hit testing, we have to add a data source to hold the mask data
        err = CDSequenceNewDataSource(seq, &mapSource, kRecoProcHitTestingImageType, 1, (Handle)gwMapDesc, nil, nil);
        if (err) goto bail;

        err = CDSequenceSetSourceData(mapSource, GetPixBaseAddr(GetGWorldPixMap(gwMap)), (**gwMapDesc).dataSize);
        if (err) goto bail;

        // What's the maximum size the compressed data could be--including hit-test data?
        err = GetCSequenceMaxCompressionSize(seq, GetGWorldPixMap(gwPrev), &dataSize);
    }
    else
    {    // not hit-testing so we only need the image buffer
        err = CompressSequenceBegin( &seq, GetGWorldPixMap(gwImage), nil, &bounds, nil, kCompressDepth, kAnimationCodecType, 0,
                                    codecLosslessQuality, codecLosslessQuality, 2, nil, 0, desc );
        if(err) goto bail;

        // What's the maximum size the compressed data could be?
        err = GetCSequenceMaxCompressionSize(seq, GetGWorldPixMap(gwImage), &dataSize);
    }
    if (err) goto bail;


    data = NewPtr( dataSize );
    if( err = MemError()) goto bail;

    if( includeHitTesting /* with or without transparency */ ) {
        // With hittesting, we use two buffers. Actually we don't have to but do so to show how it can be
        // done. Also, this code was based upon some older code that did.


        // compress the GWorld painted with the keyColor exclusively
        err = CompressSequenceFrame( seq, GetGWorldPixMap(gwPrev), nil, 0, data, &dataSize, &similarity, nil );
        if ( err ) goto bail;

        err = SetCSequencePrev(seq, GetGWorldPixMap(gwPrev), nil);
        if (err) goto bail;

        // draw the image into the GWorld over area painted with keyColor so that if picture is transparent already
        // areas it doesn't paint will be in the key color
        SetGWorld( gwImage, nil );

        GetBackColor( &saveBackColor );
        if( keyColor )
            RGBBackColor( keyColor );

            EraseRect( &bounds );

        RGBBackColor( &saveBackColor );

        err = drawProc( kRecoProcDrawMsg, &bounds, gwImage, kRecoProcOriginalImageType, drawProcRefcon );
        if(err) goto bail;

        // now compress the GWorld holding the image drawn on top of the keyColor
        err = CompressSequenceFrame(seq, GetGWorldPixMap(gwImage), nil, 0, data, &dataSize, &similarity, nil);
        if (err) goto bail;

        // At this point, data points to the image data for just the difference between the two (thus generating transparency)
        // Also, hit testing data is contained in the image data if it was specified.
    }
    else if( includeTransparency ) {
        // For transparency case without hittesting, we get by with only using a single buffer so we special case the
        // code here. This is also for clarity.

        // compress the GWorld painted with the keyColor exclusively
        err = CompressSequenceFrame( seq, GetGWorldPixMap(gwImage), nil, codecFlagUpdatePrevious, data, &dataSize, &similarity, nil );
        if ( err ) goto bail;

        // draw the image into the GWorld over area painted with keyColor so that if picture is transparent already
        // areas it doesn't paint will be in the key color
        SetGWorld( gwImage, nil );

        GetBackColor( &saveBackColor );
        if( keyColor )
            RGBBackColor( keyColor );

            EraseRect( &bounds );

        RGBBackColor( &saveBackColor );

        err = drawProc( kRecoProcDrawMsg, &bounds, gwImage, kRecoProcOriginalImageType, drawProcRefcon );
        if(err) goto bail;

        // now compress the GWorld holding the image drawn on top of the keyColor
        err = CompressSequenceFrame(seq, GetGWorldPixMap(gwImage), nil, codecFlagUpdatePrevious, data, &dataSize, &similarity, nil);
        if (err) goto bail;

        // At this point, data points to the image data for just the difference between the two (thus generating transparency)
        // Also, hit testing data is contained in the image data if it was specified.
    }
    else
    {
        SetGWorld( gwImage, nil );

        // draw the image into the GWorld
        err = drawProc( kRecoProcDrawMsg, &bounds, gwImage, kRecoProcOriginalImageType, drawProcRefcon );
        if(err) goto bail;

        // compress the GWorld containing the image painted on white
        err = CompressSequenceFrame( seq, GetGWorldPixMap(gwImage), nil, 0, data, &dataSize, &similarity, nil );
        if ( err ) goto bail;

        // At this point, data points to the image data for just the image, newly compressed. Also, hit testing data is contained
        // in the image data if it was specified.
    }

    CDSequenceEnd( seq );
    seq = 0;

    // free the GWorlds and drop references so we have more memory for PtrToHand
    if( gwImage )    DisposeGWorld( gwImage );
    gwImage = nil;
    if( gwMap )    DisposeGWorld( gwMap );
    gwMap = nil;
    if( gwPrev ) DisposeGWorld( gwPrev );
    gwPrev = nil;

    err = PtrToHand( data, imageData, dataSize );
    if ( err ) goto bail;

    *idh = desc;
    desc = nil;                // forget about this name for ImageDescriptionHandle so dispose below doesn't catch it

bail:
    // tell callback to dispose of anything it allocated. We pass 'err ' in portType if an error occurred
    drawProc( kRecoProcDisposeMsg, nil, nil, err ? FOUR_CHAR_CODE('err ') : 0, drawProcRefcon );

    CDSequenceEnd( seq );
    SetGWorld( savePort, saveDevice );

    if(gwImage)        DisposeGWorld( gwImage );
    if(gwMap )        DisposeGWorld( gwMap );
    if(gwPrev )        DisposeGWorld( gwPrev );
    if(desc)         DisposeHandle((Handle) desc );
    if(gwMapDesc)    DisposeHandle((Handle) gwMapDesc );
    if(data)        DisposePtr( data );

    return err;
}


/*
    myPictureCompressDrawProc

    Helper routine to be used with RecompressWithTransparencyFromProc to compress QuickDraw Pictures.
 */

static pascal OSErr myPictureCompressDrawProc( short message, Rect * bounds, GWorldPtr drawingPort, OSType drawingImageType, void * refcon )
{
#if TARGET_OS_MAC
#pragma unused(drawingPort)
#endif
    OSErr err = noErr;
    PictureCompressProcData * data = refcon;
    Rect r;

    switch( message ) {
        case kRecoProcInitMsg:
            break;

        case kRecoProcDisposeMsg:
            break;

        case kRecoProcGetBoundsMsg:
            r = (**data->picture).picFrame;

            r.left = EndianS16_BtoN(r.left);
            r.top = EndianS16_BtoN(r.top);
            r.bottom = EndianS16_BtoN(r.bottom);
            r.right = EndianS16_BtoN(r.right);

            MacOffsetRect(&r, (short)-r.left, (short)-r.top );

            *bounds = r;
            break;

        case kRecoProcDrawMsg:
            r = (**data->picture).picFrame;

            r.left = EndianS16_BtoN(r.left);
            r.top = EndianS16_BtoN(r.top);
            r.bottom = EndianS16_BtoN(r.bottom);
            r.right = EndianS16_BtoN(r.right);

            MacOffsetRect( &r, (short)-r.left, (short)-r.top );

            if( kRecoProcOriginalImageType == drawingImageType )
                DrawPictureNoDither( data->picture, &r );
            break;
        default:
            err = -1;
    }

    return err;
}


/*
    myImageCompressDrawProc

    Helper routine to be used with RecompressWithTransparencyFromProc to compress QuickTime compressed image data.
 */
static pascal OSErr myImageCompressDrawProc( short message, Rect * bounds, GWorldPtr drawingPort, OSType drawingImageType, void * refcon )
{
#if TARGET_OS_MAC
#pragma unused(drawingImageType)
#endif

    OSErr err = noErr;
    CompressedImageCompressProcData * data = refcon;
    Rect r;

    switch( message ) {
    case kRecoProcInitMsg:
        break;
    case kRecoProcDisposeMsg:
        break;
    case kRecoProcGetBoundsMsg:
        r.left = r.top = 0;
        r.right = (**data->imageDesc).width;
        r.bottom = (**data->imageDesc).height;

        *bounds = r;
        break;
    case kRecoProcDrawMsg:
        {
            SignedByte saveState;

            r.left = r.top = 0;
            r.right = (**data->imageDesc).width;
            r.bottom = (**data->imageDesc).height;

            saveState = HGetState( data->imageData );
            HLockHi( data->imageData );

            if( kRecoProcOriginalImageType == drawingImageType )
                err = DecompressImage( *data->imageData, data->imageDesc, GetGWorldPixMap(drawingPort), &r, &r, srcCopy, nil );

            HSetState( data->imageData, saveState );
        }
        break;
    default:
        err = -1;
    }

    return err;
}



/*
    RecompressCompressedImageWithTransparency

    Given an ImageDescriptionHandle and a handle to image data, generate new RLE compressed data
    with optional hitTesting and transparency.
 */
OSErr RecompressCompressedImageWithTransparency( ImageDescriptionHandle originalDesc, Handle originalImageData,
                                        RGBColor *keyColor,
                                        RgnHandle hitTestRegion,
                                        ImageDescriptionHandle *idh, Handle * imageData )
{
    OSErr err = noErr;
    CompressedImageCompressProcData params;

    params.imageDesc = originalDesc;
    params.imageData = originalImageData;

    err = RecompressWithTransparencyFromProc( myImageCompressDrawProc, ¶ms,
                                        (Boolean)(hitTestRegion != nil),
                                        keyColor,
                                        hitTestRegion,
                                        idh, imageData );

    return err;
}

/*
    RecompressPictureWithTransparency

    Given a QuickDraw PicHandle, generate new RLE compressed data with optional hitTesting and transparency.
 */
OSErr RecompressPictureWithTransparency( PicHandle originalPicture,
                                        RGBColor *keyColor,
                                        RgnHandle hitTestRegion,
                                        ImageDescriptionHandle *idh, Handle * imageData )
{
    OSErr err = noErr;
    PictureCompressProcData params;

    params.picture = originalPicture;

    err = RecompressWithTransparencyFromProc( myPictureCompressDrawProc, ¶ms,
                                        (Boolean)(hitTestRegion != nil),
                                        keyColor,
                                        hitTestRegion,
                                        idh, imageData );

    return err;
}

/*
    RecompressPictureFileWithTransparency

    Given a QuickDraw PICT file, generate new RLE compressed data with optional hitTesting and transparency.
    This function uses GetCompressedImageFromPicture to do the actual work on the PicHandle retrieved from
    the PICT file.
 */
OSErr RecompressPictureFileWithTransparency( FSSpec * spec,
                                        RGBColor *keyColor,
                                        RgnHandle hitTestRegion,
                                        ImageDescriptionHandle *idh, Handle * imageData )
{
    OSErr         err = noErr;
    short        sourceRefNum = 0;
    PicHandle    picture = nil;
    long        eof;
    long        countBytes;

    *idh = nil;
    *imageData = nil;

    BailOSErr(FSpOpenDF( spec, fsRdPerm, &sourceRefNum ));

    BailOSErr(GetEOF( sourceRefNum, &eof ));
    eof -= 512;

    BailOSErr(SetFPos( sourceRefNum, fsFromStart, 512 ));

    picture = (PicHandle) NewHandle(eof);
    err = MemError();
    BailOSErr(err);

    countBytes = eof;
    HLock((Handle) picture);
    BailOSErr( FSRead( sourceRefNum, &countBytes, *picture) );
    HUnlock((Handle) picture);

    BailOSErr( RecompressPictureWithTransparency( picture,  keyColor, hitTestRegion,
                                idh, imageData ));

bail:
    if ( picture )            DisposeHandle((Handle) picture );
    if ( sourceRefNum )        FSClose( sourceRefNum );

    return err;
}