/****************************************************************************
** $Id: qt/src/kernel/qmngio.cpp   2.2.0   edited 2000-08-25 $
**
** Implementation of MNG QImage IOHandler
**
** Created : 970521
**
** Copyright (C) 1992-1998 Trolltech AS.  All rights reserved.
**
** This file is part of the kernel module of the Qt GUI Toolkit.
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** as defined by Trolltech AS of Norway and appearing in the file
** LICENSE.QPL included in the packaging of this file.
**
** This file may be distributed and/or modified under the terms of the
** GNU General Public License version 2 as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL included in the
** packaging of this file.
**
** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition
** licenses may use this file in accordance with the Qt Commercial License
** Agreement provided with the Software.
**
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**   information about Qt Commercial License Agreements.
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**********************************************************************/

#define QT_CLEAN_NAMESPACE

#include "qfeatures.h"

#ifndef QT_NO_IMAGEIO_MNG

#include "qdatetime.h"
#include "qimage.h"
#include "qasyncimageio.h"
#include "qiodevice.h"
#include "qmngio.h"

#include <libmng.h>
#include <stdlib.h>


#ifndef QT_NO_ASYNC_IMAGE_IO

class Q_EXPORT QMNGFormat : public QImageFormat {
public:
    QMNGFormat();
    virtual ~QMNGFormat();

    int decode(QImage& img, QImageConsumer* consumer,
	    const uchar* buffer, int length);

    bool openstream()
    {
	return TRUE;
    }
    bool closestream( )
    {
	return TRUE;
    }
    bool readdata( mng_ptr pBuf, mng_uint32 iBuflen, mng_uint32p pRead )
    {
	uint m = ndata + nbuffer - ubuffer;
	if ( iBuflen > m ) {
	    iBuflen = m;
	}
	*pRead = iBuflen;
	uint n = nbuffer-ubuffer;
	if ( iBuflen < n ) {
	    // enough in buffer
	    memcpy(pBuf, buffer+ubuffer, iBuflen);
	    ubuffer += iBuflen;
	    return TRUE;
	}
	if ( n ) {
	    // consume buffer
	    memcpy(pBuf, buffer+ubuffer, n );
	    pBuf = (mng_ptr)((char*)pBuf + n);
	    iBuflen -= n;
	    ubuffer = nbuffer;
	}
	if ( iBuflen ) {
	    // fill from incoming data
	    memcpy(pBuf, data, iBuflen);
	    data += iBuflen;
	    ndata -= iBuflen;
	}
	return TRUE;
    }
    bool errorproc( mng_int32   iErrorcode,
		   mng_int8    iSeverity,
		   mng_chunkid iChunkname,
		   mng_uint32  /*iChunkseq*/,
		   mng_int32   iExtra1,
		   mng_int32   iExtra2,
		   mng_pchar   zErrortext )
    {
	qWarning("MNG error %d: %s; chunk %c%c%c%c; subcode %d:%d",
	    iErrorcode,zErrortext,
	    (iChunkname>>24)&0xff,
	    (iChunkname>>16)&0xff,
	    (iChunkname>>8)&0xff,
	    (iChunkname>>0)&0xff,
	    iExtra1,iExtra2);
	return TRUE;
    }
    bool processheader( mng_uint32 iWidth, mng_uint32 iHeight )
    {
	image->create(iWidth,iHeight,32);
	image->setAlphaBuffer(TRUE);
	memset(image->bits(),0,iWidth*iHeight*4);
	consumer->setSize(iWidth,iHeight);
	mng_set_canvasstyle(handle,
	    QImage::systemByteOrder() == QImage::LittleEndian
		? MNG_CANVAS_BGRA8 : MNG_CANVAS_ARGB8 );
	return TRUE;
    }
    mng_ptr getcanvasline( mng_uint32 iLinenr )
    {
	return image->scanLine(iLinenr);
    }
    mng_bool refresh( mng_uint32 x, mng_uint32 y, mng_uint32 w, mng_uint32 h )
    {
	QRect r(x,y,w,h);
	consumer->changed(r);
	consumer->setFramePeriod(0);
	consumer->frameDone();
	return TRUE;
    }
    mng_uint32 gettickcount( )
    {
	return timer.elapsed() - losttime;
    }
    bool settimer( mng_uint32 iMsecs )
    {
	consumer->setFramePeriod(iMsecs);
	consumer->frameDone();
	state = Time;
	losingtimer.start();
	losttime -= iMsecs;
	return TRUE;
    }

private:
    // Animation-level information
    enum { MovieStart, Time, Data, Data2 } state;

    // Image-level information
    mng_handle handle;

    // For storing unused data
    uchar *buffer;
    uint maxbuffer;
    uint nbuffer;

    // Timing
    QTime timer;
    QTime losingtimer;
    int losttime;

    void enlargeBuffer(uint n)
    {
	if ( n > maxbuffer ) {
	    maxbuffer = n;
	    buffer = (uchar*)realloc(buffer,n);
	}
    }

    // Temporary locals during single data-chunk processing
    const uchar* data;
    uint ndata;
    uint ubuffer;
    QImageConsumer* consumer;
    QImage* image;
};

class Q_EXPORT QMNGFormatType : public QImageFormatType
{
    QImageFormat* decoderFor(const uchar* buffer, int length);
    const char* formatName() const;
};


/*!
  \class QMNGFormat qmngio.h
  \brief Incremental image decoder for MNG image format.

  \ingroup images

  This subclass of QImageFormat decodes MNG format images,
  including animated MNGs.

  Animated MNG images are standard MNG images.  The MNG standard
  defines two extension chunks that are useful for animations:

  <dl>
   <dt>gIFg - GIF-like Graphic Control Extension
    <dd>Includes frame disposal, user input flag (we ignore this),
	    and inter-frame delay.
   <dt>gIFx - GIF-like Application Extension
    <dd>Multi-purpose, but we just use the Netscape extension
	    which specifies looping.
  </dl>

  The subimages usually contain a offset chunk (oFFs) but need not.

  The first image defines the "screen" size.  Any subsequent image that
  doesn't fit is clipped.

TODO: decide on this point.  gIFg gives disposal types, so it can be done.
  All images paste (\e not composite, just place all-channel copying)
  over the previous image to produce a subsequent frame.
*/

/*!
  \class QMNGFormatType qasyncimageio.h
  \brief Incremental image decoder for MNG image format.

  \ingroup images
  \ingroup io

  This subclass of QImageFormatType recognizes MNG
  format images, creating a QMNGFormat when required.  An instance
  of this class is created automatically before any other factories,
  so you should have no need for such objects.
*/

QImageFormat* QMNGFormatType::decoderFor(
    const uchar* buffer, int length)
{
    if (length < 8) return 0;

    if (buffer[0]==138 // MNG signature
     && buffer[1]=='M'
     && buffer[2]=='N'
     && buffer[3]=='G'
     && buffer[4]==13
     && buffer[5]==10
     && buffer[6]==26
     && buffer[7]==10
     || buffer[0]==137 // PNG signature
     && buffer[1]=='P'
     && buffer[2]=='N'
     && buffer[3]=='G'
     && buffer[4]==13
     && buffer[5]==10
     && buffer[6]==26
     && buffer[7]==10
    )
	return new QMNGFormat;
    return 0;
}

const char* QMNGFormatType::formatName() const
{
    return "MNG";
}


/*!
  Constructs a QMNGFormat.
*/
QMNGFormat::QMNGFormat()
{
    state = MovieStart;
    handle = 0;
    nbuffer = 0;
    maxbuffer = 0;
    buffer = 0;
    losttime = 0;
}

/*!
  Destructs a QMNGFormat.
*/
QMNGFormat::~QMNGFormat()
{
}


// C-callback to C++-member-function conversion
//
static mng_bool openstream( mng_handle handle )
{
    return ((QMNGFormat*)mng_get_userdata(handle))->openstream();
}
static mng_bool closestream( mng_handle handle )
{
    return ((QMNGFormat*)mng_get_userdata(handle))->closestream();
}
static mng_bool readdata( mng_handle handle, mng_ptr pBuf, mng_uint32 iBuflen, mng_uint32p pRead )
{
    return ((QMNGFormat*)mng_get_userdata(handle))->readdata(pBuf,iBuflen,pRead);
}
static mng_bool errorproc( mng_handle handle,
		       mng_int32   iErrorcode,
		       mng_int8    iSeverity,
		       mng_chunkid iChunkname,
		       mng_uint32  iChunkseq,
		       mng_int32   iExtra1,
		       mng_int32   iExtra2,
		       mng_pchar   zErrortext )
{
    return ((QMNGFormat*)mng_get_userdata(handle))->errorproc(iErrorcode,
	iSeverity,iChunkname,iChunkseq,iExtra1,iExtra2,zErrortext);
}
static mng_bool processheader( mng_handle handle,
			   mng_uint32 iWidth, mng_uint32 iHeight )
{
    return ((QMNGFormat*)mng_get_userdata(handle))->processheader(iWidth,iHeight);
}
static mng_ptr getcanvasline( mng_handle handle, mng_uint32 iLinenr )
{
    return ((QMNGFormat*)mng_get_userdata(handle))->getcanvasline(iLinenr);
}
static mng_bool refresh( mng_handle handle,
		      mng_uint32  iTop,
		      mng_uint32  iLeft,
		      mng_uint32  iBottom,
		      mng_uint32  iRight	)
{
    return ((QMNGFormat*)mng_get_userdata(handle))->refresh(iTop,iLeft,iBottom,iRight);
}
static mng_uint32 gettickcount( mng_handle handle )
{
    return ((QMNGFormat*)mng_get_userdata(handle))->gettickcount();
}
static mng_bool settimer( mng_handle handle, mng_uint32  iMsecs )
{
    return ((QMNGFormat*)mng_get_userdata(handle))->settimer(iMsecs);
}

static mng_ptr memalloc(mng_uint32 iLen)
{
    return calloc(1,iLen);
}
static void memfree(mng_ptr iPtr, mng_uint32 /*iLen*/)
{
    free(iPtr);
}

/*!
  This function decodes some data into image changes.

  Returns the number of bytes consumed.
*/
int QMNGFormat::decode(QImage& img, QImageConsumer* cons,
	const uchar* buf, int length)
{
    consumer = cons;
    image = &img;

    data = buf;
    ndata = length;
    ubuffer = 0;

    if ( state == MovieStart ) {
        handle = mng_initialize( (mng_ptr)this, ::memalloc, ::memfree, 0 );
	mng_set_suspensionmode( handle, MNG_TRUE );
	mng_setcb_openstream( handle, ::openstream );
	mng_setcb_closestream( handle, ::closestream );
	mng_setcb_readdata( handle, ::readdata );
	mng_setcb_errorproc( handle, ::errorproc );
	mng_setcb_processheader( handle, ::processheader );
	mng_setcb_getcanvasline( handle, ::getcanvasline );
	mng_setcb_refresh( handle, ::refresh );
	mng_setcb_gettickcount( handle, ::gettickcount );
	mng_setcb_settimer( handle, ::settimer );
	state = Data;
	mng_readdisplay(handle);
	losingtimer.start();
    }

    losttime += losingtimer.elapsed();
    if ( ndata || !length )
	mng_display_resume(handle);
    losingtimer.start();

    image = 0;

    nbuffer -= ubuffer;
    if ( nbuffer ) {
	// Move back unused tail
	memcpy(buffer,buffer+ubuffer,nbuffer);
    }
    if ( ndata ) {
	// Not all used.
	enlargeBuffer(nbuffer+ndata);
	memcpy(buffer+nbuffer,data,ndata);
	nbuffer += ndata;
    }

    return length;
}

static QMNGFormatType* globalMngFormatTypeObject = 0;

#endif // QT_NO_ASYNC_IMAGE_IO

#ifndef QT_NO_ASYNC_IMAGE_IO
void qCleanupMngIO()
{
    if ( globalMngFormatTypeObject ) {
	delete globalMngFormatTypeObject;
	globalMngFormatTypeObject = 0;
    }
}
#endif

void qInitMngIO()
{
    static bool done = FALSE;
    if ( !done ) {
	done = TRUE;
#ifndef QT_NO_ASYNC_IMAGE_IO
	globalMngFormatTypeObject = new QMNGFormatType;
	qAddPostRoutine( qCleanupMngIO );
#endif
    }
}

#endif // QT_NO_IMAGEIO_MNG
