AOO410/main/svtools/source/filter/igif/gifread.cxx

/**************************************************************
 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * 
 *************************************************************/



// MARKER(update_precomp.py): autogen include statement, do not remove
#include "precompiled_svtools.hxx"

#define _GIFPRIVATE

#include "decode.hxx"
#include "gifread.hxx"

// -----------
// - Defines -
// -----------

#define NO_PENDING( rStm ) ( ( rStm ).GetError() != ERRCODE_IO_PENDING )

// -------------
// - GIFReader -
// -------------

GIFReader::GIFReader( SvStream& rStm ) :
			aGPalette		( 256 ),
			aLPalette		( 256 ),
			rIStm			( rStm ),
			pAcc8			( NULL ),
			pAcc1			( NULL ),
			nLastPos		( rStm.Tell() ),
			nLogWidth100	( 0UL ),
			nLogHeight100	( 0UL ),
			nLoops			( 1 ),
			eActAction		( GLOBAL_HEADER_READING ),
			bGCTransparent	( sal_False ),
			bImGraphicReady	( sal_False )
{
	maUpperName = UniString::CreateFromAscii( "SVIGIF", 6 );
	pSrcBuf = new sal_uInt8[ 256 ];
	ClearImageExtensions();
}

// ------------------------------------------------------------------------

GIFReader::~GIFReader()
{
	aImGraphic.SetContext( NULL );

	if( pAcc1 )
		aBmp1.ReleaseAccess( pAcc1 );

	if( pAcc8 )
		aBmp8.ReleaseAccess( pAcc8 );

	delete[] pSrcBuf;
}

// ------------------------------------------------------------------------

void GIFReader::ClearImageExtensions()
{
	nGCDisposalMethod = 0;
	bGCTransparent = sal_False;
	nTimer = 0;
}

// ------------------------------------------------------------------------

sal_Bool GIFReader::CreateBitmaps( long nWidth, long nHeight, BitmapPalette* pPal,
							   sal_Bool bWatchForBackgroundColor )
{
	const Size aSize( nWidth, nHeight );

	if( bGCTransparent )
	{
		const Color aWhite( COL_WHITE );

		aBmp1 = Bitmap( aSize, 1 );

		if( !aAnimation.Count() )
			aBmp1.Erase( aWhite );

		pAcc1 = aBmp1.AcquireWriteAccess();

		if( pAcc1 )
		{
			cTransIndex1 = (sal_uInt8) pAcc1->GetBestPaletteIndex( aWhite );
			cNonTransIndex1 = cTransIndex1 ? 0 : 1;
		}
		else
			bStatus = sal_False;
	}

	if( bStatus )
	{
		aBmp8 = Bitmap( aSize, 8, pPal );

		if( !!aBmp8 && bWatchForBackgroundColor && aAnimation.Count() )
			aBmp8.Erase( (*pPal)[ nBackgroundColor ] );
		else
		  aBmp8.Erase( Color( COL_WHITE ) );

		pAcc8 = aBmp8.AcquireWriteAccess();
		bStatus = ( pAcc8 != NULL );
	}

	return bStatus;
}

// ------------------------------------------------------------------------

sal_Bool GIFReader::ReadGlobalHeader()
{
	char	pBuf[ 7 ];
	sal_uInt8	nRF;
	sal_uInt8	nAspect;
	sal_Bool	bRet = sal_False;

	rIStm.Read( pBuf, 6 );
	if( NO_PENDING( rIStm ) )
	{
		pBuf[ 6 ] = 0;
		if( !strcmp( pBuf, "GIF87a" ) || !strcmp( pBuf, "GIF89a" ) )
		{
			rIStm.Read( pBuf, 7 );
			if( NO_PENDING( rIStm ) )
			{
				SvMemoryStream aMemStm;

				aMemStm.SetBuffer( pBuf, 7, sal_False, 7 );
				aMemStm >> nGlobalWidth;
				aMemStm >> nGlobalHeight;
				aMemStm >> nRF;
				aMemStm >> nBackgroundColor;
				aMemStm >> nAspect;

				bGlobalPalette = (sal_Bool) ( nRF & 0x80 );

				if( bGlobalPalette )
					ReadPaletteEntries( &aGPalette, 1 << ( ( nRF & 7 ) + 1 ) );
				else
					nBackgroundColor = 0;

				if( NO_PENDING( rIStm ) )
					bRet = sal_True;
			}
		}
		else
			bStatus = sal_False;
	}

	return bRet;
}

// ------------------------------------------------------------------------

void GIFReader::ReadPaletteEntries( BitmapPalette* pPal, sal_uLong nCount )
{
	const sal_uLong	nLen = 3UL * nCount;
	sal_uInt8*		pBuf = new sal_uInt8[ nLen ];

	rIStm.Read( pBuf, nLen );
	if( NO_PENDING( rIStm ) )
	{
		sal_uInt8* pTmp = pBuf;

		for( sal_uLong i = 0UL; i < nCount; )
		{
			BitmapColor& rColor = (*pPal)[ (sal_uInt16) i++ ];

			rColor.SetRed( *pTmp++ );
			rColor.SetGreen( *pTmp++ );
			rColor.SetBlue( *pTmp++ );
		}

		// nach Moeglichkeit noch einige Standardfarben unterbringen
		if( nCount < 256UL )
		{
			(*pPal)[ 255UL ] = Color( COL_WHITE );

			if( nCount < 255UL )
				(*pPal)[ 254UL ] = Color( COL_BLACK );
		}
	}

	delete[] pBuf;
}

// ------------------------------------------------------------------------

sal_Bool GIFReader::ReadExtension()
{
	sal_uInt8	cFunction;
	sal_uInt8	cSize;
	sal_uInt8	cByte;
	sal_Bool	bRet = sal_False;
	sal_Bool	bOverreadDataBlocks = sal_False;

	// Extension-Label
	rIStm >> cFunction;
	if( NO_PENDING( rIStm ) )
	{
		// Block-Laenge
		rIStm >> cSize;

		switch( cFunction )
		{
			// 'Graphic Control Extension'
			case( 0xf9 ) :
			{
				sal_uInt8 cFlags;

				rIStm >> cFlags;
				rIStm >> nTimer;
				rIStm >> nGCTransparentIndex;
				rIStm >> cByte;

				if ( NO_PENDING( rIStm ) )
				{
					nGCDisposalMethod = ( cFlags >> 2) & 7;
					bGCTransparent = ( cFlags & 1 ) ? sal_True : sal_False;
					bStatus = ( cSize == 4 ) && ( cByte == 0 );
					bRet = sal_True;
				}
			}
			break;

			// Application-Extension
			case ( 0xff ) :
			{
				if ( NO_PENDING( rIStm ) )
				{
					// default diese Extension ueberlesen
					bOverreadDataBlocks = sal_True;

					// Appl.-Extension hat Laenge 11
					if ( cSize == 0x0b )
					{
						ByteString	aAppId;
						ByteString	aAppCode;

						rIStm.Read( aAppId.AllocBuffer( 8 ), 8 );
						rIStm.Read( aAppCode.AllocBuffer( 3 ), 3 );
						rIStm >> cSize;

						// NetScape-Extension
						if( aAppId == "NETSCAPE" && aAppCode == "2.0" && cSize == 3 )
						{
							rIStm >> cByte;

							// Loop-Extension
							if ( cByte == 0x01 )
							{
								rIStm >> cByte;
								nLoops = cByte;
								rIStm >> cByte;
								nLoops |= ( (sal_uInt16) cByte << 8 );
								rIStm >> cByte;

								bStatus = ( cByte == 0 );
								bRet = NO_PENDING( rIStm );
								bOverreadDataBlocks = sal_False;

								// Netscape interpretiert den LoopCount
								// als reine Anzahl der _Wiederholungen_;
								// bei uns ist es die Gesamtanzahl der
								// Durchlaeufe
								if( nLoops )
									nLoops++;
							}
							else
								rIStm.SeekRel( -1 );
						}
						else if ( aAppId == "STARDIV " && aAppCode == "5.0" && cSize == 9 )
						{
							rIStm >> cByte;

							// Loop-Extension
							if ( cByte == 0x01 )
							{
								rIStm >> nLogWidth100 >> nLogHeight100;
								rIStm >> cByte;
								bStatus = ( cByte == 0 );
								bRet = NO_PENDING( rIStm );
								bOverreadDataBlocks = sal_False;
							}
							else
								rIStm.SeekRel( -1 );
						}

					}
				}
			}
			break;

			// alles andere ueberlesen
			default:
				bOverreadDataBlocks = sal_True;
			break;
		}

		// Sub-Blocks ueberlesen
		if ( bOverreadDataBlocks )
		{
			bRet = sal_True;
			while( cSize && bStatus && !rIStm.IsEof() )
			{
				sal_uInt16	nCount = (sal_uInt16) cSize + 1;
				char*	pBuffer = new char[ nCount ];

				bRet = sal_False;
				rIStm.Read( pBuffer, nCount );
				if( NO_PENDING( rIStm ) )
				{
					cSize = (sal_uInt8) pBuffer[ cSize ];
					bRet = sal_True;
				}
				else
					cSize = 0;

				delete[] pBuffer;
			}
		}
	}

	return bRet;
}

// ------------------------------------------------------------------------

sal_Bool GIFReader::ReadLocalHeader()
{
	sal_uInt8	pBuf[ 9 ];
	sal_Bool	bRet = sal_False;

	rIStm.Read( pBuf, 9 );
	if( NO_PENDING( rIStm ) )
	{
		SvMemoryStream	aMemStm;
		BitmapPalette*	pPal;
		sal_uInt8			nFlags;

		aMemStm.SetBuffer( (char*) pBuf, 9, sal_False, 9 );
		aMemStm >> nImagePosX;
		aMemStm >> nImagePosY;
		aMemStm >> nImageWidth;
		aMemStm >> nImageHeight;
		aMemStm >> nFlags;

		// Falls Interlaced, ersten Startwert vorgeben
		bInterlaced = ( ( nFlags & 0x40 ) == 0x40 );
		nLastInterCount = 7;
		nLastImageY = 0;

		if( nFlags & 0x80 )
		{
			pPal = &aLPalette;
			ReadPaletteEntries( pPal, 1 << ( (nFlags & 7 ) + 1 ) );
		}
		else
			pPal = &aGPalette;

		// Falls alles soweit eingelesen werden konnte, kann
		// nun das lokale Bild angelegt werden;
		// es wird uebergeben, ob der BackgroundColorIndex evtl.
		// beruecksichtigt werden soll ( wenn Globale Farbtab. und
		// diese auch fuer dieses Bild gilt )
		if( NO_PENDING( rIStm ) )
		{
			CreateBitmaps( nImageWidth, nImageHeight, pPal, bGlobalPalette && ( pPal == &aGPalette ) );
			bRet = sal_True;
		}
	}

	return bRet;
}

// ------------------------------------------------------------------------

sal_uLong GIFReader::ReadNextBlock()
{
	sal_uLong	nRet = 0UL;
	sal_uLong	nRead;
	sal_uInt8	cBlockSize;

	rIStm >> cBlockSize;

	if ( rIStm.IsEof() )
		nRet = 4UL;
	else if ( NO_PENDING( rIStm ) )
	{
		if ( cBlockSize == 0 )
			nRet = 2UL;
		else
		{
			rIStm.Read( pSrcBuf, cBlockSize );

			if( NO_PENDING( rIStm ) )
			{
				if( bOverreadBlock )
					nRet = 3UL;
				else
				{
					sal_Bool	bEOI;
					HPBYTE	pTarget = pDecomp->DecompressBlock( pSrcBuf, cBlockSize, nRead, bEOI );

					nRet = ( bEOI ? 3 : 1 );

					if( nRead && !bOverreadBlock )
						FillImages( pTarget, nRead );

					rtl_freeMemory( pTarget );
				}
			}
		}
	}

	return nRet;
}

// ------------------------------------------------------------------------

void GIFReader::FillImages( HPBYTE pBytes, sal_uLong nCount )
{
	for( sal_uLong i = 0UL; i < nCount; i++ )
	{
		if( nImageX >= nImageWidth )
		{
			if( bInterlaced )
			{
				long nT1, nT2;

				// falls Interlaced, werden die Zeilen kopiert
				if( nLastInterCount )
				{
					long nMinY = Min( (long) nLastImageY + 1, (long) nImageHeight - 1 );
					long nMaxY = Min( (long) nLastImageY + nLastInterCount, (long) nImageHeight - 1 );

					// letzte gelesene Zeile kopieren, wenn Zeilen
					// nicht zusanmmenfallen ( kommt vorm wenn wir am Ende des Bildes sind )
					if( ( nMinY > nLastImageY ) && ( nLastImageY < ( nImageHeight - 1 ) ) )
					{
						HPBYTE	pScanline8 = pAcc8->GetScanline( nYAcc );
						sal_uLong	nSize8 = pAcc8->GetScanlineSize();
						HPBYTE	pScanline1 = 0;
						sal_uLong	nSize1 = 0;

						if( bGCTransparent )
						{
							pScanline1 = pAcc1->GetScanline( nYAcc );
							nSize1 = pAcc1->GetScanlineSize();
						}

						for( long j = nMinY; j <= nMaxY; j++ )
						{
							memcpy( pAcc8->GetScanline( j ), pScanline8, nSize8 );

							if( bGCTransparent )
								memcpy( pAcc1->GetScanline( j ), pScanline1, nSize1 );
						}
					}
				}

				nT1 = ( ++nImageY ) << 3;
				nLastInterCount = 7;

				if( nT1 >= nImageHeight )
				{
					nT2 = nImageY - ( ( nImageHeight + 7 ) >> 3 );
					nT1 = ( nT2 << 3 ) + 4;
					nLastInterCount = 3;

					if( nT1 >= nImageHeight )
					{
						nT2 -= ( nImageHeight + 3 ) >> 3;
						nT1 = ( nT2 << 2 ) + 2;
						nLastInterCount = 1;

						if( nT1 >= nImageHeight )
						{
							nT2 -= ( nImageHeight + 1 ) >> 2;
							nT1 = ( nT2 << 1 ) + 1;
							nLastInterCount = 0;
						}
					}
				}

				nLastImageY = (sal_uInt16) nT1;
				nYAcc = nT1;
			}
			else
			{
				nLastImageY = ++nImageY;
				nYAcc = nImageY;
			}

			// Zeile faengt von vorne an
			nImageX = 0;
		}

		if( nImageY < nImageHeight )
		{
			const sal_uInt8 cTmp = pBytes[ i ];

			if( bGCTransparent )
			{
				if( cTmp == nGCTransparentIndex )
					pAcc1->SetPixelIndex( nYAcc, nImageX++, cTransIndex1 );
				else
				{
					pAcc8->SetPixelIndex( nYAcc, nImageX, cTmp );
					pAcc1->SetPixelIndex( nYAcc, nImageX++, cNonTransIndex1 );
				}
			}
			else
				pAcc8->SetPixelIndex( nYAcc, nImageX++, cTmp );
		}
		else
		{
			bOverreadBlock = sal_True;
			break;
		}
	}
}

// ------------------------------------------------------------------------

void GIFReader::CreateNewBitmaps()
{
	AnimationBitmap	aAnimBmp;

	aBmp8.ReleaseAccess( pAcc8 );
	pAcc8 = NULL;

	if( bGCTransparent )
	{
		aBmp1.ReleaseAccess( pAcc1 );
		pAcc1 = NULL;
		aAnimBmp.aBmpEx = BitmapEx( aBmp8, aBmp1 );
	}
	else
		aAnimBmp.aBmpEx = BitmapEx( aBmp8 );

	aAnimBmp.aPosPix = Point( nImagePosX, nImagePosY );
	aAnimBmp.aSizePix = Size( nImageWidth, nImageHeight );
	aAnimBmp.nWait = ( nTimer != 65535 ) ? nTimer : ANIMATION_TIMEOUT_ON_CLICK;
	aAnimBmp.bUserInput = sal_False;

	if( nGCDisposalMethod == 2 )
		aAnimBmp.eDisposal = DISPOSE_BACK;
	else if( nGCDisposalMethod == 3 )
		aAnimBmp.eDisposal = DISPOSE_PREVIOUS;
	else
		aAnimBmp.eDisposal = DISPOSE_NOT;

	aAnimation.Insert( aAnimBmp );

	if( aAnimation.Count() == 1 )
	{
		aAnimation.SetDisplaySizePixel( Size( nGlobalWidth, nGlobalHeight ) );
		aAnimation.SetLoopCount( nLoops );
	}
}

// ------------------------------------------------------------------------

const Graphic& GIFReader::GetIntermediateGraphic()
{
	// Intermediate-Graphic nur erzeugen, wenn schon
	// Daten vorliegen, aber die Graphic noch nicht
	// vollstaendig eingelesen wurde
	if ( bImGraphicReady && !aAnimation.Count() )
	{
		Bitmap	aBmp;

		aBmp8.ReleaseAccess( pAcc8 );

		if ( bGCTransparent )
		{
			aBmp1.ReleaseAccess( pAcc1 );
			aImGraphic = BitmapEx( aBmp8, aBmp1 );

			pAcc1 = aBmp1.AcquireWriteAccess();
			bStatus = bStatus && ( pAcc1 != NULL );
		}
		else
			aImGraphic = aBmp8;

		pAcc8 = aBmp8.AcquireWriteAccess();
		bStatus = bStatus && ( pAcc8 != NULL );
	}

	return aImGraphic;
}

// ------------------------------------------------------------------------

sal_Bool GIFReader::ProcessGIF()
{
	sal_Bool bRead = sal_False;
	sal_Bool bEnd = sal_False;

	if ( !bStatus )
		eActAction = ABORT_READING;

	// Stream an die richtige Stelle bringen
	rIStm.Seek( nLastPos );

	switch( eActAction )
	{
		// naechsten Marker lesen
		case( MARKER_READING ):
		{
			sal_uInt8 cByte;

			rIStm >> cByte;

			if( rIStm.IsEof() )
				eActAction = END_READING;
			else if( NO_PENDING( rIStm ) )
			{
				bRead = sal_True;

				if( cByte == '!' )
					eActAction = EXTENSION_READING;
				else if( cByte == ',' )
					eActAction = LOCAL_HEADER_READING;
				else if( cByte == ';' )
					eActAction = END_READING;
				else
					eActAction = ABORT_READING;
			}
		}
		break;

		// ScreenDescriptor lesen
		case( GLOBAL_HEADER_READING ):
		{
			if( ( bRead = ReadGlobalHeader() ) == sal_True )
			{
				ClearImageExtensions();
				eActAction = MARKER_READING;
			}
		}
		break;


		// Extension lesen
		case( EXTENSION_READING ):
		{
			if( ( bRead = ReadExtension() ) == sal_True )
				eActAction = MARKER_READING;
		}
		break;


		// Image-Descriptor lesen
		case( LOCAL_HEADER_READING ):
		{
			if( ( bRead = ReadLocalHeader() ) == sal_True )
			{
				nYAcc = nImageX = nImageY = 0;
				eActAction = FIRST_BLOCK_READING;
			}
		}
		break;


		// ersten Datenblock lesen
		case( FIRST_BLOCK_READING ):
		{
			sal_uInt8 cDataSize;

			rIStm >> cDataSize;

			if( rIStm.IsEof() )
				eActAction = ABORT_READING;
			else if( cDataSize > 12 )
				bStatus = sal_False;
			else if( NO_PENDING( rIStm ) )
			{
				bRead = sal_True;
				pDecomp = new GIFLZWDecompressor( cDataSize );
				eActAction = NEXT_BLOCK_READING;
				bOverreadBlock = sal_False;
			}
			else
				eActAction = FIRST_BLOCK_READING;
		}
		break;

		// naechsten Datenblock lesen
		case( NEXT_BLOCK_READING ):
		{
			sal_uInt16	nLastX = nImageX;
			sal_uInt16	nLastY = nImageY;
			sal_uLong	nRet = ReadNextBlock();

			// Return: 0:Pending / 1:OK; / 2:OK und letzter Block: / 3:EOI / 4:HardAbort
			if( nRet )
			{
				bRead = sal_True;

				if ( nRet == 1UL )
				{
					bImGraphicReady = sal_True;
					eActAction = NEXT_BLOCK_READING;
					bOverreadBlock = sal_False;
				}
				else
				{
					if( nRet == 2UL )
					{
						delete pDecomp;
						CreateNewBitmaps();
						eActAction = MARKER_READING;
						ClearImageExtensions();
					}
					else if( nRet == 3UL )
					{
						eActAction = NEXT_BLOCK_READING;
						bOverreadBlock = sal_True;
					}
					else
					{
						delete pDecomp;
						CreateNewBitmaps();
						eActAction = ABORT_READING;
						ClearImageExtensions();
					}
				}
			}
			else
			{
				nImageX = nLastX;
				nImageY = nLastY;
			}
		}
		break;

		// ein Fehler trat auf
		case( ABORT_READING ):
		{
			bEnd = sal_True;
			eActAction = END_READING;
		}
		break;

		default:
		break;
	}

	// Stream an die richtige Stelle bringen,
	// falls Daten gelesen werden konnten
	// entweder alte Position oder aktuelle Position
	if( bRead || bEnd )
		nLastPos = rIStm.Tell();

	return bRead;
}

// ------------------------------------------------------------------------

ReadState GIFReader::ReadGIF( Graphic& rGraphic )
{
	ReadState eReadState;

	bStatus = sal_True;

	while( ProcessGIF() && ( eActAction != END_READING ) ) {}

	if( !bStatus )
		eReadState = GIFREAD_ERROR;
	else if( eActAction == END_READING )
		eReadState = GIFREAD_OK;
	else
	{
		if ( rIStm.GetError() == ERRCODE_IO_PENDING )
			rIStm.ResetError();

		eReadState = GIFREAD_NEED_MORE;
	}

	if( aAnimation.Count() == 1 )
	{
		rGraphic = aAnimation.Get( 0 ).aBmpEx;

		if( nLogWidth100 && nLogHeight100 )
		{
			rGraphic.SetPrefSize( Size( nLogWidth100, nLogHeight100 ) );
			rGraphic.SetPrefMapMode( MAP_100TH_MM );
		}
	}
	else
		rGraphic = aAnimation;

	return eReadState;
}


// -------------
// - ImportGIF -
// -------------

sal_Bool ImportGIF( SvStream & rStm, Graphic& rGraphic )
{
	GIFReader*	pGIFReader = (GIFReader*) rGraphic.GetContext();
	sal_uInt16		nOldFormat = rStm.GetNumberFormatInt();
	ReadState	eReadState;
	sal_Bool		bRet = sal_True;

	rStm.SetNumberFormatInt( NUMBERFORMAT_INT_LITTLEENDIAN );

	if( !pGIFReader )
		pGIFReader = new GIFReader( rStm );

	rGraphic.SetContext( NULL );
	eReadState = pGIFReader->ReadGIF( rGraphic );

	if( eReadState == GIFREAD_ERROR )
	{
		bRet = sal_False;
		delete pGIFReader;
	}
	else if( eReadState == GIFREAD_OK )
		delete pGIFReader;
	else
	{
		rGraphic = pGIFReader->GetIntermediateGraphic();
		rGraphic.SetContext( pGIFReader );
	}

	rStm.SetNumberFormatInt( nOldFormat );

	return bRet;
}