graphicsdeviceinterface/screendriver/sbit/BMDRAW4M.CPP
changeset 0 5d03bc08d59c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/graphicsdeviceinterface/screendriver/sbit/BMDRAW4M.CPP	Tue Feb 02 01:47:50 2010 +0200
@@ -0,0 +1,1407 @@
+// Copyright (c) 1997-2009 Nokia Corporation and/or its subsidiary(-ies).
+// All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of "Eclipse Public License v1.0"
+// which accompanies this distribution, and is available
+// at the URL "http://www.eclipse.org/legal/epl-v10.html".
+//
+// Initial Contributors:
+// Nokia Corporation - initial contribution.
+//
+// Contributors:
+//
+// Description:
+//
+
+#include "BMDRAW.H"
+
+GLREF_D const TUint8 ditherlutab[16][4];
+GLREF_D const TUint8 shadowlutab[256];
+
+const TInt KPixelsPerWord = 8;
+const TInt KPixelsPerByte = 2;
+const TInt KBitsPerPixel = 4;
+
+// CDrawFourBppBitmapGray
+
+//Initializes iSize, iDrawRect, iLongWidth, iScanlineWords data members.
+//It should be called every time when iSize is going to be changed - from Construct().
+//@param aSize Physical screen size in pixels.
+//@panic EScreenDriverPanicInvalidSize - Invalid aSize parameter. This might happen if the 
+//device is scaled and the scaling origin goes outside physical drawing rectangle.
+void CDrawFourBppBitmapGray::SetSize(const TSize& aSize) 
+	{
+	CDrawBitmap::SetSize(aSize);
+	__ASSERT_DEBUG(iSize == aSize, User::Invariant());
+	iLongWidth = (iSize.iWidth + (KPixelsPerWord - 1)) & ~(KPixelsPerWord - 1);
+	iScanLineWords = iLongWidth / KPixelsPerWord;
+	}
+ 
+TInt CDrawFourBppBitmapGray::Construct(TSize aSize)
+	{
+	return Construct(aSize, ((aSize.iWidth + (KPixelsPerWord - 1)) & ~(KPixelsPerWord - 1)) / KPixelsPerByte);
+	}
+
+TInt CDrawFourBppBitmapGray::Construct(TSize aSize, TInt aStride)
+	{
+	iBits = NULL;
+	iDispMode = EGray16;
+	CDrawBitmap::SetSize(aSize);
+	__ASSERT_DEBUG(iSize == aSize, User::Invariant());
+	if (aStride & 3)
+		return KErrArgument;
+	iLongWidth = aStride * KPixelsPerByte;
+	if (iLongWidth < aSize.iWidth)
+		return KErrArgument;
+	iScanLineWords = aStride >> 2;
+	TInt size = 1 + (Max(aSize.iWidth,aSize.iHeight) >> 1);
+	if(size < 0)
+		return KErrArgument;
+	iScanLineBuffer = (TUint32*)(User::Heap().Alloc(size));
+	if (iScanLineBuffer == NULL)
+		return KErrNoMemory;
+	return KErrNone;
+	}
+
+void CDrawFourBppBitmapGray::Shadow(TRgb& aColor)
+	{
+	aColor = TRgb::_Gray16(ShadowAndFadeGray16(aColor._Gray16()));
+	}
+
+TUint8 CDrawFourBppBitmapGray::ShadowAndFadeGray16(TInt aGray16)
+	{
+	if (iShadowMode & EFade)
+		aGray16 = FadeGray(aGray16 * 17) >> 4;
+
+	if (iShadowMode & EShadow)
+		aGray16 = Max(aGray16 - 5,0);
+
+	return (TUint8)aGray16;
+	}
+
+TUint32 CDrawFourBppBitmapGray::FadeWord(TUint32 aWord)
+	{
+	TUint32 fadedWord = 0;
+
+	for (TInt bitShift = 0; bitShift < 32; bitShift += 4)
+		{
+		TInt gray = (aWord >> bitShift) & 0xf;
+		gray = FadeGray(gray * 17) >> 4;
+		fadedWord |= gray << bitShift;
+		}
+
+	return fadedWord;
+	}
+
+TUint32 CDrawFourBppBitmapGray::ColorInt(TRgb aColor) const
+	{
+	TUint32 colorWord = aColor._Gray16();
+
+	colorWord |= colorWord << 4;
+	colorWord |= colorWord << 8;
+	colorWord |= colorWord << 16;
+
+	return colorWord;
+	}
+
+void CDrawFourBppBitmapGray::DitherBuffer(TInt aX,TInt aY,TInt aLength,TUint32* aBuffer)
+	{
+	aX += iDitherOrigin.iX;
+	aY += iDitherOrigin.iY;
+	aX &= 1;
+	aY &= 1;
+	aY <<= 1;
+
+	const TInt first = aX + aY;
+	aX ^= 1;
+	const TInt second = aX + aY;
+
+	TUint8* bufferPtr = (TUint8*)aBuffer;
+	const TUint8* bufferLimit = bufferPtr + ((aLength + 1) / 2);
+
+	for (; bufferPtr < bufferLimit; bufferPtr++)
+		{
+		TUint8 index1 = bufferPtr[0];
+		TUint8 index2 = TUint8(index1 >> 4);
+		index1 &= 0xf;
+
+		const TUint8 value1 = ditherlutab[index1][first];
+		const TUint8 value2 = ditherlutab[index2][second];
+		bufferPtr[0] = TUint8(value1 | (value2 << 4));
+		}
+	}
+
+TUint32 CDrawFourBppBitmapGray::HashInt(TRgb aColor,TInt aX,TInt aY) const
+	{
+	const TUint32 gray = aColor._Gray16();
+	const TUint32 int1 = Hash(gray,aX,aY);
+	const TUint32 int2 = Hash(gray,aX + 1,aY);
+
+	TUint32 colorWord = int1 | (int2 << 4);
+
+	colorWord |= colorWord << 8;
+	colorWord |= colorWord << 16;
+
+	return colorWord;
+	}
+
+void CDrawFourBppBitmapGray::InvertBuffer(TInt aLength,TUint32* aBuffer)
+	{
+	const TUint32* bufferLimit = aBuffer + ((aLength + KPixelsPerWord - 1) / KPixelsPerWord);
+
+	while (aBuffer < bufferLimit)
+		*aBuffer++ ^= 0xffffffff;
+	}
+
+/**	Copies a number of pixels into a word-aligned buffer without format translation.
+	Note that the byte length to the target buffer is honoured, 
+ 	but the end contents of the last byte are generally overwritten with extra pixel data (or garbage).
+ 	Note that I am assuming the compiler optimiser will convert all these divides and multiplies into shifts!  
+@param	aX		x coordinate to start copy from (need not be aligned at all)
+@param	aY		y coordinate to copy line from	
+@param	aLength	number of pixels to copy  
+@param	aBuffer	target word-aligned buffer (but may or may not be word length) 
+ **/
+void CDrawFourBppBitmapGray::ReadLine(TInt aX,TInt aY,TInt aLength,TAny* aBuffer) const
+	{
+	TUint32* pixelPtr = ScanLine(aY);
+	TInt startLongPix = aX & -KPixelsPerWord;
+	pixelPtr += startLongPix / KPixelsPerWord;
+	TUint32* bufferPtr = (TUint32*)aBuffer;
+	TInt wordsCnt = (aLength+KPixelsPerByte-1) / KPixelsPerWord;		//how many words to write to target
+	TInt restPixels = aLength - wordsCnt * KPixelsPerWord;				//how many pixels left to copy
+	TInt bytesCnt = (restPixels+KPixelsPerByte-1) / KPixelsPerByte ;	//how many target bytes to copy
+	TInt shiftBits = aX - startLongPix;
+	restPixels=shiftBits+restPixels;	//How many pixels are read from the second word by the final word copy
+	if (bytesCnt==0 && shiftBits && restPixels<=0)
+		{
+		// This correction is required because although a last whole word will be written to the target buffer,
+		// this special test indicates that the required significant data bits plus the shift 
+		// add up to one word (or less) to be read. 
+		// The copy words optimisation used to copy the main body of the line 
+		// will read from the next location after the copy, 
+		// but this may not always be accessable memory (on the last scanline)
+		// The correction is not required if the second word would need to be read anyway.
+		//eg we want to copy 7 nibbles with a 1 nibble shift (16 color), restpixels would be 0
+		bytesCnt=4;
+		wordsCnt--;
+		}
+	//How many pixels are read from the second word in the final byte copy?
+	//If zero (or less) then the second word should not be read in the copy bytes phase
+	//really this should be an else of the if above, but this gives the same end condition.
+	//eg we want to copy 5 nibbles with a 2 nibble shift (16 color), restpixels would be -1.
+	restPixels-=KPixelsPerWord;	
+	ReadLineCommon(pixelPtr,bufferPtr,wordsCnt,restPixels,bytesCnt,shiftBits*KBitsPerPixel);
+	}
+
+
+TRgb CDrawFourBppBitmapGray::ReadRgbNormal(TInt aX,TInt aY) const
+	{
+	TUint32 colorWord = *(ScanLine(aY) + (aX / KPixelsPerWord));
+	colorWord >>= ((aX & 7) * KBitsPerPixel);
+	return TRgb::_Gray16(colorWord & 0xf);
+	}
+
+void CDrawFourBppBitmapGray::ShadowArea(const TRect& aRect)
+	{
+	__ASSERT_DEBUG(aRect.iTl.iX>=0 && aRect.iBr.iX<=iSize.iWidth,Panic(EScreenDriverPanicOutOfBounds));
+	__ASSERT_DEBUG(aRect.iTl.iY>=0 && aRect.iBr.iY<=iSize.iHeight,Panic(EScreenDriverPanicOutOfBounds));
+
+	TInt startLong = (aRect.iTl.iX + KPixelsPerWord - 1) & ~7;
+	TInt finishLong = aRect.iBr.iX & ~7;
+	TInt startShift = (startLong - aRect.iTl.iX) * KBitsPerPixel;
+	TInt finishShift = (KPixelsPerWord - aRect.iBr.iX + finishLong) * KBitsPerPixel;
+	TInt startLongAdjust = startLong / KPixelsPerWord;
+	TInt finishLongAdjust = finishLong / KPixelsPerWord;
+	TUint32* base = ScanLine(aRect.iTl.iY);
+
+	if (iShadowMode & EFade)
+		{
+		TUint32* pixelPtr = base + startLongAdjust;
+		TUint32* pixelPtrLimit = base + finishLongAdjust;
+
+		if (finishLong < startLong)
+			{
+			const TUint32 mask = (0xffffffff >> finishShift) & (0xffffffff << (32 - startShift));
+			const TUint32 invertedMask = ~mask;
+
+			for (TInt y = aRect.iTl.iY; y < aRect.iBr.iY; y++)
+				{
+				TUint32 shadowed = FadeWord(pixelPtrLimit[0]) & mask;
+				pixelPtrLimit[0] &= invertedMask;
+				pixelPtrLimit[0] |= shadowed;
+				pixelPtrLimit += iScanLineWords;
+				}
+			}
+		else
+			{
+			for (TInt y = aRect.iTl.iY; y < aRect.iBr.iY; y++)
+				{
+				if (aRect.iTl.iX < startLong)
+					{
+					TUint32 shadowed = FadeWord(pixelPtr[-1]);
+					pixelPtr[-1] = PasteInt(pixelPtr[-1],shadowed,startShift);
+					}
+
+				for (TUint32* tempPixelPtr = pixelPtr; tempPixelPtr < pixelPtrLimit; tempPixelPtr++)
+					tempPixelPtr[0] = FadeWord(tempPixelPtr[0]);
+
+				if (finishLong < aRect.iBr.iX)
+					{
+					TUint32 shadowed = FadeWord(pixelPtrLimit[0]);
+					pixelPtrLimit[0] = PasteInt(shadowed,pixelPtrLimit[0],finishShift);
+					}
+
+				pixelPtr += iScanLineWords;
+				pixelPtrLimit += iScanLineWords;
+				}
+			}
+		}
+
+	if (iShadowMode & EShadow)
+		{
+		if (iUserDispMode == EGray2)
+			{
+			WriteRgbMulti(aRect.iTl.iX,aRect.iTl.iY,aRect.Width(),aRect.Height(),KRgbBlack);
+			return;
+			}
+
+		TUint32* pixelPtr = base + startLongAdjust;
+		TUint32* pixelPtrLimit = base + finishLongAdjust;
+
+		if (finishLong < startLong)
+			{
+			const TUint32 mask = (0xffffffff >> finishShift) & (0xffffffff << (32 - startShift));
+			const TUint32 invertedMask = ~mask;
+
+			for (TInt y = aRect.iTl.iY; y < aRect.iBr.iY; y++)
+				{
+				TUint32 shadowed = shadowlutab[pixelPtrLimit[0] & 0xff];
+				shadowed |= (shadowlutab[(pixelPtrLimit[0] >> 8) & 0xff] << 8);
+				shadowed |= (shadowlutab[(pixelPtrLimit[0] >> 16) & 0xff] << 16);
+				shadowed |= (shadowlutab[(pixelPtrLimit[0] >> 24) & 0xff] << 24);
+
+				pixelPtrLimit[0] &= invertedMask;
+				pixelPtrLimit[0] |= (shadowed & mask);
+				pixelPtrLimit += iScanLineWords;
+				}
+			}
+		else
+			{
+			for (TInt y = aRect.iTl.iY; y < aRect.iBr.iY; y++)
+				{
+				if (aRect.iTl.iX < startLong)
+					{
+					TUint32 shadowed = shadowlutab[pixelPtr[-1] & 0xff];
+					shadowed |= (shadowlutab[(pixelPtr[-1] >> 8) & 0xff] << 8);
+					shadowed |= (shadowlutab[(pixelPtr[-1] >> 16) & 0xff] << 16);
+					shadowed |= (shadowlutab[(pixelPtr[-1] >> 24) & 0xff] << 24);
+					pixelPtr[-1] = PasteInt(pixelPtr[-1],shadowed,startShift);
+					}
+
+				for (TUint32* tempPixelPtr = pixelPtr; tempPixelPtr < pixelPtrLimit; tempPixelPtr++)
+					{
+					TUint32 shadowed = shadowlutab[tempPixelPtr[0] & 0xff];
+					shadowed |= (shadowlutab[(tempPixelPtr[0] >> 8) & 0xff] << 8);
+					shadowed |= (shadowlutab[(tempPixelPtr[0] >> 16) & 0xff] << 16);
+					shadowed |= (shadowlutab[(tempPixelPtr[0] >> 24) & 0xff] << 24);
+					tempPixelPtr[0] = shadowed;
+					}
+
+				if (finishLong < aRect.iBr.iX)
+					{
+					TUint32 shadowed = shadowlutab[pixelPtrLimit[0] & 0xff];
+					shadowed |= (shadowlutab[(pixelPtrLimit[0] >> 8) & 0xff] << 8);
+					shadowed |= (shadowlutab[(pixelPtrLimit[0] >> 16) & 0xff] << 16);
+					shadowed |= (shadowlutab[(pixelPtrLimit[0] >> 24) & 0xff] << 24);
+					pixelPtrLimit[0] = PasteInt(shadowed,pixelPtrLimit[0],finishShift);
+					}
+
+				pixelPtr += iScanLineWords;
+				pixelPtrLimit += iScanLineWords;
+				}
+			}
+		}
+	}
+
+void CDrawFourBppBitmapGray::ShadeBuffer(TInt aLength,TUint32* aBuffer)
+	{
+	__ASSERT_DEBUG(aBuffer != NULL,Panic(EScreenDriverPanicInvalidParameter));
+
+	const TUint32* bufferLimit = aBuffer + ((aLength + KPixelsPerWord - 1) / KPixelsPerWord);
+
+	while (aBuffer < bufferLimit)
+		{
+		TUint32 fourthbit = (0x88888888 & aBuffer[0]);
+		aBuffer[0] = fourthbit | (fourthbit >> 1);
+		aBuffer[0] |= aBuffer[0] >> 2;
+		aBuffer++;
+		}
+	}
+
+void CDrawFourBppBitmapGray::ShadowBuffer(TInt aLength,TUint32* aBuffer)
+	{
+	__ASSERT_DEBUG(aBuffer != NULL,Panic(EScreenDriverPanicInvalidParameter));
+
+	const TUint32* bufferLimit = aBuffer + ((aLength + KPixelsPerWord - 1) / KPixelsPerWord);
+
+	if (iShadowMode & EFade)
+		{
+		for (TUint32* bufferPtr = aBuffer; bufferPtr < bufferLimit; bufferPtr++)
+			bufferPtr[0] = FadeWord(bufferPtr[0]);
+		}
+
+	if (iShadowMode & EShadow)
+		{
+		for (TUint32* bufferPtr = aBuffer; bufferPtr < bufferLimit; bufferPtr++)
+			{
+			TUint32 bufferWord = bufferPtr[0];
+
+			TUint firstbyte = shadowlutab[bufferWord & 0xff];
+			bufferWord >>= 8;
+			firstbyte |= (shadowlutab[bufferWord & 0xff] << 8);
+			bufferWord >>= 8;
+			firstbyte |= (shadowlutab[bufferWord & 0xff] << 16);
+			bufferWord >>= 8;
+			firstbyte |= (shadowlutab[bufferWord & 0xff] << 24);
+
+			bufferPtr[0] = firstbyte;
+			}
+		}
+	}
+
+void CDrawFourBppBitmapGray::WriteRgb(TInt aX,TInt aY,TRgb aColor)
+	{
+	TUint32 colorIndex = aColor._Gray16();
+
+	if (iUserDispMode == EGray2)
+		colorIndex = (colorIndex > 7) ? 15 : 0;
+	else if (iUserDispMode == EGray4)
+		colorIndex = Hash(colorIndex,aX,aY);
+
+	TUint32* pixelPtr = ScanLine(aY) + (aX / KPixelsPerWord);
+	TInt shift = (aX & 7) * KBitsPerPixel;
+
+	pixelPtr[0] &= ~(0xf << shift);
+	pixelPtr[0] |= colorIndex << shift;
+	}
+
+void CDrawFourBppBitmapGray::WriteBinary(TInt aX,TInt aY,TUint32* aData,TInt aLength,TInt aHeight,TRgb aColor)
+	{
+	TUint32 color1 = 0;
+	TUint32 color2 = 0;
+	const TInt yLimit = aY + aHeight;
+	const TUint32 gray16 = aColor._Gray16();
+
+	if (iUserDispMode == EGray2)
+		{
+		if (gray16 > 7)
+			{
+			color1 = 15;
+			color2 = 15;
+			}
+		}
+	else if (iUserDispMode != EGray4)
+		{
+		color1 = gray16;
+		color2 = gray16;
+		}
+
+	for (; aY < yLimit; aY++,aData++)
+		{
+		if (iUserDispMode == EGray4)
+			{
+			color1 = Hash(gray16,aX,aY);
+			color2 = Hash(gray16,aX + 1,aY);
+			}
+
+		TUint32 color = color1;
+		TUint32 dataMask = 1;
+		const TInt xLimit = aX + aLength;
+		TUint8* pixelPtr = ((TUint8*)ScanLine(aY)) + (aX / 2);
+
+		if (color1 || color2)
+			{
+			for (TInt x = aX; x < xLimit; x++,dataMask <<= 1)
+				{
+				if (aData[0] & dataMask)
+					{
+					if(x & 1)
+						pixelPtr[0] = (TUint8)(color << 4 | (pixelPtr[0] & 0x0f));
+					else
+						pixelPtr[0] = (TUint8)(color | (pixelPtr[0] & 0xf0));
+					}
+
+				color = (color == color2) ? color1 : color2;
+				if (x & 1)
+					pixelPtr++;
+				}
+			}
+		else
+			{
+			TUint8 bytemask = TUint8((aX & 1) ? 0x0f : 0xf0);
+
+			for (TInt x = aX; x < xLimit; x++,dataMask <<= 1,bytemask = (TUint8)~bytemask)
+				{
+				if (aData[0] & dataMask)
+					pixelPtr[0] &= bytemask;
+
+				if (x & 1)
+					pixelPtr++;
+				}
+			}
+		}
+	}
+
+void CDrawFourBppBitmapGray::WriteBinaryOp(TInt aX,TInt aY,TUint32* aData,TInt aLength,TInt aHeight,TRgb aColor,CGraphicsContext::TDrawMode aDrawMode)
+	{
+	TUint32 color1 = 0;
+	TUint32 color2 = 0;
+	const TUint32 gray16 = aColor._Gray16();
+	const TInt yLimit = aY + aHeight;
+
+	if (iUserDispMode == EGray2)
+		{
+		if (gray16 > 7)
+			{
+			color1 = 15;
+			color2 = 15;
+			}
+		}
+	else if(iUserDispMode != EGray4)
+		{
+		color1 = gray16;
+		color2 = gray16;
+		}
+
+	for (; aY < yLimit; aY++)
+		{
+		if (iUserDispMode == EGray4)
+			{
+			color1 = Hash(gray16,aX,aY);
+			color2 = Hash(gray16,aX + 1,aY);
+			}
+
+		TUint32 color = color1;
+		TUint32 dataMask = 1;
+		const TInt xLimit = aX + aLength;
+		TUint8* pixelPtr = ((TUint8*)ScanLine(aY)) + (aX / 2);
+
+		if(color1 || color2)
+			{
+			for (TInt x = aX; x < xLimit; x++,dataMask <<= 1)
+				{
+				if (aData[0] & dataMask)
+					{
+					if (x & 1)
+						{
+						if (aDrawMode == CGraphicsContext::EDrawModeXOR)
+							pixelPtr[0] = (TUint8)((color << 4) ^ pixelPtr[0]);
+						else if (aDrawMode == CGraphicsContext::EDrawModeAND)
+							pixelPtr[0] = (TUint8)(((color << 4) | 0x0f) & pixelPtr[0]);
+						else if (aDrawMode==CGraphicsContext::EDrawModeOR)
+							pixelPtr[0] = (TUint8)((color << 4) | pixelPtr[0]);
+						}
+					else
+						{
+						if (aDrawMode == CGraphicsContext::EDrawModeXOR)
+							pixelPtr[0] = (TUint8)(color ^ pixelPtr[0]);
+						else if (aDrawMode == CGraphicsContext::EDrawModeAND)
+							pixelPtr[0] = (TUint8)((color | 0xf0) & pixelPtr[0]);
+						else if (aDrawMode==CGraphicsContext::EDrawModeOR)
+							pixelPtr[0] = (TUint8)(color | pixelPtr[0]);
+						}
+					}
+
+				color = (color == color2) ? color1 : color2;
+				if (x & 1)
+					pixelPtr++;
+				}
+			}
+		else
+			{
+			TUint8 bytemask = TUint8((aX & 1) ? 0x0f : 0xf0);
+
+			if (aDrawMode == CGraphicsContext::EDrawModeAND)
+				{
+				for (TInt x = aX; x < xLimit; x++,dataMask <<= 1,bytemask = (TUint8)~bytemask)
+					{
+					if (aData[0] & dataMask)
+						pixelPtr[0] &= bytemask;
+
+					if (x & 1)
+						pixelPtr++;
+					}
+				}
+			}
+
+		aData++;
+		}
+	}
+
+void CDrawFourBppBitmapGray::WriteBinaryLineVertical(TInt aX,TInt aY,TUint32* aData,TInt aLength,TRgb aColor,TBool aUp)
+	{
+	if (iUserDispMode == EGray2)
+		aColor = TRgb::_Gray2(aColor._Gray2());
+
+	TUint32 color1 = 0;
+	TUint32 color2 = 0;
+	const TUint32 gray16 = aColor._Gray16();
+
+	if (iUserDispMode == EGray4 && gray16 % 5 != 0)
+		{
+		color1 = Hash(gray16,aX,aY);
+		color2 = Hash(gray16,aX,aY + 1);
+		}
+	else
+		color1 = color2 = gray16;
+
+	const TInt yLimit = aY + (aUp ? -aLength : aLength);
+	const TInt scanLineWords = aUp ? -iScanLineWords : iScanLineWords;
+	const TInt startword = aX / KPixelsPerWord;
+	const TInt startShift = (aX & 7) * KBitsPerPixel;
+	TUint32* pixelPtr = ScanLine(aY) + startword;
+	const TUint32* pixelPtrLimit = ScanLine(yLimit) + startword;
+	const TUint32 mask = ~(0xf << startShift);
+	TUint32 dataMask = 1;
+
+	if (color1 || color2)
+		{
+		color1 <<= startShift;
+		color2 <<= startShift;
+		TUint32 color = color1;
+
+		while (pixelPtr != pixelPtrLimit)
+			{
+			if (!dataMask)
+				{
+				dataMask = 1;
+				aData++;
+				}
+
+			if (aData[0] & dataMask)
+				{
+				pixelPtr[0] &= mask;
+				pixelPtr[0] |= color;
+				}
+
+			dataMask <<= 1;
+			pixelPtr += scanLineWords;
+			color = (color == color2) ? color1 : color2;
+			}
+		}
+	else
+		{
+		while (pixelPtr != pixelPtrLimit)
+			{
+			if (!dataMask)
+				{
+				dataMask = 1;
+				aData++;
+				}
+
+			if (aData[0] & dataMask)
+				pixelPtr[0] &= mask;
+
+			dataMask <<= 1;
+			pixelPtr += scanLineWords;
+			}
+		}
+	}
+
+void CDrawFourBppBitmapGray::WriteLine(TInt aX,TInt aY,TInt aLength,TUint32* aBuffer)
+	{
+	if (iUserDispMode == EGray2)
+		ShadeBuffer(aLength,aBuffer);
+	else if (iUserDispMode == EGray4)
+		DitherBuffer(aX,aY,aLength,aBuffer);
+
+	const TInt startLong = (aX + KPixelsPerWord - 1) & (~7);
+	const TInt finishLong = (aX + aLength) & (~7);
+	const TInt startShift = (startLong - aX) * KBitsPerPixel;
+	const TInt startShiftExtra = 32 - startShift;
+	const TInt finishShift = (KPixelsPerWord - aX - aLength + finishLong) * KBitsPerPixel;
+	TUint32* base = ScanLine(aY);
+	TUint32* pixelPtr = base + (startLong / KPixelsPerWord);
+	TUint32* pixelPtrLimit = base + (finishLong / KPixelsPerWord);
+
+	if (finishLong < startLong)
+		{
+		const TUint32 mask = (0xffffffff >> finishShift) & (0xffffffff << startShiftExtra);
+		pixelPtrLimit[0] &= ~mask;
+		pixelPtrLimit[0] |= (aBuffer[0] << startShiftExtra) & mask;
+		return;
+		}
+
+	const TInt wordsToCopy = pixelPtrLimit - pixelPtr;
+
+	if (startShift > 0)
+		{
+		pixelPtr[-1] &= 0xffffffff >> startShift;
+		pixelPtr[-1] |= aBuffer[0] << startShiftExtra;
+
+		CopyOffset(pixelPtr,aBuffer,wordsToCopy,startShift);
+		aBuffer += wordsToCopy;
+
+		if (finishLong < aX + aLength)
+			{
+			TUint32 first = (aBuffer[0] >> startShift) | (aBuffer[1] << startShiftExtra);
+			pixelPtrLimit[0] = PasteInt(first,pixelPtrLimit[0],finishShift);
+			}
+		}
+	else
+		{
+		while (pixelPtr < pixelPtrLimit)
+			*pixelPtr++ = *aBuffer++;
+
+		if (finishLong < aX + aLength)
+			pixelPtrLimit[0] = PasteInt(aBuffer[0],pixelPtrLimit[0],finishShift);
+		}
+	}
+
+void CDrawFourBppBitmapGray::WriteLineXOR(TInt aX,TInt aY,TInt aLength,TUint32* aBuffer)
+	{
+	if (iUserDispMode == EGray2)
+		ShadeBuffer(aLength,aBuffer);
+	else if (iUserDispMode == EGray4)
+		DitherBuffer(aX,aY,aLength,aBuffer);
+
+	const TInt startLong = (aX + KPixelsPerWord - 1) & (~7);
+	const TInt finishLong = (aX + aLength) & (~7);
+	const TInt startShift = (startLong - aX) * KBitsPerPixel;
+	const TInt startShiftExtra = 32 - startShift;
+	const TInt finishShift = (KPixelsPerWord - aX - aLength + finishLong) * KBitsPerPixel;
+	TUint32* base = ScanLine(aY);
+	TUint32* pixelPtr = base + (startLong / KPixelsPerWord);
+	TUint32* pixelPtrLimit = base + (finishLong / KPixelsPerWord);
+
+	if (finishLong < startLong)
+		{
+		const TUint32 mask = (0xffffffff >> finishShift) & (0xffffffff << startShiftExtra);
+		pixelPtrLimit[0] ^= (aBuffer[0] << startShiftExtra) & mask;
+		return;
+		}
+
+	if (startShift > 0)
+		{
+		pixelPtr[-1] ^= aBuffer[0] << startShiftExtra;
+
+		while (pixelPtr < pixelPtrLimit)
+			{
+			pixelPtr[0] ^= (aBuffer[0] >> startShift) | (aBuffer[1] << startShiftExtra);
+
+			pixelPtr++;
+			aBuffer++;
+			}
+
+		if (finishLong < aX + aLength)
+			{
+			TUint32 first = (aBuffer[0] >> startShift) | (aBuffer[1] << startShiftExtra);
+			pixelPtrLimit[0] ^= PasteInt(first,0,finishShift);
+			}
+		}
+	else
+		{
+		while (pixelPtr < pixelPtrLimit)
+			*pixelPtr++ ^= *aBuffer++;
+
+		if (finishLong < aX + aLength)
+			pixelPtrLimit[0] ^= PasteInt(aBuffer[0],0,finishShift);
+		}
+	}
+
+void CDrawFourBppBitmapGray::WriteLineAND(TInt aX,TInt aY,TInt aLength,TUint32* aBuffer)
+	{
+	if (iUserDispMode == EGray2)
+		ShadeBuffer(aLength,aBuffer);
+	else if (iUserDispMode == EGray4)
+		DitherBuffer(aX,aY,aLength,aBuffer);
+
+	const TInt startLong = (aX + KPixelsPerWord - 1) & (~7);
+	const TInt finishLong = (aX + aLength) & (~7);
+	const TInt startShift = (startLong - aX) * KBitsPerPixel;
+	const TInt startShiftExtra = 32 - startShift;
+	const TInt finishShift = (KPixelsPerWord - aX - aLength + finishLong) * KBitsPerPixel;
+	TUint32* base = ScanLine(aY);
+	TUint32* pixelPtr = base + (startLong / KPixelsPerWord);
+	TUint32* pixelPtrLimit = base + (finishLong / KPixelsPerWord);
+
+	if (finishLong < startLong)
+		{
+		const TUint32 mask = (0xffffffff >> finishShift) & (0xffffffff << startShiftExtra);
+		pixelPtrLimit[0] &= (aBuffer[0] << startShiftExtra) | ~mask;
+		return;
+		}
+
+	if (startShift > 0)
+		{
+		pixelPtr[-1] &= (aBuffer[0] << startShiftExtra) | (0xffffffff >> startShift);
+
+		while (pixelPtr < pixelPtrLimit)
+			{
+			pixelPtr[0] &= (aBuffer[0] >> startShift) | (aBuffer[1] << startShiftExtra);
+
+			pixelPtr++;
+			aBuffer++;
+			}
+
+		if (finishLong < aX + aLength)
+			{
+			TUint32 first = (aBuffer[0] >> startShift) | (aBuffer[1] << startShiftExtra);
+			pixelPtrLimit[0] &= PasteInt(first,0xffffffff,finishShift);
+			}
+		}
+	else
+		{
+		while (pixelPtr < pixelPtrLimit)
+			*pixelPtr++ &= *aBuffer++;
+
+		if (finishLong < aX + aLength)
+			pixelPtrLimit[0] &= PasteInt(aBuffer[0],0xffffffff,finishShift);
+		}
+	}
+
+void CDrawFourBppBitmapGray::WriteLineOR(TInt aX,TInt aY,TInt aLength,TUint32* aBuffer)
+	{
+	if (iUserDispMode == EGray2)
+		ShadeBuffer(aLength,aBuffer);
+	else if (iUserDispMode == EGray4)
+		DitherBuffer(aX,aY,aLength,aBuffer);
+
+	const TInt startLong = (aX + KPixelsPerWord - 1) & (~7);
+	const TInt finishLong = (aX + aLength) & (~7);
+	const TInt startShift = (startLong - aX) * KBitsPerPixel;
+	const TInt startShiftExtra = 32 - startShift;
+	const TInt finishShift = (KPixelsPerWord - aX - aLength + finishLong) * KBitsPerPixel;
+	TUint32* base = ScanLine(aY);
+	TUint32* pixelPtr = base + (startLong / KPixelsPerWord);
+	TUint32* pixelPtrLimit = base + (finishLong / KPixelsPerWord);
+
+	if (finishLong < startLong)
+		{
+		const TUint32 mask = (0xffffffff >> finishShift) & (0xffffffff << startShiftExtra);
+		pixelPtrLimit[0] |= (aBuffer[0] << startShiftExtra) & mask;
+		return;
+		}
+
+	if (startShift > 0)
+		{
+		pixelPtr[-1] |= aBuffer[0] << startShiftExtra;
+
+		while (pixelPtr < pixelPtrLimit)
+			{
+			pixelPtr[0] |= (aBuffer[0] >> startShift) | (aBuffer[1] << startShiftExtra);
+
+			pixelPtr++;
+			aBuffer++;
+			}
+
+		if (finishLong < aX + aLength)
+			{
+			TUint32 first = (aBuffer[0] >> startShift) | (aBuffer[1] << startShiftExtra);
+			pixelPtrLimit[0] |= PasteInt(first,0,finishShift);
+			}
+		}
+	else
+		{
+		while (pixelPtr < pixelPtrLimit)
+			*pixelPtr++ |= *aBuffer++;
+
+		if (finishLong < aX + aLength)
+			pixelPtrLimit[0] |= PasteInt(aBuffer[0],0,finishShift);
+		}
+	}
+
+/**
+MAlphaBlend::WriteRgbAlphaLine() implementation.
+@see MAlphaBlend::WriteRgbAlphaLine()
+*/
+void CDrawFourBppBitmapGray::WriteRgbAlphaLine(TInt aX, TInt aY, TInt aLength,
+                                               const TUint8* aRgbBuffer,
+                                               const TUint8* aMaskBuffer,
+                                               MAlphaBlend::TShadowing aShadowing,
+                                               CGraphicsContext::TDrawMode /*aDrawMode*/)
+    {
+	TUint8* pixelPtr = REINTERPRET_CAST(TUint8*,ScanLine(aY)) + (aX / 2);
+	TRgb pixelClr;
+
+	if (aX & 1)
+		{
+        TRgb srcColor(aRgbBuffer[2],aRgbBuffer[1],aRgbBuffer[0]);
+        if(aShadowing == MAlphaBlend::EShdwBefore)
+            {
+		    Shadow(srcColor);
+            }
+		TInt pixelValue = (pixelPtr[0] >> 4) * (255 - aMaskBuffer[0]);
+		TInt srceValue = (((srcColor.Red() << 1) + 
+                            srcColor.Green() + (srcColor.Green() << 2) + 
+                            srcColor.Blue()) >> 7) * aMaskBuffer[0];
+
+		pixelValue += srceValue;
+		pixelValue /= 255;
+
+		pixelClr = TRgb::_Gray16(pixelValue);
+        if(aShadowing == MAlphaBlend::EShdwAfter)
+            {
+	    	Shadow(pixelClr);
+            }
+		MapColorToUserDisplayMode(pixelClr);
+
+		pixelPtr[0] &= 0x0f;
+		pixelPtr[0] |= TUint8(pixelClr._Gray16() << 4);
+
+		pixelPtr++;
+		aRgbBuffer += 4;
+		aMaskBuffer++;
+		aLength--;
+		}
+
+	const TUint8* pixelPtrLimit = pixelPtr + (aLength / 2);
+
+	while (pixelPtr < pixelPtrLimit)
+		{
+        TRgb srcColor1(aRgbBuffer[2],aRgbBuffer[1],aRgbBuffer[0]);
+        if(aShadowing == MAlphaBlend::EShdwBefore)
+            {
+		    Shadow(srcColor1);
+            }
+		TInt pixelValue = (pixelPtr[0] & 0x0f) * (255 - aMaskBuffer[0]);
+		TInt srceValue = (((srcColor1.Red() << 1) + 
+                            srcColor1.Green() + (srcColor1.Green() << 2) + 
+                            srcColor1.Blue()) >> 7) * aMaskBuffer[0];
+
+		pixelValue += srceValue;
+		pixelValue /= 255;
+
+		TInt nextValue = (pixelPtr[0] >> 4) * (255 - aMaskBuffer[1]);
+
+		pixelClr = TRgb::_Gray16(pixelValue);
+        if(aShadowing == MAlphaBlend::EShdwAfter)
+            {
+	    	Shadow(pixelClr);
+            }
+		MapColorToUserDisplayMode(pixelClr);
+
+		pixelPtr[0] = TUint8(pixelClr._Gray16());
+
+        TRgb srcColor2(aRgbBuffer[6],aRgbBuffer[5],aRgbBuffer[4]);
+        if(aShadowing == MAlphaBlend::EShdwBefore)
+            {
+		    Shadow(srcColor2);
+            }
+		srceValue = (((srcColor2.Red() << 1) + 
+                       srcColor2.Green() + (srcColor2.Green() << 2) + 
+                       srcColor2.Blue()) >> 7) * aMaskBuffer[1];
+
+		nextValue += srceValue;
+		nextValue /= 255;
+
+		pixelClr = TRgb::_Gray16(nextValue);
+        if(aShadowing == MAlphaBlend::EShdwAfter)
+            {
+	    	Shadow(pixelClr);
+            }
+		MapColorToUserDisplayMode(pixelClr);
+
+		pixelPtr[0] |= TUint8(pixelClr._Gray16() << 4);
+
+		pixelPtr++;
+		aRgbBuffer += 8;
+		aMaskBuffer += 2;
+		}
+
+	if (aLength & 1)
+		{
+        TRgb srcColor(aRgbBuffer[2],aRgbBuffer[1],aRgbBuffer[0]);
+        if(aShadowing == MAlphaBlend::EShdwBefore)
+            {
+		    Shadow(srcColor);
+            }
+		TInt pixelValue = (pixelPtr[0] & 0x0f) * (255 - aMaskBuffer[0]);
+		TInt srceValue = (((srcColor.Red() << 1) + 
+                            srcColor.Green() + (srcColor.Green() << 2) + 
+                            srcColor.Blue()) >> 7) * aMaskBuffer[0];
+
+		pixelValue += srceValue;
+		pixelValue /= 255;
+
+		pixelClr = TRgb::_Gray16(pixelValue);
+        if(aShadowing == MAlphaBlend::EShdwAfter)
+            {
+	    	Shadow(pixelClr);
+            }
+		MapColorToUserDisplayMode(pixelClr);
+
+		pixelPtr[0] &= 0xf0;
+		pixelPtr[0] |= TUint8(pixelClr._Gray16());
+		}
+	}
+
+void CDrawFourBppBitmapGray::WriteRgbMulti(TInt aX,TInt aY,TInt aLength,TInt aHeight,TRgb aColor)
+	{
+	if (iUserDispMode == EGray2)
+		aColor = TRgb::_Gray2(aColor._Gray2());
+
+	const TInt startLong = (aX + KPixelsPerWord - 1) & (~7);
+	const TInt finishLong = (aX + aLength) & (~7);
+	const TInt yLimit = aY + aHeight;
+	const TInt startShift = (startLong - aX) * KBitsPerPixel;
+	const TInt finishShift = (KPixelsPerWord - aX - aLength + finishLong) * KBitsPerPixel;
+	TUint32* base = ScanLine(aY);
+	TUint32* pixelPtr = base + (startLong / KPixelsPerWord);
+	TUint32* pixelPtrLimit = base + (finishLong / KPixelsPerWord);
+
+	TUint32 colorWord1,colorWord2;
+	if (iUserDispMode == EGray4 && aColor._Gray16() % 5 != 0)
+		{
+		colorWord1 = HashInt(aColor,startLong,aY);
+		colorWord2 = HashInt(aColor,startLong,aY + 1);
+		}
+	else
+		colorWord1 = colorWord2 = ColorInt(aColor);
+	TUint32 colorWord = colorWord1;
+
+	if (finishLong < startLong)
+		{
+		const TUint32 mask = (0xffffffff >> finishShift) & (0xffffffff << (32 - startShift));
+		const TUint32 invertedMask = ~mask;
+		colorWord &= mask;
+		colorWord1 &= mask;
+		colorWord2 &= mask;
+
+		for (; aY < yLimit; aY++)
+			{
+			pixelPtrLimit[0] &= invertedMask;
+			pixelPtrLimit[0] |= colorWord;
+			pixelPtrLimit += iScanLineWords;
+			colorWord = (colorWord == colorWord2) ? colorWord1 : colorWord2;
+			}
+		return;
+		}
+
+	const TBool extra = (finishLong < aX + aLength);
+
+	for (; aY < yLimit; aY++)
+		{
+		if (startShift > 0)
+			pixelPtr[-1] = PasteInt(pixelPtr[-1],colorWord,startShift);
+
+		for (TUint32* tempPixelPtr = pixelPtr; tempPixelPtr < pixelPtrLimit; tempPixelPtr++)
+			tempPixelPtr[0] = colorWord;
+
+		if (extra)
+			pixelPtrLimit[0] = PasteInt(colorWord,pixelPtrLimit[0],finishShift);
+
+		pixelPtr += iScanLineWords;
+		pixelPtrLimit += iScanLineWords;
+		colorWord = (colorWord == colorWord2) ? colorWord1 : colorWord2;
+		}
+	}
+
+void CDrawFourBppBitmapGray::WriteRgbMultiXOR(TInt aX,TInt aY,TInt aLength,TInt aHeight,TRgb aColor)
+	{
+	if (iUserDispMode == EGray2)
+		aColor = TRgb::_Gray2(aColor._Gray2());
+
+	const TInt startLong = (aX + KPixelsPerWord - 1) & (~7);
+	const TInt finishLong = (aX + aLength) & (~7);
+	const TInt yLimit = aY + aHeight;
+	const TInt startShift = (startLong - aX) * KBitsPerPixel;
+	const TInt finishShift = (KPixelsPerWord - aX - aLength + finishLong) * KBitsPerPixel;
+	TUint32* base = ScanLine(aY);
+	TUint32* pixelPtr = base + (startLong / KPixelsPerWord);
+	TUint32* pixelPtrLimit = base + (finishLong / KPixelsPerWord);
+
+	TUint32 colorWord1,colorWord2;
+	if (iUserDispMode == EGray4 && aColor._Gray16() % 5 != 0)
+		{
+		colorWord1 = HashInt(aColor,startLong,aY);
+		colorWord2 = HashInt(aColor,startLong,aY + 1);
+		}
+	else
+		colorWord1 = colorWord2 = ColorInt(aColor);
+	TUint32 colorWord = colorWord1;
+
+	if (finishLong < startLong)
+		{
+		const TUint32 mask = (0xffffffff >> finishShift) & (0xffffffff << (32 - startShift));
+		colorWord &= mask;
+		colorWord1 &= mask;
+		colorWord2 &= mask;
+
+		for (; aY < yLimit; aY++)
+			{
+			pixelPtrLimit[0] ^= colorWord;
+			pixelPtrLimit += iScanLineWords;
+			colorWord = (colorWord == colorWord2) ? colorWord1 : colorWord2;
+			}
+		return;
+		}
+
+	const TBool extra = (finishLong < aX + aLength);
+
+	for (; aY < yLimit; aY++)
+		{
+		if (startShift > 0)
+			pixelPtr[-1] ^= PasteInt(0,colorWord,startShift);
+
+		for (TUint32* tempPixelPtr = pixelPtr; tempPixelPtr < pixelPtrLimit; tempPixelPtr++)
+			tempPixelPtr[0] ^= colorWord;
+
+		if (extra)
+			pixelPtrLimit[0] ^= PasteInt(colorWord,0,finishShift);
+
+		pixelPtr += iScanLineWords;
+		pixelPtrLimit += iScanLineWords;
+		colorWord = (colorWord == colorWord2) ? colorWord1 : colorWord2;
+		}
+	}
+
+void CDrawFourBppBitmapGray::WriteRgbMultiAND(TInt aX,TInt aY,TInt aLength,TInt aHeight,TRgb aColor)
+	{
+	if (iUserDispMode == EGray2)
+		aColor = TRgb::_Gray2(aColor._Gray2());
+
+	const TInt startLong = (aX + KPixelsPerWord - 1) & (~7);
+	const TInt finishLong = (aX + aLength) & (~7);
+	const TInt yLimit = aY + aHeight;
+	const TInt startShift = (startLong - aX) * KBitsPerPixel;
+	const TInt finishShift = (KPixelsPerWord - aX - aLength + finishLong) * KBitsPerPixel;
+	TUint32* base = ScanLine(aY);
+	TUint32* pixelPtr = base + (startLong / KPixelsPerWord);
+	TUint32* pixelPtrLimit = base + (finishLong / KPixelsPerWord);
+
+	TUint32 colorWord1,colorWord2;
+	if (iUserDispMode == EGray4 && aColor._Gray16() % 5 != 0)
+		{
+		colorWord1 = HashInt(aColor,startLong,aY);
+		colorWord2 = HashInt(aColor,startLong,aY + 1);
+		}
+	else
+		colorWord1 = colorWord2 = ColorInt(aColor);
+	TUint32 colorWord = colorWord1;
+
+	if (finishLong < startLong)
+		{
+		const TUint32 mask = (0xffffffff >> finishShift) & (0xffffffff << (32 - startShift));
+		const TUint32 invertedMask = ~mask;
+		colorWord &= mask;
+		colorWord1 &= mask;
+		colorWord2 &= mask;
+		colorWord |= invertedMask;
+		colorWord1 |= invertedMask;
+		colorWord2 |= invertedMask;
+
+		for (; aY < yLimit; aY++)
+			{
+			pixelPtrLimit[0] &= colorWord;
+			pixelPtrLimit += iScanLineWords;
+			colorWord = (colorWord == colorWord2) ? colorWord1 : colorWord2;
+			}
+		return;
+		}
+
+	const TBool extra = (finishLong < aX + aLength);
+
+	for (; aY < yLimit; aY++)
+		{
+		if (startShift > 0)
+			pixelPtr[-1] &= PasteInt(0xffffffff,colorWord,startShift);
+
+		for (TUint32* tempPixelPtr = pixelPtr; tempPixelPtr < pixelPtrLimit; tempPixelPtr++)
+			tempPixelPtr[0] &= colorWord;
+
+		if (extra)
+			pixelPtrLimit[0] &= PasteInt(colorWord,0xffffffff,finishShift);
+
+		pixelPtr += iScanLineWords;
+		pixelPtrLimit += iScanLineWords;
+		colorWord = (colorWord == colorWord2) ? colorWord1 : colorWord2;
+		}
+	}
+
+void CDrawFourBppBitmapGray::WriteRgbMultiOR(TInt aX,TInt aY,TInt aLength,TInt aHeight,TRgb aColor)
+	{
+	if (iUserDispMode == EGray2)
+		aColor = TRgb::_Gray2(aColor._Gray2());
+
+	const TInt startLong = (aX + KPixelsPerWord - 1) & (~7);
+	const TInt finishLong = (aX + aLength) & (~7);
+	const TInt yLimit = aY + aHeight;
+	const TInt startShift = (startLong - aX) * KBitsPerPixel;
+	const TInt finishShift = (KPixelsPerWord - aX - aLength + finishLong) * KBitsPerPixel;
+	TUint32* base = ScanLine(aY);
+	TUint32* pixelPtr = base + (startLong / KPixelsPerWord);
+	TUint32* pixelPtrLimit = base + (finishLong / KPixelsPerWord);
+
+	TUint32 colorWord1,colorWord2;
+	if (iUserDispMode == EGray4 && aColor._Gray16() % 5 != 0)
+		{
+		colorWord1 = HashInt(aColor,startLong,aY);
+		colorWord2 = HashInt(aColor,startLong,aY + 1);
+		}
+	else
+		colorWord1 = colorWord2 = ColorInt(aColor);
+	TUint32 colorWord = colorWord1;
+
+	if (finishLong < startLong)
+		{
+		const TUint32 mask = (0xffffffff >> finishShift) & (0xffffffff << (32 - startShift));
+		colorWord &= mask;
+		colorWord1 &= mask;
+		colorWord2 &= mask;
+
+		for (; aY < yLimit; aY++)
+			{
+			pixelPtrLimit[0] |= colorWord;
+			pixelPtrLimit += iScanLineWords;
+			colorWord = (colorWord == colorWord2) ? colorWord1 : colorWord2;
+			}
+		return;
+		}
+
+	const TBool extra = (finishLong < aX + aLength);
+
+	for (; aY < yLimit; aY++)
+		{
+		if (startShift > 0)
+			pixelPtr[-1] |= PasteInt(0,colorWord,startShift);
+
+		for (TUint32* tempPixelPtr = pixelPtr; tempPixelPtr < pixelPtrLimit; tempPixelPtr++)
+			tempPixelPtr[0] |= colorWord;
+
+		if (extra)
+			pixelPtrLimit[0] |= PasteInt(colorWord,0,finishShift);
+
+		pixelPtr += iScanLineWords;
+		pixelPtrLimit += iScanLineWords;
+		colorWord = (colorWord == colorWord2) ? colorWord1 : colorWord2;
+		}
+	}
+
+void CDrawFourBppBitmapGray::WriteRgbAlphaMulti(TInt aX,TInt aY,TInt aLength,TRgb aColor,const TUint8* aMaskBuffer)
+	{
+	DeOrientate(aX,aY);
+	TUint8* pixelPtr = REINTERPRET_CAST(TUint8*,ScanLine(aY)) + (aX / 2);
+	const TBool oddEndCoord = (aX + aLength) & 1;
+	const TUint8* maskBufferPtrLimit = aMaskBuffer + aLength - (oddEndCoord ? 1 : 0);
+
+	if (iShadowMode)
+		Shadow(aColor);
+	
+	const TInt gray = aColor._Gray256();
+	if (aX & 1)
+		{
+		const TInt upper = ((gray * aMaskBuffer[0]) + ((255 - aMaskBuffer[0]) * (pixelPtr[0] >> 4) * 17)) / (255 * 17);
+		pixelPtr[0] &= 0x0f;
+		pixelPtr[0] |= TUint8(upper << 4);
+
+		pixelPtr++;
+		aMaskBuffer++;
+		}
+
+	while (aMaskBuffer < maskBufferPtrLimit)
+		{
+		const TInt lower = ((gray * aMaskBuffer[0]) + ((255 - aMaskBuffer[0]) * (pixelPtr[0] & 0x0f) * 17)) / (255 * 17);
+		const TInt upper = ((gray * aMaskBuffer[1]) + ((255 - aMaskBuffer[1]) * (pixelPtr[0] >> 4) * 17)) / (255 * 17);
+		pixelPtr[0] = TUint8(lower);
+		pixelPtr[0] |= TUint8(upper << 4);
+
+		pixelPtr++;
+		aMaskBuffer += 2;
+		}
+
+	if (oddEndCoord)
+		{
+		const TInt lower = ((gray * aMaskBuffer[0]) + ((255 - aMaskBuffer[0]) * (pixelPtr[0] & 0x0f) * 17)) / (255 * 17);
+		pixelPtr[0] &= 0xf0;
+		pixelPtr[0] |= TUint8(lower);
+		}
+	}
+
+void CDrawFourBppBitmapGray::MapColorToUserDisplayMode(TRgb& aColor)
+	{
+	switch (iUserDispMode)
+		{
+	case EGray2:
+		aColor = TRgb::_Gray2(aColor._Gray2());
+		break;
+	case EColor16:
+		aColor = TRgb::_Gray4(aColor._Gray4());
+		break;
+	default:
+		break;
+		}
+	}
+
+void CDrawFourBppBitmapGray::MapBufferToUserDisplayMode(TInt aLength,TUint32* aBuffer)
+	{
+	TUint8* bufferPtr = (TUint8*)aBuffer;
+	const TUint8* bufferLimit = bufferPtr + ((aLength + 1) / 2);
+
+	switch (iUserDispMode)
+		{
+	case EGray2:
+		while (bufferPtr < bufferLimit)
+			{
+			TUint8 value = TUint8(*bufferPtr & 0x88);
+			value |= value >> 1;
+			*bufferPtr++ = TUint8(value | (value >> 2));
+			}
+		break;
+	case EColor16:
+		while (bufferPtr < bufferLimit)
+			{
+			TUint8 value = TUint8(*bufferPtr & 0xcc);
+			*bufferPtr++ = TUint8(value | (value >> 2));
+			}
+		break;
+	default:
+		break;
+		}
+	}
+
+TInt CDrawFourBppBitmapGray::WriteRgbOutlineAndShadow(TInt aX, TInt aY, const TInt aLength,
+	                                   TUint32 aOutlinePenColor, TUint32 aShadowColor,
+	                                   TUint32 aFillColor, const TUint8* aDataBuffer)
+	{
+	//This is non-optimised since this screen mode is rarely used and is usually 
+	//fast enough without optimisation.
+	DeOrientate(aX,aY);
+	TUint8* pixelPtr = REINTERPRET_CAST(TUint8*,ScanLine(aY)) + (aX / 2);
+	const TBool oddEndCoord = (aX + aLength) & 1;
+	const TUint8* dataBufferPtrLimit = aDataBuffer + aLength - (oddEndCoord ? 1 : 0);
+
+	TUint8 index = 0;
+	TRgb finalColor;
+	TRgb lowerPixelColor;
+	TRgb upperPixelColor;
+
+	TRgb outlinePenColor;
+	outlinePenColor.SetInternal(aOutlinePenColor);
+	TRgb shadowColor;
+	shadowColor.SetInternal(aShadowColor);
+	TRgb fillColor;
+	fillColor.SetInternal(aFillColor);
+
+	const TInt redOutlinePenColor = outlinePenColor.Red();
+	const TInt redShadowColor = shadowColor.Red();
+	const TInt redFillColor = fillColor.Red();
+
+	const TInt greenOutlinePenColor = outlinePenColor.Green();
+	const TInt greenShadowColor = shadowColor.Green();
+	const TInt greenFillColor = fillColor.Green();
+
+	const TInt blueOutlinePenColor = outlinePenColor.Blue();
+	const TInt blueShadowColor = shadowColor.Blue();
+	const TInt blueFillColor = fillColor.Blue();
+
+	if (aX & 1)
+		{
+		index = *aDataBuffer;
+		
+		if (255 != FourColorBlendLookup[index][KBackgroundColorIndex])
+			{
+			TRgb backgroundColor = TRgb::_Gray16(pixelPtr[0] >> 4);
+			finalColor = BlendFourColors(aOutlinePenColor, aShadowColor, aFillColor,
+										redOutlinePenColor, redShadowColor, redFillColor,
+										greenOutlinePenColor, greenShadowColor, greenFillColor,
+										blueOutlinePenColor, blueShadowColor, blueFillColor,
+										backgroundColor, index);
+			pixelPtr[0] &= 0x0f;
+			pixelPtr[0] |= TUint8(finalColor._Gray16() << 4);
+			}
+			
+		pixelPtr++;
+		aDataBuffer++;
+		}
+
+	while (aDataBuffer < dataBufferPtrLimit)
+		{
+		index = aDataBuffer[0];
+		TRgb upperPixelBackgroundColor = TRgb::_Gray16(pixelPtr[0] >> 4);
+		if (255 != FourColorBlendLookup[index][KBackgroundColorIndex])
+			{
+			TRgb lowerPixelBackgroundColor = TRgb::_Gray16(pixelPtr[0] & 0x0f);
+			lowerPixelColor = BlendFourColors(aOutlinePenColor, aShadowColor, aFillColor,
+											redOutlinePenColor, redShadowColor, redFillColor,
+											greenOutlinePenColor, greenShadowColor, greenFillColor,
+											blueOutlinePenColor, blueShadowColor, blueFillColor,
+											lowerPixelBackgroundColor, index);
+			pixelPtr[0] = TUint8(lowerPixelColor._Gray16());
+			}
+		
+		index = aDataBuffer[1];
+		if (255 != FourColorBlendLookup[index][KBackgroundColorIndex])
+			{
+			upperPixelColor = BlendFourColors(aOutlinePenColor, aShadowColor, aFillColor,
+											redOutlinePenColor, redShadowColor, redFillColor,
+											greenOutlinePenColor, greenShadowColor, greenFillColor,
+											blueOutlinePenColor, blueShadowColor, blueFillColor,
+											upperPixelBackgroundColor, index);
+			pixelPtr[0] |= TUint8(upperPixelColor._Gray16() << 4);
+			}
+		pixelPtr++;
+		aDataBuffer += 2;
+		}
+
+	if (oddEndCoord)
+		{
+		index = aDataBuffer[0];
+		if (255 != FourColorBlendLookup[index][KBackgroundColorIndex])
+			{
+			TRgb backgroundColor = TRgb::_Gray16(pixelPtr[0] & 0x0f);
+			finalColor = BlendFourColors(aOutlinePenColor, aShadowColor, aFillColor,
+										redOutlinePenColor, redShadowColor, redFillColor,
+										greenOutlinePenColor, greenShadowColor, greenFillColor,
+										blueOutlinePenColor, blueShadowColor, blueFillColor,
+										backgroundColor, index);
+			pixelPtr[0] &= 0xf0;
+			pixelPtr[0] |= TUint8(finalColor._Gray16());
+			}
+		}
+	return KErrNone;
+	}
+
+TRgb CDrawFourBppBitmapGray::BlendFourColors(TUint32 aOutlinePenColor, TUint32 aShadowColor, TUint32 aFillColor,
+											TInt aRedOutlinePenColor, TInt aRedShadowColor, TInt aRedFillColor,
+											TInt aGreenOutlinePenColor, TInt aGreenShadowColor, TInt aGreenFillColor,
+											TInt aBlueOutlinePenColor,	TInt aBlueShadowColor,	TInt aBlueFillColor,
+											TRgb aBackgroundColor, TUint8 aIndex) const
+	{
+	TRgb finalColor;
+	if (255 == FourColorBlendLookup[aIndex][KFillColorIndex])
+		{
+		//fill colour
+		finalColor.SetInternal(aFillColor);
+		}
+	else if (255 == FourColorBlendLookup[aIndex][KShadowColorIndex])
+		{
+		//Shadow colour
+		finalColor.SetInternal(aShadowColor);
+		}
+	else if (255 == FourColorBlendLookup[aIndex][KOutlineColorIndex])
+		{
+		//Outline colour
+		finalColor.SetInternal(aOutlinePenColor);
+		}
+	else
+		{
+		TInt blendedRedColor = (aRedOutlinePenColor * FourColorBlendLookup[aIndex][KOutlineColorIndex] + 
+						   		aRedShadowColor * FourColorBlendLookup[aIndex][KShadowColorIndex] +
+						  		aRedFillColor * FourColorBlendLookup[aIndex][KFillColorIndex] + 
+						  		aBackgroundColor.Red() * FourColorBlendLookup[aIndex][KBackgroundColorIndex]) >> 8;
+
+		TInt blendedGreenColor = (aGreenOutlinePenColor * FourColorBlendLookup[aIndex][KOutlineColorIndex] + 
+								aGreenShadowColor * FourColorBlendLookup[aIndex][KShadowColorIndex] +
+								aGreenFillColor * FourColorBlendLookup[aIndex][KFillColorIndex] + 
+								aBackgroundColor.Green() * FourColorBlendLookup[aIndex][KBackgroundColorIndex]) >> 8;
+
+		TInt blendedBlueColor = (aBlueOutlinePenColor * FourColorBlendLookup[aIndex][KOutlineColorIndex] + 
+								aBlueShadowColor * FourColorBlendLookup[aIndex][KShadowColorIndex] +
+								aBlueFillColor * FourColorBlendLookup[aIndex][KFillColorIndex] + 
+								aBackgroundColor.Blue() * FourColorBlendLookup[aIndex][KBackgroundColorIndex]) >> 8;
+		finalColor = TRgb(blendedRedColor, blendedGreenColor, blendedBlueColor);
+		}
+	return finalColor;
+	}