// Copyright (c) 2008-2009 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 "directgdiadapter.h"

#include "swdirectgdiengine.h"

#include "swdirectgdiimagesourceimpl.h"

#include "swdirectgdidriverimpl.h"

#include <bitdrawinterfaceid.h>

#include <e32cmn.h>

#include <bitdraw.h>

#include <bmalphablend.h>

#include <graphics/directgdidrawablesource.h>

#include <pixelformats.h>

#include "pixelutil.h"

/**

Helper class to deal with the case of blending 32-bit MAP source into 16-bit target which is not 

supported by screen driver CDrawSixteenBppBitmap implementation.

@publishedPartner

@prototype

@deprecated

*/

class TDrawDeviceWrapper

	{

public:

	TDrawDeviceWrapper(CFbsDrawDevice* aDrawDevice, CGraphicsContext::TDrawMode aDrawMode);

	inline void WriteLine(TInt aX, TInt aY, TInt aLength, TUint32* aBuffer, CGraphicsContext::TDrawMode aDrawMode);

private:

	inline TUint16 ConvertTo64K(TUint32 aColor);

	inline TUint16 Blend16MapTo64K(TUint16 aDest, TUint32 aSrc);

	void BlendLine16MapTo64K(TInt aX, TInt aY, TInt aLength, TUint32* aBuffer, CGraphicsContext::TDrawMode aDrawMode);

	void OriginalWriteLine(TInt aX, TInt aY, TInt aLength, TUint32* aBuffer, CGraphicsContext::TDrawMode aDrawMode);

private:

	CFbsDrawDevice* iDrawDevice;

	TUint32* iBits;

	typedef void (TDrawDeviceWrapper::*TWriteLineFunc)(TInt,TInt,TInt,TUint32*,CGraphicsContext::TDrawMode);

	TWriteLineFunc iWriteLineFunc;

	};

TDrawDeviceWrapper::TDrawDeviceWrapper(CFbsDrawDevice* aDrawDevice, CGraphicsContext::TDrawMode aDrawMode):

	iDrawDevice(aDrawDevice)

	{

	TAny* interface = NULL;

	TInt err = iDrawDevice->GetInterface(KFastBlit2InterfaceID, interface);

	// interface is guaranted to exist for 16-bit and 32-bit draw device

	GRAPHICS_ASSERT_DEBUG(err == KErrNone, EDirectGdiPanicUnexpectedError);

	iBits = (TUint32*) reinterpret_cast<MFastBlit2*>(interface)->Bits();

	// setup which funtion to call here rather tha making decision inside WriteLine which is usually called within

	// a tight scanline loop

	iWriteLineFunc = iDrawDevice->DisplayMode() == EColor64K && aDrawMode == CGraphicsContext::EDrawModePEN ? 

			&TDrawDeviceWrapper::BlendLine16MapTo64K : &TDrawDeviceWrapper::OriginalWriteLine;

	}

inline void TDrawDeviceWrapper::WriteLine(TInt aX, TInt aY, TInt aLength, TUint32* aBuffer, CGraphicsContext::TDrawMode aDrawMode)

	{

	// calling member functions via pointer to member functions i.e.

	// (object.*member_fn)(arg)

	//

	(this->*iWriteLineFunc)(aX, aY, aLength, aBuffer, aDrawMode);

	}

void TDrawDeviceWrapper::OriginalWriteLine(TInt aX, TInt aY, TInt aLength, TUint32* aBuffer, CGraphicsContext::TDrawMode aDrawMode)

	{

	iDrawDevice->WriteLine(aX, aY, aLength, aBuffer, aDrawMode);

	}

void TDrawDeviceWrapper::BlendLine16MapTo64K(TInt aX, TInt aY, TInt aLength, TUint32* aBuffer, CGraphicsContext::TDrawMode)

	{

	TUint16* pixelPtr = reinterpret_cast<TUint16*>(iBits);

	pixelPtr += (aY * iDrawDevice->LongWidth()) + aX;

	const TUint32* bufferPtr = aBuffer;

	const TUint32* bufferPtrLimit = bufferPtr + aLength;

	while (bufferPtr < bufferPtrLimit)

		{

		*pixelPtr = Blend16MapTo64K(*pixelPtr, *bufferPtr);

		++bufferPtr;

		++pixelPtr;

		}

	}

inline TUint16 TDrawDeviceWrapper::ConvertTo64K(TUint32 aSrc)

	{

	TInt col = (aSrc & 0x0000f8) >> 3;

	col |= (aSrc & 0x00fc00) >> 5;

	col |= (aSrc & 0xf80000) >> 8;

	return col;

	}

inline TUint16 TDrawDeviceWrapper::Blend16MapTo64K(TUint16 aDst, TUint32 aSrc)

	{

	const TInt alpha = aSrc >> 24;

	if(alpha == 0x00)

		{

		return aDst;

		}

	if (alpha == 0xff)

		{

		return ConvertTo64K(aSrc);

		}

	// extract source components from 16MAP

	const TInt src_rb = aSrc & 0x00ff00ff;

	const TInt src_g = aSrc & 0x0000ff00;

	const TInt oneMinusAlpha = 0x0100 - alpha;

	// extract destination components from 64K format

    TInt dr = (aDst & 0xf800) >> 8;

    dr += dr >> 5;

    TInt dg = (aDst & 0x07e0) >> 3;

    dg += dg >> 6;

    TInt db = (aDst & 0x001f) << 3;

    db += db >> 5;

	// combine red and blue components into a word to combine mult in one go

	TInt dst_rb = (dr << 16) | db;

	TInt dst_g = dg << 8;

	// dst and src are in pre-multiplied format (64K can be treated both as pre or non-pre)

	// dst = src + (1-alpha) * dst

	//

	dst_rb = (src_rb + ((oneMinusAlpha * dst_rb) >> 8)) & 0x00ff00ff;

	dst_g = (src_g + ((oneMinusAlpha * dst_g) >> 8)) & 0x0000ff00;

	const TUint32 argb = 0xff000000 | dst_rb | dst_g;

	return ConvertTo64K(argb);

	}

//

// implements MDirectGdiEngine interfaces

//

/**

@see MDirectGdiEngine::DrawResource(const TRect&,const RDirectGdiDrawableSource&,const TDesC8&)

*/

void CSwDirectGdiEngine::DrawResource(

		const TRect& aDestRect,

		const RDirectGdiDrawableSource& aSource,

		const TDesC8& /*aParam*/)

	{

	// DirectGDI reference implementation only support pixel based resource

	// see CSwDirectGdiDriverImpl::CreateDrawableSource()

	//

	CSwDirectGdiImageSourceImpl* imgSrc = NULL;

	TSize imgSize;

	if (CheckImageSource(aSource.Handle(), imgSrc, &imgSize) != KErrNone)

		{

		return;

		}

	// drawing resource unscaled with no rotation

	//

	DrawResourceCommon(aDestRect, imgSrc, TRect(TPoint(0,0), imgSize), DirectGdi::EGraphicsRotationNone);

	}

/**

@see MDirectGdiEngine::DrawResource(const TPoint&,const RDirectGdiDrawableSource&,DirectGdi::TGraphicsRotation)

*/

void CSwDirectGdiEngine::DrawResource(const TPoint& aPos,

		const RDirectGdiDrawableSource& aSource,

		DirectGdi::TGraphicsRotation aRotation)

	{

	CSwDirectGdiImageSourceImpl* imgSrc = NULL;

	TSize imgSize;

	if (CheckImageSource(aSource.Handle(), imgSrc, &imgSize) != KErrNone)

		{

		return;

		}

	// drawing resource unscaled

	//

	// rotation will be applied before scaling, we must create destination rectangle 

	// that match the size of rotated image

	TRect destRect(aPos, imgSize);

	if (aRotation==DirectGdi::EGraphicsRotation90 || aRotation==DirectGdi::EGraphicsRotation270)

		{

		// keep the top left corner in the same position but swap width and height

		destRect.SetWidth(imgSize.iHeight);

		destRect.SetHeight(imgSize.iWidth);

		}

	DrawResourceCommon(destRect, imgSrc, TRect(TPoint(0,0), imgSize), aRotation);

	}

/**

@see MDirectGdiEngine::DrawResource(const TRect&,const RDirectGdiDrawableSource&,DirectGdi::TGraphicsRotation)

*/

void CSwDirectGdiEngine::DrawResource(const TRect& aDestRect,

		const RDirectGdiDrawableSource& aSource,

		DirectGdi::TGraphicsRotation aRotation)

	{

	// aDestRect is not empty when we reach here

	//

	CSwDirectGdiImageSourceImpl* imgSrc = NULL;

	TSize imgSize;

	if (CheckImageSource(aSource.Handle(), imgSrc, &imgSize) != KErrNone)

		{

		return;

		}

	DrawResourceCommon(aDestRect, imgSrc, TRect(TPoint(0,0), imgSize), aRotation);

	}

/**

@see MDirectGdiEngine::DrawResource(const TRect&,const RDirectGdiDrawableSource&,const TRect&,DirectGdi::TGraphicsRotation)

*/

void CSwDirectGdiEngine::DrawResource(

		const TRect& aDestRect,				

		const RDirectGdiDrawableSource& aSource, 

		const TRect& aSrcRect,

		DirectGdi::TGraphicsRotation aRotation)

	{

	// pre:

	// aDestRect and aSrcRect are not empty

	//

	CSwDirectGdiImageSourceImpl* imgSrc = NULL;

	TSize imgSize;

	if (CheckImageSource(aSource.Handle(), imgSrc, &imgSize) != KErrNone)

		{

		return;

		}

	// check source rectangle is fully contained within the image resource extent

	if (aSrcRect.iTl.iX < 0 ||

		aSrcRect.iTl.iY < 0 ||

		aSrcRect.iBr.iX > imgSize.iWidth ||

		aSrcRect.iBr.iY > imgSize.iHeight)

		{

		iDriver->SetError(KErrArgument);

		return;

		}   	

	DrawResourceCommon(aDestRect, imgSrc, aSrcRect, aRotation);

	}

//

// internal functions

//

/**

Checks image resource is fully constructed and registered with the driver.

@param  aHandle A valid handle to an image source.

@param  aImg On return, contains the image source.

@param  aSize If not NULL, will contain the dimensions of the image source.

@return KErrNone if successful, KErrBadHandle if aHandle is not a valid handle to an image source.

*/

TInt CSwDirectGdiEngine::CheckImageSource(TInt aHandle, CSwDirectGdiImageSourceImpl*& aImg, TSize* aSize)

	{

	// check image exist

	if (!iDriver->ValidImageSource(aHandle))

		{

		// replace KErrNotFound

		const TInt err = KErrBadHandle;

		iDriver->SetError(err);

		return err;

		}

	aImg = reinterpret_cast<CSwDirectGdiImageSourceImpl*>(aHandle);

	// RSgImage cannot be created with zero size, so there is no point in validating its size and

	// simply return image size if requested

	if (aSize)

		{		

		*aSize = aImg->Size();

		}

	return KErrNone;

	}

/**

Implements common DrawResource() functionality used by all DrawResource() variants.

*/

void CSwDirectGdiEngine::DrawResourceCommon(

		const TRect& aDestRect,

		const CSwDirectGdiImageSourceImpl* aImg,

		const TRect& aSrcRect,

		DirectGdi::TGraphicsRotation aRotation)

	{

	// pre:

	// aDestRect and aSrcRect are not empty

	// aSrcRect is within the image extent

	//

	// translate relative coord to target absolute coord system

	TRect destRectAbs(aDestRect);

	destRectAbs.Move(iOrigin);

	// check whether we need to blend or write

	const TBool opaqueSource = (!PixelFormatUtil::HasAlpha(aImg->PixelFormat())) && (iDrawMode == DirectGdi::EDrawModePEN);

	if (opaqueSource)

		{

		iDrawMode = DirectGdi::EDrawModeWriteAlpha;

		}

	// repeat drawing op for each rectangle in the clipping region

	const TInt numOfRects = iDefaultRegionPtr->Count();	

	for (TInt idx = 0; idx < numOfRects; ++idx)

		{

		TRect clipRectAbs = (*iDefaultRegionPtr)[idx];

		if (!clipRectAbs.Intersects(destRectAbs))

			{

			continue;

			}

		// intersect current clip rect with dest rect to get actual draw area

		clipRectAbs.Intersection(destRectAbs);

		DoDrawResource(destRectAbs, aImg, aSrcRect, aRotation, clipRectAbs);

		iDrawDevice->UpdateRegion(clipRectAbs);

		}

	if (opaqueSource)

		{

		iDrawMode = DirectGdi::EDrawModePEN;

		}	

	}

/**

Rotate a given rectangle 90 degree clockwise around the specified origin.

*/

void CSwDirectGdiEngine::Rotate90(TRect& aRect, const TPoint& aOrigin)

	{

	// rotated bottom-left become top-left of rotated rect

	//

	TPoint bl(aRect.iTl.iX, aRect.iBr.iY);

	const TInt w = aRect.Width();

	const TInt h = aRect.Height();

	const TPoint dbl = bl - aOrigin;

	bl.iX = aOrigin.iX - dbl.iY;

	bl.iY = aOrigin.iY + dbl.iX;

	aRect = TRect(bl, TSize(h,w));

	}

/**

Rotate a given rectangle 180 degree clockwise around the specified origin.

*/

void CSwDirectGdiEngine::Rotate180(TRect& aRect, const TPoint& aOrigin)

	{

	// rotated bottom-right become top-left of rotated rect

	//

	TPoint br(aRect.iBr);

	const TSize sz = aRect.Size();

	const TPoint dbr = br - aOrigin;

	br.iX = aOrigin.iX - dbr.iX;

	br.iY = aOrigin.iY - dbr.iY;

	aRect = TRect(br, sz);

	}

/**

Rotate a given rectangle 270 degree clockwise around the specified origin.

*/

void CSwDirectGdiEngine::Rotate270(TRect& aRect, const TPoint& aOrigin)

	{

	// rotated top-right become top-left of rotated rect

	//

	TPoint tr(aRect.iBr.iX, aRect.iTl.iY);

	const TInt w = aRect.Width();

	const TInt h = aRect.Height();

	const TPoint dtr = tr - aOrigin;

	tr.iX = aOrigin.iX + dtr.iY;

	tr.iY = aOrigin.iY - dtr.iX;

	aRect = TRect(tr, TSize(h,w));

	}

/**

Tests that the size of a given rotated rectangle match the image source extent.

*/

TBool CSwDirectGdiEngine::RotatedSizeMatch(const TRect& aDst, const TRect& aSrc, DirectGdi::TGraphicsRotation aRot)

	{

	if (aRot==DirectGdi::EGraphicsRotationNone || aRot==DirectGdi::EGraphicsRotation180)

		{

		return aDst.Size()==aSrc.Size();

		}

	else

		{

		return aDst.Width()==aSrc.Height() && aDst.Height()==aSrc.Width();

		}

	}

/**

Draws a rectangular area of resource and apply rotation and/or scaling if requested.

*/

void CSwDirectGdiEngine::DoDrawResource(

		const TRect& aDestRectAbs,

		const CSwDirectGdiImageSourceImpl* aImg,

		const TRect& aSrcRect,

		DirectGdi::TGraphicsRotation aRotation,

		const TRect& aClipRectAbs)

	{

	// pre:

	// SetClippingRegion() already check that clipping region is always contained

	// within device full extent.

	// check src rect match the size of rotated dest rect

	if (RotatedSizeMatch(aDestRectAbs, aSrcRect, aRotation))

		{

		// aClipRect is the effective drawing clipped area, it has been intersected with dest rect by the

		// calling function/DoDrawResourceCommon() and it is not empty when we reach here

		// image size has been checked at the top level DrawResource() no need to check it again

		// use aClipRect to determine how much area should be read from the image and transform

		// the effective read area into source rect depending on rotation parameter

		// start with aClipRect

		TRect xformSrcRect(aClipRectAbs);

		switch (aRotation)

			{

			case DirectGdi::EGraphicsRotationNone:

				// align top-left corner of dest rect with top-left corner of src rect

				xformSrcRect.Move(aSrcRect.iTl - aDestRectAbs.iTl);

				break;

			case DirectGdi::EGraphicsRotation90:

				{

				// align top-right corner of dest rect with top-left corner of src rect

				xformSrcRect.Move(aSrcRect.iTl - TPoint(aDestRectAbs.iBr.iX, aDestRectAbs.iTl.iY));

				// rotate 270 (-90) degree using top-left corner of src rect as pivot point

				Rotate270(xformSrcRect, aSrcRect.iTl);

				}

				break;

			case DirectGdi::EGraphicsRotation180:

				{

				// align bottom-right corner of dest rect with top-left corner of src rect

				xformSrcRect.Move(aSrcRect.iTl - aDestRectAbs.iBr);

				// rotate 180 (-180) degree using top-left corner of src rect as pivot point

				Rotate180(xformSrcRect, aSrcRect.iTl);

				}

				break;

			case DirectGdi::EGraphicsRotation270:

				{

				// align bottom-left corner of dest rect with top-left corner of src rect

				xformSrcRect.Move(aSrcRect.iTl - TPoint(aDestRectAbs.iTl.iX, aDestRectAbs.iBr.iY));

				// rotate 90 (-270) degree using top-left corner of src rect as pivot point

				Rotate90(xformSrcRect, aSrcRect.iTl);

				}

				break;

			// no need for extra check, aRotation has been checked at generic layer

			}

		DoBlitResource(aClipRectAbs.iTl, aImg, xformSrcRect, aRotation);

		return;

		}

	DoScaledBlitResource(aDestRectAbs, aImg, aSrcRect, aRotation, aClipRectAbs);

	}

/**

Draws a rectangular area of resource rotated with no scaling.

@panic DGDIAdapter 1009, if the pixel format of the draw device is unknown (debug only). 

*/

void CSwDirectGdiEngine::DoBlitResource(

		const TPoint& aDest,

		const CSwDirectGdiImageSourceImpl* aImg,

		const TRect& aSrcRect,

		DirectGdi::TGraphicsRotation aRotation)

	{		

	// pre:

	// aDest is the top-left of clipped destination rectangle i.e. intersection of user destination

	// rectangle with current clipping rect

	// aSrcRect is rotated clipped read area i.e. effective read area with respect to original 

	// image orientation i.e.it no longer represents user specified source rect.

	// no need to do extra check on parameters here because:

	// aDest is guaranteed to be within device drawing area

	// aSrcRect is guaranteed to be within image source area

	const TUidPixelFormat devFormat = PixelFormatUtil::ConvertToPixelFormat(iDrawDevice->DisplayMode());

	GRAPHICS_ASSERT_DEBUG(devFormat != EUidPixelFormatUnknown, EDirectGdiPanicInvalidDisplayMode);

	const TUidPixelFormat imgFormat = aImg->PixelFormat();

	const TUint32* imgAddr = reinterpret_cast<TUint32*>(aImg->DataBuffer());

	const TInt imgStride = aImg->Stride();

	const TSize imgSize = aImg->Size();

	const CGraphicsContext::TDrawMode drawMode = GcDrawMode(iDrawMode);

	const TInt width = aSrcRect.Width();

	const TInt height = aSrcRect.Height();

	// write scanline starting from top dest row

	TInt destY = aDest.iY;

	// setup pixel reader toolkit

	TPixelBufferReader reader(imgAddr, imgSize, imgStride, imgFormat);

	TDrawDeviceWrapper writer(iDrawDevice, GcDrawMode(iDrawMode));

	//

	// special case when rotation is none

	//

	if (aRotation == DirectGdi::EGraphicsRotationNone)

		{

		TAny* interface = NULL;

		// source and destination format match and using write alpha mode i.e. reduce blit to memcpy

		if (iDrawMode == DirectGdi::EDrawModeWriteAlpha && devFormat == imgFormat)

			{

			TInt err = iDrawDevice->GetInterface(KFastBlit2InterfaceID, interface);

			if (err == KErrNone)

				{

				GRAPHICS_ASSERT_DEBUG(interface, EDirectGdiPanicInvalidPointer);

				MFastBlit2* fblit = static_cast<MFastBlit2*>(interface);

				err = fblit->WriteBitmapBlock(aDest, imgAddr, imgStride, imgSize, aSrcRect);

				if (err == KErrNone)

					{

					return;

					}

				}

			}

		// fallback from MFastBlit2  when source and destination format match. 

		// Note that there was previously an optimization added here that used MFlastBlend if 

		// available, however it did not work correctly for some cases using DrawResource so has been 

		// removed from this code. (A source drawn with OpenGLES on to a target in XRGB_8888 format

		// actually had alpha in the unused channel which was being drawn by MFastBlend)

		if (devFormat == imgFormat)

			{

			for (TInt row=aSrcRect.iTl.iY; row<aSrcRect.iBr.iY; ++row,++destY)

				{

				const TPoint pos(aSrcRect.iTl.iX, row);

				const TUint32* slptr = reader.GetPixelAddr(pos);

				writer.WriteLine(aDest.iX, destY, width, const_cast<TUint32*>(slptr), drawMode);

				}

			return;

			}

		// there is one additional case that can be optimised by eleminating copy when:

		// rotation : none

		// scaling 	: none

		// dst		: opaque

		// src		: has alpha and premultiplied

		// mode 	: PEN

		}

	//

	// generic cases

	//

	// copying is necessary either to convert pixel format or to read back buffer in reverse order 

	// to achieve rotation

	//

	const TInt scanLineBytes = iDrawDevice->ScanLineBytes();

	TUint32* scanLineBuffer = iDrawDevice->ScanLineBuffer();

	TPtr8 scanLineDes(reinterpret_cast<TUint8*>(scanLineBuffer),scanLineBytes,scanLineBytes);

	// if destination is opaque e.g. RGB_565, XRGB_8888 and the source has alpha, it shall blend

	// (because iDrawMode is set to WritePEN)

	// we treat opaque destination as in pre-multiplied format (with alpha value 1), and read the 

	// source in pre-multiplied format too, to enable optimum blending computation i.e.

	// "src + (1-alpha) * dst"

	const TUidPixelFormat readFormat = !PixelFormatUtil::HasAlpha(devFormat) &&

							iDrawMode == DirectGdi::EDrawModePEN ?

							EUidPixelFormatARGB_8888_PRE : devFormat;

	if (aRotation == DirectGdi::EGraphicsRotationNone)

		{

		// general fallback from FastBlendBitmap

		//

		const TInt readLen = width;

		// normal read scanline, left to right

		//

		for (TInt row=aSrcRect.iTl.iY; row<aSrcRect.iBr.iY; ++row,++destY)

			{

			const TPoint pos(aSrcRect.iTl.iX, row);

			reader.GetScanLine(scanLineDes,pos, readLen, readFormat, TPixelBufferReader::EReadHorizontal);

			writer.WriteLine(aDest.iX, destY, readLen, scanLineBuffer, drawMode);

			}

		}

	else if (aRotation == DirectGdi::EGraphicsRotation90)

		{

		const TInt readLen = height;

		// read scanline vertically from bottom to up, and from the lef-most column

		//

		for (TInt col=aSrcRect.iTl.iX; col<aSrcRect.iBr.iX; ++col,++destY)

			{

			const TPoint pos(col, aSrcRect.iBr.iY-1);

			reader.GetScanLine(scanLineDes, pos, readLen, readFormat, TPixelBufferReader::EReadVerticalReverse);

			writer.WriteLine(aDest.iX, destY, readLen, scanLineBuffer, drawMode);

			}

		}

	else if (aRotation == DirectGdi::EGraphicsRotation180)

		{

		const TInt readLen = width;

		// read scanline from right to left, starting from the most bottom scanline

		//

		for (TInt row=aSrcRect.iBr.iY-1; row>=aSrcRect.iTl.iY; --row,++destY)

			{

			const TPoint pos(aSrcRect.iBr.iX-1, row);

			reader.GetScanLine(scanLineDes, pos, readLen, readFormat, TPixelBufferReader::EReadHorizontalReverse);

			writer.WriteLine(aDest.iX, destY, readLen, scanLineBuffer, drawMode);

			}

		}

	else if (aRotation == DirectGdi::EGraphicsRotation270)

		{

		const TInt readLen = height;

		// read scanline vertically top to bottom, and from the right-most column

		//

		for (TInt col=aSrcRect.iBr.iX-1; col>=aSrcRect.iTl.iX; --col,++destY)

			{

			const TPoint pos(col, aSrcRect.iTl.iY);

			reader.GetScanLine(scanLineDes, pos, readLen, readFormat, TPixelBufferReader::EReadVertical);

			writer.WriteLine(aDest.iX, destY, readLen, scanLineBuffer, drawMode);

			}

		}

	}

/**

Draws a rectangular area of resource rotated and/or scaled up/down.

@panic DGDIAdapter 1009, if the pixel format of the draw device is unknown (debug only).

*/

void CSwDirectGdiEngine::DoScaledBlitResource(

		const TRect& aDestRectAbs,

		const CSwDirectGdiImageSourceImpl* aImg,

		const TRect& aSrcRect,

		DirectGdi::TGraphicsRotation aRotation,

		const TRect& aClipRectAbs)

	{

	// pre:

	// aDestRectAbs is the user specified dest rect that has been translated to target coord system. It may

	// be larger/outside the target drawing area. We must not modify this rect as it will be used to

	// determine the scaling factor.

	// aSrcRect is the user specified src rect, it is within the image extent.

	// aClipRectAbs is the intersection of current clipping rect and aDestRectAbs and is within the

	// target drawing area.

	const TUidPixelFormat devFormat = PixelFormatUtil::ConvertToPixelFormat(iDrawDevice->DisplayMode());

	GRAPHICS_ASSERT_DEBUG(devFormat != EUidPixelFormatUnknown, EDirectGdiPanicInvalidDisplayMode);

	const TUint32* imgAddr = reinterpret_cast<TUint32*>(aImg->DataBuffer());

	const TInt imgStride = aImg->Stride();

	const TSize imgSize = aImg->Size();

	const TUidPixelFormat imgFormat = aImg->PixelFormat();

	const CGraphicsContext::TDrawMode drawMode = GcDrawMode(iDrawMode);

	// if destination is opaque e.g. RGB_565, XRGB_8888 and the source has alpha, it shall blend

	// (because iDrawMode is set to WritePEN)

	// we treat opaque destination as in pre-multiplied format (with alpha value 1), and read the 

	// source in pre-multiplied format too, to enable optimum blending computation i.e.

	// "src + (1-alpha) * dst"

	const TUidPixelFormat readFormat = !PixelFormatUtil::HasAlpha(devFormat) &&

							iDrawMode == DirectGdi::EDrawModePEN ?

							EUidPixelFormatARGB_8888_PRE : devFormat;

	TUint32* scanLineBuffer = iDrawDevice->ScanLineBuffer();

	const TInt scanLineBytes = iDrawDevice->ScanLineBytes();

	TPtr8 scanLineDes(reinterpret_cast<TUint8*>(scanLineBuffer), scanLineBytes, scanLineBytes);

	// setup pixel reader toolkit

	//

	TPixelBufferReader reader(imgAddr, imgSize, imgStride, imgFormat);

	TDrawDeviceWrapper writer(iDrawDevice, GcDrawMode(iDrawMode));

	if (aRotation == DirectGdi::EGraphicsRotationNone)

		{		

		// Note that there was previously an optimization added here that used MFlastBlend if 

		// available, however it did not work correctly for some cases using DrawResource so has been 

		// removed from this code. (A source drawn with OpenGLES on to a target in XRGB_8888 format

		// actually had alpha in the unused channel which was being drawn by MFastBlend)

		//

		const TInt srcLen = aSrcRect.Width();

		const TInt destLen = aDestRectAbs.Width();

		const TInt clipLen = aClipRectAbs.Width();

		const TInt clipPos = aClipRectAbs.iTl.iX - aDestRectAbs.iTl.iX;

		// setup DDA for scaling in Y direction based on src rect and dst rect size

		// scaling in X direction will be done by GetScaledScanLine()

		//

		// setup Y scaler and start from top-left of src/dest to bottom-right of src/dest

		TLinearDDA yScaler;

		yScaler.Construct(

				TPoint(aSrcRect.iTl.iY, aDestRectAbs.iTl.iY),

				TPoint(aSrcRect.iBr.iY, aDestRectAbs.iBr.iY),

				TLinearDDA::ELeft);

		// move to position of current clip rect top row as the start of dest Y

		TInt srcY;	

		yScaler.JumpToYCoord2(srcY, aClipRectAbs.iTl.iY);

		// yPos contains mapping between src Y (TPoint.iX) and dest Y (TPoint.iY)

		TPoint yPos(srcY, aClipRectAbs.iTl.iY);

		// write to target from top to bottom

		//

		while (yPos.iY < aClipRectAbs.iBr.iY)

			{

			reader.GetScaledScanLine(scanLineDes,

									TPoint(aSrcRect.iTl.iX, yPos.iX),	// src X and Y

									clipPos,							// clipped dest X

									clipLen,

									destLen,

									srcLen,

									readFormat,

									TPixelBufferReader::EReadHorizontal);

			// use dest Y here

			writer.WriteLine(aClipRectAbs.iTl.iX, yPos.iY, clipLen, scanLineBuffer, drawMode);

			// move scaler one position

			yScaler.NextStep(yPos);

			};

		}

	else if (aRotation == DirectGdi::EGraphicsRotation90)

		{

		// we're going to read source vertically from bottom to up, swap relevant bits and pieces

		// dst-width corresponds to src-height

		// dst-height corresponds to src-width

		//

		const TInt srcLen = aSrcRect.Height();

		const TInt destLen = aDestRectAbs.Width();

		// the following doesn't change, the amount of pixel read (vertically) will be based on

		// the drawing area witdh i.e. clip width

		//

		const TInt clipLen = aClipRectAbs.Width();

		// offset into read area doesn't change either, it will be translated into some Y position

		// from bottom row of source image

		const TInt clipPos = aClipRectAbs.iTl.iX - aDestRectAbs.iTl.iX;

		// setup DDA for scaling in src X direction based on src rect and dst rect size

		// scaling in src Y direction will be done by GetScaledScanLine(EReadVerticalReverse)

		//

		// scaler map dest Y to src X because of 90 degre rotation

		// start from  top row dest, left-most column src to bottom row dest, right-most column src

		//

		TLinearDDA xScaler;

		xScaler.Construct(

				TPoint(aSrcRect.iTl.iX, aDestRectAbs.iTl.iY),

				TPoint(aSrcRect.iBr.iX, aDestRectAbs.iBr.iY),

				TLinearDDA::ELeft);

		// move to position of current clip rect top row as the start of src X

		TInt srcX;	

		xScaler.JumpToYCoord2(srcX, aClipRectAbs.iTl.iY);

		// xPos contains mapping between src X (TPoint.iX) and dest Y (TPoint.iY)

		TPoint xPos(srcX, aClipRectAbs.iTl.iY);

		// write to target from top to bottom

		//

		while (xPos.iY < aClipRectAbs.iBr.iY)

			{

			// read pixel vertically from left column to right

			reader.GetScaledScanLine(scanLineDes,

									TPoint(xPos.iX, aSrcRect.iBr.iY - 1),	// src X, src Y

									clipPos,								// distance from bottom source

									clipLen,

									destLen,

									srcLen,

									readFormat,

									TPixelBufferReader::EReadVerticalReverse);

			// use dest Y here

			writer.WriteLine(aClipRectAbs.iTl.iX, xPos.iY, clipLen, scanLineBuffer, drawMode);

			// move scaler one position

			xScaler.NextStep(xPos);

			}

		}

	else if (aRotation == DirectGdi::EGraphicsRotation180)

		{

		const TInt srcLen = aSrcRect.Width();

		const TInt destLen = aDestRectAbs.Width();

		const TInt clipLen = aClipRectAbs.Width();

		// clipPos doesn't need to be inverted (using iBr.iX) because the yScaler below

		// will do that for us (by stepping backward)

		//

		const TInt clipPos = aClipRectAbs.iTl.iX - aDestRectAbs.iTl.iX;

		// setup DDA for scaling in Y direction based on src rect and dst rect size

		// scaling in X direction will be done by GetScaledScanLine()

		//

		// setup Y scaler and start from bottom-right of src/dest to top-left of src/dest

		// to do backward stepping (src Y inversion)

		TLinearDDA yScaler;

		yScaler.Construct(

				// we starting from 1st pixel from bottom of source image, we need to

				// step back 1 position as bottom-row coord is beyond the last pixel in the source rect

				TPoint(aSrcRect.iBr.iY - 1, aDestRectAbs.iTl.iY),

				TPoint(aSrcRect.iTl.iY - 1, aDestRectAbs.iBr.iY),

				TLinearDDA::ELeft);

		// move to position of current clip rect top row as the start of dest Y

		// which will calculate inverted src Y distance from bottom of source rectangle

		TInt invSrcY;	

		yScaler.JumpToYCoord2(invSrcY, aClipRectAbs.iTl.iY);

		// yPos contains mapping between inverted src Y (TPoint.iX) and dest Y (TPoint.iY)

		TPoint yPos(invSrcY, aClipRectAbs.iTl.iY);

		// write to target from top to bottom

		//

		while (yPos.iY < aClipRectAbs.iBr.iY)

			{

			// read scanline from righ to left i.e. use aSrcRect.iBr.iX-1 (last column)

			// as starting src X value

			reader.GetScaledScanLine(scanLineDes,

									TPoint(aSrcRect.iBr.iX - 1, yPos.iX),	// src X and inverted src Y

									clipPos,								// clipped dest X

									clipLen,

									destLen,

									srcLen,

									readFormat,

									TPixelBufferReader::EReadHorizontalReverse);

			// use dest Y here

			writer.WriteLine(aClipRectAbs.iTl.iX, yPos.iY, clipLen, scanLineBuffer, drawMode);

			// move scaler one position

			yScaler.NextStep(yPos);

			}

		}

	else if(aRotation == DirectGdi::EGraphicsRotation270)

		{

		// we're going to read source vertically from top to bottom, swap relevant bits and pieces

		// dst-width corresponds to src-height

		// dst-height corresponds to src-width

		const TInt srcLen = aSrcRect.Height();

		const TInt destLen = aDestRectAbs.Width();

		// the following doesn't change, the amount of pixel read (vertically) will be based on

		// the drawing area witdh i.e. clip width

		const TInt clipLen = aClipRectAbs.Width();

		// offset into read area doesn't change either, it will be translated into some Y position

		// from top row of source image

		const TInt clipPos = aClipRectAbs.iTl.iX - aDestRectAbs.iTl.iX;

		// setup DDA for scaling in src X direction based on src rect and dst rect size

		// scaling in src Y direction will be done by GetScaledScanLine(EReadVertical)

		//

		// scaler map dest Y to src X because of 270 degre rotation

		// start from top row dest, right-most column src to bottom row dest, left-most column src

		TLinearDDA xScaler;

		xScaler.Construct(

				// decrement 1 pixel to get into last pixel within source

				TPoint(aSrcRect.iBr.iX - 1, aDestRectAbs.iTl.iY),

				TPoint(aSrcRect.iTl.iX - 1, aDestRectAbs.iBr.iY),

				TLinearDDA::ELeft);

		// move to position of current clip rect top row as the start of src X

		TInt srcX;	

		xScaler.JumpToYCoord2(srcX, aClipRectAbs.iTl.iY);

		// xPos contains mapping between src X (TPoint.iX) and dest Y (TPoint.iY)

		TPoint xPos(srcX, aClipRectAbs.iTl.iY);

		// write to target from top to bottom

		//

		while (xPos.iY < aClipRectAbs.iBr.iY)

			{

			// read pixel vertically from left column to right

			reader.GetScaledScanLine(scanLineDes,

									TPoint(xPos.iX, aSrcRect.iTl.iY),		// src X, src Y

									clipPos,								// distance from bottom source

									clipLen,

									destLen,

									srcLen,

									readFormat,

									TPixelBufferReader::EReadVertical);

			// use dest Y here

			writer.WriteLine(aClipRectAbs.iTl.iX, xPos.iY, clipLen, scanLineBuffer, drawMode);

			// move scaler one position

			xScaler.NextStep(xPos);

			}

		}

	}