// Copyright (c) 2007-2009 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:

 //

 const TUint32 KRBMask = 0x00ff00ff;

 const TUint32 KAGMask = 0xff00ff00;

 const TUint32 KGMask  = 0x0000ff00;

 //Algoriths for Premultiplied alpha screenmode/pixel format.

 inline TUint32 PMAPixelBlend(TUint32 aDestPixel, TUint32 aSrcPixel, TUint8 aMask)

 	{

 	if(aMask)

 		{

 		if(aMask == 0xff) // opaque, so unchanged

 			{

 			return aSrcPixel;

 			}

 		else

 			{

 			return PMABlend_noChecks(aDestPixel, aSrcPixel, aMask);

 			}

 		}

 	 else // completely transparent

 		{

 		return aDestPixel;

  		}

 	}

 inline TUint32 PMAPixelBlend(TUint32 aDestPixel, TUint32 aSrcPixel)

 	{

 	TUint8 mask = (TUint8)(aSrcPixel >> 24);

 	return PMAPixelBlend(aDestPixel, aSrcPixel, mask);

 	}

 inline TUint32 PMABlend_noChecks(TUint32 aDestPixel, TUint32 aSrcPixel, TUint8 aMaskingFactor)

 	{

 	TUint32 src_c = aSrcPixel & KRBMask;

 	TUint32 dst_c = aDestPixel  & KRBMask;

 	const TUint32 mask = 0x0100 - aMaskingFactor;

 	dst_c = (src_c +  ((mask * dst_c)>>8)) & KRBMask;

 	src_c = (aSrcPixel & KAGMask)>>8;

 	TUint32 dst_ag = (aDestPixel & KAGMask)>>8;

 	dst_c |= ((src_c +  ((mask * dst_ag)>>8)) & KRBMask)<<8;

 	return dst_c;

 	}

 inline void PMABlend_noChecksInplace(TUint32& aDest_io, const TUint32& aSrcPixel, TUint8 aMaskingFactor)

 	{

 	TUint32 src_c = aSrcPixel & KRBMask;

 	TUint32 dst_ag = (aDest_io & KAGMask) >> 8;

 	aDest_io = aDest_io  & KRBMask;

 	const TUint32 mask = 0x0100 - aMaskingFactor;

 	aDest_io = (src_c +  ((mask * aDest_io) >> 8)) & KRBMask;

 	src_c = (aSrcPixel & KAGMask) >> 8;

 	aDest_io |= ((src_c +  ((mask * dst_ag) >> 8)) & KRBMask)<<8;

 	}

 inline void PMAInplaceBlend(TUint32& aDest_io, TUint32& aSrc_in)

 	{

 	TUint8 mask = (TUint8)(aSrc_in >> 24);

 	if(mask)

 		{

 		if(mask == 0xff) // opaque, so dst = src.

 			{

 			aDest_io = aSrc_in;

 			}

 		else

 			{

 			PMABlend_noChecksInplace(aDest_io, aSrc_in, mask);

 			}

 		}

 	//else src completely transparent, so dst unchanged.

 	}

 inline TUint32 NonPMA2PMAPixel(TUint32 aPixel)

 	{

 	TUint8 tA = (TUint8)(aPixel >> 24);

 	if (tA==0)

 		{ 

 		return 0;

 		}

 	if (tA==0xff) 

 		{

 		return aPixel;

 		}

 	// Use a bias value of 128 rather than 255, but also add 1/256 of the numerator 

 	// before dividing the sum by 256.

 	TUint32 tap1=tA+1;

 	TUint32 scaledRB = (aPixel & KRBMask) * tap1;

 	TUint32 scaledG = (aPixel & KGMask ) * tap1;

 	return (aPixel & 0xff000000) | ((scaledRB>>8) & KRBMask) | ((scaledG>>8)& KGMask);

 	}

 inline TUint32 PMA2NonPMAPixel(TUint32 aPixel, const TUint16* aNormTable)

 	{

 	TUint8 alpha = (TUint8)(aPixel >> 24);

 	if (alpha==0)

 		{ 

 		return 0;

 		}

 	if (alpha==0xff) 

 		{

 		return aPixel;

 		}

 	TUint16 norm = aNormTable[alpha];

 	TUint32 norm_rb = (((aPixel & KRBMask) * norm) >> 8) & KRBMask;

 	TUint32 norm_g =  (((aPixel & KGMask ) * norm) >> 8) & KGMask;

 	return ((aPixel & 0xff000000) | norm_rb | norm_g);

 	}

 inline void Convert2PMA(TUint32& aInOutValue)

 	{

 	aInOutValue = NonPMA2PMAPixel(aInOutValue);

 	}

 inline void Convert2NonPMA(TUint32& aInOutValue, const TUint16* aNormTable)

 	{

 	aInOutValue = PMA2NonPMAPixel(aInOutValue, aNormTable);

 	}