diff -r e1b950c65cb4 -r 837f303aceeb epoc32/include/graphics/blendingalgorithms.h --- a/epoc32/include/graphics/blendingalgorithms.h Wed Mar 31 12:27:01 2010 +0100 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,130 +0,0 @@ -// Copyright (c) 2006-2009 Nokia Corporation and/or its subsidiary(-ies). -// All rights reserved. -// This component and the accompanying materials are made available -// under the terms of the License "Symbian Foundation License v1.0" to Symbian Foundation members and "Symbian Foundation End User License Agreement v1.0" to non-members -// which accompanies this distribution, and is available -// at the URL "http://www.symbianfoundation.org/legal/licencesv10.html". -// -// Initial Contributors: -// Nokia Corporation - initial contribution. -// -// Contributors: -// -// Description: -// - -#ifndef __BLENDINGALGORITHMS_H__ -#define __BLENDINGALGORITHMS_H__ - -#include -/** -@file -@internalTechnology -*/ - -/** Premultiplied Alpha (PMA) Blending algorithm. -Assumes src and target pixels are in PMA format (i.e., the color channels are already multiplied -with the alpha channel. -Blending Equations: -Cd' = Cs + ((255 - As) * Cd)/255 -Ad' = As + ((255 - As) * Ad)/255 -where Cd' and Ad' are destination values for color and alpha channels respectively, after blending, -Cd and Ad are destination values before blending, and Cs and As are source values (color and -alpha values respectively). -Optimisations: -Use of 256 instead of 255 converts the division to shift (faster). -Red and Blue channels are calculated together in one 32 bit operation. -Alpha and Green channels are calculated in the same way. However, due the -position of these channels within the pixel format, an extra shift is required. -The equations used are: -Cd' = Cs + (((0x100 - As) * Cd)>>8) -Ad' = As + (((0x100 - As) * Ad)>>8) -For the results to not overflow, it is required that the value of any of the color channels -is no greater than the alpha channel, which is what is exepected of pma format. -It is also assumed that the aMask is equal to source alpha. -@param aDestPixel The destination pixel value. -@param aSrcPixel The source pixel value. -@param aMask The source alpha. It is assumed to be same as source alpha. -@return the alpha-blended pixel (within the PMA space). -@internalTechnology -@released -*/ -inline TUint32 PMAPixelBlend(TUint32 aDestPixel, TUint32 aSrcPixel, TUint8 aMask); - -/** Same as inline TUint32 PMAPixelBlend(TUint32 aDestPixel, TUint32 aSrcPixel, TUint8 aMask) -Calls inline TUint32 PMAPixelBlend(TUint32 aDestPixel, TUint32 aSrcPixel, TUint8 aMask), with aMask -extracted from the source pixel. -@see PMAPixelBlend(TUint32 aDestPixel, TUint32 aSrcPixel, TUint8 aMask) -@internalTechnology -@released -*/ -inline TUint32 PMAPixelBlend(TUint32 aDestPixel, TUint32 aSrcPixel); - -/** -Does the premultiplied alpha blend, but does not check for any pre/post conditions. -Please DO NOT Add any optimisations to check for these conditions in this code! -@internalTechnology -@released -*/ -inline TUint32 PMABlend_noChecks(TUint32 aDestPixel, TUint32 aSrcPixel, TUint8 aMaskingFactor); - -/** -The version of PMABlend_noChecks which does the blending in place. -@internalTechnology -@released -*/ -inline void PMABlend_noChecksInplace(TUint32& aDest_io, TUint32& aSrcPixel,TUint8& aMaskingFactor); - -/** -The in-place version of the PMAPixelBlend algorithm -@internalTechnology -@released -*/ -inline void PMAInplaceBlend(TUint32& aDest_io, TUint32& aSrc_in); -/** -Premultiplies the color channel values with the Alpha channel value. -Alpha value remains unchanged. An approximation is used in the operation where the division -by 255 is approximated by a shift-by-8-bits operation (i.e. division by 256). -@param aPixel The 32 bit pixel value to be pre-multiplied. -@return The PMA value. -@internalTechnology -@released -*/ -inline TUint32 NonPMA2PMAPixel(TUint32 aPixel); - -/** -Divives the PMA pixel color channels with the Alpha value, to convert them to non-PMA format. -Alpha value remains unchanged. -@param aPixel the premultiplied 32 bit pixel value. -@param aNormTable The lookup table used to do the normalisation (the table converts the division - to multiplication operation). - The table is usually obtainable by a call to the method: - PtrTo16BitNormalisationTable, which is defined in lookuptable.dll(.lib). - The lookup table for normalised alpha is compluted using this equation: - Table[index] = (255*256) / index (where index is an 8 bit value). -@return The NON-PMA 32 bit pixel value. -@internalTechnology -@released -*/ -inline TUint32 PMA2NonPMAPixel(TUint32 aPixel, const TUint16* aNormTable); - -/** -In-place version of NonPMA2PMAPixel. -@see NonPMA2PMAPixel -@internalTechnology -@released -*/ -inline void Convert2PMA(TUint32& aInOutValue); - -/** -In-place version of PMA2NonPMAPixel -@see PMA2NonPMAPixel -@internalTechnology -@released -*/ -inline void Convert2NonPMA(TUint32& aInOutValue, const TUint16* aNormTable); - - -#include - -#endif //__BLENDINGALGORITHMS_H__