diff -r 000000000000 -r 5d03bc08d59c graphicsdeviceinterface/directgdiadaptation/hwsrc/blendingalgorithms.inl --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/graphicsdeviceinterface/directgdiadaptation/hwsrc/blendingalgorithms.inl Tue Feb 02 01:47:50 2010 +0200 @@ -0,0 +1,134 @@ +// 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; + +const TUint16 NormalisationTable[256] = { + 0,65280,32640,21760,16320,13056,10880,9326,8160,7254,6528, + 5935,5440,5022,4663,4352,4080,3840,3627,3436,3264, + 3109,2968,2839,2720,2612,2511,2418,2332,2252,2176, + 2106,2040,1979,1920,1866,1814,1765,1718,1674,1632, + 1593,1555,1519,1484,1451,1420,1389,1360,1333,1306, + 1280,1256,1232,1209,1187,1166,1146,1126,1107,1088, + 1071,1053,1037,1020,1005,990,975,960,947,933, + 920,907,895,883,871,859,848,837,827,816, + 806,797,787,778,768,760,751,742,734,726, + 718,710,702,695,688,680,673,667,660,653, + 647,640,634,628,622,616,611,605,599,594, + 589,583,578,573,568,563,558,554,549,544, + 540,536,531,527,523,519,515,510,507,503, + 499,495,491,488,484,480,477,474,470,467, + 463,460,457,454,451,448,445,442,439,436, + 433,430,427,424,422,419,416,414,411,408, + 406,403,401,399,396,394,391,389,387,384, + 382,380,378,376,374,371,369,367,365,363, + 361,359,357,355,353,351,350,348,346,344, + 342,340,339,337,335,334,332,330,329,327, + 325,324,322,320,319,317,316,314,313,311, + 310,308,307,306,304,303,301,300,299,297, + 296,295,293,292,291,289,288,287,286,284, + 283,282,281,279,278,277,276,275,274,272, + 271,270,269,268,267,266,265,264,263,262, + 261,260,259,258,256, +}; + +//Algoriths for Premultiplied alpha screenmode/pixel format. + +/** +Blend A over B. From Porter & Duff: +C = CaFa+CbFb, where Ca = aSrcPixel, Cb = aDest_io, Fa = 1, Fb=(1-Alpha(a)) +C = Ca+Cb(1-Alpha(a)) + +@param aDestPixel Destination pixel. +@param aSrcPixel Source pixel. +@param aMaskingFactor Alpha channel of aSrcPixel. +*/ +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 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 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) + { + TUint8 alpha = (TUint8)(aPixel >> 24); + if (alpha==0) + { + return 0; + } + if (alpha==0xff) + { + return aPixel; + } + TUint16 norm = NormalisationTable[alpha]; + TUint32 norm_rb = (((aPixel & KRBMask) * norm) >> 8) & KRBMask; + TUint32 norm_g = (((aPixel & KGMask ) * norm) >> 8) & KGMask; + return ((aPixel & 0xff000000) | norm_rb | norm_g); + } +