Symaptic: os/graphics/fbs/fontandbitmapserver/sfbs/BITCOMP.CPP@bde4ae8d615e

     1 // Copyright (c) 1995-2009 Nokia Corporation and/or its subsidiary(-ies).

     2 // All rights reserved.

     3 // This component and the accompanying materials are made available

     4 // under the terms of "Eclipse Public License v1.0"

     5 // which accompanies this distribution, and is available

     6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".

     7 //

     8 // Initial Contributors:

     9 // Nokia Corporation - initial contribution.

    10 //

    11 // Contributors:

    12 //

    13 // Description:

    14 //

    16 #include <f32file.h>

    17 #include <s32file.h>

    18 #include <fbs.h>

    19 #include <bitmap.h>

    20 #include "UTILS.H"

    21 #include <e32hashtab.h>

    23 GLREF_C void Panic(TFbsPanic aPanic);

    25 void CBitwiseBitmap::DoInternalizeCompressedDataL(RReadStream& aStream,TInt aSrceSizeInBytes,TUint32* aBase,TBitmapfileCompression aCompression)

    26 	{

    27 	TInt destSizeInBytes = iHeader.iSizeInPixels.iHeight * iByteWidth;

    28 	TUint8* destPtr = (TUint8*)aBase;

    30 	// try to allocate memory for the compressed bitmap

    31 	TUint8* decompressionBuffer = (TUint8*)User::Alloc(aSrceSizeInBytes);

    33 	if (decompressionBuffer)

    34 		{

    35 		// read the compressed bitmap, then decompress

    36 		CleanupStack::PushL(decompressionBuffer);

    37 		aStream.ReadL(decompressionBuffer,aSrceSizeInBytes);

    38 		switch (aCompression)

    39 			{

    40 		case EByteRLECompression:

    41 			DoDecompressByteData(destPtr,destSizeInBytes,decompressionBuffer,aSrceSizeInBytes);

    42 			break;

    43 		case ETwelveBitRLECompression:

    44 			DoDecompressTwelveBitData(destPtr,destSizeInBytes,decompressionBuffer,aSrceSizeInBytes);

    45 			break;

    46 		case ESixteenBitRLECompression:

    47 			DoDecompressSixteenBitData(destPtr,destSizeInBytes,decompressionBuffer,aSrceSizeInBytes);

    48 			break;

    49 		case ETwentyFourBitRLECompression:

    50 			DoDecompressTwentyFourBitData(destPtr,destSizeInBytes,decompressionBuffer,aSrceSizeInBytes);

    51 			break;

    52 		case EThirtyTwoUBitRLECompression:

    53 			DoDecompressThirtyTwoUBitData(destPtr,destSizeInBytes,decompressionBuffer,aSrceSizeInBytes);

    54 			break;

    55 		case EThirtyTwoABitRLECompression:

    56 			DoDecompressThirtyTwoABitData(destPtr,destSizeInBytes,decompressionBuffer,aSrceSizeInBytes);

    57 			break;

    58 		default:

    59 			break;

    60 			}

    61 		CleanupStack::PopAndDestroy(); // decompressionBuffer

    62 		return;

    63 		}

    65 	// not enough heap to pre-load the source bitmap

    66 	switch (aCompression)

    67 		{

    68 	case EByteRLECompression:

    69 		DoDecompressByteDataAltL(aStream,aSrceSizeInBytes,aBase);

    70 		break;

    71 	case ETwelveBitRLECompression:

    72 		DoDecompressTwelveBitDataAltL(aStream,aSrceSizeInBytes,aBase);

    73 		break;

    74 	case ESixteenBitRLECompression:

    75 		DoDecompressSixteenBitDataAltL(aStream,aSrceSizeInBytes,aBase);

    76 		break;

    77 	case ETwentyFourBitRLECompression:

    78 		DoDecompressTwentyFourBitDataAltL(aStream,aSrceSizeInBytes,aBase);

    79 		break;

    80 	case EThirtyTwoUBitRLECompression:

    81 		DoDecompressThirtyTwoUBitDataAltL(aStream,aSrceSizeInBytes,aBase);

    82 		break;

    83 	case EThirtyTwoABitRLECompression:

    84 		DoDecompressThirtyTwoABitDataAltL(aStream,aSrceSizeInBytes,aBase);

    85 		break;

    86 	default:

    87 		break;

    88 		}

    89 	}

    91 void CBitwiseBitmap::DoDecompressByteData(TUint8* aDestBuffer,TInt aDestSize,TUint8* aSrceBuffer,TInt aSrceSize)

    92 	{

    93 	TUint8* srcePtr = aSrceBuffer;

    94 	TUint8* destPtr = aDestBuffer;

    95 	TUint8* srcePtrLimit = aSrceBuffer + aSrceSize;

    96 	TUint8* destPtrLimit = aDestBuffer + aDestSize;

    98 	while (srcePtr < srcePtrLimit && destPtr < destPtrLimit)

    99 		{

   100 		TInt8 count = *srcePtr++;

   102 		if (count >= 0)

   103 			{

   104 			const TInt numBytes = Min(count + 1, destPtrLimit - destPtr);

   105 			Mem::Fill(destPtr,numBytes,*srcePtr++);

   106 			destPtr += numBytes;

   107 			}

   108 		else

   109 			{

   110 			const TInt numBytes = Min(-count, destPtrLimit - destPtr);

   111 			Mem::Copy(destPtr,srcePtr,numBytes);

   112 			srcePtr += numBytes;

   113 			destPtr += numBytes;

   114 			}

   115 		}

   116 	__ASSERT_DEBUG(srcePtr == srcePtrLimit && destPtr == destPtrLimit,Panic(EFbsBitmapDecompressionError));

   117 	}

   119 void CBitwiseBitmap::DoDecompressByteDataAltL(RReadStream& aStream,TInt aSrceSizeInBytes,TUint32* aBase)

   120 	{

   121 	TInt destSizeInBytes = iHeader.iSizeInPixels.iHeight * iByteWidth;

   122 	TUint8* destPtr = (TUint8*)aBase;

   123 	TUint8* destPtrLimit = destPtr + destSizeInBytes;

   125 	while(aSrceSizeInBytes > 0 && destPtr < destPtrLimit)

   126 		{

   127 		TInt8 count = aStream.ReadInt8L();

   128 		aSrceSizeInBytes--;

   130 		if (count >= 0)

   131 			{

   132 			const TInt numBytes = Min(count + 1, destPtrLimit - destPtr);

   133 			TUint8 value = aStream.ReadUint8L();

   134 			aSrceSizeInBytes--;

   135 			Mem::Fill(destPtr,numBytes,value);

   136 			destPtr += numBytes;

   137 			}

   138 		else

   139 			{

   140 			const TInt numBytes = Min(-count, destPtrLimit - destPtr);

   141 			aStream.ReadL(destPtr,numBytes);

   142 			aSrceSizeInBytes -= numBytes;

   143 			destPtr += numBytes;

   144 			}

   145 		}

   146 	__ASSERT_DEBUG(aSrceSizeInBytes == 0 && destPtr == destPtrLimit,Panic(EFbsBitmapDecompressionError));

   147 	}

   149 /** Fills the 32bit pixels into the destination pointer

   150 This method uses the concept of Duff's Device

   151 @param aDestPtr32 pointer to 32bit destination buffer.

   152 @param aCount Number of 32bit pixels to be copied.

   153 @param aValue32 32bit pixel data. */

   154 void CBitwiseBitmap::BitmapFill32(TUint32* aDestPtr32, TInt aCount, TUint32 aValue32)

   155 	{

   156 	__ASSERT_DEBUG(aCount > 0, Panic(EFbsBitmapDecompressionError));

   157 	if (aCount > 0)

   158 		{ // for performance loop is unrolled, using "Duff's Device" pattern

   159 		TInt blocksOf16 = aCount / 16;	// number of blocks of 16 full words to write

   160 		// the first iteration writes 1 to 15 words

   162 		switch (aCount & 0x0f)

   163 			{ // note that case statements intentionally cascade

   164 		case 0:

   165 write16dblPixels:	// second and subsequent iterations always write 16 words

   166 			--blocksOf16;

   167 			*aDestPtr32++ = aValue32;

   168 			//coverity [fallthrough]

   169 		case 15:

   170 			*aDestPtr32++ = aValue32;

   171 			//coverity [fallthrough]

   172 		case 14:

   173 			*aDestPtr32++ = aValue32;

   174 			//coverity [fallthrough]

   175 		case 13:

   176 			*aDestPtr32++ = aValue32;

   177 			//coverity [fallthrough]

   178 		case 12:

   179 			*aDestPtr32++ = aValue32;

   180 			//coverity [fallthrough]

   181 		case 11:

   182 			*aDestPtr32++ = aValue32;

   183 			//coverity [fallthrough]

   184 		case 10:

   185 			*aDestPtr32++ = aValue32;

   186 			//coverity [fallthrough]

   187 		case 9:

   188 			*aDestPtr32++ = aValue32;

   189 			//coverity [fallthrough]

   190 		case 8:

   191 			*aDestPtr32++ = aValue32;

   192 			//coverity [fallthrough]

   193 		case 7:

   194 			*aDestPtr32++ = aValue32;

   195 			//coverity [fallthrough]

   196 		case 6:

   197 			*aDestPtr32++ = aValue32;

   198 			//coverity [fallthrough]

   199 		case 5:

   200 			*aDestPtr32++ = aValue32;

   201 			//coverity [fallthrough]

   202 		case 4:

   203 			*aDestPtr32++ = aValue32;

   204 			//coverity [fallthrough]

   205 		case 3:

   206 			*aDestPtr32++ = aValue32;

   207 			//coverity [fallthrough]

   208 		case 2:

   209 			*aDestPtr32++ = aValue32;

   210 			//coverity [fallthrough]

   211 		case 1:

   212 			*aDestPtr32++ = aValue32;

   213 			}

   215 		if (blocksOf16 > 0)

   216 			{

   217 			goto write16dblPixels;

   218 			}

   219 		}

   220 	}

   222 /** Fills the 16bit pixels into the destination pointer

   223 This method uses the concept of Duff's Device

   224 @param aDestPtr16 pointer to 16bit destination buffer.

   225 @param aCount Number of 16bit pixels to be copied.

   226 @param aValue16 16bit pixel data. */

   227 inline void CBitwiseBitmap::BitmapFill16(TUint16* aDestPtr16, TInt aCount, TUint16 aValue16)

   228 	{

   229 	// Call the 32-bit fill method if there at least 8 pixels to fill

   230 	if (aCount >= 8)

   231 		{

   232 		// first pixel is on half word address?

   233 		if (reinterpret_cast<TUint32>(aDestPtr16) & 2)

   234 			{

   235 			*aDestPtr16++ = aValue16;

   236 			--aCount;

   237 			}

   239 		// destPtr16 is now full Word aligned

   240 		const TInt countDoublePixels = aCount / 2;

   241 		TUint32* destPtr32 = (TUint32*) aDestPtr16;

   242 		BitmapFill32(destPtr32, countDoublePixels, (aValue16 << 16) | aValue16);

   244 		aCount -= countDoublePixels * 2;

   245 		if (aCount == 1)

   246 			{ // last pixel is on a half-word

   247 			aDestPtr16 += countDoublePixels * 2;

   248 			*aDestPtr16++ = aValue16;

   249 			}

   250 		}

   251 	else

   252 		{ // less than 8 pixels to fill

   253 		switch (aCount)

   254 			{ // note that case statements intentionally cascade

   255 		case 7:

   256 			*aDestPtr16++ = aValue16;

   257 		case 6:

   258 			*aDestPtr16++ = aValue16;

   259 		case 5:

   260 			*aDestPtr16++ = aValue16;

   261 		case 4:

   262 			*aDestPtr16++ = aValue16;

   263 		case 3:

   264 			*aDestPtr16++ = aValue16;

   265 		case 2:

   266 			*aDestPtr16++ = aValue16;

   267 		case 1:

   268 			*aDestPtr16++ = aValue16;

   269 		case 0: // nothing to do

   270 			;

   271 			}

   272 		}

   273 	}

   275 void CBitwiseBitmap::DoDecompressTwelveBitData(TUint8* aDestBuffer,TInt aDestSize,TUint8* aSrceBuffer,TInt aSrceSize)

   276 	{

   277 	TUint16* srcePtr = (TUint16*)aSrceBuffer;

   278 	TUint16* destPtr = (TUint16*)aDestBuffer;

   279 	TUint16* srcePtrLimit = srcePtr + (aSrceSize / 2);

   280 	TUint16* destPtrLimit = destPtr + (aDestSize / 2);

   282 	while (srcePtr < srcePtrLimit && destPtr < destPtrLimit)

   283 		{

   284 		TUint16 value = *srcePtr++;

   285 		TInt count = Min(value >> 12, destPtrLimit - destPtr);

   286 		value &= 0x0fff;

   288 		while (count >= 0)

   289 			{

   290 			*destPtr++ = value;

   291 			count--;

   292 			}

   293 		}

   295 	__ASSERT_DEBUG(srcePtr == srcePtrLimit && destPtr == destPtrLimit,Panic(EFbsBitmapDecompressionError));

   296 	}

   298 void CBitwiseBitmap::DoDecompressTwelveBitDataAltL(RReadStream& aStream,TInt aSrceSizeInBytes,TUint32* aBase)

   299 	{

   300 	TInt destSizeInBytes = iHeader.iSizeInPixels.iHeight * iByteWidth;

   301 	TUint16* destPtr = (TUint16*)aBase;

   302 	TUint16* destPtrLimit = destPtr + (destSizeInBytes / 2);

   304 	while(aSrceSizeInBytes > 0 && destPtr < destPtrLimit)

   305 		{

   306 		TUint16 value = aStream.ReadUint16L();

   307 		TInt count = Min(value >> 12, destPtrLimit - destPtr);

   308 		value &= 0x0fff;

   309 		aSrceSizeInBytes -= 2;

   311 		while (count >= 0)

   312 			{

   313 			*destPtr++ = value;

   314 			count--;

   315 			}

   316 		}

   317 	__ASSERT_DEBUG(aSrceSizeInBytes == 0 && destPtr == destPtrLimit,Panic(EFbsBitmapDecompressionError));

   318 	}

   320 /** The function decodes 24-bit compressed buffer to the 16-bit stream with unused top bytes by using RLE compression algorithm*/

   321 void CBitwiseBitmap::DoDecompressSixteenBitData(TUint8* aDestBuffer,TInt aDestSize,TUint8* aSrceBuffer,TInt aSrceSize)

   322 	{

   323 	__ASSERT_DEBUG((reinterpret_cast<TUint32>(aDestBuffer) & 0x2)==0,Panic(EFbsBitmapDecompressionError)); // make sure the start address is half-word aligned

   324 	__ASSERT_DEBUG((aDestSize & 0x2)==0,Panic(EFbsBitmapDecompressionError)); // make sure the start address is half-word aligned

   326 	TUint8* srcePtr8 = aSrceBuffer; // pointer to compressed source Byte(8-bit) stream

   327 	TUint16* destPtr16 = reinterpret_cast<TUint16*>(aDestBuffer); //pointer to uncompressed destination HalfWord(16-bit) pixel stream

   328 	TUint8* srcePtrLimit8 = aSrceBuffer + aSrceSize; //maximum number of compressed source bytes

   329 	TUint16* destPtrLimit16 = reinterpret_cast<TUint16*>(aDestBuffer + aDestSize); //maximum number of uncompressed destination pixel stream

   330 	const TInt KPixelSize = 2; //number of bytes of the source stream that is to be considered as one Pixel

   332 	while (srcePtr8 < srcePtrLimit8 && destPtr16 < destPtrLimit16)

   333 		{

   334 		TInt8 count = *srcePtr8++; //number of pixels to be retrieved from the source stream

   336 		if (count >= 0) //repeating number of pixels

   337 			{

   338 			const TInt numPixels = 1 + Min(count, (destPtrLimit16 - destPtr16));

   339 			const TUint8 lowByte = *srcePtr8++;

   340 			const TUint8 highByte = *srcePtr8++;

   341 			const TUint16 pixel = highByte<<8 | lowByte; //Pixel buffer which needs to be stored in destPtr16

   343 			BitmapFill16(destPtr16, numPixels, pixel);

   344 			destPtr16 += numPixels;

   345 			}

   346 		else

   347 			{

   348 			const TInt numPixels = Min(-count, destPtrLimit16 - destPtr16); //number of pixels to be copied

   349 			const TInt numBytes = numPixels * KPixelSize; //number of bytes needs to be retrieved from the srcePtr

   350 			Mem::Copy(destPtr16, srcePtr8, numBytes); // copy bytes

   351 			srcePtr8 += numBytes; //incrementing the srcePtr by number of bytes

   352 			destPtr16 += numPixels; //incrementing the destPtr16 by number of pixels

   353 			}

   354 		}

   355 	__ASSERT_DEBUG(srcePtr8 == srcePtrLimit8 && destPtr16 == destPtrLimit16, Panic(EFbsBitmapDecompressionError));

   356 	}

   358 /** The alternative decoding function which decompresses 24-bit buffer to the 16-bit stream with unused top bytes

   359  	by using RLE compression algorithm. The function is used under low memory conditions. */

   360 void CBitwiseBitmap::DoDecompressSixteenBitDataAltL(RReadStream& aStream,TInt aSrceSizeInBytes,TUint32* aBase)

   361 	{

   362 	__ASSERT_DEBUG((reinterpret_cast<TUint32>(aBase) & 0x2)==0,Panic(EFbsBitmapDecompressionError)); // make sure the start address is half-word aligned

   364 	TInt destSizeInPixels = (iHeader.iSizeInPixels.iHeight * iByteWidth); //size of destination Byte pixel buffers

   365 	destSizeInPixels >>= 1; //dividing by two, to get size of destination interms of Halfword pixel buffers

   366 	TUint16* destPtr16 = reinterpret_cast<TUint16*>(aBase); //pointer to uncompressed destination HalfWord(16-bit) pixel stream

   367 	TUint16* destPtrLimit16 = destPtr16 + destSizeInPixels; //maximum number of compressed source bytes

   368 	const TInt KPixelSize = 2; //number of bytes of the source stream that is to be considered as one Pixel

   370 	while(aSrceSizeInBytes > 0 && destPtr16 < destPtrLimit16)

   371 		{

   372 		TInt8 count = aStream.ReadInt8L(); //number of pixels to be retrieved from the source stream

   373 		aSrceSizeInBytes--; //One byte from source stream read, hence reduce size by one Byte

   375 		if (count >= 0)

   376 			{

   377 			const TInt numPixels = 1 + Min(count, (destPtrLimit16 - destPtr16));

   378 			const TUint16 pixel = aStream.ReadUint16L(); //Pixel buffer which needs to be stored in destPtr16

   379 			aSrceSizeInBytes -= KPixelSize; //Two bytes (Halfword pixel) read, reduce size by two Bytes

   381 			BitmapFill16(destPtr16, numPixels, pixel);

   382 			destPtr16 += numPixels;

   383 			}

   384 		else

   385 			{

   386 			const TInt numPixels = Min(-count, destPtrLimit16 - destPtr16); //number of pixels to be stored into destPtr16

   387 			const TInt numBytes = numPixels * KPixelSize; //number of bytes needs to be retrieved from the srcePtr

   388 			aStream.ReadL(destPtr16, numPixels); //read TUint16's

   389 			aSrceSizeInBytes -= numBytes; //two-byte (halfword) pixel buffers read, reduce by number of bytes

   390 			destPtr16 += numPixels; //incrementing the destPtr16 by number of pixels

   391 			}

   392 		}

   393 	__ASSERT_DEBUG(aSrceSizeInBytes == 0 && destPtr16 == destPtrLimit16, Panic(EFbsBitmapDecompressionError));

   394 	}

   396 void CBitwiseBitmap::DoDecompressTwentyFourBitData(TUint8* aDestBuffer,TInt aDestSize,TUint8* aSrceBuffer,TInt aSrceSize)

   397 	{

   398 	TUint8* srcePtr = aSrceBuffer;

   399 	TUint8* destPtr = aDestBuffer;

   400 	TUint8* srcePtrLimit = aSrceBuffer + aSrceSize;

   401 	TUint8* destPtrLimit = aDestBuffer + aDestSize;

   403 	while (srcePtr < srcePtrLimit && destPtr < destPtrLimit)

   404 		{

   405 		TInt8 count = *srcePtr++;

   407 		if (count >= 0)

   408 			{

   409 			count = Min(count, (destPtrLimit - destPtr) / 3);

   410 			TUint8 component1 = *srcePtr++;

   411 			TUint8 component2 = *srcePtr++;

   412 			TUint8 component3 = *srcePtr++;

   414 			while (count >= 0)

   415 				{

   416 				*destPtr++ = component1;

   417 				*destPtr++ = component2;

   418 				*destPtr++ = component3;

   419 				count--;

   420 				}

   421 			}

   422 		else

   423 			{

   424 			const TInt numBytes = Min(count * -3, destPtrLimit - destPtr);

   425 			Mem::Copy(destPtr,srcePtr,numBytes);

   426 			srcePtr += numBytes;

   427 			destPtr += numBytes;

   428 			}

   429 		}

   430 	__ASSERT_DEBUG(srcePtr == srcePtrLimit && destPtr == destPtrLimit,Panic(EFbsBitmapDecompressionError));

   431 	}

   433 void CBitwiseBitmap::DoDecompressTwentyFourBitDataAltL(RReadStream& aStream,TInt aSrceSizeInBytes,TUint32* aBase)

   434 	{

   435 	TInt destSizeInBytes = iHeader.iSizeInPixels.iHeight * iByteWidth;

   436 	TUint8* destPtr = (TUint8*)aBase;

   437 	TUint8* destPtrLimit = destPtr + destSizeInBytes;

   439 	while(aSrceSizeInBytes > 0 && destPtr < destPtrLimit)

   440 		{

   441 		TInt8 count = aStream.ReadInt8L();

   442 		aSrceSizeInBytes--;

   444 		if (count >= 0)

   445 			{

   446 			count = Min(count, (destPtrLimit - destPtr) / 3);

   447 			TUint8 component1 = aStream.ReadUint8L();

   448 			TUint8 component2 = aStream.ReadUint8L();

   449 			TUint8 component3 = aStream.ReadUint8L();

   450 			aSrceSizeInBytes -= 3;

   452 			while (count >= 0)

   453 				{

   454 				*destPtr++ = component1;

   455 				*destPtr++ = component2;

   456 				*destPtr++ = component3;

   457 				count--;

   458 				}

   459 			}

   460 		else

   461 			{

   462 			const TInt numBytes = Min(count * -3, destPtrLimit - destPtr);

   463 			aStream.ReadL(destPtr, numBytes);

   464 			aSrceSizeInBytes -= numBytes;

   465 			destPtr += numBytes;

   466 			}

   467 		}

   468 	__ASSERT_DEBUG(aSrceSizeInBytes == 0 && destPtr == destPtrLimit,Panic(EFbsBitmapDecompressionError));

   469 	}

   471 /** The function decodes 24-bit compressed buffer to the 32-bit stream with unused top bytes by using RLE compression algorithm*/

   472 void CBitwiseBitmap::DoDecompressThirtyTwoUBitData(TUint8* aDestBuffer,TInt aDestSize,TUint8* aSrceBuffer,TInt aSrceSize)

   473 	{

   475 	__ASSERT_DEBUG((reinterpret_cast<TUint32>(aDestBuffer) & 0x3)==0,Panic(EFbsBitmapDecompressionError)); // make sure the start address is word aligned

   476 	__ASSERT_DEBUG((aDestSize & 0x3)==0,Panic(EFbsBitmapDecompressionError)); // make sure the size is whole no of pixels

   478 	TUint8* srcePtr8 = aSrceBuffer;

   479 	TUint8* srcePtrLimit8 = aSrceBuffer + aSrceSize;

   481 	TUint32* destPtr32 = reinterpret_cast<TUint32*>(aDestBuffer);

   482 	TUint32* destPtrLimit32 = reinterpret_cast<TUint32*>(aDestBuffer + aDestSize);

   484 	while (srcePtr8 < srcePtrLimit8 && destPtr32 < destPtrLimit32)

   485 		{

   487 		TInt8 count = *srcePtr8++; // important to read into a byte variable

   489 		if (count >= 0) //repeating pixel buffer

   490 			{

   491 			count  = Min(count, (destPtrLimit32 - destPtr32));

   492 			const TUint8 component1 = *srcePtr8++;

   493 			const TUint8 component2 = *srcePtr8++;

   494 			const TUint8 component3 = *srcePtr8++;

   496 			const TUint32 pixel = 0xff000000 | (component3<<16) | (component2<<8) | component1;

   498 			// for performance loop is unrolled, using "Duff's Device" pattern

   499 			TInt blocksOf16 = (count >> 4);	// number of blocks of 16 full words to write

   500 			// the first iteration writes 1 to 15 words

   501 			switch (count & 0x0f)

   502 				{ // note that case statements intentionally cascade

   503 			case 15:

   504 				do {	// second and subsequent iterations always write 16 words

   505 				*destPtr32++ = pixel;

   506 			case 14:

   507 				*destPtr32++ = pixel;

   508 			case 13:

   509 				*destPtr32++ = pixel;

   510 			case 12:

   511 				*destPtr32++ = pixel;

   512 			case 11:

   513 				*destPtr32++ = pixel;

   514 			case 10:

   515 				*destPtr32++ = pixel;

   516 			case 9:

   517 				*destPtr32++ = pixel;

   518 			case 8:

   519 				*destPtr32++ = pixel;

   520 			case 7:

   521 				*destPtr32++ = pixel;

   522 			case 6:

   523 				*destPtr32++ = pixel;

   524 			case 5:

   525 				*destPtr32++ = pixel;

   526 			case 4:

   527 				*destPtr32++ = pixel;

   528 			case 3:

   529 				*destPtr32++ = pixel;

   530 			case 2:

   531 				*destPtr32++ = pixel;

   532 			case 1:

   533 				*destPtr32++ = pixel;

   534 			case 0:

   535 				*destPtr32++ = pixel;

   537 				} while(0 <= --blocksOf16);

   538 				}

   539 			}

   540 		else // negative value corresponds non repeating pixel buffer

   541 			{

   542 			const TInt numPixel = Min(-count, destPtrLimit32 - destPtr32) ;

   543 			for(TInt ii = 0; ii < numPixel; ii++)

   544 				{

   545 				TUint8 component1 = *srcePtr8++;

   546 				TUint8 component2 = *srcePtr8++;

   547 				TUint8 component3 = *srcePtr8++;

   549 				*destPtr32++ =  0xff000000 | (component3<<16) | (component2<<8) | component1;

   550 				}

   551 			}

   552 		}

   554 	__ASSERT_DEBUG(srcePtr8 == srcePtrLimit8 && destPtr32 == destPtrLimit32,Panic(EFbsBitmapDecompressionError));

   555 	}

   557 /** The alternative decoding function which decompresses 24-bit buffer to the 32-bit stream with unused top bytes

   558 	by using RLE compression algorithm. The function is using in case of memory shortage. */

   559 void CBitwiseBitmap::DoDecompressThirtyTwoUBitDataAltL(RReadStream& aStream,TInt aSrceSizeInBytes,TUint32* aBase)

   560 	{

   561 	const TInt destSizeInDwords = iHeader.iSizeInPixels.iHeight * (iByteWidth>>2);

   562 	TUint32* destPtr32 = aBase;

   563 	TUint32* destPtrLimit32 = destPtr32 + destSizeInDwords;

   565 	const TInt KMaxRLENonRepeatingPixelBufferSize = 128 * 3;

   566 	TUint8 dataBuffer[KMaxRLENonRepeatingPixelBufferSize];

   568 	while(aSrceSizeInBytes > 0 && destPtr32 < destPtrLimit32)

   569 		{

   570 		TInt8 count = aStream.ReadInt8L();

   571 		aSrceSizeInBytes--;

   573 		if (count >= 0) //repeating pixel buffer

   574 			{

   575 			count = Min(count, (destPtrLimit32 - destPtr32));

   576 			const TUint8 component1 = aStream.ReadUint8L();

   577 			const TUint8 component2 = aStream.ReadUint8L();

   578 			const TUint8 component3 = aStream.ReadUint8L();

   579 			aSrceSizeInBytes -= 3;

   581 			const TUint32 pixel = 0xff000000 | (component3<<16) | (component2<<8) | component1;

   583 			TInt blocksOf16 = (count >> 4);	// number of blocks of 16 full words to write

   584 			// the first iteration writes 1 to 15 words

   585 			switch (count & 0x0f)

   586 				{ // note that case statements intentionally cascade

   587 			case 15:

   588 				do {	// second and subsequent iterations always write 16 words

   589 				*destPtr32++ = pixel;

   590 			case 14:

   591 				*destPtr32++ = pixel;

   592 			case 13:

   593 				*destPtr32++ = pixel;

   594 			case 12:

   595 				*destPtr32++ = pixel;

   596 			case 11:

   597 				*destPtr32++ = pixel;

   598 			case 10:

   599 				*destPtr32++ = pixel;

   600 			case 9:

   601 				*destPtr32++ = pixel;

   602 			case 8:

   603 				*destPtr32++ = pixel;

   604 			case 7:

   605 				*destPtr32++ = pixel;

   606 			case 6:

   607 				*destPtr32++ = pixel;

   608 			case 5:

   609 				*destPtr32++ = pixel;

   610 			case 4:

   611 				*destPtr32++ = pixel;

   612 			case 3:

   613 				*destPtr32++ = pixel;

   614 			case 2:

   615 				*destPtr32++ = pixel;

   616 			case 1:

   617 				*destPtr32++ = pixel;

   618 			case 0:

   619  				*destPtr32++ = pixel;

   621 				} while(0 <= --blocksOf16);

   622 				}

   623 			}

   624 		else // negative value corresponds non repeating pixel buffer

   625 			{

   626 			const TInt numDestDwords = Min(-count, destPtrLimit32 - destPtr32);

   627 			const TInt numSrcBytes = numDestDwords * 3;

   628 			aStream.ReadL(&dataBuffer[0], numSrcBytes);

   629 			aSrceSizeInBytes -= numSrcBytes;

   630 			TUint8* srcPtr = dataBuffer;

   631 			const TInt& numPixel = numDestDwords;

   632 			for(TInt ii = 0; ii < numPixel; ii++)

   633 				{

   634 				const TUint8 component1 = *srcPtr++;

   635 				const TUint8 component2 = *srcPtr++;

   636 				const TUint8 component3 = *srcPtr++;

   638 				*destPtr32++ = 0xff000000 | (component3<<16) | (component2<<8) | component1;

   639 				}

   640 			}

   641 		}

   643 	__ASSERT_DEBUG(aSrceSizeInBytes == 0 && destPtr32 == destPtrLimit32,Panic(EFbsBitmapDecompressionError));

   644 	}

   646 /** The function decodes 32-bit compressed buffer (where top bytes are used as alpha channel) to the 32-bit stream by using RLE compression algorithm*/

   647 void CBitwiseBitmap::DoDecompressThirtyTwoABitData(TUint8* aDestBuffer,TInt aDestSize,TUint8* aSrceBuffer,TInt aSrceSize)

   648 	{

   649 	TUint8* srcePtr = aSrceBuffer;

   650 	TUint8* srcePtrLimit = aSrceBuffer + aSrceSize;

   652 	TUint32* destPtr32 = reinterpret_cast<TUint32*>(aDestBuffer);

   653 	TUint32* destPtrLimit32 = reinterpret_cast<TUint32*>(aDestBuffer + aDestSize);

   655 	while (srcePtr < srcePtrLimit && destPtr32 < destPtrLimit32)

   656 		{

   657 		TInt8 count = *srcePtr++;

   659 		if (count >= 0) //repeating pixel buffer

   660 			{

   661 			count = Min(count, (destPtrLimit32 - destPtr32));

   662 			TUint8 component1 = *srcePtr++;

   663 			TUint8 component2 = *srcePtr++;

   664 			TUint8 component3 = *srcePtr++;

   665 			TUint8 component4 = *srcePtr++;

   666 			const TUint32 pixel = (component4<<24) | (component3<<16) | (component2<<8) | component1;

   668 			// for performance loop is unrolled, using "Duff's Device" pattern

   669 			TInt blocksOf16 = (count >> 4);	// number of blocks of 16 full words to write

   670 			// the first iteration writes 1 to 15 words

   671 			switch (count & 0x0f)

   672 				{ // note that case statements intentionally cascade

   673 			case 15:

   674 				do {	// second and subsequent iterations always write 16 words

   675 				*destPtr32++ = pixel;

   676 			case 14:

   677 				*destPtr32++ = pixel;

   678 			case 13:

   679 				*destPtr32++ = pixel;

   680 			case 12:

   681 				*destPtr32++ = pixel;

   682 			case 11:

   683 				*destPtr32++ = pixel;

   684 			case 10:

   685 				*destPtr32++ = pixel;

   686 			case 9:

   687 				*destPtr32++ = pixel;

   688 			case 8:

   689 				*destPtr32++ = pixel;

   690 			case 7:

   691 				*destPtr32++ = pixel;

   692 			case 6:

   693 				*destPtr32++ = pixel;

   694 			case 5:

   695 				*destPtr32++ = pixel;

   696 			case 4:

   697 				*destPtr32++ = pixel;

   698 			case 3:

   699 				*destPtr32++ = pixel;

   700 			case 2:

   701 				*destPtr32++ = pixel;

   702 			case 1:

   703 				*destPtr32++ = pixel;

   704 			case 0:

   705  				*destPtr32++ = pixel;

   707 				} while(0 <= --blocksOf16);

   708 				}

   709 			}

   710 		else // negative value corresponds non repeating pixel buffer

   711 			{

   712 			const TInt numPixel = Min(-count, destPtrLimit32 - destPtr32);

   714 			Mem::Copy(destPtr32, srcePtr, numPixel*4);

   715 			destPtr32 += numPixel;

   716 			srcePtr += numPixel*4;

   718 			}

   719 		}

   721 	__ASSERT_DEBUG(srcePtr == srcePtrLimit && destPtr32 == destPtrLimit32,Panic(EFbsBitmapDecompressionError));

   722 	}

   724 /** The alternative decoding function which decompresses 32-bit buffer (where top bytes are used as alpha channel)

   725 	to the 32-bit stream by using RLE compression algorithm. The function is using in case of memory shortage. */

   726 void CBitwiseBitmap::DoDecompressThirtyTwoABitDataAltL(RReadStream& aStream,TInt aSrceSizeInBytes,TUint32* aBase)

   727 	{

   728 	const TInt destSizeInDwords = iHeader.iSizeInPixels.iHeight * (iByteWidth>>2);

   729 	TUint32* destPtr32 = aBase;

   730 	TUint32* destPtrLimit32 = destPtr32 + destSizeInDwords;

   732 	while(aSrceSizeInBytes > 0 && destPtr32 < destPtrLimit32)

   733 		{

   734 		TInt8 count = aStream.ReadInt8L();

   735 		aSrceSizeInBytes--;

   737 		if (count >= 0) //repeating pixel buffer

   738 			{

   739 			count = Min(count, (destPtrLimit32 - destPtr32));

   740 			const TUint32 pixel = aStream.ReadUint32L();

   741 			aSrceSizeInBytes -= 4;

   743 			// for performance loop is unrolled, using "Duff's Device" pattern

   744 			TInt blocksOf16 = (count >> 4);	// number of blocks of 16 full words to write

   745 			// the first iteration writes 1 to 15 words

   746 			switch (count & 0x0f)

   747 				{ // note that case statements intentionally cascade

   748 			case 15:

   749 				do {	// second and subsequent iterations always write 16 words

   750 				*destPtr32++ = pixel;

   751 			case 14:

   752 				*destPtr32++ = pixel;

   753 			case 13:

   754 				*destPtr32++ = pixel;

   755 			case 12:

   756 				*destPtr32++ = pixel;

   757 			case 11:

   758 				*destPtr32++ = pixel;

   759 			case 10:

   760 				*destPtr32++ = pixel;

   761 			case 9:

   762 				*destPtr32++ = pixel;

   763 			case 8:

   764 				*destPtr32++ = pixel;

   765 			case 7:

   766 				*destPtr32++ = pixel;

   767 			case 6:

   768 				*destPtr32++ = pixel;

   769 			case 5:

   770 				*destPtr32++ = pixel;

   771 			case 4:

   772 				*destPtr32++ = pixel;

   773 			case 3:

   774 				*destPtr32++ = pixel;

   775 			case 2:

   776 				*destPtr32++ = pixel;

   777 			case 1:

   778 				*destPtr32++ = pixel;

   779 			case 0:

   780  				*destPtr32++ = pixel;

   782 				} while(0 <= --blocksOf16);

   783 				}

   784 			}

   785 		else // negative value corresponds non repeating pixel buffer

   786 			{

   787 			const TInt numPixels = Min(-count, destPtrLimit32 - destPtr32);

   788 			aStream.ReadL((TUint16*)destPtr32, numPixels * 2); // read TUint16's

   789 			aSrceSizeInBytes -= numPixels * 4;

   790 			destPtr32 += numPixels;

   791 			}

   792 		}

   794 	__ASSERT_DEBUG(aSrceSizeInBytes == 0 && destPtr32 == destPtrLimit32,Panic(EFbsBitmapDecompressionError));

   795 	}

   797 void CBitwiseBitmap::DoExternalizeDataCompressedL(RWriteStream& aStream,TUint8* aData,TInt aSizeInBytes) const

   798 	{

   799 	switch (iHeader.iBitsPerPixel)

   800 		{

   801 	case 1:

   802 	case 2:

   803 	case 4:

   804 	case 8:

   805 		DoExternalizeByteDataCompressedL(aStream,aData,aSizeInBytes);

   806 		break;

   807 	case 12:

   808 		DoExternalizeTwelveBitDataCompressedL(aStream,aData,aSizeInBytes);

   809 		break;

   810 	case 16:

   811 		DoExternalizeSixteenBitDataCompressedL(aStream,aData,aSizeInBytes);

   812 		break;

   813 	case 24:

   814 		DoExternalizeTwentyFourBitDataCompressedL(aStream,aData,aSizeInBytes);

   815 		break;

   816 	case 32:

   817 		__ASSERT_DEBUG(iHeader.iColor == SEpocBitmapHeader::EColor||

   818 						iHeader.iColor == SEpocBitmapHeader::EColorAlpha||

   819 						iHeader.iColor == SEpocBitmapHeader::EColorAlphaPM,

   820 						Panic(EFbsBitmapInvalidCompression));

   821 		if(iHeader.iColor == SEpocBitmapHeader::EColor)

   822 			{

   823 			DoExternalizeThirtyTwoUBitDataCompressedL(aStream,aData,aSizeInBytes);

   824 			}

   825 		else

   826 			{

   827 			DoExternalizeThirtyTwoABitDataCompressedL(aStream,aData,aSizeInBytes);

   828 			}

   829 		break;

   830 	default:

   831 		break;

   832 		}

   833 	}

   835 void CBitwiseBitmap::DoExternalizeByteDataCompressedL(RWriteStream& aStream,TUint8* aData,TInt aSizeInBytes) const

   836 	{

   837 	TUint8* dataLimit=aData+aSizeInBytes-2;

   838 	TUint8 runPair[2];

   839 	while(aData<dataLimit)

   840 		{

   841 		TUint8 value=*aData;

   842 		TUint8* runStartPtr = aData;

   844 		if (*(aData+1)==value && *(aData+2)==value)

   845 			{

   846 			aData+=3;

   847 			while(aData<dataLimit && *aData==value)

   848 				aData++;

   849 			TInt runLength=aData-runStartPtr;

   850 			runPair[0]=127;

   851 			runPair[1]=value;

   852 			while(runLength>128)

   853 				{

   854 				aStream.WriteL(&runPair[0],2);

   855 				runLength-=128;

   856 				}

   857 			runPair[0]=TUint8(runLength-1);

   858 			aStream.WriteL(&runPair[0],2);

   859 			}

   860 		else

   861 			{

   862 			while(aData<dataLimit && (*(aData+1)!=value || *(aData+2)!=value))

   863 				{

   864 				aData++;

   865 				value=*aData;

   866 				}

   867 			TInt runLength = aData - runStartPtr;

   868 			while (runLength > 128)

   869 				{

   870 				aStream.WriteInt8L(-128);

   871 				aStream.WriteL(runStartPtr,128);

   872 				runLength-=128;

   873 				runStartPtr+=128;

   874 				}

   875 			aStream.WriteInt8L(-runLength);

   876 			aStream.WriteL(runStartPtr,runLength);

   877 			}

   878 		}

   879 	dataLimit+=2;

   880 	if (aData<dataLimit)

   881 		{

   882 		TInt runLength=dataLimit-aData;

   883 		aStream.WriteInt8L(-runLength);

   884 		aStream.WriteL(aData,runLength);

   885 		}

   886 	}

   888 void CBitwiseBitmap::DoExternalizeTwelveBitDataCompressedL(RWriteStream& aStream,TUint8* aData,TInt aSizeInBytes) const

   889 	{

   890 	TUint16* srcePtr = (TUint16*)aData;

   891 	TUint16* srcePtrLimit = srcePtr + (aSizeInBytes / 2);

   893 	while (srcePtr < srcePtrLimit)

   894 		{

   895 		TUint16* runStartPtr = srcePtr;

   896 		TUint16 value = TUint16(*srcePtr & 0x0fff);

   897 		do

   898 			{

   899 			srcePtr++;

   900 			}

   901 		while (srcePtr < srcePtrLimit && *srcePtr == value);

   903 		TInt pixelLength = srcePtr - runStartPtr;

   904 		TUint16 maxLengthData = TUint16(value | 0xf000);

   906 		while (pixelLength > 16)

   907 			{

   908 			aStream.WriteUint16L(maxLengthData);

   909 			pixelLength -= 16;

   910 			}

   912 		if (pixelLength > 0)

   913 			aStream.WriteUint16L(value | TUint16((pixelLength - 1) << 12));

   914 		}

   915 	}

   917 void CBitwiseBitmap::DoExternalizeSixteenBitDataCompressedL(RWriteStream& aStream,TUint8* aData,TInt aSizeInBytes) const

   918 	{

   919 	TUint16* srcePtr = (TUint16*)aData;

   920 	TUint16* srceLimitPtr = srcePtr + (aSizeInBytes / 2);

   921 	TUint16* srceLimitPtrMinusOne = srceLimitPtr - 1;

   923 	while (srcePtr < srceLimitPtrMinusOne)

   924 		{

   925 		TUint16 value = *srcePtr;

   926 		TUint16* runStartPtr = srcePtr++;

   928 		if(*srcePtr == value)

   929 			{

   930 			do

   931 				{

   932 				srcePtr++;

   933 				}

   934 			while(srcePtr < srceLimitPtr && *srcePtr == value);

   936 			TInt pixelLength = srcePtr-runStartPtr;

   937 			while (pixelLength > 128)

   938 				{

   939 				aStream.WriteInt8L(127);

   940 				aStream.WriteUint16L(value);

   941 				pixelLength -= 128;

   942 				}

   944 			aStream.WriteUint8L(pixelLength - 1);

   945 			aStream.WriteUint16L(value);

   946 			}

   947 		else

   948 			{

   949 			value = *srcePtr;

   950 			while (srcePtr < srceLimitPtrMinusOne && *(srcePtr + 1) != value)

   951 				{

   952 				srcePtr++;

   953 				value = *srcePtr;

   954 				}

   956 			TInt pixelLength = srcePtr - runStartPtr;

   957 			while (pixelLength > 128)

   958 				{

   959 				aStream.WriteInt8L(-128);

   960 				aStream.WriteL(runStartPtr,128);

   961 				runStartPtr += 128;

   962 				pixelLength -= 128;

   963 				}

   965 			aStream.WriteInt8L(-pixelLength);

   966 			aStream.WriteL(runStartPtr,pixelLength);

   967 			}

   968 		}

   970 	TInt remainingPixels = srceLimitPtr - srcePtr;

   971 	if (remainingPixels > 0)

   972 		{

   973 		aStream.WriteInt8L(-remainingPixels);

   974 		aStream.WriteL(srcePtr,remainingPixels);

   975 		}

   976 	}

   978 void CBitwiseBitmap::DoExternalizeTwentyFourBitDataCompressedL(RWriteStream& aStream,TUint8* aData,TInt aSizeInBytes) const

   979 	{

   980 	TUint8* srceLimitPtr = aData + aSizeInBytes;

   981 	TUint8* srceLimitPtrMinusThree = srceLimitPtr - 3; // three bytes == one pixel

   983 	while (aData < srceLimitPtrMinusThree)

   984 		{

   985 		TUint8* runStartPtr = aData;

   986 		TUint8 component1 = *aData++;

   987 		TUint8 component2 = *aData++;

   988 		TUint8 component3 = *aData++;

   990 		if (TrueColorPointerCompare(aData,component1,component2,component3))

   991 			{

   992 			do

   993 				{

   994 				aData += 3;

   995 				}

   996 			while (aData < srceLimitPtr && TrueColorPointerCompare(aData,component1,component2,component3));

   998 			TInt pixelLength = (aData - runStartPtr) / 3;

   999 			while (pixelLength > 128)

  1000 				{

  1001 				aStream.WriteInt8L(127);

  1002 				aStream.WriteUint8L(component1);

  1003 				aStream.WriteUint8L(component2);

  1004 				aStream.WriteUint8L(component3);

  1005 				pixelLength -= 128;

  1006 				}

  1008 			aStream.WriteInt8L(pixelLength - 1);

  1009 			aStream.WriteUint8L(component1);

  1010 			aStream.WriteUint8L(component2);

  1011 			aStream.WriteUint8L(component3);

  1012 			}

  1013 		else

  1014 			{

  1015 			TBool more  = ETrue;

  1016 			TBool eqRun = EFalse;

  1017 			do

  1018 				{

  1019 				component1 = *aData++;

  1020 				component2 = *aData++;

  1021 				component3 = *aData++;

  1022 				more = (aData < srceLimitPtr);

  1023 				eqRun = more && TrueColorPointerCompare(aData,component1,component2,component3);

  1024 				}

  1025 			while (more && !eqRun);

  1026 			if (eqRun)

  1027 				aData -= 3;

  1028 			TInt pixelLength = (aData - runStartPtr) / 3;

  1029 			while (pixelLength > 128)

  1030 				{

  1031 				aStream.WriteInt8L(-128);

  1032 				aStream.WriteL(runStartPtr,384);

  1033 				runStartPtr += 384;

  1034 				pixelLength -= 128;

  1035 				}

  1037 			aStream.WriteInt8L(-pixelLength);

  1038 			aStream.WriteL(runStartPtr,pixelLength * 3);

  1039 			}

  1040 		}

  1042 	TInt remainingPixels = srceLimitPtr - aData;

  1043 	if (remainingPixels > 0)

  1044 		{

  1045 		TInt pixelLength = remainingPixels / 3;

  1046 		aStream.WriteInt8L(-pixelLength);

  1047 		aStream.WriteL(aData,remainingPixels);

  1048 		}

  1049 	}

  1051 /** The function externalizes 32-bit buffer with unused top bytes to the 24-bit compressed stream by using RLE compression algorithm*/

  1052 void CBitwiseBitmap::DoExternalizeThirtyTwoUBitDataCompressedL(RWriteStream& aStream,TUint8* aData8,TInt aSizeInBytes) const

  1053 	{

  1055 	__ASSERT_DEBUG((reinterpret_cast<TUint32>(aData8) & 0x3)==0,Panic(EFbsBitmapDecompressionError)); // make sure the start address is word aligned

  1056 	__ASSERT_DEBUG((aSizeInBytes & 0x3)==0,Panic(EFbsBitmapDecompressionError)); // make sure the size is whole no of pixels

  1058 	TUint32* ptr = reinterpret_cast<TUint32*>(aData8);

  1059 	TUint32* srceLimitPtr = reinterpret_cast<TUint32*>(aData8 + aSizeInBytes);

  1060 	TUint32* srceLimitPtr2ndLast = srceLimitPtr - 1;

  1062 	while (ptr < srceLimitPtr2ndLast)

  1063 		{

  1064 		TUint32* runStartPtr = ptr;

  1065 		TUint32 pixel = *ptr++ & 0x00ffffff;

  1067 		if ( (((*ptr)&0x00ffffff)==pixel) )

  1068 			{

  1069 			do

  1070 				{

  1071 				ptr++;

  1072 				}

  1073 			while (ptr< srceLimitPtr && (((*ptr)&0x00ffffff)==pixel) );

  1075 			TInt pixelLength = (ptr - runStartPtr);

  1076 			while (pixelLength > 128)

  1077 				{

  1078 				aStream.WriteInt8L(127);

  1079 				aStream.WriteUint8L(pixel&0x000000ff);

  1080 				aStream.WriteUint8L((pixel>>8)&0x000000ff);

  1081 				aStream.WriteUint8L((pixel>>16)&0x000000ff);

  1082 				pixelLength -= 128;

  1083 				}

  1085 			aStream.WriteInt8L(pixelLength - 1);

  1086 			aStream.WriteUint8L(pixel&0x000000ff);

  1087 			aStream.WriteUint8L((pixel>>8)&0x000000ff);

  1088 			aStream.WriteUint8L((pixel>>16)&0x000000ff);

  1089 			}

  1090 		else

  1091 			{

  1092 			TBool more  = ETrue;

  1093 			TBool eqRun = EFalse;

  1094 			do

  1095 				{

  1096 				pixel = *ptr++ & 0x00ffffff;

  1097 				more = (ptr < srceLimitPtr);

  1098 				eqRun = more && (((*ptr)&0x00ffffff)==pixel);

  1099 				} while (more && !eqRun);

  1100 			if (eqRun)

  1101 				ptr--;

  1102 			TInt pixelLength = (ptr - runStartPtr);

  1103 			while (pixelLength > 128)

  1104 				{

  1105 				aStream.WriteInt8L(-128);

  1106 				for(TInt ii = 0; ii < 128; ii++)

  1107 					{

  1108 					aStream.WriteL(reinterpret_cast<TUint8*>(runStartPtr), 3);

  1109 					runStartPtr++;

  1110 					}

  1111 				pixelLength -= 128;

  1112 				}

  1114 			aStream.WriteInt8L(-pixelLength);

  1115 			for(TInt kk = 0; kk < pixelLength; kk++)

  1116 				{

  1117 				aStream.WriteL(reinterpret_cast<TUint8*>(runStartPtr), 3);

  1118 				runStartPtr++;

  1119 				}

  1120 			}

  1121 		}

  1123 	const TInt remainingPixels = srceLimitPtr - ptr;

  1124 	if (remainingPixels > 0)

  1125 		{

  1126 		__ASSERT_DEBUG(remainingPixels == 1, Panic(EFbsBitmapDecompressionError));

  1128 		aStream.WriteInt8L(-remainingPixels);

  1129 		for(TInt ii = 0; ii < remainingPixels; ii++)

  1130 			{

  1131 			aStream.WriteL(reinterpret_cast<TUint8*>(ptr), 3);

  1132 			ptr++;

  1133 			}

  1134 		}

  1135 	}

  1137 /** The function externalizes 32-bit buffer with alpha channel in top byte to the 32-bit compressed stream by using RLE compression algorithm*/

  1138 void CBitwiseBitmap::DoExternalizeThirtyTwoABitDataCompressedL(RWriteStream& aStream,TUint8* aData8,TInt aSizeInBytes) const

  1139 	{

  1141 	__ASSERT_DEBUG((reinterpret_cast<TUint32>(aData8) & 0x3)==0,Panic(EFbsBitmapDecompressionError)); // make sure the start address is word aligned

  1142 	__ASSERT_DEBUG((aSizeInBytes & 0x3)==0,Panic(EFbsBitmapDecompressionError)); // make sure the size is whole no of pixels

  1144 	TUint32* ptr = reinterpret_cast<TUint32*>(aData8);

  1145 	TUint32* srceLimitPtr = reinterpret_cast<TUint32*>(aData8 + aSizeInBytes);

  1146 	TUint32* srceLimitPtr2ndLast = srceLimitPtr - 1;

  1148 	while (ptr < srceLimitPtr2ndLast)

  1149 		{

  1150 		TUint32* runStartPtr = ptr;

  1151 		TUint32 pixel = *ptr++;

  1153 		if (*ptr==pixel)

  1154 			{

  1155 			do

  1156 				{

  1157 				ptr++;

  1158 				}

  1159 			while (ptr < srceLimitPtr && *ptr==pixel);

  1161 			TInt pixelLength = (ptr - runStartPtr);

  1162 			while (pixelLength > 128)

  1163 				{

  1164 				aStream.WriteInt8L(127);

  1165 				aStream.WriteUint32L(pixel);

  1166 				pixelLength -= 128;

  1167 				}

  1169 			aStream.WriteInt8L(pixelLength - 1);

  1170 			aStream.WriteUint32L(pixel);

  1171 			}

  1172 		else

  1173 			{

  1174 			TBool more  = ETrue;

  1175 			TBool eqRun = EFalse;

  1176 			do

  1177 				{

  1178 				pixel = *ptr++;

  1179 				more = (ptr < srceLimitPtr);

  1180 				eqRun = more && *ptr==pixel;

  1181 				} while (more && !eqRun);

  1183 			if (eqRun)

  1184 				ptr--;

  1186 			TInt pixelLength = (ptr - runStartPtr);

  1187 			while (pixelLength > 128)

  1188 				{

  1189 				aStream.WriteInt8L(-128);

  1190 				aStream.WriteL(reinterpret_cast<TUint8*>(runStartPtr), 128*4);

  1191 				runStartPtr += 128;

  1192 				pixelLength -= 128;

  1193 				}

  1195 			aStream.WriteInt8L(-pixelLength);

  1196 			aStream.WriteL(reinterpret_cast<TUint8*>(runStartPtr), pixelLength*4);

  1197 			}

  1198 		}

  1200 	const TInt remainingPixels = srceLimitPtr - ptr;

  1201 	if (remainingPixels > 0)

  1202 		{

  1203 		__ASSERT_DEBUG(remainingPixels == 1, Panic(EFbsBitmapDecompressionError));

  1205 		aStream.WriteInt8L(-remainingPixels);

  1206 		aStream.WriteL(reinterpret_cast<TUint8*>(ptr), remainingPixels*4);

  1207 		}

  1208 	}

  1210 TInt CBitwiseBitmap::SizeOfDataCompressed(TUint8* aData,TInt aSizeInBytes) const

  1211 	{

  1212 	if(aSizeInBytes<=0)

  1213 		return 0;

  1215 	switch (iHeader.iBitsPerPixel)

  1216 		{

  1217 	case 1:

  1218 	case 2:

  1219 	case 4:

  1220 	case 8:

  1221 		return SizeOfByteDataCompressed(aData,aSizeInBytes);

  1222 	case 12:

  1223 		return SizeOfTwelveBitDataCompressed(aData,aSizeInBytes);

  1224 	case 16:

  1225 		return SizeOfSixteenBitDataCompressed(aData,aSizeInBytes);

  1226 	case 24:

  1227 		return SizeOfTwentyFourBitDataCompressed(aData,aSizeInBytes);

  1228 	case 32:

  1229 		__ASSERT_DEBUG(iHeader.iColor == SEpocBitmapHeader::EColor||

  1230 						iHeader.iColor == SEpocBitmapHeader::EColorAlpha||

  1231 						iHeader.iColor == SEpocBitmapHeader::EColorAlphaPM,

  1232 						Panic(EFbsBitmapInvalidCompression));

  1233 		if(iHeader.iColor == SEpocBitmapHeader::EColor)

  1234 			{

  1235 			return SizeOfThirtyTwoUBitDataCompressed(aData,aSizeInBytes);

  1236 			}

  1237 		else

  1238 			{

  1239 			return SizeOfThirtyTwoABitDataCompressed(aData,aSizeInBytes);

  1240 			}

  1241 	default:

  1242 		break;

  1243 		}

  1245 	return 0;

  1246 	}

  1248 TInt CBitwiseBitmap::SizeOfByteDataCompressed(TUint8* aData,TInt aSizeInBytes) const

  1249 	{

  1250 	if(aSizeInBytes<=0)

  1251 		return 0;

  1253 	TInt compressedSize=0;

  1254 	TUint8* dataLimit=aData+aSizeInBytes-2;

  1256 	while(aData<dataLimit)

  1257 		{

  1258 		TUint8 value=*aData;

  1259 		if (*(aData+1)==value && *(aData+2)==value)

  1260 			{

  1261 			TUint8* runStartPtr=aData;

  1262 			aData+=3;

  1263 			while(aData<dataLimit && *aData==value)

  1264 				aData++;

  1265 			TInt runLength=aData-runStartPtr;

  1267 			compressedSize+= 2*(((runLength-1)>>7) + 1) ;

  1268 			}

  1269 		else

  1270 			{

  1271 			TUint8* runStartPtr=aData;

  1272 			while(aData<dataLimit && (*(aData+1)!=value || *(aData+2)!=value))

  1273 				{

  1274 				aData++;

  1275 				value=*aData;

  1276 				}

  1277 			TInt runLength=aData-runStartPtr;

  1279 			compressedSize+= runLength + ((runLength-1)>>7) + 1;

  1280 			}

  1281 		}

  1282 	dataLimit+=2;

  1283 	if (aData<dataLimit)

  1284 		compressedSize+=dataLimit-aData+1;

  1285 	return(compressedSize);

  1286 	}

  1288 TInt CBitwiseBitmap::SizeOfTwelveBitDataCompressed(TUint8* aData,TInt aSizeInBytes) const

  1289 	{

  1290 	if(aSizeInBytes<=0)

  1291 		return 0;

  1293 	TInt compressedSize = 0;

  1294 	TUint16* srcePtr = (TUint16*)aData;

  1295 	TUint16* srcePtrLimit = srcePtr + (aSizeInBytes / 2);

  1297 	while (srcePtr < srcePtrLimit)

  1298 		{

  1299 		TUint16* runStartPtr = srcePtr;

  1300 		TUint16 value = TUint16(*srcePtr & 0x0fff);

  1301 		do

  1302 			{

  1303 			srcePtr++;

  1304 			}

  1305 		while (srcePtr < srcePtrLimit && *srcePtr == value);

  1307 		TInt pixelLength = srcePtr - runStartPtr;

  1309 		compressedSize += 2*( ((pixelLength-1)>>4) + 1);

  1310 		}

  1311 	return compressedSize;

  1312 	}

  1314 TInt CBitwiseBitmap::SizeOfSixteenBitDataCompressed(TUint8* aData,TInt aSizeInBytes) const

  1315 	{

  1316 	if(aSizeInBytes<=0)

  1317 		return 0;

  1319 	TInt compressedSize = 0;

  1320 	TUint16* srcePtr = (TUint16*)aData;

  1321 	TUint16* srceLimitPtr = srcePtr + (aSizeInBytes / 2);

  1322 	TUint16* srceLimitPtrMinusOne = srceLimitPtr - 1;

  1324 	while (srcePtr < srceLimitPtrMinusOne)

  1325 		{

  1326 		TUint16 value = *srcePtr;

  1327 		TUint16* runStartPtr = srcePtr++;

  1329 		if(*srcePtr == value)

  1330 			{

  1331 			do

  1332 				{

  1333 				srcePtr++;

  1334 				}

  1335 			while(srcePtr < srceLimitPtr && *srcePtr == value);

  1337 			TInt pixelLength = srcePtr-runStartPtr;

  1339 			compressedSize += 3*( ((pixelLength-1)>>7) + 1);

  1340 			}

  1341 		else

  1342 			{

  1343 			value = *srcePtr;

  1344 			while (srcePtr < srceLimitPtrMinusOne && *(srcePtr + 1) != value)

  1345 				{

  1346 				srcePtr++;

  1347 				value = *srcePtr;

  1348 				}

  1350 			TInt pixelLength = srcePtr-runStartPtr;

  1352 			compressedSize += (pixelLength * 2) + ((pixelLength-1)>>7) + 1;

  1353 			}

  1354 		}

  1355 	if (srcePtr < srceLimitPtr)

  1356 		compressedSize += ((srceLimitPtr - srcePtr) * 2) + 1;

  1357 	return compressedSize;

  1358 	}

  1360 TInt CBitwiseBitmap::SizeOfTwentyFourBitDataCompressed(TUint8* aData,TInt aSizeInBytes) const

  1361 	{

  1362 	if(aSizeInBytes<=0)

  1363 		return 0;

  1365 	TInt compressedSize = 0;

  1366 	TUint8* srceLimitPtr = aData + aSizeInBytes;

  1367 	TUint8* srceLimitPtrMinusThree = srceLimitPtr - 3; // three bytes == one pixel

  1369 	while (aData < srceLimitPtrMinusThree)

  1370 		{

  1371 		TUint8* runStartPtr = aData;

  1372 		TUint8 component1 = *aData++;

  1373 		TUint8 component2 = *aData++;

  1374 		TUint8 component3 = *aData++;

  1376 		if (TrueColorPointerCompare(aData,component1,component2,component3))

  1377 			{

  1378 			do

  1379 				{

  1380 				aData += 3;

  1381 				}

  1382 			while (aData < srceLimitPtr && TrueColorPointerCompare(aData,component1,component2,component3));

  1384 			TInt pixelLength = (aData - runStartPtr) / 3;

  1386 			compressedSize += 4*( ((pixelLength-1)>>7) + 1);

  1387 			}

  1388 		else

  1389 			{

  1390 			TBool more  = ETrue;

  1391 			TBool eqRun = EFalse;

  1392 			do

  1393 				{

  1394 				component1 = *aData++;

  1395 				component2 = *aData++;

  1396 				component3 = *aData++;

  1397 				more = (aData < srceLimitPtr);

  1398 				eqRun = more && TrueColorPointerCompare(aData,component1,component2,component3);

  1399 				}

  1400 			while (more && !eqRun);

  1401 			if (eqRun)

  1402 				aData -= 3;

  1403 			TInt pixelLength = (aData - runStartPtr) / 3;

  1405 			compressedSize += (pixelLength * 3) + ((pixelLength-1)>>7) + 1;

  1406 			}

  1407 		}

  1409 	if (aData < srceLimitPtr)

  1410 		compressedSize += srceLimitPtr - aData + 1;

  1412 	return compressedSize;

  1413 	}

  1415 /** The function calculates the size of 24-bit RLE compression stream which could be obtain from given 32-bit buffer,

  1416 	where the top bytes are unused*/

  1417 TInt CBitwiseBitmap::SizeOfThirtyTwoUBitDataCompressed(TUint8* aData8,TInt aSizeInBytes) const

  1418 	{

  1419 	if(aSizeInBytes<=0)

  1420 		return 0;

  1422 	__ASSERT_DEBUG((reinterpret_cast<TUint32>(aData8) & 0x3)==0,Panic(EFbsBitmapDecompressionError)); // make sure the start address is word aligned

  1423 	__ASSERT_DEBUG((aSizeInBytes & 0x3)==0,Panic(EFbsBitmapDecompressionError)); // make sure the size is whole no of pixels

  1426 	TInt compressedSize = 0;

  1429 	TUint32* ptr = reinterpret_cast<TUint32*>(aData8);

  1430 	TUint32* srceLimitPtr = reinterpret_cast<TUint32*>(aData8 + aSizeInBytes);

  1431 	TUint32* srceLimitPtr2ndLast = srceLimitPtr - 1;

  1432 	while (ptr < srceLimitPtr2ndLast)

  1433 		{

  1434 		TUint32* runStartPtr = ptr;

  1435 		TUint32 pixel = *ptr++ & 0x00ffffff;

  1437 		if ((((*ptr)&0x00ffffff)==pixel))

  1438 			{

  1439 			do

  1440 				{

  1441 				ptr++;

  1442 				}

  1443 			while (ptr < srceLimitPtr && (((*ptr)&0x00ffffff)==pixel));

  1445 			TInt pixelLength = (ptr - runStartPtr);

  1446 			compressedSize += 4*( ((pixelLength-1)>>7) + 1);

  1447 			}

  1448 		else

  1449 			{

  1450 			TBool more  = ETrue;

  1451 			TBool eqRun = EFalse;

  1452 			do

  1453 				{

  1454 				pixel = *ptr++ & 0x00ffffff;

  1455 				more = (ptr < srceLimitPtr);

  1456 				eqRun = more && (((*ptr)&0x00ffffff)==pixel);

  1457 				} while (more && !eqRun);

  1459 			if (eqRun)

  1460 				ptr--;

  1462 			TInt pixelLength = (ptr - runStartPtr) ;

  1463 			compressedSize += 3*pixelLength + ((pixelLength-1)>>7) + 1;

  1464 			}

  1465 		}

  1467 	if (ptr < srceLimitPtr)

  1468 		compressedSize += (srceLimitPtr - ptr)*3 + 1;

  1470 	return compressedSize;

  1471 	}

  1474 TBool CBitwiseBitmap::TrueColorPointerCompare(TUint8* aColorPointer,TUint8 aComponent1,TUint8 aComponent2,TUint8 aComponent3) const

  1475 	{

  1476 	return (*aColorPointer == aComponent1 && *(aColorPointer + 1) == aComponent2 && *(aColorPointer + 2) == aComponent3);

  1477 	}

  1479 /** This function calculates the size of 32-bit RLE compression stream which is obtained from a given 32-bit buffer,

  1480 	where the top 8 bits are used to represent the alpha channel*/

  1481 TInt CBitwiseBitmap::SizeOfThirtyTwoABitDataCompressed(TUint8* aData8,TInt aSizeInBytes) const

  1482 	{

  1483 	if(aSizeInBytes<=0)

  1484 		return 0;

  1486 	__ASSERT_DEBUG((reinterpret_cast<TUint32>(aData8) & 0x3)==0,Panic(EFbsBitmapDecompressionError)); // make sure the start address is word aligned

  1487 	__ASSERT_DEBUG((aSizeInBytes & 0x3)==0,Panic(EFbsBitmapDecompressionError)); // make sure the size is whole no of pixels

  1490 	TInt compressedSize = 0;

  1493 	TUint32* ptr = reinterpret_cast<TUint32*>(aData8);

  1494 	TUint32* srceLimitPtr = reinterpret_cast<TUint32*>(aData8 + aSizeInBytes);

  1495 	TUint32* srceLimitPtr2ndLast = srceLimitPtr - 1;

  1496 	while (ptr < srceLimitPtr2ndLast)

  1497 		{

  1498 		TUint32* runStartPtr = ptr;

  1499 		TUint32 pixel = *ptr++;

  1501 		if (*ptr==pixel)

  1502 			{

  1503 			do

  1504 				{

  1505 				ptr++;

  1506 				}

  1507 			while (ptr < srceLimitPtr && *ptr==pixel);

  1509 			TInt pixelLength = (ptr - runStartPtr);

  1510 			compressedSize += 5*( ((pixelLength-1)>>7) + 1);

  1511 			}

  1512 		else

  1513 			{

  1514 			TBool more  = ETrue;

  1515 			TBool eqRun = EFalse;

  1516 			do

  1517 				{

  1518 				pixel = *ptr++;

  1519 				more = (ptr < srceLimitPtr);

  1520 				eqRun = more && *ptr==pixel;

  1521 				} while (more && !eqRun);

  1523 			if (eqRun)

  1524 				ptr--;

  1526 			TInt pixelLength = (ptr - runStartPtr) ;

  1527 			compressedSize += 4*pixelLength + ((pixelLength-1)>>7) + 1;

  1528 			}

  1529 		}

  1531 	if (ptr < srceLimitPtr)

  1532 		compressedSize += (srceLimitPtr - ptr)*4 + 1;

  1534 	return compressedSize;

  1535 	}

  1538 /*	Here's a BNF description of the RLE encoding in use for all but the 12-bit compression:

  1540 	encoding := run*

  1541 	run := equal-run | unequal-run

  1542 	equal-run := <runlength - 1> pixel-value

  1543 	unequal-run := <-runlength> pixel-value+    (i.e. pixel-value repeated <runlength> times)

  1544 	runlength := uint8 in 1..128

  1545 	pixelvalue := byte-pixel | 16bit-pixel | 24bit-pixel | 32bit-u-pixel | 32bit-a-pixel

  1546 	byte-pixel := octet

  1547 	16bit-pixel := octet octet

  1548 	24bit-pixel := rr gg bb

  1549 	32bit-u-pixel := rr gg bb

  1550 	32bit-a-pixel := rr gg bb aa

  1551 	rr := octet  (red component)

  1552 	gg := octet  (green component)

  1553 	bb := octet  (blue component)

  1554 	aa := octet  (alpha channel)

  1556 	This scheme models runs of 2-128 equal pixels or of upto 127 unequal pixels.

  1557 	Obviously a run of 0 is meaningless.  A run of 1 is considered to be an 'unequal' run containing

  1558 	a single pixel.

  1560 	For 12-bit compression a different encoding scheme is used. Only equal-runs are written, and the

  1561 	run	length is encoded into the top 4 bits of a 16 bit word.  Here's a BNF for 12-bit compression:

  1563 	12-bit-encoding := run*

  1564 	run := equal-run

  1565 	equal-run := high-octet low-octet

  1566 	high-octet := [<runlength - 1> rr]

  1567 	low-octet := [gg bb]

  1568 	runlength := 1..16

  1569 	rr := quartet  (red component)

  1570 	gg := quartet  (green component)

  1571 	bb := quartet  (blue component)

  1573 */

  1575 //Palette compression additions

  1577 /**

  1578 Attempts to compress a bitmap by reducing it to a palette + data.

  1579 If the compression fails, for any of the reasons detailed below, RLE compression will be attempted instead.

  1580 Prerequisites:

  1581 - Bitmap must not already be compressed.

  1582 - Bitmap must contain no more than 255 colors - If bitmap contains >255 colors then palette compression is unlikely to be effective.

  1583 - Bitmap must be 16, 24 or 32 (non alpha) bpp.  Other modes could be implemented, but smaller bit depths will yield less compression

  1584 Small bitmaps (under 1000 pixels) will be unlikely to compress well if at all

  1585 Structure of compressed bitmap will be as follows;

  1586 size of palette[4 bytes] | palette[size * 4 bytes per entry] | data[pixels * upto 1 byte per pixel]

  1587 Bitmap data is packed into memory as efficiently as possible, according to the number of bits required.

  1588 Each line of the compressed bitmap will start on a byte boundary, but not necessarily on a word boundary.

  1589 */

  1590 TInt CBitwiseBitmap::PaletteCompress()

  1591 	{

  1592 	//Compression algorithm

  1593 	//1.Iterate bitmap data, building hash of unique colours found

  1594 	//2.Iterate the hash, and build linear array of the unique colours (this is the palette)

  1595 	//3.Iterate the array, and set the array index of each colour back into the hash

  1596 	//4.Iterate the bitmap data again, for each pixel replace with palette index found from hash

  1598 	//Bitmap must be uncompressed

  1599 	if (iHeader.iCompression != ENoBitmapCompression)

  1600 		return KErrNone;

  1602 	//There must be some data in the bitmap

  1603 	TUint8* base = REINTERPRET_CAST(TUint8*, DataAddress());

  1604 	if (!base)

  1605 		return KErrNone;

  1607 	//Get the bytes per pixel, and make sure it is a supported configuration

  1608 	TUint sourceBytesPerPixel = PaletteBytesPerPixel(iHeader.iBitsPerPixel);

  1609 	if (sourceBytesPerPixel == 0)

  1610 		return KErrNotSupported;

  1612 	//Create a hash table and give it a decent amount of RAM to start with

  1613 	RHashMap<TInt,TInt> colors;

  1614 	if (colors.Reserve(256) != KErrNone)

  1615 		return KErrNoMemory;

  1617 	//Loop the data area of the bitmap, one pixel (sourceBytesPerPixel bytes) at a time

  1618 	TInt numPixels = (iHeader.iSizeInPixels.iWidth * iHeader.iSizeInPixels.iHeight);

  1619 	//we need some pixels!

  1620 	if (numPixels == 0)

  1621 		{

  1622 		colors.Close();

  1623 		return KErrNone;

  1624 		}

  1626 	TUint8* top = base + (iHeader.iSizeInPixels.iHeight * iByteWidth) ; //address of lastmost byte

  1627 	TInt32 lineLengthInBytes = iHeader.iSizeInPixels.iWidth * sourceBytesPerPixel;  //The actual useful data on each line

  1628 	TInt32 lineLengthInBytesPadded = iByteWidth ; //the actual (aligned) length of each line

  1629 	TUint8* pixelAddress;

  1630 	TUint8* lineAddress;

  1631 	//Loop each line of the bitmap data.  Note that each line ends on a 32bit align in the source MBM data.

  1632 	TUint8* lineEnd=0;

  1634 	//Separate looping for 16 & 24+ bpp.  Adds a chunk of duplicated code but saves checking bpp for  every pixel

  1635 	if (iHeader.iBitsPerPixel < 24)

  1636 		{

  1637 		for (lineAddress=base;lineAddress<top;lineAddress+=iByteWidth)

  1638 			{

  1639 			//Loop each pixel within the line

  1640 			lineEnd = lineAddress + lineLengthInBytes;

  1641 			for (pixelAddress = lineAddress; pixelAddress < lineEnd; pixelAddress += sourceBytesPerPixel)

  1642 				{

  1643 				//Extract colour value

  1644 				TUint color = *pixelAddress;

  1645 				color |= (*(pixelAddress+1)) << 8;

  1646 				//Insert colour value into hash

  1647 				//Quicker to use Find() to eliminate duplicates Insert()

  1648 				if (colors.Find(color) == NULL)

  1649 					{

  1650 					if (colors.Insert(color,0) != KErrNone)

  1651 						{

  1652 						colors.Close();

  1653 						return KErrNoMemory;

  1654 						}

  1655 					}

  1656 				}

  1657 			//Test each line whether it's worth continuing to the end

  1658 			//We aren't interested if there's more than 256 colours (RLE compression will probably do a better job in this case)

  1659 			if (colors.Count() > 256)

  1660 				{

  1661 				colors.Close();

  1662 				return KErrNotSupported ;

  1663 				}

  1664 			}

  1665 		}

  1666 	else //>=24 bpp

  1667 		{

  1668 		for (lineAddress = base; lineAddress<top; lineAddress += iByteWidth)

  1669 			{

  1670 			//Loop each pixel within the line

  1671 			lineEnd = lineAddress + lineLengthInBytes;

  1672 			for (pixelAddress = lineAddress; pixelAddress < lineEnd; pixelAddress += sourceBytesPerPixel)

  1673 				{

  1674 				//Extract colour value

  1675 				TUint color = *pixelAddress;

  1676 				color |= (*(pixelAddress+1)) << 8;

  1677 				color |= (*(pixelAddress+2)) << 16;

  1678 				//Insert colour value into hash

  1679 				//Quicker to use Find() to eliminate duplicates Insert()

  1681 				if (colors.Find(color) == NULL)

  1682 					{

  1683 					if (colors.Insert(color,0) != KErrNone)

  1684 						{

  1685 						colors.Close();

  1686 						return KErrNoMemory;

  1687 						}

  1688 					}

  1689 				}

  1690 			//Test each line whether it's worth continuing to the end

  1691 			//We aren't interested if there's more than 256 colours (RLE compression will probably do a better job in this case)

  1692 			if (colors.Count() > 256)

  1693 				{

  1694 				colors.Close();

  1695 				return KErrNotSupported;

  1696 				}

  1697 			} //for

  1698 		}//end if

  1701 	//Now we have enough data to build the palette by iterating all the entries in the colors hash

  1702 	RArray<TUint> palette(colors.Count());

  1703 	THashMapIter<TInt,TInt> colorIterator(colors);

  1704 	const TInt* color = colorIterator.NextKey();

  1705 	while (color)

  1706 		{

  1707 		if (palette.Append(*color) != KErrNone)

  1708 			{

  1709 			palette.Close();

  1710 			colors.Close();

  1711 			return KErrNoMemory;

  1712 			}

  1713 		//set the index of each entry back into the color hash for lookup later

  1714 		//const cast needed as CurrentValue returns a const pointer; for no good reason?

  1715 		TInt* index = CONST_CAST(TInt*, colorIterator.CurrentValue());

  1716 		*index = palette.Count() - 1;

  1717 		color = colorIterator.NextKey();

  1718 		}

  1720 	//Set up some new memory for the palettised bitmap

  1721 	//size is (4 bytes for palette size) + (4 bytes per palette entry) + (upto 1 byte per pixel)

  1722 	//pixels are packed according to number of colors

  1723 	TUint compressedBitsPerPixel = PaletteBitsPerPixel(colors.Count());

  1724 	TUint compressedPixelsPerByte = 8 / compressedBitsPerPixel;

  1725 	TUint compressedLineLengthInBytesPadded = (iHeader.iSizeInPixels.iWidth + compressedPixelsPerByte - 1)/ compressedPixelsPerByte;

  1726 	TInt compressedDataBytes = 4 + 4 * colors.Count() + compressedLineLengthInBytesPadded * iHeader.iSizeInPixels.iHeight;

  1728 	//add two extra ints for storing function pointers (8 bytes )

  1729 	compressedDataBytes += 8 ;

  1731 	TUint8* compressedBase = NULL;

  1732 	compressedBase = iPile->Alloc(compressedDataBytes);

  1733 	if (!compressedBase)

  1734 		{

  1735 		palette.Close();

  1736 		colors.Close();

  1737 		return KErrNoMemory;

  1738 		}

  1739 	iDataOffset = compressedBase - iPile->ChunkBase();

  1741 	iHeader.iBitmapSize = sizeof(SEpocBitmapHeader) + compressedDataBytes;

  1742 	iHeader.iCompression = EGenericPaletteCompression;

  1744 	//copy the palette length into the data area...

  1745 	*(REINTERPRET_CAST(TInt*, compressedBase)) = palette.Count(); //let's hope we're 4 byte aligned...

  1746 	compressedBase+=4;

  1747 	//...then the palette itself...

  1748 	for (TUint loop = 0; loop < palette.Count(); loop++)

  1749 		{

  1750 		*(REINTERPRET_CAST(TInt*, compressedBase)) = palette[loop];

  1751 		compressedBase +=4;

  1752 		}

  1754 	//Work out, then store, the decoding functions required for packing density and colour depth.

  1755 	//This saves having to do it for every scanline during decompression.

  1757 	TDecodeFunction decodeFunction = NULL;

  1758 	switch (compressedPixelsPerByte)

  1759 		{

  1760 		case 1:

  1761 			decodeFunction=CBitwiseBitmap::PaletteDecode1PixelPerByte;

  1762 			break;

  1763 		case 2:

  1764 			decodeFunction=CBitwiseBitmap::PaletteDecode2PixelPerByte;

  1765 			break;

  1766 		case 4:

  1767 			decodeFunction=CBitwiseBitmap::PaletteDecode4PixelPerByte;

  1768 			break;

  1769 		case 8:

  1770 			decodeFunction=CBitwiseBitmap::PaletteDecode8PixelPerByte;

  1771 			break;

  1772 		default:

  1773 			::Panic(EFbsNotSupportedForCompression);

  1774 		}

  1775 	*(REINTERPRET_CAST(TDecodeFunction*, compressedBase))  = decodeFunction ;

  1776 	compressedBase += 4 ;

  1778 	//Select the appropriate assignment function based on the bits-per-pixel of the target

  1779 	TAssignFunction assignFunction = NULL;

  1780 	switch (iHeader.iBitsPerPixel)

  1781 		{

  1782 		case 16:

  1783 			assignFunction=CBitwiseBitmap::PaletteAssign16BitColor;

  1784 			break;

  1785 		case 24:

  1786 			assignFunction=CBitwiseBitmap::PaletteAssign24BitColor;

  1787 			break;

  1788 		case 32:

  1789 			assignFunction=CBitwiseBitmap::PaletteAssign32BitColor;

  1790 			break;

  1791 		default:

  1792 			::Panic(EFbsNotSupportedForCompression);

  1793 		}

  1794 	*(REINTERPRET_CAST(TAssignFunction*, compressedBase)) = assignFunction ;

  1795 	compressedBase += 4 ;

  1797  	//...and finally the data

  1798 	pixelAddress = base;

  1800 	//separate loops for 16 & 24+ bpp again

  1802 	if ( iHeader.iBitsPerPixel < 24 )

  1803 		{

  1804 		for (lineAddress = base; lineAddress < top; lineAddress += lineLengthInBytesPadded)

  1805 			{

  1806 			//Loop each pixel within the line

  1807 			pixelAddress = lineAddress;

  1808 			while (pixelAddress < lineAddress + lineLengthInBytes)

  1809 				{

  1810 				TUint8 pack = 0;

  1811 				//loop for each pixel to pack into the byte.  If we run out of pixels in the line, we write out the pack byte and continue on the next line

  1812 				for (TInt ii = 0; ii < compressedPixelsPerByte && pixelAddress < lineAddress + lineLengthInBytes; ii++)

  1813 					{

  1814 					pack <<= compressedBitsPerPixel;

  1815 					//extract the color

  1816 					TUint color = *pixelAddress;

  1817 					color |= (*(pixelAddress+1)) << 8;

  1819 					//lookup the palette index for the color

  1820 					TInt* paletteIndex = colors.Find(color);

  1821 					//pack the palette index into the target byte

  1822 					pack |= *paletteIndex;

  1823 					//next pixel

  1824 					pixelAddress += sourceBytesPerPixel;

  1825 					}

  1826 				//store the packed pixel data into the new compressed data area

  1827 				*compressedBase = pack;

  1828 				compressedBase++;

  1829 				}

  1830 			}

  1831 		}

  1832 	else //>= 24bpp

  1833 		{

  1834 		for (lineAddress = base; lineAddress < top; lineAddress += lineLengthInBytesPadded)

  1835 			{

  1836 			//Loop each pixel within the line

  1837 			pixelAddress = lineAddress;

  1838 			while (pixelAddress < lineAddress + lineLengthInBytes)

  1839 				{

  1840 				TUint8 pack = 0;

  1841 				//loop for each pixel to pack into the byte.  If we run out of pixels in the line, we write out the pack byte and continue on the next line

  1842 				for (TInt ii = 0; ii < compressedPixelsPerByte && pixelAddress < lineAddress + lineLengthInBytes; ii++)

  1843 					{

  1844 					pack <<= compressedBitsPerPixel;

  1845 					//extract the color

  1846 				TUint color = *pixelAddress;

  1847 					color |= (*(pixelAddress+1)) << 8;

  1848 					color |= (*(pixelAddress+2)) << 16;

  1849 					//if 32 bit, just ignore the 4th byte as it is unused for color data

  1851 					//lookup the palette index for the color

  1852 					TInt* paletteIndex = colors.Find(color);

  1853 					//pack the palette index into the target byte

  1854 					pack |= *paletteIndex;

  1855 					//next pixel

  1856 					pixelAddress += sourceBytesPerPixel;

  1857 					}

  1858 				//store the packed pixel data into the new compressed data area

  1859 				*compressedBase = pack;

  1860 				compressedBase++;

  1861 				}

  1862 			}

  1863 		}//if

  1866 	//Set the RAM compression flag

  1867 	iIsCompressedInRAM = ETrue;

  1869 	//Free the old data.

  1870 	iPile->Free(base);

  1871 	//Clean up

  1872 	palette.Close();

  1873 	colors.Close();

  1874 	return KErrNone;

  1875 	}

  1877 /**

  1878 Create a scan line from a palette compressed bitmap.

  1879 Starting from aPixel in the bitmap pointed to be aBase, populate aDestBuffer with aLength pixels looked up in the palette.

  1880 Note this function assumes 16, 24 or 32 non alpha bit uncompressed bitmaps, compressed into 8 bit palettes (ie <256 colors)

  1881 Structure of bitmap is (4 bytes for palette size) + (4 bytes per palette entry) + (1 byte per pixel)

  1882 @param aDestBuffer Points to the destination buffer. After the call it will be filled

  1883 with the decompressed data.

  1884 @param aPixel The decompression starts from this pixel

  1885 @param aLength Length of requested decompressed data - in pixels

  1886 @param aBase Points to the beginning of compressed bitmap data

  1887 @param aLineScannngPosition Saved information about the last used position in the compressed data

  1888 */

  1889 void CBitwiseBitmap::GenerateLineFromPaletteCompressedData(

  1890 									 TUint8* aDestBuffer,

  1891 									 const TPoint& aPixel,

  1892 									 TInt aLength,

  1893 									 TUint32* aBase,

  1894 									 TLineScanningPosition& /*aLineScanningPosition*/) const

  1895 	{

  1896 	//At entry, aBase will point to the start of the compressed data, ie the palette size

  1897 	//Each line in the bitmap will start at a byte boundary in the compressed data.

  1899 	TUint32* srcPalette = aBase + 1; //Address of the palette in the source data

  1900 	TUint srcNumPaletteEntries = *aBase;	//Number of entries in the palette (will be <=255)

  1901 	TUint compressedBitsPerPixel = PaletteBitsPerPixel(srcNumPaletteEntries);

  1902 	__ASSERT_DEBUG(compressedBitsPerPixel <= 8, Panic( EFbsBitmapDecompressionError )) ;

  1903 	const TUint8 lookup[] = {0, 8, 4, 0, 2, 0, 0, 0, 1};

  1904 	//TUint compressedPixelsPerByte = 8 / compressedBitsPerPixel;

  1905 	TUint compressedPixelsPerByte = lookup[compressedBitsPerPixel];

  1906 	__ASSERT_DEBUG(compressedPixelsPerByte>0, ::Panic(EFbsNotSupportedForCompression));

  1908 	TUint8* srcData = REINTERPRET_CAST(TUint8*, srcPalette + srcNumPaletteEntries);	//Address of the pixel data in the source data

  1910 	//Extract the function pointers for decoding functions. Set up decode & assign functions.

  1911 	TDecodeFunction decodeFunction = NULL ;

  1912 	decodeFunction = reinterpret_cast<TDecodeFunction>(*((TUint32*)srcData )) ;

  1913 	srcData += 4 ;

  1914 	TAssignFunction assignFunction = NULL;

  1915 	assignFunction = reinterpret_cast<TAssignFunction>(*((TUint32*)srcData )) ;

  1916 	srcData += 4 ;

  1918 	//Note: The following lines have been optimised to avoid divisions.

  1919 	//By way of explanation the original lines have been left as comments

  1921 	//TUint srcBytesPerLinePadded = (iHeader.iSizeInPixels.iWidth + compressedPixelsPerByte - 1) / compressedPixelsPerByte;	//number of bytes occupied by each line in the compressed bitmap.

  1922 	TUint srcBytesPerLinePadded = ((iHeader.iSizeInPixels.iWidth + compressedPixelsPerByte - 1)  * compressedBitsPerPixel) >> 3;	//number of bytes occupied by each line in the compressed bitmap.

  1923 	//TUint srcStartBytesFromBase = aPixel.iY * srcBytesPerLinePadded + aPixel.iX / compressedPixelsPerByte;	//Starting bytes from the start of the bitmap

  1924 	TUint srcStartBytesFromBase = aPixel.iY * srcBytesPerLinePadded + ((aPixel.iX * compressedBitsPerPixel) >> 3);	//Starting bytes from the start of the bitmap

  1925 	//TUint srcStartPixelInByte = aPixel.iX  % compressedPixelsPerByte;		//starting pixel position in byte (lines start on byte boundary)

  1926 	TUint srcStartPixelInByte = aPixel.iX & ((compressedPixelsPerByte)- 1);		//starting pixel position in byte (lines start on byte boundary)

  1927 	//TUint srcEndBytesFromBase = srcStartBytesFromBase + (aLength + compressedPixelsPerByte - 1) / compressedPixelsPerByte;		//Ending bytes from the start of the bitmap

  1928 	TUint srcEndBytesFromBase = srcStartBytesFromBase + (((aLength + compressedPixelsPerByte - 1) * compressedBitsPerPixel) >> 3);		//Ending bytes from the start of the bitmap

  1929 	//TUint srcEndPixelInByte = (aPixel.iX + aLength) % compressedPixelsPerByte;		//Ending pixel position in byte

  1930 	TUint srcEndPixelInByte = (aPixel.iX + aLength) & ((compressedPixelsPerByte)-1);		//Ending pixel position in byte

  1931 	TUint8* srcStartData = srcData + srcStartBytesFromBase;	//Address of the first byte of packed pixels in the source

  1932 	TUint8* srcEndData = srcData + srcEndBytesFromBase;	//Address of the last+1 byte of packed pixels in the source

  1933 	TUint8* destStartData = aDestBuffer + ((aPixel.iX*iHeader.iBitsPerPixel) >> 3); //Address of the first pixel in the destination

  1935 	//3 stages to the decompression:

  1936 	//1. Decompress any pixels which are a subset of the first byte

  1937 	//2. Loop whole bytes extracting all pixels at once

  1938 	//3. Decompress any pixels which are a subset of the last byte

  1940 	TUint8* srcDataPtr = srcStartData;

  1942 	//Stage 1: Decompress any pixels which are a subset of the first byte

  1943 	if (srcStartPixelInByte > 0)

  1944 		PaletteDecodeAndAssignGeneric(srcDataPtr++, srcPalette, destStartData, srcStartPixelInByte, compressedPixelsPerByte-1, compressedPixelsPerByte, compressedBitsPerPixel);

  1946 	//If the last byte is only partly packed with pixels from this line, stop one byte short in the main loop

  1947 	if (srcEndPixelInByte > 0)

  1948 		srcEndData--;

  1950 	//Stage 2: Loop all the required pixels and call the appropriate functions

  1951 	while (srcDataPtr < srcEndData)

  1952 		{

  1953 		__ASSERT_DEBUG(srcDataPtr <= srcEndData, ::Panic(EFbsNotSupportedForCompression));

  1954 		__ASSERT_DEBUG(destStartData <= aDestBuffer + ((aPixel.iX*iHeader.iBitsPerPixel) >> 3) + aLength * PaletteBytesPerPixel(iHeader.iBitsPerPixel), ::Panic(EFbsNotSupportedForCompression));

  1955 		(*decodeFunction)(srcDataPtr++, srcPalette, destStartData, assignFunction);

  1956 		}

  1958 	//Stage 3: Decompress any pixels which are a subset of the last byte

  1959 	if (srcEndPixelInByte > 0)

  1960 		PaletteDecodeAndAssignGeneric(srcDataPtr++, srcPalette, destStartData, 0, srcEndPixelInByte-1, compressedPixelsPerByte, compressedBitsPerPixel);

  1961 	}

  1963 /**

  1964 This function deals with all different bit depths & color counts dynamically - smaller but slower

  1965 @param aDataPtr Address in compressed data to read from

  1966 @param aPalettePtr Address of the start of the palette in the compressed data

  1967 @param aDestPtr Address to write uncompressed data to.  Will be incremented on return from function.

  1968 @param aStartPixel Zero based position within the compressed byte of the first pixel to decompress

  1969 @param aEndPixel Zero based position within the compressed byte of the last pixel to decompress

  1970 @param aCompressedPixelsPerByte Number of pixels packed into each byte of the compressed data

  1971 @param aCompressedBitsPerPixel Number of bits used to express each pixel in the compressed data.  Nothing to do with the color depth of the image.

  1972 */

  1973 void CBitwiseBitmap::PaletteDecodeAndAssignGeneric(	TUint8* aDataPtr,

  1974 												TUint32* aPalettePtr,

  1975 												TUint8*& aDestPtr,

  1976 												TUint aStartPixel,

  1977 												TUint aEndPixel,

  1978 												TUint aCompressedPixelsPerByte,

  1979 												TUint aCompressedBitsPerPixel) const

  1980 	{

  1981 	__ASSERT_DEBUG(aStartPixel<aCompressedPixelsPerByte, ::Panic(EFbsNotSupportedForCompression));

  1982 	__ASSERT_DEBUG(aEndPixel<aCompressedPixelsPerByte, ::Panic(EFbsNotSupportedForCompression));

  1984 	//create a mask for the appropriate number of bits

  1985 	TUint8 mask = 0xFF;

  1986 	mask <<= 8 - aCompressedBitsPerPixel;

  1988 	//Adjust the mask in case we've been asked to start at an intermediate pixel

  1989 	mask >>= aStartPixel * aCompressedBitsPerPixel;

  1991 	TUint8 pack = *aDataPtr; //max of 8 bits for palette entry

  1993 	//Loop the pixel data from the requested start to the requested end

  1994 	for (TInt ii = aStartPixel;  ii <= aEndPixel;  ii++)

  1995 		{

  1996 		//extract the bits corresponding to the required color index from the pack using the mask

  1997 		TUint8 index = pack&mask;

  1998 		//shift the index to the right to get true value

  1999 		index >>= (aCompressedPixelsPerByte- ii - 1) * aCompressedBitsPerPixel;

  2000 		//get the address of the required color value from the palette

  2001 		TUint32 color = *(aPalettePtr + index);

  2002 		//and copy the actual color value into the scanline buffer

  2003 		*aDestPtr ++= color;

  2004 		*aDestPtr ++= color >> 8;

  2005 		if (iHeader.iBitsPerPixel >= 24)

  2006 			*aDestPtr ++= color >> 16;

  2007 		if (iHeader.iBitsPerPixel == 32)

  2008 			*aDestPtr ++= 0xFF;  //use 0xFF rather than 0x00 as it is more alpha friendly

  2010 		//shift the mask to get the next required bits

  2011 		mask >>= aCompressedBitsPerPixel;

  2012 		}

  2013 	}

  2015 /**

  2016 Specialised function for decoding pixels from a palette compressed bitmap with 1 pixel packed in each byte.

  2017 Implemented for speed, not size

  2018 @param aDataPtr Address in compressed data to read from

  2019 @param aPalettePtr Address of the start of the palette in the compressed data

  2020 @param aDestPtr Address to write uncompressed data to.  Will be incremented on return from function.

  2021 @param aAssignFunction Function pointer to assigment function to use to write actual pixel data to uncompressed scanline

  2022 */

  2023 void CBitwiseBitmap::PaletteDecode1PixelPerByte(TUint8* aDataPtr, TUint32* aPalettePtr, TUint8*& aDestPtr, TAssignFunction aAssignFunction)

  2024 	{

  2025 	(*aAssignFunction)(aDestPtr, *(aPalettePtr + *aDataPtr));

  2026 	}

  2028 /**

  2029 Specialised function for decoding pixels from a palette compressed bitmap with 2 pixels packed in each byte.

  2030 Implemented for speed, not size

  2031 @param aDataPtr Address in compressed data to read from

  2032 @param aPalettePtr Address of the start of the palette in the compressed data

  2033 @param aDestPtr Address to write uncompressed data to.  Will be incremented on return from function.

  2034 @param aAssignFunction Function pointer to assigment function to use to write actual pixel data to uncompressed scanline

  2035 */

  2036 void CBitwiseBitmap::PaletteDecode2PixelPerByte(TUint8* aDataPtr, TUint32* aPalettePtr, TUint8*& aDestPtr, TAssignFunction aAssignFunction)

  2037 	{

  2038 	TUint8 mask = 0xF0; //binary 11110000

  2039 	TUint8 pack = *aDataPtr;

  2040 	//Pixel 1

  2041 	TUint8 index = pack&mask;

  2042 	index >>= 4;

  2043 	TUint32 color = *(aPalettePtr + index);

  2044 	(*aAssignFunction)(aDestPtr, color);

  2045 	mask >>= 4;

  2046  	//Pixel 2

  2047  	index = pack&mask;

  2048  	color = *(aPalettePtr + index);

  2049 	(*aAssignFunction)(aDestPtr, color);

  2050 	}

  2052 /**

  2053 Specialised function for decoding pixels from a palette compressed bitmap with 4 pixels packed in each byte.

  2054 Implemented for speed, not size

  2055 @param aDataPtr Address in compressed data to read from

  2056 @param aPalettePtr Address of the start of the palette in the compressed data

  2057 @param aDestPtr Address to write uncompressed data to.  Will be incremented on return from function.

  2058 @param aAssignFunction Function pointer to assigment function to use to write actual pixel data to uncompressed scanline

  2059 */

  2060 void CBitwiseBitmap::PaletteDecode4PixelPerByte(TUint8* aDataPtr, TUint32* aPalettePtr, TUint8*& aDestPtr, TAssignFunction aAssignFunction)

  2061 	{

  2062 	TUint8 mask = 0xC0; //binary 11000000

  2063 	TUint8 pack = *aDataPtr;

  2064 	//Pixel 1

  2065 	TUint8 index = pack&mask;

  2066 	index >>= 6;

  2067 	TUint32 color = *(aPalettePtr + index);

  2068 	(*aAssignFunction)(aDestPtr, color);

  2069 	mask >>= 2;

  2070  	//Pixel 2

  2071  	index = pack&mask;

  2072 	index >>= 4;

  2073  	color = *(aPalettePtr + index);

  2074 	(*aAssignFunction)(aDestPtr, color);

  2075 	mask >>= 2;

  2076  	//Pixel 3

  2077  	index = pack&mask;

  2078 	index >>= 2;

  2079  	color = *(aPalettePtr + index);

  2080 	(*aAssignFunction)(aDestPtr, color);

  2081 	mask >>= 2;

  2082  	//Pixel 4

  2083  	index = pack&mask;

  2084  	color = *(aPalettePtr + index);

  2085 	(*aAssignFunction)(aDestPtr, color);

  2086 	}

  2088 /**

  2089 Specialised function for decoding pixels from a palette compressed bitmap with 8 pixels packed in each byte.

  2090 Implemented for speed, not size

  2091 @param aDataPtr Address in compressed data to read from

  2092 @param aPalettePtr Address of the start of the palette in the compressed data

  2093 @param aDestPtr Address to write uncompressed data to.  Will be incremented on return from function.

  2094 @param aAssignFunction Function pointer to assigment function to use to write actual pixel data to uncompressed scanline

  2095 */

  2096 void CBitwiseBitmap::PaletteDecode8PixelPerByte(TUint8* aDataPtr, TUint32* aPalettePtr, TUint8*& aDestPtr, TAssignFunction aAssignFunction)

  2097 	{

  2098 	TUint8 mask = 0x80; //binary 10000000

  2099 	TUint8 pack = *aDataPtr;

  2100 	//Pixel 1

  2101 	TUint8 index = pack&mask;

  2102 	index >>= 7;

  2103 	TUint32 color = *(aPalettePtr + index);

  2104 	(*aAssignFunction)(aDestPtr, color);

  2105 	mask >>= 1;

  2106  	//Pixel 2

  2107  	index = pack&mask;

  2108 	index >>= 6;

  2109  	color = *(aPalettePtr + index);

  2110 	(*aAssignFunction)(aDestPtr, color);

  2111 	mask>>=1;

  2112  	//Pixel 3

  2113  	index = pack&mask;

  2114 	index >>= 5;

  2115  	color = *(aPalettePtr + index);

  2116 	(*aAssignFunction)(aDestPtr, color);

  2117 	mask >>= 1;

  2118   	//Pixel 4

  2119  	index = pack&mask;

  2120 	index >>= 4;

  2121  	color = *(aPalettePtr + index);

  2122 	(*aAssignFunction)(aDestPtr, color);

  2123 	mask >>= 1;

  2124   	//Pixel 5

  2125  	index = pack&mask;

  2126 	index >>= 3;

  2127  	color = *(aPalettePtr + index);

  2128 	(*aAssignFunction)(aDestPtr, color);

  2129 	mask >>= 1;

  2130   	//Pixel 6

  2131  	index = pack&mask;

  2132 	index >>= 2;

  2133  	color = *(aPalettePtr + index);

  2134 	(*aAssignFunction)(aDestPtr, color);

  2135 	mask >>= 1;

  2136   	//Pixel 7

  2137  	index = pack&mask;

  2138 	index >>= 1;

  2139  	color = *(aPalettePtr + index);

  2140 	(*aAssignFunction)(aDestPtr, color);

  2141 	mask >>= 1;

  2142  	//Pixel 8

  2143  	index = pack&mask;

  2144  	color = *(aPalettePtr + index);

  2145 	(*aAssignFunction)(aDestPtr, color);

  2146 	}

  2148 /**

  2149 Specialised function for assigning pixels into an uncompressed scanline of 16 bit color depth.

  2150 Implemented for speed, not size

  2151 @param aDestPtr Address to write uncompressed data to.  Will be incremented on return from function.

  2152 @param aColor Color info to write.

  2153 */

  2154 void CBitwiseBitmap::PaletteAssign16BitColor(TUint8*& aDestPtr, TUint32 aColor)

  2155 	{

  2156 	*aDestPtr ++= aColor;

  2157 	*aDestPtr ++= aColor >> 8;

  2158 	}

  2160 /**

  2161 Specialised function for assigning pixels into an uncompressed scanline of 24 bit color depth.

  2162 Implemented for speed, not size

  2163 @param aDestPtr Address to write uncompressed data to.  Will be incremented on return from function.

  2164 @param aColor Color info to write.

  2165 */

  2166 void CBitwiseBitmap::PaletteAssign24BitColor(TUint8*& aDestPtr, TUint32 aColor)

  2167 	{

  2168 	*aDestPtr ++= aColor;

  2169 	*aDestPtr ++= aColor >> 8;

  2170 	*aDestPtr ++= aColor >> 16;

  2171 	}

  2173 /**

  2174 Specialised function for assigning pixels into an uncompressed scanline of 32 bit color depth.

  2175 Implemented for speed, not size

  2176 @param aDestPtr Address to write uncompressed data to.  Will be incremented on return from function.

  2177 @param aColor Color info to write.

  2178 */

  2179 void CBitwiseBitmap::PaletteAssign32BitColor(TUint8*& aDestPtr, TUint32 aColor)

  2180 	{

  2181 	*aDestPtr ++= aColor;

  2182 	*aDestPtr ++= aColor >> 8;

  2183 	*aDestPtr ++= aColor >> 16;

  2184 	*aDestPtr ++= 0xFF;  //use 0xFF rather than 0x00 as it is more alpha friendly

  2185 	}

  2187 /**

  2188 Get the bits used per pixel when packing multiple pixels in palette compression.

  2189 The value returned is a power of 2, not always the most efficient pack, for alignment reasons, Eg

  2190  65537 -> KMaxTInt : 32 bpp

  2191  257 -> 65536 colors : 16 bpp

  2192  17 -> 256 colors : 8 bpp

  2193  5  -> 16  colors : 4 bpp

  2194  3  -> 4   colors : 2 bpp

  2195  0  -> 2   colors : 1 bpp

  2196 @param aNumColors The number of colors in the bitmap.  This governs the size of the palette and thus

  2197 the number of bits needed to represent an index into it.

  2198 */

  2199 TUint CBitwiseBitmap::PaletteBitsPerPixel(TInt aNumColors) const

  2200 	{

  2201 	if (aNumColors <= 2)

  2202 		return 1;

  2203 	else if (aNumColors <= 4)

  2204 		return 2;

  2205 	else if (aNumColors <= 16)

  2206 		return 4;

  2207 	else if (aNumColors <= 256)

  2208 		return 8;

  2209 	else if (aNumColors <= 65536)

  2210 		return 16;

  2211 	else

  2212 		return 32;

  2213 	}

  2215 /**

  2216 Gets the bytes used per pixel according to the bits per pixel of a bitmap.

  2217 Also used to find which bit per pixel values are supported by palette compression, hence this is not

  2218 a case of simple division by 8.

  2219 If return value is zero, the supplied bit per pixel value is not supported by palette compression.

  2220 @param aBitsPerPixel The bits per pixel value to transform into bytes

  2221 */

  2222 TUint CBitwiseBitmap::PaletteBytesPerPixel(TInt aBitsPerPixel) const

  2223 	{

  2224 	if (aBitsPerPixel == 16)

  2225 		return 2;  //16 bit

  2226 	else if (aBitsPerPixel == 24)

  2227 		return 3;   //24 bit

  2228 	else if (aBitsPerPixel == 32 && iHeader.iColor == SEpocBitmapHeader::EColor)

  2229 		return 4;	//32 bit with no alpha

  2230 	else

  2231 		return 0;

  2232 	}

author	sl@SLION-WIN7.fritz.box
	Fri, 15 Jun 2012 03:10:57 +0200
changeset 0	bde4ae8d615e
permissions	-rw-r--r--