Symbian3/Examples/guid-6013a680-57f9-415b-8851-c4fa63356636/_png_scanline_encoder_8cpp_source.html
Week 32 contribution of PDK documentation content. See release notes for details. Fixes bug Bug 3582
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<h1>examples/Multimedia/ICL/ICLCodec/PngScanlineEncoder.cpp</h1><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">// PngScanlineEncoder.cpp</span>
<a name="l00002"></a>00002 <span class="comment">//</span>
<a name="l00003"></a>00003 <span class="comment">// Copyright (c) 2007-2009 Nokia Corporation and/or its subsidiary(-ies).</span>
<a name="l00004"></a>00004 <span class="comment">// All rights reserved.</span>
<a name="l00005"></a>00005 <span class="comment">// This component and the accompanying materials are made available</span>
<a name="l00006"></a>00006 <span class="comment">// under the terms of "Eclipse Public License v1.0"</span>
<a name="l00007"></a>00007 <span class="comment">// which accompanies this distribution, and is available</span>
<a name="l00008"></a>00008 <span class="comment">// at the URL "http://www.eclipse.org/legal/epl-v10.html".</span>
<a name="l00009"></a>00009 <span class="comment">//</span>
<a name="l00010"></a>00010 <span class="comment">// Initial Contributors:</span>
<a name="l00011"></a>00011 <span class="comment">// Nokia Corporation - initial contribution.</span>
<a name="l00012"></a>00012 <span class="comment">//</span>
<a name="l00013"></a>00013 <span class="comment">// Contributors:</span>
<a name="l00014"></a>00014 <span class="comment">//</span>
<a name="l00015"></a>00015 <span class="comment">// Description:</span>
<a name="l00016"></a>00016 <span class="comment">//</span>
<a name="l00017"></a>00017 <span class="comment">//</span>
<a name="l00018"></a>00018
<a name="l00019"></a>00019 <span class="preprocessor">#include "PngScanlineEncoder.h"</span>
<a name="l00020"></a>00020
<a name="l00021"></a>00021 <span class="comment">//</span>
<a name="l00022"></a>00022 <span class="comment">// CPngWriteSubCodec: base class for writing PNG scanlines</span>
<a name="l00023"></a>00023 <span class="comment">//</span>
<a name="l00024"></a>00024
<a name="l00025"></a>00025 <span class="comment">// Factory function</span>
<a name="l00026"></a>00026 <a class="code" href="class_c_png_write_sub_codec.html">CPngWriteSubCodec</a>* CPngWriteSubCodec::NewL(<span class="keyword">const</span> <a class="code" href="class_t_png_image_information.html">TPngImageInformation</a>& aInfo, <span class="keyword">const</span> CFbsBitmap* aSource)
<a name="l00027"></a>00027 {
<a name="l00028"></a>00028 <a class="code" href="class_c_png_write_sub_codec.html">CPngWriteSubCodec</a>* <span class="keyword">self</span> = NULL;
<a name="l00029"></a>00029
<a name="l00030"></a>00030 <span class="keywordflow">switch</span> (aInfo.iBitDepth)
<a name="l00031"></a>00031 {
<a name="l00032"></a>00032 <span class="keywordflow">case</span> 1:
<a name="l00033"></a>00033 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) <a class="code" href="class_c_bit_depth1_encoder.html">CBitDepth1Encoder</a>;
<a name="l00034"></a>00034 <span class="keywordflow">break</span>;
<a name="l00035"></a>00035 <span class="keywordflow">case</span> 2:
<a name="l00036"></a>00036 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) <a class="code" href="class_c_bit_depth2_encoder.html">CBitDepth2Encoder</a>;
<a name="l00037"></a>00037 <span class="keywordflow">break</span>;
<a name="l00038"></a>00038 <span class="keywordflow">case</span> 4:
<a name="l00039"></a>00039 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) <a class="code" href="class_c_bit_depth4_encoder.html">CBitDepth4Encoder</a>;
<a name="l00040"></a>00040 <span class="keywordflow">break</span>;
<a name="l00041"></a>00041 <span class="keywordflow">case</span> 8:
<a name="l00042"></a>00042 <span class="keywordflow">switch</span> (aInfo.iColorType)
<a name="l00043"></a>00043 {
<a name="l00044"></a>00044 <span class="keywordflow">case</span> TPngImageInformation::EGrayscale:
<a name="l00045"></a>00045 <span class="keywordflow">case</span> TPngImageInformation::EIndexedColor:
<a name="l00046"></a>00046 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) <a class="code" href="class_c_bit_depth8_encoder.html">CBitDepth8Encoder</a>;
<a name="l00047"></a>00047 <span class="keywordflow">break</span>;
<a name="l00048"></a>00048 <span class="keywordflow">case</span> TPngImageInformation::EDirectColor:
<a name="l00049"></a>00049 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) <a class="code" href="class_c_bit_depth8_color_type2_encoder.html">CBitDepth8ColorType2Encoder</a>;
<a name="l00050"></a>00050 <span class="keywordflow">break</span>;
<a name="l00051"></a>00051 <span class="keywordflow">default</span>:
<a name="l00052"></a>00052 User::Leave(KErrNotSupported);
<a name="l00053"></a>00053 <span class="keywordflow">break</span>;
<a name="l00054"></a>00054 }
<a name="l00055"></a>00055 <span class="keywordflow">break</span>;
<a name="l00056"></a>00056 <span class="keywordflow">default</span>:
<a name="l00057"></a>00057 User::Leave(KErrNotSupported);
<a name="l00058"></a>00058 <span class="keywordflow">break</span>;
<a name="l00059"></a>00059 }
<a name="l00060"></a>00060 ASSERT(<span class="keyword">self</span>);
<a name="l00061"></a>00061 CleanupStack::PushL(<span class="keyword">self</span>);
<a name="l00062"></a>00062 <span class="keyword">self</span>->ConstructL(aInfo, aSource);
<a name="l00063"></a>00063 CleanupStack::Pop(<span class="keyword">self</span>);
<a name="l00064"></a>00064 <span class="keywordflow">return</span> <span class="keyword">self</span>;
<a name="l00065"></a>00065 }
<a name="l00066"></a>00066
<a name="l00067"></a>00067 CPngWriteSubCodec::CPngWriteSubCodec()
<a name="l00068"></a>00068 : iScanlineDes(NULL, 0)
<a name="l00069"></a>00069 {
<a name="l00070"></a>00070 }
<a name="l00071"></a>00071
<a name="l00072"></a>00072 CPngWriteSubCodec::~CPngWriteSubCodec()
<a name="l00073"></a>00073 {
<a name="l00074"></a>00074 <span class="keyword">delete</span> iScanlineBuffer;
<a name="l00075"></a>00075 <span class="keyword">delete</span> iPalette;
<a name="l00076"></a>00076 }
<a name="l00077"></a>00077
<a name="l00078"></a>00078 <span class="keywordtype">void</span> CPngWriteSubCodec::ConstructL(<span class="keyword">const</span> <a class="code" href="class_t_png_image_information.html">TPngImageInformation</a>& aInfo, <span class="keyword">const</span> CFbsBitmap* aSource)
<a name="l00079"></a>00079 {
<a name="l00080"></a>00080 iInfo = aInfo;
<a name="l00081"></a>00081 iSource = aSource;
<a name="l00082"></a>00082 iScanlineBufferSize = ScanlineBufferSize(iInfo.iSize.iWidth);
<a name="l00083"></a>00083 iScanlineBuffer = HBufC8::NewMaxL(iScanlineBufferSize);
<a name="l00084"></a>00084 iScanlineDes.Set(&(iScanlineBuffer->Des())[0], iScanlineBufferSize, iScanlineBufferSize);
<a name="l00085"></a>00085
<a name="l00086"></a>00086 <span class="comment">// Init stuff specific to derived class</span>
<a name="l00087"></a>00087 DoConstructL();
<a name="l00088"></a>00088 }
<a name="l00089"></a>00089
<a name="l00090"></a>00090 <span class="keywordtype">void</span> CPngWriteSubCodec::DoConstructL()
<a name="l00091"></a>00091 {
<a name="l00092"></a>00092 }
<a name="l00093"></a>00093
<a name="l00094"></a>00094 TDes8& CPngWriteSubCodec::Buffer()
<a name="l00095"></a>00095 {
<a name="l00096"></a>00096 iScanlineDes.FillZ();
<a name="l00097"></a>00097 <span class="keywordflow">return</span> iScanlineDes;
<a name="l00098"></a>00098 }
<a name="l00099"></a>00099
<a name="l00100"></a>00100 TDes8& CPngWriteSubCodec::EncodeL(<span class="keyword">const</span> TInt aScanline)
<a name="l00101"></a>00101 {
<a name="l00102"></a>00102 <span class="keywordflow">if</span> (aScanline < iInfo.iSize.iHeight)
<a name="l00103"></a>00103 {
<a name="l00104"></a>00104 TUint8* dataPtr = <span class="keyword">const_cast<</span>TUint8*<span class="keyword">></span>(iScanlineDes.Ptr());
<a name="l00105"></a>00105 <span class="keyword">const</span> TUint8* dataPtrLimit = dataPtr + iScanlineBufferSize;
<a name="l00106"></a>00106
<a name="l00107"></a>00107 DoEncode(iSource, aScanline, dataPtr, dataPtrLimit);
<a name="l00108"></a>00108 }
<a name="l00109"></a>00109 <span class="keywordflow">else</span>
<a name="l00110"></a>00110 {
<a name="l00111"></a>00111 iScanlineDes.Set(NULL, 0, 0);
<a name="l00112"></a>00112 }
<a name="l00113"></a>00113 <span class="keywordflow">return</span> iScanlineDes;
<a name="l00114"></a>00114 }
<a name="l00115"></a>00115
<a name="l00116"></a>00116 TUint8 CPngWriteSubCodec::ReverseBits(<span class="keyword">const</span> TUint8 aValue)<span class="keyword"> const</span>
<a name="l00117"></a>00117 <span class="keyword"> </span>{
<a name="l00118"></a>00118 TUint value = aValue;
<a name="l00119"></a>00119 TUint reverseVal = 0;
<a name="l00120"></a>00120 <span class="keywordflow">for</span> (TInt i = 0; i < 8; i++)
<a name="l00121"></a>00121 {
<a name="l00122"></a>00122 reverseVal <<= 1;
<a name="l00123"></a>00123 reverseVal |= value & 1;
<a name="l00124"></a>00124 value >>= 1;
<a name="l00125"></a>00125 }
<a name="l00126"></a>00126 <span class="keywordflow">return</span> TUint8(reverseVal);
<a name="l00127"></a>00127 }
<a name="l00128"></a>00128
<a name="l00129"></a>00129 <span class="keywordtype">void</span> CPngWriteSubCodec::EncodePalettedScanline(TUint8* aDataPtr, <span class="keyword">const</span> CFbsBitmap* aSource, <span class="keyword">const</span> TInt aScanline,
<a name="l00130"></a>00130 <span class="keyword">const</span> TInt aPixelsPerByte, <span class="keyword">const</span> TInt aShiftValue)
<a name="l00131"></a>00131 {
<a name="l00132"></a>00132 <span class="comment">// Encode a single scanline with indexes into the current palette</span>
<a name="l00133"></a>00133 ASSERT(iInfo.iPalettePresent);
<a name="l00134"></a>00134 TPoint pos(0, aScanline);
<a name="l00135"></a>00135 <span class="keyword">const</span> TInt scanLength = iInfo.iSize.iWidth;
<a name="l00136"></a>00136 <span class="keywordflow">for</span> (TInt i=0; i < scanLength; i += aPixelsPerByte)
<a name="l00137"></a>00137 {
<a name="l00138"></a>00138 <span class="comment">// Pack each byte with 'aPixelsPerByte' index values</span>
<a name="l00139"></a>00139 TUint8 pixels = 0;
<a name="l00140"></a>00140 <span class="keywordflow">for</span> (TInt j=0; j < aPixelsPerByte; j++)
<a name="l00141"></a>00141 {
<a name="l00142"></a>00142 pixels <<= aShiftValue;
<a name="l00143"></a>00143 TRgb rgb;
<a name="l00144"></a>00144 aSource->GetPixel(rgb, pos);
<a name="l00145"></a>00145 pixels |= TUint8(iPalette->NearestIndex(rgb));
<a name="l00146"></a>00146 pos.iX++;
<a name="l00147"></a>00147 }
<a name="l00148"></a>00148 *aDataPtr = pixels;
<a name="l00149"></a>00149 aDataPtr++;
<a name="l00150"></a>00150 }
<a name="l00151"></a>00151 }
<a name="l00152"></a>00152
<a name="l00153"></a>00153 <span class="comment">//</span>
<a name="l00154"></a>00154 <span class="comment">// These classes specialise the PNG writer to write</span>
<a name="l00155"></a>00155 <span class="comment">// scanlines with different bitmap depths/colour types</span>
<a name="l00156"></a>00156 <span class="comment">//</span>
<a name="l00157"></a>00157
<a name="l00158"></a>00158 <span class="comment">//</span>
<a name="l00159"></a>00159 <span class="comment">// CBitDepth1Encoder</span>
<a name="l00160"></a>00160 <span class="comment">//</span>
<a name="l00161"></a>00161
<a name="l00162"></a>00162 <span class="keywordtype">void</span> CBitDepth1Encoder::DoConstructL()
<a name="l00163"></a>00163 {
<a name="l00164"></a>00164 <span class="keywordflow">if</span> (iInfo.iColorType == TPngImageInformation::EIndexedColor)
<a name="l00165"></a>00165 {
<a name="l00166"></a>00166 <span class="comment">// Setup palette</span>
<a name="l00167"></a>00167 iPalette = CPalette::NewL(2);
<a name="l00168"></a>00168 iPalette->SetEntry(0, KRgbBlack);
<a name="l00169"></a>00169 iPalette->SetEntry(1, KRgbWhite);
<a name="l00170"></a>00170 iInfo.iPalettePresent = ETrue;
<a name="l00171"></a>00171 }
<a name="l00172"></a>00172 }
<a name="l00173"></a>00173
<a name="l00174"></a>00174 TInt CBitDepth1Encoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00175"></a>00175 {
<a name="l00176"></a>00176 <span class="comment">// 8 pixels per byte</span>
<a name="l00177"></a>00177 <span class="keywordflow">return</span> ((aPixelLength + KPngDepth1RoundUpValue) / KPngDepth1PixelsPerByte) + KPngScanlineFilterTypeLength;
<a name="l00178"></a>00178 }
<a name="l00179"></a>00179
<a name="l00180"></a>00180 <span class="keywordtype">void</span> CBitDepth1Encoder::DoEncode(<span class="keyword">const</span> CFbsBitmap* aSource, <span class="keyword">const</span> TInt aScanline,
<a name="l00181"></a>00181 TUint8* aDataPtr, <span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00182"></a>00182 {
<a name="l00183"></a>00183 <span class="comment">// Filter method</span>
<a name="l00184"></a>00184 PtrWriteUtil::WriteInt8(aDataPtr, iInfo.iFilterMethod);
<a name="l00185"></a>00185 aDataPtr++;
<a name="l00186"></a>00186
<a name="l00187"></a>00187 <span class="comment">// Pixel data</span>
<a name="l00188"></a>00188 <span class="keyword">const</span> TInt scanLength = iInfo.iSize.iWidth;
<a name="l00189"></a>00189 <span class="keywordflow">if</span> (iInfo.iColorType == TPngImageInformation::EIndexedColor)
<a name="l00190"></a>00190 {
<a name="l00191"></a>00191 <span class="comment">// Write palette indexes</span>
<a name="l00192"></a>00192 EncodePalettedScanline(aDataPtr, aSource, aScanline, KPngDepth1PixelsPerByte, KPngDepth1ShiftValue);
<a name="l00193"></a>00193 }
<a name="l00194"></a>00194 <span class="keywordflow">else</span>
<a name="l00195"></a>00195 {
<a name="l00196"></a>00196 <span class="comment">// Write RGB data</span>
<a name="l00197"></a>00197 TInt dataLength = (scanLength + KPngDepth1RoundUpValue) / KPngDepth1PixelsPerByte;
<a name="l00198"></a>00198 TPtr8 dataPtr(aDataPtr, dataLength, dataLength);
<a name="l00199"></a>00199
<a name="l00200"></a>00200 aSource->GetScanLine(dataPtr, TPoint(0, aScanline), scanLength, EGray2);
<a name="l00201"></a>00201
<a name="l00202"></a>00202 <span class="comment">// Reverse the order of the bits</span>
<a name="l00203"></a>00203 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00204"></a>00204 {
<a name="l00205"></a>00205 aDataPtr[0] = ReverseBits(aDataPtr[0]);
<a name="l00206"></a>00206 aDataPtr++;
<a name="l00207"></a>00207 }
<a name="l00208"></a>00208 }
<a name="l00209"></a>00209 }
<a name="l00210"></a>00210
<a name="l00211"></a>00211 <span class="comment">//</span>
<a name="l00212"></a>00212 <span class="comment">// CBitDepth2Encoder</span>
<a name="l00213"></a>00213 <span class="comment">//</span>
<a name="l00214"></a>00214
<a name="l00215"></a>00215 <span class="keywordtype">void</span> CBitDepth2Encoder::DoConstructL()
<a name="l00216"></a>00216 {
<a name="l00217"></a>00217 <span class="keywordflow">if</span> (iInfo.iColorType == TPngImageInformation::EIndexedColor)
<a name="l00218"></a>00218 {
<a name="l00219"></a>00219 <span class="comment">// Setup palette entries</span>
<a name="l00220"></a>00220 iPalette = CPalette::NewL(4);
<a name="l00221"></a>00221 iPalette->SetEntry(0, KRgbBlack);
<a name="l00222"></a>00222 iPalette->SetEntry(1, KRgbDarkGray);
<a name="l00223"></a>00223 iPalette->SetEntry(2, KRgbGray);
<a name="l00224"></a>00224 iPalette->SetEntry(3, KRgbWhite);
<a name="l00225"></a>00225 iInfo.iPalettePresent = ETrue;
<a name="l00226"></a>00226 }
<a name="l00227"></a>00227 }
<a name="l00228"></a>00228
<a name="l00229"></a>00229 TInt CBitDepth2Encoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00230"></a>00230 {
<a name="l00231"></a>00231 <span class="keywordflow">return</span> ((aPixelLength + KPngDepth2RoundUpValue) / KPngDepth2PixelsPerByte) + KPngScanlineFilterTypeLength;
<a name="l00232"></a>00232 }
<a name="l00233"></a>00233
<a name="l00234"></a>00234 <span class="keywordtype">void</span> CBitDepth2Encoder::DoEncode(<span class="keyword">const</span> CFbsBitmap* aSource, <span class="keyword">const</span> TInt aScanline,
<a name="l00235"></a>00235 TUint8* aDataPtr, <span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00236"></a>00236 {
<a name="l00237"></a>00237 <span class="comment">// Filter method</span>
<a name="l00238"></a>00238 PtrWriteUtil::WriteInt8(aDataPtr, iInfo.iFilterMethod);
<a name="l00239"></a>00239 aDataPtr++;
<a name="l00240"></a>00240
<a name="l00241"></a>00241 <span class="comment">// Pixel data</span>
<a name="l00242"></a>00242 <span class="keyword">const</span> TInt scanLength = iInfo.iSize.iWidth;
<a name="l00243"></a>00243 <span class="keywordflow">if</span> (iInfo.iColorType == TPngImageInformation::EIndexedColor)
<a name="l00244"></a>00244 {
<a name="l00245"></a>00245 <span class="comment">// Write palette indexes</span>
<a name="l00246"></a>00246 EncodePalettedScanline(aDataPtr, aSource, aScanline, KPngDepth2PixelsPerByte, KPngDepth2ShiftValue);
<a name="l00247"></a>00247 }
<a name="l00248"></a>00248 <span class="keywordflow">else</span>
<a name="l00249"></a>00249 {
<a name="l00250"></a>00250 <span class="comment">// RGB values</span>
<a name="l00251"></a>00251 TPtr8 dataPtr(aDataPtr, (scanLength + KPngDepth2RoundUpValue) / KPngDepth2PixelsPerByte);
<a name="l00252"></a>00252 aSource->GetScanLine(dataPtr, TPoint(0, aScanline), scanLength, EGray4);
<a name="l00253"></a>00253
<a name="l00254"></a>00254 <span class="comment">// Reverse the order of the bits</span>
<a name="l00255"></a>00255 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00256"></a>00256 {
<a name="l00257"></a>00257 TUint8 value = aDataPtr[0];
<a name="l00258"></a>00258 TUint8 reverse = 0;
<a name="l00259"></a>00259 <span class="keywordflow">for</span> (TInt i=0; i < KPngDepth2PixelsPerByte; i++)
<a name="l00260"></a>00260 {
<a name="l00261"></a>00261 reverse <<= 2; <span class="comment">// advance the bits for the reverse value</span>
<a name="l00262"></a>00262 reverse |= value & 0x3; <span class="comment">// mask off the 2 bits, then OR with existing reverse value</span>
<a name="l00263"></a>00263 value >>= 2; <span class="comment">// advance the bits for the actual value</span>
<a name="l00264"></a>00264 }
<a name="l00265"></a>00265 aDataPtr[0] = reverse;
<a name="l00266"></a>00266 aDataPtr++;
<a name="l00267"></a>00267 }
<a name="l00268"></a>00268 }
<a name="l00269"></a>00269 }
<a name="l00270"></a>00270
<a name="l00271"></a>00271 <span class="comment">//</span>
<a name="l00272"></a>00272 <span class="comment">// CBitDepth4Encoder</span>
<a name="l00273"></a>00273 <span class="comment">//</span>
<a name="l00274"></a>00274
<a name="l00275"></a>00275 <span class="keywordtype">void</span> CBitDepth4Encoder::DoConstructL()
<a name="l00276"></a>00276 {
<a name="l00277"></a>00277 <span class="keywordflow">if</span> (iInfo.iColorType == TPngImageInformation::EIndexedColor)
<a name="l00278"></a>00278 {
<a name="l00279"></a>00279 <span class="comment">// Calculate palette for image</span>
<a name="l00280"></a>00280 iPalette = CPalette::NewDefaultL(EColor16);
<a name="l00281"></a>00281 iInfo.iPalettePresent = ETrue;
<a name="l00282"></a>00282 }
<a name="l00283"></a>00283 }
<a name="l00284"></a>00284
<a name="l00285"></a>00285 TInt CBitDepth4Encoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00286"></a>00286 {
<a name="l00287"></a>00287 <span class="keywordflow">return</span> ((aPixelLength + KPngDepth4RoundUpValue) / KPngDepth4PixelsPerByte) + KPngScanlineFilterTypeLength;
<a name="l00288"></a>00288 }
<a name="l00289"></a>00289
<a name="l00290"></a>00290 <span class="keywordtype">void</span> CBitDepth4Encoder::DoEncode(<span class="keyword">const</span> CFbsBitmap* aSource, <span class="keyword">const</span> TInt aScanline,
<a name="l00291"></a>00291 TUint8* aDataPtr, <span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00292"></a>00292 {
<a name="l00293"></a>00293 <span class="comment">// Filter method</span>
<a name="l00294"></a>00294 PtrWriteUtil::WriteInt8(aDataPtr, iInfo.iFilterMethod);
<a name="l00295"></a>00295 aDataPtr++;
<a name="l00296"></a>00296
<a name="l00297"></a>00297 <span class="comment">// Pixel data</span>
<a name="l00298"></a>00298 <span class="keyword">const</span> TInt scanLength = iInfo.iSize.iWidth;
<a name="l00299"></a>00299 <span class="keywordflow">if</span> (iInfo.iColorType == TPngImageInformation::EIndexedColor)
<a name="l00300"></a>00300 {
<a name="l00301"></a>00301 <span class="comment">// Write palette indexes</span>
<a name="l00302"></a>00302 EncodePalettedScanline(aDataPtr, aSource, aScanline, KPngDepth4PixelsPerByte, KPngDepth4ShiftValue);
<a name="l00303"></a>00303 }
<a name="l00304"></a>00304 <span class="keywordflow">else</span>
<a name="l00305"></a>00305 {
<a name="l00306"></a>00306 TPtr8 dataPtr(aDataPtr, (scanLength + KPngDepth4RoundUpValue) / KPngDepth4PixelsPerByte);
<a name="l00307"></a>00307 aSource->GetScanLine(dataPtr, TPoint(0, aScanline), scanLength,
<a name="l00308"></a>00308 (iInfo.iColorType == TPngImageInformation::EDirectColor) ? EColor16 : EGray16);
<a name="l00309"></a>00309
<a name="l00310"></a>00310 <span class="comment">// Swap order of the low/high bits</span>
<a name="l00311"></a>00311 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00312"></a>00312 {
<a name="l00313"></a>00313 TUint value = aDataPtr[0];
<a name="l00314"></a>00314 TUint low = value << KPngDepth4ShiftValue;
<a name="l00315"></a>00315 TUint high = value >> KPngDepth4ShiftValue;
<a name="l00316"></a>00316 aDataPtr[0] = TUint8(low | high);
<a name="l00317"></a>00317 aDataPtr++;
<a name="l00318"></a>00318 }
<a name="l00319"></a>00319 }
<a name="l00320"></a>00320 }
<a name="l00321"></a>00321
<a name="l00322"></a>00322 <span class="comment">//</span>
<a name="l00323"></a>00323 <span class="comment">// CBitDepth8ColorType2Encoder</span>
<a name="l00324"></a>00324 <span class="comment">//</span>
<a name="l00325"></a>00325
<a name="l00326"></a>00326 TInt CBitDepth8ColorType2Encoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00327"></a>00327 {
<a name="l00328"></a>00328 <span class="keywordflow">return</span> (aPixelLength * KPngDepth8RgbBytesPerPixel) + KPngScanlineFilterTypeLength;
<a name="l00329"></a>00329 }
<a name="l00330"></a>00330
<a name="l00331"></a>00331 <span class="keywordtype">void</span> CBitDepth8ColorType2Encoder::DoEncode(<span class="keyword">const</span> CFbsBitmap* aSource, <span class="keyword">const</span> TInt aScanline,
<a name="l00332"></a>00332 TUint8* aDataPtr, <span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00333"></a>00333 {
<a name="l00334"></a>00334 <span class="comment">// Filter method</span>
<a name="l00335"></a>00335 PtrWriteUtil::WriteInt8(aDataPtr, iInfo.iFilterMethod);
<a name="l00336"></a>00336 aDataPtr++;
<a name="l00337"></a>00337
<a name="l00338"></a>00338 <span class="comment">// Pixel data</span>
<a name="l00339"></a>00339 TPtr8 dataPtr(aDataPtr, iInfo.iSize.iWidth * KPngDepth8RgbBytesPerPixel);
<a name="l00340"></a>00340 aSource->GetScanLine(dataPtr, TPoint(0, aScanline), iInfo.iSize.iWidth, EColor16M);
<a name="l00341"></a>00341
<a name="l00342"></a>00342 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00343"></a>00343 {
<a name="l00344"></a>00344 <span class="comment">// Swap the red and blue components of the image data</span>
<a name="l00345"></a>00345 TUint8 temp = aDataPtr[0]; <span class="comment">// temp = Red</span>
<a name="l00346"></a>00346 aDataPtr[0] = aDataPtr[2]; <span class="comment">// Red = Blue</span>
<a name="l00347"></a>00347 aDataPtr[2] = temp; <span class="comment">// Blue = temp</span>
<a name="l00348"></a>00348 aDataPtr += KPngDepth8RgbBytesPerPixel;
<a name="l00349"></a>00349 }
<a name="l00350"></a>00350 }
<a name="l00351"></a>00351
<a name="l00352"></a>00352 <span class="comment">//</span>
<a name="l00353"></a>00353 <span class="comment">// CBitDepth8Encoder</span>
<a name="l00354"></a>00354 <span class="comment">//</span>
<a name="l00355"></a>00355
<a name="l00356"></a>00356 <span class="keywordtype">void</span> CBitDepth8Encoder::DoConstructL()
<a name="l00357"></a>00357 {
<a name="l00358"></a>00358 <span class="keywordflow">if</span> (iInfo.iColorType == TPngImageInformation::EIndexedColor)
<a name="l00359"></a>00359 {
<a name="l00360"></a>00360 <span class="comment">// Calculate palette for image</span>
<a name="l00361"></a>00361 iPalette = CPalette::NewDefaultL(EColor256);
<a name="l00362"></a>00362 iInfo.iPalettePresent = ETrue;
<a name="l00363"></a>00363 }
<a name="l00364"></a>00364 }
<a name="l00365"></a>00365
<a name="l00366"></a>00366 TInt CBitDepth8Encoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00367"></a>00367 {
<a name="l00368"></a>00368 <span class="keywordflow">return</span> aPixelLength + KPngScanlineFilterTypeLength;
<a name="l00369"></a>00369 }
<a name="l00370"></a>00370
<a name="l00371"></a>00371 <span class="keywordtype">void</span> CBitDepth8Encoder::DoEncode(<span class="keyword">const</span> CFbsBitmap* aSource, <span class="keyword">const</span> TInt aScanline,
<a name="l00372"></a>00372 TUint8* aDataPtr, <span class="keyword">const</span> TUint8* <span class="comment">/*aDataPtrLimit*/</span>)
<a name="l00373"></a>00373 {
<a name="l00374"></a>00374 <span class="comment">// Filter method</span>
<a name="l00375"></a>00375 PtrWriteUtil::WriteInt8(aDataPtr, iInfo.iFilterMethod);
<a name="l00376"></a>00376 aDataPtr++;
<a name="l00377"></a>00377
<a name="l00378"></a>00378 <span class="keyword">const</span> TInt scanLength = iInfo.iSize.iWidth;
<a name="l00379"></a>00379 <span class="keywordflow">if</span> (iInfo.iColorType == TPngImageInformation::EIndexedColor)
<a name="l00380"></a>00380 {
<a name="l00381"></a>00381 <span class="comment">// Write palette indexes</span>
<a name="l00382"></a>00382 EncodePalettedScanline(aDataPtr, aSource, aScanline, KPngDepth8PixelsPerByte, KPngDepth8ShiftValue);
<a name="l00383"></a>00383 }
<a name="l00384"></a>00384 <span class="keywordflow">else</span>
<a name="l00385"></a>00385 {
<a name="l00386"></a>00386 <span class="comment">// Pixel data</span>
<a name="l00387"></a>00387 TPtr8 dataPtr(aDataPtr, scanLength);
<a name="l00388"></a>00388 aSource->GetScanLine(dataPtr, TPoint(0, aScanline), scanLength, EGray256);
<a name="l00389"></a>00389 }
<a name="l00390"></a>00390 }
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