Symbian3/Examples/guid-6013a680-57f9-415b-8851-c4fa63356636/_png_scanline_decoder_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/PngScanlineDecoder.cpp</h1><div class="fragment"><pre class="fragment"><a name="l00001"></a>00001 <span class="comment">// PNGSCANLINEDECODER.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 "PNGCodec.h"</span>
<a name="l00020"></a>00020
<a name="l00021"></a>00021 <span class="keyword">const</span> TInt KPngScanlineFilterTypeLength = 1;
<a name="l00022"></a>00022
<a name="l00023"></a>00023 <span class="keyword">const</span> TInt KColStart[KPngNumInterlacedPasses] = { 0, 4, 0, 2, 0, 1, 0, 0 };
<a name="l00024"></a>00024 <span class="keyword">const</span> TInt KRowStart[KPngNumInterlacedPasses] = { 0, 0, 4, 0, 2, 0, 1, 0 };
<a name="l00025"></a>00025 <span class="keyword">const</span> TInt KColIncrement[KPngNumInterlacedPasses] = { 8, 8, 4, 4, 2, 2, 1, 0 };
<a name="l00026"></a>00026 <span class="keyword">const</span> TInt KRowIncrement[KPngNumInterlacedPasses] = { 8, 8, 8, 4, 4, 2, 2, 0 };
<a name="l00027"></a>00027 <span class="keyword">const</span> TInt KBlockWidth[KPngNumInterlacedPasses] = { 8, 4, 4, 2, 2, 1, 1, 0 };
<a name="l00028"></a>00028 <span class="keyword">const</span> TInt KBlockHeight[KPngNumInterlacedPasses] = { 8, 8, 4, 4, 2, 2, 1, 0 };
<a name="l00029"></a>00029
<a name="l00030"></a>00030 <span class="comment">//</span>
<a name="l00031"></a>00031 <span class="comment">// These classes specialise the PNG reader to read</span>
<a name="l00032"></a>00032 <span class="comment">// scanlines with different bitmap depths/colour types</span>
<a name="l00033"></a>00033 <span class="comment">//</span>
<a name="l00034"></a>00034
<a name="l00035"></a>00035 <span class="keyword">class </span>CBitDepth1Decoder : <span class="keyword">public</span> <a class="code" href="class_c_png_read_sub_codec.html">CPngReadSubCodec</a>
<a name="l00036"></a>00036 {
<a name="l00037"></a>00037 <span class="keyword">private</span>:
<a name="l00038"></a>00038 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoConstructL();
<a name="l00039"></a>00039 <span class="keyword">virtual</span> TInt ScanlineBufferSize(TInt aPixelLength);
<a name="l00040"></a>00040 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit);
<a name="l00041"></a>00041 };
<a name="l00042"></a>00042
<a name="l00043"></a>00043 <span class="keyword">class </span>CBitDepth2Decoder : <span class="keyword">public</span> <a class="code" href="class_c_png_read_sub_codec.html">CPngReadSubCodec</a>
<a name="l00044"></a>00044 {
<a name="l00045"></a>00045 <span class="keyword">private</span>:
<a name="l00046"></a>00046 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoConstructL();
<a name="l00047"></a>00047 <span class="keyword">virtual</span> TInt ScanlineBufferSize(TInt aPixelLength);
<a name="l00048"></a>00048 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit);
<a name="l00049"></a>00049 };
<a name="l00050"></a>00050
<a name="l00051"></a>00051 <span class="keyword">class </span>CBitDepth4Decoder : <span class="keyword">public</span> <a class="code" href="class_c_png_read_sub_codec.html">CPngReadSubCodec</a>
<a name="l00052"></a>00052 {
<a name="l00053"></a>00053 <span class="keyword">private</span>:
<a name="l00054"></a>00054 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoConstructL();
<a name="l00055"></a>00055 <span class="keyword">virtual</span> TInt ScanlineBufferSize(TInt aPixelLength);
<a name="l00056"></a>00056 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit);
<a name="l00057"></a>00057 };
<a name="l00058"></a>00058
<a name="l00059"></a>00059 <span class="keyword">class </span>CBitDepth8Decoder : <span class="keyword">public</span> <a class="code" href="class_c_png_read_sub_codec.html">CPngReadSubCodec</a>
<a name="l00060"></a>00060 {
<a name="l00061"></a>00061 <span class="keyword">private</span>:
<a name="l00062"></a>00062 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoConstructL();
<a name="l00063"></a>00063 <span class="keyword">virtual</span> TInt ScanlineBufferSize(TInt aPixelLength);
<a name="l00064"></a>00064 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit);
<a name="l00065"></a>00065 };
<a name="l00066"></a>00066
<a name="l00067"></a>00067 <span class="keyword">class </span>CBitDepth8ColorType2Decoder : <span class="keyword">public</span> <a class="code" href="class_c_png_read_sub_codec.html">CPngReadSubCodec</a>
<a name="l00068"></a>00068 {
<a name="l00069"></a>00069 <span class="keyword">private</span>:
<a name="l00070"></a>00070 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoConstructL();
<a name="l00071"></a>00071 <span class="keyword">virtual</span> TInt ScanlineBufferSize(TInt aPixelLength);
<a name="l00072"></a>00072 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit);
<a name="l00073"></a>00073 };
<a name="l00074"></a>00074
<a name="l00075"></a>00075 <span class="keyword">class </span>CBitDepth8ColorType4Decoder : <span class="keyword">public</span> <a class="code" href="class_c_png_read_sub_codec.html">CPngReadSubCodec</a>
<a name="l00076"></a>00076 {
<a name="l00077"></a>00077 <span class="keyword">private</span>:
<a name="l00078"></a>00078 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoConstructL();
<a name="l00079"></a>00079 <span class="keyword">virtual</span> TInt ScanlineBufferSize(TInt aPixelLength);
<a name="l00080"></a>00080 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit);
<a name="l00081"></a>00081 };
<a name="l00082"></a>00082
<a name="l00083"></a>00083 <span class="keyword">class </span>CBitDepth8ColorType6Decoder : <span class="keyword">public</span> <a class="code" href="class_c_png_read_sub_codec.html">CPngReadSubCodec</a>
<a name="l00084"></a>00084 {
<a name="l00085"></a>00085 <span class="keyword">private</span>:
<a name="l00086"></a>00086 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoConstructL();
<a name="l00087"></a>00087 <span class="keyword">virtual</span> TInt ScanlineBufferSize(TInt aPixelLength);
<a name="l00088"></a>00088 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit);
<a name="l00089"></a>00089 };
<a name="l00090"></a>00090
<a name="l00091"></a>00091 <span class="keyword">class </span>CBitDepth16ColorType0Decoder : <span class="keyword">public</span> <a class="code" href="class_c_png_read_sub_codec.html">CPngReadSubCodec</a>
<a name="l00092"></a>00092 {
<a name="l00093"></a>00093 <span class="keyword">private</span>:
<a name="l00094"></a>00094 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoConstructL();
<a name="l00095"></a>00095 <span class="keyword">virtual</span> TInt ScanlineBufferSize(TInt aPixelLength);
<a name="l00096"></a>00096 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit);
<a name="l00097"></a>00097 };
<a name="l00098"></a>00098
<a name="l00099"></a>00099 <span class="keyword">class </span>CBitDepth16ColorType2Decoder : <span class="keyword">public</span> <a class="code" href="class_c_png_read_sub_codec.html">CPngReadSubCodec</a>
<a name="l00100"></a>00100 {
<a name="l00101"></a>00101 <span class="keyword">private</span>:
<a name="l00102"></a>00102 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoConstructL();
<a name="l00103"></a>00103 <span class="keyword">virtual</span> TInt ScanlineBufferSize(TInt aPixelLength);
<a name="l00104"></a>00104 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit);
<a name="l00105"></a>00105 };
<a name="l00106"></a>00106
<a name="l00107"></a>00107 <span class="keyword">class </span>CBitDepth16ColorType4Decoder : <span class="keyword">public</span> <a class="code" href="class_c_png_read_sub_codec.html">CPngReadSubCodec</a>
<a name="l00108"></a>00108 {
<a name="l00109"></a>00109 <span class="keyword">private</span>:
<a name="l00110"></a>00110 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoConstructL();
<a name="l00111"></a>00111 <span class="keyword">virtual</span> TInt ScanlineBufferSize(TInt aPixelLength);
<a name="l00112"></a>00112 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit);
<a name="l00113"></a>00113 };
<a name="l00114"></a>00114
<a name="l00115"></a>00115 <span class="keyword">class </span>CBitDepth16ColorType6Decoder : <span class="keyword">public</span> <a class="code" href="class_c_png_read_sub_codec.html">CPngReadSubCodec</a>
<a name="l00116"></a>00116 {
<a name="l00117"></a>00117 <span class="keyword">private</span>:
<a name="l00118"></a>00118 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoConstructL();
<a name="l00119"></a>00119 <span class="keyword">virtual</span> TInt ScanlineBufferSize(TInt aPixelLength);
<a name="l00120"></a>00120 <span class="keyword">virtual</span> <span class="keywordtype">void</span> DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit);
<a name="l00121"></a>00121 };
<a name="l00122"></a>00122
<a name="l00123"></a>00123 <span class="comment">//</span>
<a name="l00124"></a>00124 <span class="comment">// CPngReadSubCodec: base class for classes that read scanlines</span>
<a name="l00125"></a>00125 <span class="comment">//</span>
<a name="l00126"></a>00126
<a name="l00127"></a>00127 <span class="comment">// Factory function</span>
<a name="l00128"></a>00128 <a class="code" href="class_c_png_read_sub_codec.html">CPngReadSubCodec</a>* CPngReadSubCodec::NewL(CImageProcessor* aImageProc,CImageProcessor* aMaskProc,<span class="keyword">const</span> <a class="code" href="class_t_png_image_information.html">TPngImageInformation</a>& aInfo)
<a name="l00129"></a>00129 {
<a name="l00130"></a>00130 <a class="code" href="class_c_png_read_sub_codec.html">CPngReadSubCodec</a>* <span class="keyword">self</span> = NULL;
<a name="l00131"></a>00131
<a name="l00132"></a>00132 <span class="keywordflow">switch</span> (aInfo.iBitDepth)
<a name="l00133"></a>00133 {
<a name="l00134"></a>00134 <span class="keywordflow">case</span> 1:
<a name="l00135"></a>00135 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) CBitDepth1Decoder;
<a name="l00136"></a>00136 <span class="keywordflow">break</span>;
<a name="l00137"></a>00137 <span class="keywordflow">case</span> 2:
<a name="l00138"></a>00138 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) CBitDepth2Decoder;
<a name="l00139"></a>00139 <span class="keywordflow">break</span>;
<a name="l00140"></a>00140 <span class="keywordflow">case</span> 4:
<a name="l00141"></a>00141 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) CBitDepth4Decoder;
<a name="l00142"></a>00142 <span class="keywordflow">break</span>;
<a name="l00143"></a>00143 <span class="keywordflow">case</span> 8:
<a name="l00144"></a>00144 <span class="keywordflow">switch</span> (aInfo.iColorType)
<a name="l00145"></a>00145 {
<a name="l00146"></a>00146 <span class="keywordflow">case</span> TPngImageInformation::EGrayscale:
<a name="l00147"></a>00147 <span class="keywordflow">case</span> TPngImageInformation::EIndexedColor:
<a name="l00148"></a>00148 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) CBitDepth8Decoder;
<a name="l00149"></a>00149 <span class="keywordflow">break</span>;
<a name="l00150"></a>00150 <span class="keywordflow">case</span> TPngImageInformation::EDirectColor:
<a name="l00151"></a>00151 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) CBitDepth8ColorType2Decoder;
<a name="l00152"></a>00152 <span class="keywordflow">break</span>;
<a name="l00153"></a>00153 <span class="keywordflow">case</span> TPngImageInformation::EAlphaGrayscale:
<a name="l00154"></a>00154 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) CBitDepth8ColorType4Decoder;
<a name="l00155"></a>00155 <span class="keywordflow">break</span>;
<a name="l00156"></a>00156 <span class="keywordflow">case</span> TPngImageInformation::EAlphaDirectColor:
<a name="l00157"></a>00157 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) CBitDepth8ColorType6Decoder;
<a name="l00158"></a>00158 <span class="keywordflow">break</span>;
<a name="l00159"></a>00159 <span class="keywordflow">default</span>:
<a name="l00160"></a>00160 User::Leave(KErrNotSupported);
<a name="l00161"></a>00161 <span class="keywordflow">break</span>;
<a name="l00162"></a>00162 }
<a name="l00163"></a>00163 <span class="keywordflow">break</span>;
<a name="l00164"></a>00164 <span class="keywordflow">case</span> 16:
<a name="l00165"></a>00165 <span class="keywordflow">switch</span> (aInfo.iColorType)
<a name="l00166"></a>00166 {
<a name="l00167"></a>00167 <span class="keywordflow">case</span> TPngImageInformation::EGrayscale:
<a name="l00168"></a>00168 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) CBitDepth16ColorType0Decoder;
<a name="l00169"></a>00169 <span class="keywordflow">break</span>;
<a name="l00170"></a>00170 <span class="keywordflow">case</span> TPngImageInformation::EDirectColor:
<a name="l00171"></a>00171 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) CBitDepth16ColorType2Decoder;
<a name="l00172"></a>00172 <span class="keywordflow">break</span>;
<a name="l00173"></a>00173 <span class="keywordflow">case</span> TPngImageInformation::EAlphaGrayscale:
<a name="l00174"></a>00174 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) CBitDepth16ColorType4Decoder;
<a name="l00175"></a>00175 <span class="keywordflow">break</span>;
<a name="l00176"></a>00176 <span class="keywordflow">case</span> TPngImageInformation::EAlphaDirectColor:
<a name="l00177"></a>00177 <span class="keyword">self</span> = <span class="keyword">new</span>(ELeave) CBitDepth16ColorType6Decoder;
<a name="l00178"></a>00178 <span class="keywordflow">break</span>;
<a name="l00179"></a>00179 <span class="keywordflow">case</span> TPngImageInformation::EIndexedColor:
<a name="l00180"></a>00180 <span class="keywordflow">default</span>:
<a name="l00181"></a>00181 User::Leave(KErrNotSupported);
<a name="l00182"></a>00182 <span class="keywordflow">break</span>;
<a name="l00183"></a>00183 }
<a name="l00184"></a>00184 <span class="keywordflow">break</span>;
<a name="l00185"></a>00185 <span class="keywordflow">default</span>:
<a name="l00186"></a>00186 User::Leave(KErrNotSupported);
<a name="l00187"></a>00187 <span class="keywordflow">break</span>;
<a name="l00188"></a>00188 }
<a name="l00189"></a>00189
<a name="l00190"></a>00190 CleanupStack::PushL(<span class="keyword">self</span>);
<a name="l00191"></a>00191 <span class="keyword">self</span>->ConstructL(aImageProc,aMaskProc,aInfo);
<a name="l00192"></a>00192 CleanupStack::Pop(); <span class="comment">// self</span>
<a name="l00193"></a>00193 <span class="keywordflow">return</span> <span class="keyword">self</span>;
<a name="l00194"></a>00194 }
<a name="l00195"></a>00195
<a name="l00196"></a>00196 CPngReadSubCodec::CPngReadSubCodec():
<a name="l00197"></a>00197 iScanlineDes1(NULL,0),
<a name="l00198"></a>00198 iScanlineDes2(NULL,0)
<a name="l00199"></a>00199 {}
<a name="l00200"></a>00200
<a name="l00201"></a>00201 CPngReadSubCodec::~CPngReadSubCodec()
<a name="l00202"></a>00202 {
<a name="l00203"></a>00203 <span class="keyword">delete</span> iScanlineBuffer1;
<a name="l00204"></a>00204 <span class="keyword">delete</span> iScanlineBuffer2;
<a name="l00205"></a>00205 }
<a name="l00206"></a>00206
<a name="l00207"></a>00207 <span class="keywordtype">void</span> CPngReadSubCodec::ConstructL(CImageProcessor* aImageProc,CImageProcessor* aMaskProc,<span class="keyword">const</span> <a class="code" href="class_t_png_image_information.html">TPngImageInformation</a>& aInfo)
<a name="l00208"></a>00208 {
<a name="l00209"></a>00209 iImageProc = aImageProc;
<a name="l00210"></a>00210 iMaskProc = aMaskProc;
<a name="l00211"></a>00211 iInfo = aInfo;
<a name="l00212"></a>00212 iScanlineBufferSize = ScanlineBufferSize(iInfo.iSize.iWidth);
<a name="l00213"></a>00213
<a name="l00214"></a>00214 DoConstructL();
<a name="l00215"></a>00215
<a name="l00216"></a>00216 iScanlineBuffer1 = HBufC8::NewMaxL(iScanlineBufferSize);
<a name="l00217"></a>00217 iScanlineBuffer2 = HBufC8::NewMaxL(iScanlineBufferSize);
<a name="l00218"></a>00218
<a name="l00219"></a>00219 <span class="keywordflow">if</span> (iInfo.iInterlaceMethod == TPngImageInformation::EAdam7Interlace)
<a name="l00220"></a>00220 {
<a name="l00221"></a>00221 iInterlacedScanlineBufferSize[0] = ScanlineBufferSize((iInfo.iSize.iWidth + 7) >> 3);
<a name="l00222"></a>00222 iInterlacedScanlineBufferSize[1] = ScanlineBufferSize((iInfo.iSize.iWidth + 3) >> 3);
<a name="l00223"></a>00223 iInterlacedScanlineBufferSize[2] = ScanlineBufferSize((iInfo.iSize.iWidth + 3) >> 2);
<a name="l00224"></a>00224 iInterlacedScanlineBufferSize[3] = ScanlineBufferSize((iInfo.iSize.iWidth + 1) >> 2);
<a name="l00225"></a>00225 iInterlacedScanlineBufferSize[4] = ScanlineBufferSize((iInfo.iSize.iWidth + 1) >> 1);
<a name="l00226"></a>00226 iInterlacedScanlineBufferSize[5] = ScanlineBufferSize(iInfo.iSize.iWidth >> 1);
<a name="l00227"></a>00227 iInterlacedScanlineBufferSize[6] = iScanlineBufferSize;
<a name="l00228"></a>00228 iInterlacedScanlineBufferSize[7] = 0;
<a name="l00229"></a>00229 iPass = 0;
<a name="l00230"></a>00230
<a name="l00231"></a>00231 iScanlineDes1.Set(&(iScanlineBuffer1->Des())[0],iInterlacedScanlineBufferSize[0],iInterlacedScanlineBufferSize[0]);
<a name="l00232"></a>00232 iScanlineDes2.Set(&(iScanlineBuffer2->Des())[0],iInterlacedScanlineBufferSize[0],iInterlacedScanlineBufferSize[0]);
<a name="l00233"></a>00233 }
<a name="l00234"></a>00234 <span class="keywordflow">else</span>
<a name="l00235"></a>00235 {
<a name="l00236"></a>00236 iScanlineDes1.Set(&(iScanlineBuffer1->Des())[0],iScanlineBufferSize,iScanlineBufferSize);
<a name="l00237"></a>00237 iScanlineDes2.Set(&(iScanlineBuffer2->Des())[0],iScanlineBufferSize,iScanlineBufferSize);
<a name="l00238"></a>00238 }
<a name="l00239"></a>00239 }
<a name="l00240"></a>00240
<a name="l00241"></a>00241 TDes8& CPngReadSubCodec::FirstBuffer()
<a name="l00242"></a>00242 {
<a name="l00243"></a>00243 iScanlineDes1.FillZ();
<a name="l00244"></a>00244 iCurrentScanlineBuffer = 2;
<a name="l00245"></a>00245 <span class="keywordflow">return</span> iScanlineDes2;
<a name="l00246"></a>00246 }
<a name="l00247"></a>00247
<a name="l00248"></a>00248 TDes8& CPngReadSubCodec::DecodeL()
<a name="l00249"></a>00249 {
<a name="l00250"></a>00250 TUint8* dataPtr = (iCurrentScanlineBuffer == 1) ? &iScanlineDes1[1] : &iScanlineDes2[1];
<a name="l00251"></a>00251 <span class="keyword">const</span> TUint8* dataPtrLimit = dataPtr + iScanlineDes1.Length() - 1;
<a name="l00252"></a>00252
<a name="l00253"></a>00253 FilterScanlineDataL(dataPtr,dataPtrLimit);
<a name="l00254"></a>00254 DoDecode(dataPtr,dataPtrLimit);
<a name="l00255"></a>00255 UpdatePos();
<a name="l00256"></a>00256
<a name="l00257"></a>00257 <span class="keywordflow">if</span> (iCurrentScanlineBuffer == 1)
<a name="l00258"></a>00258 {
<a name="l00259"></a>00259 iCurrentScanlineBuffer = 2;
<a name="l00260"></a>00260 <span class="keywordflow">return</span> iScanlineDes2;
<a name="l00261"></a>00261 }
<a name="l00262"></a>00262 <span class="keywordflow">else</span>
<a name="l00263"></a>00263 {
<a name="l00264"></a>00264 iCurrentScanlineBuffer = 1;
<a name="l00265"></a>00265 <span class="keywordflow">return</span> iScanlineDes1;
<a name="l00266"></a>00266 }
<a name="l00267"></a>00267 }
<a name="l00268"></a>00268
<a name="l00269"></a>00269 <span class="keywordtype">void</span> CPngReadSubCodec::FilterScanlineDataL(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00270"></a>00270 {
<a name="l00271"></a>00271 TInt filterType = (iCurrentScanlineBuffer == 1) ? iScanlineDes1[0] : iScanlineDes2[0];
<a name="l00272"></a>00272
<a name="l00273"></a>00273 <span class="keywordflow">switch</span> (filterType)
<a name="l00274"></a>00274 {
<a name="l00275"></a>00275 <span class="keywordflow">case</span> 0: <span class="comment">// None</span>
<a name="l00276"></a>00276 <span class="keywordflow">break</span>;
<a name="l00277"></a>00277 <span class="keywordflow">case</span> 1: <span class="comment">// Sub</span>
<a name="l00278"></a>00278 {
<a name="l00279"></a>00279 aDataPtr += iBytesPerPixel;
<a name="l00280"></a>00280
<a name="l00281"></a>00281 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00282"></a>00282 {
<a name="l00283"></a>00283 aDataPtr[0] = TUint8(aDataPtr[0] + aDataPtr[-iBytesPerPixel]);
<a name="l00284"></a>00284 aDataPtr++;
<a name="l00285"></a>00285 }
<a name="l00286"></a>00286 }
<a name="l00287"></a>00287 <span class="keywordflow">break</span>;
<a name="l00288"></a>00288 <span class="keywordflow">case</span> 2: <span class="comment">// Up</span>
<a name="l00289"></a>00289 {
<a name="l00290"></a>00290 TUint8* altDataPtr = (iCurrentScanlineBuffer == 1) ? &iScanlineDes2[1] : &iScanlineDes1[1];
<a name="l00291"></a>00291
<a name="l00292"></a>00292 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00293"></a>00293 *aDataPtr++ = TUint8(*aDataPtr + *altDataPtr++);
<a name="l00294"></a>00294 }
<a name="l00295"></a>00295 <span class="keywordflow">break</span>;
<a name="l00296"></a>00296 <span class="keywordflow">case</span> 3: <span class="comment">// Average</span>
<a name="l00297"></a>00297 {
<a name="l00298"></a>00298 <span class="keyword">const</span> TUint8* tempDataPtrLimit = Min<const TUint8*>(aDataPtr + iBytesPerPixel,aDataPtrLimit);
<a name="l00299"></a>00299 TUint8* altDataPtr = (iCurrentScanlineBuffer == 1) ? &iScanlineDes2[1] : &iScanlineDes1[1];
<a name="l00300"></a>00300
<a name="l00301"></a>00301 <span class="keywordflow">while</span> (aDataPtr < tempDataPtrLimit)
<a name="l00302"></a>00302 {
<a name="l00303"></a>00303 aDataPtr[0] = TUint8(aDataPtr[0] + (altDataPtr[0] / 2));
<a name="l00304"></a>00304 aDataPtr++;
<a name="l00305"></a>00305 altDataPtr++;
<a name="l00306"></a>00306 }
<a name="l00307"></a>00307
<a name="l00308"></a>00308 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00309"></a>00309 {
<a name="l00310"></a>00310 aDataPtr[0] = TUint8(aDataPtr[0] + ((altDataPtr[0] + aDataPtr[-iBytesPerPixel]) / 2));
<a name="l00311"></a>00311 aDataPtr++;
<a name="l00312"></a>00312 altDataPtr++;
<a name="l00313"></a>00313 }
<a name="l00314"></a>00314 }
<a name="l00315"></a>00315 <span class="keywordflow">break</span>;
<a name="l00316"></a>00316 <span class="keywordflow">case</span> 4: <span class="comment">// Paeth</span>
<a name="l00317"></a>00317 {
<a name="l00318"></a>00318 <span class="keyword">const</span> TUint8* tempDataPtrLimit = Min<const TUint8*>(aDataPtr + iBytesPerPixel,aDataPtrLimit);
<a name="l00319"></a>00319 TUint8* altDataPtr = (iCurrentScanlineBuffer == 1) ? &iScanlineDes2[1] : &iScanlineDes1[1];
<a name="l00320"></a>00320
<a name="l00321"></a>00321 <span class="keywordflow">while</span> (aDataPtr < tempDataPtrLimit)
<a name="l00322"></a>00322 {
<a name="l00323"></a>00323 aDataPtr[0] = TUint8(aDataPtr[0] + altDataPtr[0]);
<a name="l00324"></a>00324 aDataPtr++;
<a name="l00325"></a>00325 altDataPtr++;
<a name="l00326"></a>00326 }
<a name="l00327"></a>00327
<a name="l00328"></a>00328 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00329"></a>00329 {
<a name="l00330"></a>00330 aDataPtr[0] = TUint8(aDataPtr[0] + PaethPredictor(aDataPtr[-iBytesPerPixel],altDataPtr[0],altDataPtr[-iBytesPerPixel]));
<a name="l00331"></a>00331 aDataPtr++;
<a name="l00332"></a>00332 altDataPtr++;
<a name="l00333"></a>00333 }
<a name="l00334"></a>00334 }
<a name="l00335"></a>00335 <span class="keywordflow">break</span>;
<a name="l00336"></a>00336 <span class="keywordflow">default</span>: <span class="comment">// Error</span>
<a name="l00337"></a>00337 User::Leave(KErrCorrupt);
<a name="l00338"></a>00338 <span class="keywordflow">break</span>;
<a name="l00339"></a>00339 }
<a name="l00340"></a>00340 }
<a name="l00341"></a>00341
<a name="l00342"></a>00342 TInt CPngReadSubCodec::PaethPredictor(TInt aLeft,TInt aAbove,TInt aAboveLeft)
<a name="l00343"></a>00343 {
<a name="l00344"></a>00344 TInt p = aLeft + aAbove - aAboveLeft;
<a name="l00345"></a>00345 TInt pa = Abs(p - aLeft);
<a name="l00346"></a>00346 TInt pb = Abs(p - aAbove);
<a name="l00347"></a>00347 TInt pc = Abs(p - aAboveLeft);
<a name="l00348"></a>00348
<a name="l00349"></a>00349 <span class="keywordflow">if</span> (pa <= pb && pa <= pc)
<a name="l00350"></a>00350 <span class="keywordflow">return</span> aLeft;
<a name="l00351"></a>00351 <span class="keywordflow">else</span> <span class="keywordflow">if</span> (pb <= pc)
<a name="l00352"></a>00352 <span class="keywordflow">return</span> aAbove;
<a name="l00353"></a>00353 <span class="keywordflow">else</span>
<a name="l00354"></a>00354 <span class="keywordflow">return</span> aAboveLeft;
<a name="l00355"></a>00355 }
<a name="l00356"></a>00356
<a name="l00357"></a>00357 <span class="keywordtype">void</span> CPngReadSubCodec::WritePixel(TRgb aPixelColor)
<a name="l00358"></a>00358 {
<a name="l00359"></a>00359 <span class="keywordflow">if</span> (iInfo.iInterlaceMethod == TPngImageInformation::EAdam7Interlace)
<a name="l00360"></a>00360 {
<a name="l00361"></a>00361 <span class="keyword">const</span> TInt width = Min(KBlockWidth[iPass],iInfo.iSize.iWidth - iPos.iX);
<a name="l00362"></a>00362 <span class="keyword">const</span> TInt endY = Min(iPos.iY + KBlockHeight[iPass],iInfo.iSize.iHeight);
<a name="l00363"></a>00363
<a name="l00364"></a>00364 TPoint pos(iPos);
<a name="l00365"></a>00365
<a name="l00366"></a>00366 <span class="keywordflow">while</span> (pos.iY < endY)
<a name="l00367"></a>00367 {
<a name="l00368"></a>00368 iImageProc->SetPos(pos);
<a name="l00369"></a>00369
<a name="l00370"></a>00370 <span class="keywordflow">for</span> (TInt col = 0; col < width; col++)
<a name="l00371"></a>00371 iImageProc->SetPixel(aPixelColor);
<a name="l00372"></a>00372
<a name="l00373"></a>00373 pos.iY++;
<a name="l00374"></a>00374 }
<a name="l00375"></a>00375
<a name="l00376"></a>00376 iPos.iX += KColIncrement[iPass];
<a name="l00377"></a>00377 }
<a name="l00378"></a>00378 <span class="keywordflow">else</span>
<a name="l00379"></a>00379 iImageProc->SetPixel(aPixelColor);
<a name="l00380"></a>00380 }
<a name="l00381"></a>00381
<a name="l00382"></a>00382 <span class="keywordtype">void</span> CPngReadSubCodec::WritePixel(TRgb aPixelColor,TUint8 aAlphaValue)
<a name="l00383"></a>00383 {
<a name="l00384"></a>00384 ASSERT(iMaskProc);
<a name="l00385"></a>00385
<a name="l00386"></a>00386 TRgb maskColor(TRgb::Gray256(aAlphaValue));
<a name="l00387"></a>00387
<a name="l00388"></a>00388 <span class="keywordflow">if</span> (iInfo.iInterlaceMethod == TPngImageInformation::EAdam7Interlace)
<a name="l00389"></a>00389 {
<a name="l00390"></a>00390 iImageProc->SetPos(iPos);
<a name="l00391"></a>00391 iMaskProc->SetPos(iPos);
<a name="l00392"></a>00392 iImageProc->SetPixel(aPixelColor);
<a name="l00393"></a>00393 iMaskProc->SetPixel(maskColor);
<a name="l00394"></a>00394
<a name="l00395"></a>00395 iPos.iX += KColIncrement[iPass];
<a name="l00396"></a>00396 }
<a name="l00397"></a>00397 <span class="keywordflow">else</span>
<a name="l00398"></a>00398 {
<a name="l00399"></a>00399 iImageProc->SetPixel(aPixelColor);
<a name="l00400"></a>00400 iMaskProc->SetPixel(maskColor);
<a name="l00401"></a>00401 }
<a name="l00402"></a>00402 }
<a name="l00403"></a>00403
<a name="l00404"></a>00404 <span class="keywordtype">void</span> CPngReadSubCodec::UpdatePos()
<a name="l00405"></a>00405 {
<a name="l00406"></a>00406 <span class="keywordflow">if</span> (iInfo.iInterlaceMethod == TPngImageInformation::EAdam7Interlace)
<a name="l00407"></a>00407 {
<a name="l00408"></a>00408 ASSERT(iPass <= 7);
<a name="l00409"></a>00409
<a name="l00410"></a>00410 iPos.iX = KColStart[iPass];
<a name="l00411"></a>00411 iPos.iY += KRowIncrement[iPass];
<a name="l00412"></a>00412
<a name="l00413"></a>00413 <span class="keywordflow">while</span> (iPos.iX >= iInfo.iSize.iWidth || iPos.iY >= iInfo.iSize.iHeight)
<a name="l00414"></a>00414 {
<a name="l00415"></a>00415 iPass++;
<a name="l00416"></a>00416 iPos.iX = KColStart[iPass];
<a name="l00417"></a>00417 iPos.iY = KRowStart[iPass];
<a name="l00418"></a>00418 iScanlineDes1.Set(&(iScanlineBuffer1->Des())[0],iInterlacedScanlineBufferSize[iPass],iInterlacedScanlineBufferSize[iPass]);
<a name="l00419"></a>00419 iScanlineDes2.Set(&(iScanlineBuffer2->Des())[0],iInterlacedScanlineBufferSize[iPass],iInterlacedScanlineBufferSize[iPass]);
<a name="l00420"></a>00420 iScanlineDes1.FillZ();
<a name="l00421"></a>00421 iScanlineDes2.FillZ();
<a name="l00422"></a>00422 }
<a name="l00423"></a>00423 }
<a name="l00424"></a>00424 }
<a name="l00425"></a>00425
<a name="l00426"></a>00426 <span class="comment">//</span>
<a name="l00427"></a>00427 <span class="comment">// CBitDepth1Decoder: specialised reader for 1bpp scanlines</span>
<a name="l00428"></a>00428 <span class="comment">//</span>
<a name="l00429"></a>00429 <span class="keywordtype">void</span> CBitDepth1Decoder::DoConstructL()
<a name="l00430"></a>00430 {
<a name="l00431"></a>00431 <span class="keywordflow">if</span> (!(iInfo.iColorType & TPngImageInformation::EPaletteUsed))
<a name="l00432"></a>00432 { <span class="comment">// Set up palette to be grayscale values</span>
<a name="l00433"></a>00433 iInfo.iPalette[0] = KRgbBlack;
<a name="l00434"></a>00434 iInfo.iPalette[1] = KRgbWhite;
<a name="l00435"></a>00435
<a name="l00436"></a>00436
<a name="l00437"></a>00437 <span class="keywordflow">if</span> (iInfo.iTransparencyPresent)
<a name="l00438"></a>00438 {
<a name="l00439"></a>00439 <span class="keywordflow">if</span> (iInfo.iTransparentGray <= 1)
<a name="l00440"></a>00440 iInfo.iTransparencyValue[iInfo.iTransparentGray] = 0;
<a name="l00441"></a>00441 }
<a name="l00442"></a>00442 }
<a name="l00443"></a>00443
<a name="l00444"></a>00444 <span class="comment">// Replicate values to avoid shifts when decoding</span>
<a name="l00445"></a>00445 iInfo.iPalette[2] = iInfo.iPalette[1];
<a name="l00446"></a>00446 iInfo.iPalette[4] = iInfo.iPalette[1];
<a name="l00447"></a>00447 iInfo.iPalette[8] = iInfo.iPalette[1];
<a name="l00448"></a>00448 iInfo.iPalette[16] = iInfo.iPalette[1];
<a name="l00449"></a>00449 iInfo.iPalette[32] = iInfo.iPalette[1];
<a name="l00450"></a>00450 iInfo.iPalette[64] = iInfo.iPalette[1];
<a name="l00451"></a>00451 iInfo.iPalette[128] = iInfo.iPalette[1];
<a name="l00452"></a>00452
<a name="l00453"></a>00453 <span class="keywordflow">if</span> (iInfo.iTransparencyPresent && iInfo.iTransparencyValue[1] != 255)
<a name="l00454"></a>00454 {
<a name="l00455"></a>00455 iInfo.iTransparencyValue[2] = iInfo.iTransparencyValue[1];
<a name="l00456"></a>00456 iInfo.iTransparencyValue[4] = iInfo.iTransparencyValue[1];
<a name="l00457"></a>00457 iInfo.iTransparencyValue[8] = iInfo.iTransparencyValue[1];
<a name="l00458"></a>00458 iInfo.iTransparencyValue[16] = iInfo.iTransparencyValue[1];
<a name="l00459"></a>00459 iInfo.iTransparencyValue[32] = iInfo.iTransparencyValue[1];
<a name="l00460"></a>00460 iInfo.iTransparencyValue[64] = iInfo.iTransparencyValue[1];
<a name="l00461"></a>00461 iInfo.iTransparencyValue[128] = iInfo.iTransparencyValue[1];
<a name="l00462"></a>00462 }
<a name="l00463"></a>00463
<a name="l00464"></a>00464 iBytesPerPixel = 1;
<a name="l00465"></a>00465 <span class="keywordflow">if</span> (iInfo.iInterlaceMethod == TPngImageInformation::ENoInterlace)
<a name="l00466"></a>00466 {
<a name="l00467"></a>00467 TInt pixelPadding = ((iInfo.iSize.iWidth + 7) & ~7) - iInfo.iSize.iWidth;
<a name="l00468"></a>00468 iImageProc->SetPixelPadding(pixelPadding);
<a name="l00469"></a>00469 <span class="keywordflow">if</span> (iMaskProc)
<a name="l00470"></a>00470 iMaskProc->SetPixelPadding(pixelPadding);
<a name="l00471"></a>00471 }
<a name="l00472"></a>00472 }
<a name="l00473"></a>00473
<a name="l00474"></a>00474 TInt CBitDepth1Decoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00475"></a>00475 {
<a name="l00476"></a>00476 <span class="keywordflow">return</span> ((aPixelLength + 7) / 8) + KPngScanlineFilterTypeLength;
<a name="l00477"></a>00477 }
<a name="l00478"></a>00478
<a name="l00479"></a>00479 <span class="keywordtype">void</span> CBitDepth1Decoder::DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00480"></a>00480 {
<a name="l00481"></a>00481 <span class="keywordflow">if</span> (iMaskProc && iInfo.iTransparencyPresent)
<a name="l00482"></a>00482 {
<a name="l00483"></a>00483 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00484"></a>00484 {
<a name="l00485"></a>00485 TInt dataValue = *aDataPtr++;
<a name="l00486"></a>00486
<a name="l00487"></a>00487 <span class="keywordflow">for</span> (TUint mask=0x80; mask!=0; mask>>=1) <span class="comment">// iterate with 0x80, 0x40 .. 0x01</span>
<a name="l00488"></a>00488 WritePixel(iInfo.iPalette[dataValue & mask],iInfo.iTransparencyValue[dataValue & mask]);
<a name="l00489"></a>00489 }
<a name="l00490"></a>00490 }
<a name="l00491"></a>00491 <span class="keywordflow">else</span>
<a name="l00492"></a>00492 {
<a name="l00493"></a>00493 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00494"></a>00494 {
<a name="l00495"></a>00495 TInt dataValue = *aDataPtr++;
<a name="l00496"></a>00496
<a name="l00497"></a>00497 <span class="keywordflow">for</span> (TUint mask=0x80; mask!=0; mask>>=1) <span class="comment">// iterate with 0x80, 0x40 .. 0x01</span>
<a name="l00498"></a>00498 WritePixel(iInfo.iPalette[dataValue & mask]);
<a name="l00499"></a>00499 }
<a name="l00500"></a>00500 }
<a name="l00501"></a>00501 }
<a name="l00502"></a>00502
<a name="l00503"></a>00503
<a name="l00504"></a>00504 <span class="comment">//</span>
<a name="l00505"></a>00505 <span class="comment">// CBitDepth2Decoder: specialised reader for 2bpp scanlines</span>
<a name="l00506"></a>00506 <span class="comment">//</span>
<a name="l00507"></a>00507 <span class="keywordtype">void</span> CBitDepth2Decoder::DoConstructL()
<a name="l00508"></a>00508 {
<a name="l00509"></a>00509 <span class="keywordflow">if</span> (!(iInfo.iColorType & TPngImageInformation::EPaletteUsed))
<a name="l00510"></a>00510 { <span class="comment">// Set up palette to be grayscale values</span>
<a name="l00511"></a>00511 iInfo.iPalette[0] = KRgbBlack;
<a name="l00512"></a>00512 iInfo.iPalette[1] = KRgbDarkGray;
<a name="l00513"></a>00513 iInfo.iPalette[2] = KRgbGray;
<a name="l00514"></a>00514 iInfo.iPalette[3] = KRgbWhite;
<a name="l00515"></a>00515
<a name="l00516"></a>00516 <span class="keywordflow">if</span> (iInfo.iTransparencyPresent)
<a name="l00517"></a>00517 {
<a name="l00518"></a>00518 <span class="keywordflow">if</span> (iInfo.iTransparentGray <= 3)
<a name="l00519"></a>00519 iInfo.iTransparencyValue[iInfo.iTransparentGray] = 0;
<a name="l00520"></a>00520 }
<a name="l00521"></a>00521 }
<a name="l00522"></a>00522
<a name="l00523"></a>00523 <span class="comment">// Replicate values to avoid shifts when decoding</span>
<a name="l00524"></a>00524 iInfo.iPalette[4] = iInfo.iPalette[1];
<a name="l00525"></a>00525 iInfo.iPalette[8] = iInfo.iPalette[2];
<a name="l00526"></a>00526 iInfo.iPalette[12] = iInfo.iPalette[3];
<a name="l00527"></a>00527
<a name="l00528"></a>00528 iInfo.iPalette[16] = iInfo.iPalette[1];
<a name="l00529"></a>00529 iInfo.iPalette[32] = iInfo.iPalette[2];
<a name="l00530"></a>00530 iInfo.iPalette[48] = iInfo.iPalette[3];
<a name="l00531"></a>00531
<a name="l00532"></a>00532 iInfo.iPalette[64] = iInfo.iPalette[1];
<a name="l00533"></a>00533 iInfo.iPalette[128] = iInfo.iPalette[2];
<a name="l00534"></a>00534 iInfo.iPalette[192] = iInfo.iPalette[3];
<a name="l00535"></a>00535
<a name="l00536"></a>00536 <span class="keywordflow">if</span> (iInfo.iTransparencyPresent)
<a name="l00537"></a>00537 {
<a name="l00538"></a>00538 iInfo.iTransparencyValue[4] = iInfo.iTransparencyValue[1];
<a name="l00539"></a>00539 iInfo.iTransparencyValue[8] = iInfo.iTransparencyValue[2];
<a name="l00540"></a>00540 iInfo.iTransparencyValue[12] = iInfo.iTransparencyValue[3];
<a name="l00541"></a>00541
<a name="l00542"></a>00542 iInfo.iTransparencyValue[16] = iInfo.iTransparencyValue[1];
<a name="l00543"></a>00543 iInfo.iTransparencyValue[32] = iInfo.iTransparencyValue[2];
<a name="l00544"></a>00544 iInfo.iTransparencyValue[48] = iInfo.iTransparencyValue[3];
<a name="l00545"></a>00545
<a name="l00546"></a>00546 iInfo.iTransparencyValue[64] = iInfo.iTransparencyValue[1];
<a name="l00547"></a>00547 iInfo.iTransparencyValue[128] = iInfo.iTransparencyValue[2];
<a name="l00548"></a>00548 iInfo.iTransparencyValue[192] = iInfo.iTransparencyValue[3];
<a name="l00549"></a>00549 }
<a name="l00550"></a>00550
<a name="l00551"></a>00551 iBytesPerPixel = 1;
<a name="l00552"></a>00552 <span class="keywordflow">if</span> (iInfo.iInterlaceMethod == TPngImageInformation::ENoInterlace)
<a name="l00553"></a>00553 {
<a name="l00554"></a>00554 TInt pixelPadding = ((iInfo.iSize.iWidth + 3) & ~3) - iInfo.iSize.iWidth;
<a name="l00555"></a>00555 iImageProc->SetPixelPadding(pixelPadding);
<a name="l00556"></a>00556 <span class="keywordflow">if</span> (iMaskProc)
<a name="l00557"></a>00557 iMaskProc->SetPixelPadding(pixelPadding);
<a name="l00558"></a>00558 }
<a name="l00559"></a>00559 }
<a name="l00560"></a>00560
<a name="l00561"></a>00561 TInt CBitDepth2Decoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00562"></a>00562 {
<a name="l00563"></a>00563 <span class="keywordflow">return</span> ((aPixelLength + 3) / 4) + KPngScanlineFilterTypeLength;
<a name="l00564"></a>00564 }
<a name="l00565"></a>00565
<a name="l00566"></a>00566 <span class="keywordtype">void</span> CBitDepth2Decoder::DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00567"></a>00567 {
<a name="l00568"></a>00568 <span class="keywordflow">if</span> (iMaskProc && iInfo.iTransparencyPresent)
<a name="l00569"></a>00569 {
<a name="l00570"></a>00570 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00571"></a>00571 {
<a name="l00572"></a>00572 TInt dataValue = *aDataPtr++;
<a name="l00573"></a>00573
<a name="l00574"></a>00574 <span class="keywordflow">for</span> (TInt mask=0xc0; mask!=0; mask>>=2) <span class="comment">// iterate through 0xc0, 0x30, 0x0c and 0x03</span>
<a name="l00575"></a>00575 WritePixel(iInfo.iPalette[dataValue & mask],iInfo.iTransparencyValue[dataValue & mask]);
<a name="l00576"></a>00576 }
<a name="l00577"></a>00577 }
<a name="l00578"></a>00578 <span class="keywordflow">else</span>
<a name="l00579"></a>00579 {
<a name="l00580"></a>00580 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00581"></a>00581 {
<a name="l00582"></a>00582 TInt dataValue = *aDataPtr++;
<a name="l00583"></a>00583
<a name="l00584"></a>00584 <span class="keywordflow">for</span> (TInt mask=0xc0; mask!=0; mask>>=2) <span class="comment">// iterate through 0xc0, 0x30, 0x0c and 0x03</span>
<a name="l00585"></a>00585 WritePixel(iInfo.iPalette[dataValue & mask]);
<a name="l00586"></a>00586 }
<a name="l00587"></a>00587 }
<a name="l00588"></a>00588 }
<a name="l00589"></a>00589
<a name="l00590"></a>00590
<a name="l00591"></a>00591 <span class="comment">//</span>
<a name="l00592"></a>00592 <span class="comment">// CBitDepth4Decoder: specialised reader for 4bpp scanlines</span>
<a name="l00593"></a>00593 <span class="comment">//</span>
<a name="l00594"></a>00594
<a name="l00595"></a>00595 <span class="keywordtype">void</span> CBitDepth4Decoder::DoConstructL()
<a name="l00596"></a>00596 {
<a name="l00597"></a>00597 <span class="keywordflow">if</span> (!(iInfo.iColorType & TPngImageInformation::EPaletteUsed))
<a name="l00598"></a>00598 { <span class="comment">// Set up palette to be grayscale values</span>
<a name="l00599"></a>00599 <span class="keywordflow">for</span> (TInt index = 0; index < 16; index++)
<a name="l00600"></a>00600 iInfo.iPalette[index] = TRgb::Gray16(index);
<a name="l00601"></a>00601
<a name="l00602"></a>00602 <span class="keywordflow">if</span> (iInfo.iTransparencyPresent)
<a name="l00603"></a>00603 {
<a name="l00604"></a>00604 <span class="keywordflow">if</span> (iInfo.iTransparentGray <= 15)
<a name="l00605"></a>00605 iInfo.iTransparencyValue[iInfo.iTransparentGray] = 0;
<a name="l00606"></a>00606 }
<a name="l00607"></a>00607 }
<a name="l00608"></a>00608
<a name="l00609"></a>00609 iBytesPerPixel = 1;
<a name="l00610"></a>00610 <span class="keywordflow">if</span> (iInfo.iInterlaceMethod == TPngImageInformation::ENoInterlace)
<a name="l00611"></a>00611 {
<a name="l00612"></a>00612 TInt pixelPadding = ((iInfo.iSize.iWidth + 1) & ~1) - iInfo.iSize.iWidth;
<a name="l00613"></a>00613 iImageProc->SetPixelPadding(pixelPadding);
<a name="l00614"></a>00614 <span class="keywordflow">if</span> (iMaskProc)
<a name="l00615"></a>00615 iMaskProc->SetPixelPadding(pixelPadding);
<a name="l00616"></a>00616 }
<a name="l00617"></a>00617 }
<a name="l00618"></a>00618
<a name="l00619"></a>00619 TInt CBitDepth4Decoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00620"></a>00620 {
<a name="l00621"></a>00621 <span class="keywordflow">return</span> ((aPixelLength + 1) / 2) + KPngScanlineFilterTypeLength;
<a name="l00622"></a>00622 }
<a name="l00623"></a>00623
<a name="l00624"></a>00624 <span class="keywordtype">void</span> CBitDepth4Decoder::DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00625"></a>00625 {
<a name="l00626"></a>00626 <span class="keywordflow">if</span> (iMaskProc && iInfo.iTransparencyPresent)
<a name="l00627"></a>00627 {
<a name="l00628"></a>00628 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00629"></a>00629 {
<a name="l00630"></a>00630 TInt dataValue = *aDataPtr++;
<a name="l00631"></a>00631
<a name="l00632"></a>00632 WritePixel(iInfo.iPalette[dataValue >> 4],iInfo.iTransparencyValue[dataValue >> 4]);
<a name="l00633"></a>00633 WritePixel(iInfo.iPalette[dataValue & 0x0f],iInfo.iTransparencyValue[dataValue & 0x0f]);
<a name="l00634"></a>00634 }
<a name="l00635"></a>00635 }
<a name="l00636"></a>00636 <span class="keywordflow">else</span>
<a name="l00637"></a>00637 {
<a name="l00638"></a>00638 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00639"></a>00639 {
<a name="l00640"></a>00640 TInt dataValue = *aDataPtr++;
<a name="l00641"></a>00641
<a name="l00642"></a>00642 WritePixel(iInfo.iPalette[dataValue >> 4]);
<a name="l00643"></a>00643 WritePixel(iInfo.iPalette[dataValue & 0x0f]);
<a name="l00644"></a>00644 }
<a name="l00645"></a>00645 }
<a name="l00646"></a>00646 }
<a name="l00647"></a>00647
<a name="l00648"></a>00648
<a name="l00649"></a>00649 <span class="comment">//</span>
<a name="l00650"></a>00650 <span class="comment">// CBitDepth8Decoder: specialised reader for 8bpp scanlines</span>
<a name="l00651"></a>00651 <span class="comment">//</span>
<a name="l00652"></a>00652
<a name="l00653"></a>00653 <span class="keywordtype">void</span> CBitDepth8Decoder::DoConstructL()
<a name="l00654"></a>00654 {
<a name="l00655"></a>00655 <span class="keywordflow">if</span> (!(iInfo.iColorType & TPngImageInformation::EPaletteUsed))
<a name="l00656"></a>00656 { <span class="comment">// Set up palette to be grayscale values</span>
<a name="l00657"></a>00657 <span class="keywordflow">for</span> (TInt index = 0; index < 256; index++)
<a name="l00658"></a>00658 iInfo.iPalette[index] = TRgb::Gray256(index);
<a name="l00659"></a>00659
<a name="l00660"></a>00660 <span class="keywordflow">if</span> (iInfo.iTransparencyPresent)
<a name="l00661"></a>00661 {
<a name="l00662"></a>00662 <span class="keywordflow">if</span> (iInfo.iTransparentGray <= 255)
<a name="l00663"></a>00663 iInfo.iTransparencyValue[iInfo.iTransparentGray] = 0;
<a name="l00664"></a>00664 }
<a name="l00665"></a>00665 }
<a name="l00666"></a>00666
<a name="l00667"></a>00667 iBytesPerPixel = 1;
<a name="l00668"></a>00668 }
<a name="l00669"></a>00669
<a name="l00670"></a>00670 TInt CBitDepth8Decoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00671"></a>00671 {
<a name="l00672"></a>00672 <span class="keywordflow">return</span> aPixelLength + KPngScanlineFilterTypeLength;
<a name="l00673"></a>00673 }
<a name="l00674"></a>00674
<a name="l00675"></a>00675 <span class="keywordtype">void</span> CBitDepth8Decoder::DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00676"></a>00676 {
<a name="l00677"></a>00677 <span class="keywordflow">if</span> (iMaskProc && iInfo.iTransparencyPresent)
<a name="l00678"></a>00678 {
<a name="l00679"></a>00679 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00680"></a>00680 {
<a name="l00681"></a>00681 WritePixel(iInfo.iPalette[aDataPtr[0]],iInfo.iTransparencyValue[aDataPtr[0]]);
<a name="l00682"></a>00682 aDataPtr++;
<a name="l00683"></a>00683 }
<a name="l00684"></a>00684 }
<a name="l00685"></a>00685 <span class="keywordflow">else</span>
<a name="l00686"></a>00686 {
<a name="l00687"></a>00687 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00688"></a>00688 WritePixel(iInfo.iPalette[*aDataPtr++]);
<a name="l00689"></a>00689 }
<a name="l00690"></a>00690 }
<a name="l00691"></a>00691
<a name="l00692"></a>00692
<a name="l00693"></a>00693 <span class="comment">//</span>
<a name="l00694"></a>00694 <span class="comment">// CBitDepth8ColorType2Decoder: specialised reader for 8bpp scanlines, direct colour</span>
<a name="l00695"></a>00695 <span class="comment">//</span>
<a name="l00696"></a>00696
<a name="l00697"></a>00697 <span class="keywordtype">void</span> CBitDepth8ColorType2Decoder::DoConstructL()
<a name="l00698"></a>00698 {
<a name="l00699"></a>00699 iBytesPerPixel = 3;
<a name="l00700"></a>00700 }
<a name="l00701"></a>00701
<a name="l00702"></a>00702 TInt CBitDepth8ColorType2Decoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00703"></a>00703 {
<a name="l00704"></a>00704 <span class="keywordflow">return</span> (aPixelLength * 3) + KPngScanlineFilterTypeLength;
<a name="l00705"></a>00705 }
<a name="l00706"></a>00706
<a name="l00707"></a>00707 <span class="keywordtype">void</span> CBitDepth8ColorType2Decoder::DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00708"></a>00708 {
<a name="l00709"></a>00709 <span class="keywordflow">if</span> (iMaskProc && iInfo.iTransparencyPresent)
<a name="l00710"></a>00710 {
<a name="l00711"></a>00711 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00712"></a>00712 {
<a name="l00713"></a>00713 TInt red = aDataPtr[0];
<a name="l00714"></a>00714 TInt green = aDataPtr[1];
<a name="l00715"></a>00715 TInt blue = aDataPtr[2];
<a name="l00716"></a>00716 TRgb pixelColor(red,green,blue);
<a name="l00717"></a>00717 <span class="keywordflow">if</span> (red == iInfo.iTransparentRed && green == iInfo.iTransparentGreen && blue == iInfo.iTransparentBlue)
<a name="l00718"></a>00718 WritePixel(pixelColor,0);
<a name="l00719"></a>00719 <span class="keywordflow">else</span>
<a name="l00720"></a>00720 WritePixel(pixelColor,255);
<a name="l00721"></a>00721 aDataPtr += 3;
<a name="l00722"></a>00722 }
<a name="l00723"></a>00723 }
<a name="l00724"></a>00724 <span class="keywordflow">else</span>
<a name="l00725"></a>00725 {
<a name="l00726"></a>00726 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00727"></a>00727 {
<a name="l00728"></a>00728 WritePixel(TRgb(aDataPtr[0],aDataPtr[1],aDataPtr[2]));
<a name="l00729"></a>00729 aDataPtr += 3;
<a name="l00730"></a>00730 }
<a name="l00731"></a>00731 }
<a name="l00732"></a>00732 }
<a name="l00733"></a>00733
<a name="l00734"></a>00734
<a name="l00735"></a>00735 <span class="comment">//</span>
<a name="l00736"></a>00736 <span class="comment">// CBitDepth8ColorType4Decoder: specialised reader for 8bpp scanlines, alpha greyscale</span>
<a name="l00737"></a>00737 <span class="comment">//</span>
<a name="l00738"></a>00738
<a name="l00739"></a>00739 <span class="keywordtype">void</span> CBitDepth8ColorType4Decoder::DoConstructL()
<a name="l00740"></a>00740 {
<a name="l00741"></a>00741 iBytesPerPixel = 2;
<a name="l00742"></a>00742 }
<a name="l00743"></a>00743
<a name="l00744"></a>00744 TInt CBitDepth8ColorType4Decoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00745"></a>00745 {
<a name="l00746"></a>00746 <span class="keywordflow">return</span> (aPixelLength * 2) + KPngScanlineFilterTypeLength;
<a name="l00747"></a>00747 }
<a name="l00748"></a>00748
<a name="l00749"></a>00749 <span class="keywordtype">void</span> CBitDepth8ColorType4Decoder::DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00750"></a>00750 {
<a name="l00751"></a>00751 <span class="keywordflow">if</span> (iMaskProc)
<a name="l00752"></a>00752 {
<a name="l00753"></a>00753 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00754"></a>00754 {
<a name="l00755"></a>00755 WritePixel(TRgb::Gray256(aDataPtr[0]),aDataPtr[1]);
<a name="l00756"></a>00756 aDataPtr += 2;
<a name="l00757"></a>00757 }
<a name="l00758"></a>00758 }
<a name="l00759"></a>00759 <span class="keywordflow">else</span>
<a name="l00760"></a>00760 {
<a name="l00761"></a>00761 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00762"></a>00762 {
<a name="l00763"></a>00763 WritePixel(TRgb::Gray256(aDataPtr[0]));
<a name="l00764"></a>00764 aDataPtr += 2;
<a name="l00765"></a>00765 }
<a name="l00766"></a>00766 }
<a name="l00767"></a>00767 }
<a name="l00768"></a>00768
<a name="l00769"></a>00769
<a name="l00770"></a>00770 <span class="comment">//</span>
<a name="l00771"></a>00771 <span class="comment">// CBitDepth8ColorType4Decoder: specialised reader for 8bpp scanlines, alpha colour</span>
<a name="l00772"></a>00772 <span class="comment">//</span>
<a name="l00773"></a>00773
<a name="l00774"></a>00774 <span class="keywordtype">void</span> CBitDepth8ColorType6Decoder::DoConstructL()
<a name="l00775"></a>00775 {
<a name="l00776"></a>00776 iBytesPerPixel = 4;
<a name="l00777"></a>00777 }
<a name="l00778"></a>00778
<a name="l00779"></a>00779 TInt CBitDepth8ColorType6Decoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00780"></a>00780 {
<a name="l00781"></a>00781 <span class="keywordflow">return</span> (aPixelLength * 4) + KPngScanlineFilterTypeLength;
<a name="l00782"></a>00782 }
<a name="l00783"></a>00783
<a name="l00784"></a>00784 <span class="keywordtype">void</span> CBitDepth8ColorType6Decoder::DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00785"></a>00785 {
<a name="l00786"></a>00786 <span class="keywordflow">if</span> (iMaskProc)
<a name="l00787"></a>00787 {
<a name="l00788"></a>00788 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00789"></a>00789 {
<a name="l00790"></a>00790 WritePixel(TRgb(aDataPtr[0],aDataPtr[1],aDataPtr[2]),aDataPtr[3]);
<a name="l00791"></a>00791 aDataPtr += 4;
<a name="l00792"></a>00792 }
<a name="l00793"></a>00793 }
<a name="l00794"></a>00794 <span class="keywordflow">else</span>
<a name="l00795"></a>00795 {
<a name="l00796"></a>00796 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00797"></a>00797 {
<a name="l00798"></a>00798 WritePixel(TRgb(aDataPtr[0],aDataPtr[1],aDataPtr[2]));
<a name="l00799"></a>00799 aDataPtr += 4;
<a name="l00800"></a>00800 }
<a name="l00801"></a>00801 }
<a name="l00802"></a>00802 }
<a name="l00803"></a>00803
<a name="l00804"></a>00804
<a name="l00805"></a>00805 <span class="comment">//</span>
<a name="l00806"></a>00806 <span class="comment">// CBitDepth16ColorType0Decoder: specialised reader for 16bpp scanlines, greyscale</span>
<a name="l00807"></a>00807 <span class="comment">//</span>
<a name="l00808"></a>00808
<a name="l00809"></a>00809 <span class="keywordtype">void</span> CBitDepth16ColorType0Decoder::DoConstructL()
<a name="l00810"></a>00810 {
<a name="l00811"></a>00811 iBytesPerPixel = 2;
<a name="l00812"></a>00812 }
<a name="l00813"></a>00813
<a name="l00814"></a>00814 TInt CBitDepth16ColorType0Decoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00815"></a>00815 {
<a name="l00816"></a>00816 <span class="keywordflow">return</span> (aPixelLength * 2) + KPngScanlineFilterTypeLength;
<a name="l00817"></a>00817 }
<a name="l00818"></a>00818
<a name="l00819"></a>00819 <span class="keywordtype">void</span> CBitDepth16ColorType0Decoder::DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00820"></a>00820 {
<a name="l00821"></a>00821 <span class="keywordflow">if</span> (iMaskProc && iInfo.iTransparencyPresent)
<a name="l00822"></a>00822 {
<a name="l00823"></a>00823 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00824"></a>00824 {
<a name="l00825"></a>00825 TInt gray = (aDataPtr[0] << 8) | aDataPtr[1];
<a name="l00826"></a>00826 TRgb pixelColor(TRgb::Gray256(aDataPtr[0]));
<a name="l00827"></a>00827 <span class="keywordflow">if</span> (gray == iInfo.iTransparentGray)
<a name="l00828"></a>00828 WritePixel(pixelColor,0);
<a name="l00829"></a>00829 <span class="keywordflow">else</span>
<a name="l00830"></a>00830 WritePixel(pixelColor,255);
<a name="l00831"></a>00831 aDataPtr += 2;
<a name="l00832"></a>00832 }
<a name="l00833"></a>00833 }
<a name="l00834"></a>00834 <span class="keywordflow">else</span>
<a name="l00835"></a>00835 {
<a name="l00836"></a>00836 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00837"></a>00837 {
<a name="l00838"></a>00838 WritePixel(TRgb::Gray256(aDataPtr[0]));
<a name="l00839"></a>00839 aDataPtr += 2;
<a name="l00840"></a>00840 }
<a name="l00841"></a>00841 }
<a name="l00842"></a>00842 }
<a name="l00843"></a>00843
<a name="l00844"></a>00844
<a name="l00845"></a>00845 <span class="comment">//</span>
<a name="l00846"></a>00846 <span class="comment">// CBitDepth16ColorType2Decoder: specialised reader for 16bpp scanlines, RGB colour</span>
<a name="l00847"></a>00847 <span class="comment">//</span>
<a name="l00848"></a>00848
<a name="l00849"></a>00849 <span class="keywordtype">void</span> CBitDepth16ColorType2Decoder::DoConstructL()
<a name="l00850"></a>00850 {
<a name="l00851"></a>00851 iBytesPerPixel = 6;
<a name="l00852"></a>00852 }
<a name="l00853"></a>00853
<a name="l00854"></a>00854 TInt CBitDepth16ColorType2Decoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00855"></a>00855 {
<a name="l00856"></a>00856 <span class="keywordflow">return</span> (aPixelLength * 6) + KPngScanlineFilterTypeLength;
<a name="l00857"></a>00857 }
<a name="l00858"></a>00858
<a name="l00859"></a>00859 <span class="keywordtype">void</span> CBitDepth16ColorType2Decoder::DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00860"></a>00860 {
<a name="l00861"></a>00861 <span class="keywordflow">if</span> (iMaskProc && iInfo.iTransparencyPresent)
<a name="l00862"></a>00862 {
<a name="l00863"></a>00863 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00864"></a>00864 {
<a name="l00865"></a>00865 TInt red = (aDataPtr[0] << 8) | aDataPtr[1];
<a name="l00866"></a>00866 TInt green = (aDataPtr[2] << 8) | aDataPtr[3];
<a name="l00867"></a>00867 TInt blue = (aDataPtr[4] << 8) | aDataPtr[5];
<a name="l00868"></a>00868 TRgb pixelColor(aDataPtr[0],aDataPtr[2],aDataPtr[4]);
<a name="l00869"></a>00869 <span class="keywordflow">if</span> (red == iInfo.iTransparentRed && green == iInfo.iTransparentGreen && blue == iInfo.iTransparentBlue)
<a name="l00870"></a>00870 WritePixel(pixelColor,0);
<a name="l00871"></a>00871 <span class="keywordflow">else</span>
<a name="l00872"></a>00872 WritePixel(pixelColor,255);
<a name="l00873"></a>00873 aDataPtr += 6;
<a name="l00874"></a>00874 }
<a name="l00875"></a>00875 }
<a name="l00876"></a>00876 <span class="keywordflow">else</span>
<a name="l00877"></a>00877 {
<a name="l00878"></a>00878 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00879"></a>00879 {
<a name="l00880"></a>00880 WritePixel(TRgb(aDataPtr[0],aDataPtr[2],aDataPtr[4]));
<a name="l00881"></a>00881 aDataPtr += 6;
<a name="l00882"></a>00882 }
<a name="l00883"></a>00883 }
<a name="l00884"></a>00884 }
<a name="l00885"></a>00885
<a name="l00886"></a>00886
<a name="l00887"></a>00887 <span class="comment">//</span>
<a name="l00888"></a>00888 <span class="comment">// CBitDepth16ColorType4Decoder: specialised reader for 16bpp scanlines, alpha greyscale</span>
<a name="l00889"></a>00889 <span class="comment">//</span>
<a name="l00890"></a>00890
<a name="l00891"></a>00891 <span class="keywordtype">void</span> CBitDepth16ColorType4Decoder::DoConstructL()
<a name="l00892"></a>00892 {
<a name="l00893"></a>00893 iBytesPerPixel = 4;
<a name="l00894"></a>00894 }
<a name="l00895"></a>00895
<a name="l00896"></a>00896 TInt CBitDepth16ColorType4Decoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00897"></a>00897 {
<a name="l00898"></a>00898 <span class="keywordflow">return</span> (aPixelLength * 4) + KPngScanlineFilterTypeLength;
<a name="l00899"></a>00899 }
<a name="l00900"></a>00900
<a name="l00901"></a>00901 <span class="keywordtype">void</span> CBitDepth16ColorType4Decoder::DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00902"></a>00902 {
<a name="l00903"></a>00903 <span class="keywordflow">if</span> (iMaskProc)
<a name="l00904"></a>00904 {
<a name="l00905"></a>00905 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00906"></a>00906 {
<a name="l00907"></a>00907 WritePixel(TRgb::Gray256(aDataPtr[0]),aDataPtr[2]);
<a name="l00908"></a>00908 aDataPtr += 4;
<a name="l00909"></a>00909 }
<a name="l00910"></a>00910 }
<a name="l00911"></a>00911 <span class="keywordflow">else</span>
<a name="l00912"></a>00912 {
<a name="l00913"></a>00913 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00914"></a>00914 {
<a name="l00915"></a>00915 WritePixel(TRgb::Gray256(aDataPtr[0]));
<a name="l00916"></a>00916 aDataPtr += 4;
<a name="l00917"></a>00917 }
<a name="l00918"></a>00918 }
<a name="l00919"></a>00919 }
<a name="l00920"></a>00920
<a name="l00921"></a>00921
<a name="l00922"></a>00922 <span class="comment">//</span>
<a name="l00923"></a>00923 <span class="comment">// CBitDepth16ColorType6Decoder: specialised reader for 16bpp scanlines, alpha colour</span>
<a name="l00924"></a>00924 <span class="comment">//</span>
<a name="l00925"></a>00925
<a name="l00926"></a>00926 <span class="keywordtype">void</span> CBitDepth16ColorType6Decoder::DoConstructL()
<a name="l00927"></a>00927 {
<a name="l00928"></a>00928 iBytesPerPixel = 8;
<a name="l00929"></a>00929 }
<a name="l00930"></a>00930
<a name="l00931"></a>00931 TInt CBitDepth16ColorType6Decoder::ScanlineBufferSize(TInt aPixelLength)
<a name="l00932"></a>00932 {
<a name="l00933"></a>00933 <span class="keywordflow">return</span> (aPixelLength * 8) + KPngScanlineFilterTypeLength;
<a name="l00934"></a>00934 }
<a name="l00935"></a>00935
<a name="l00936"></a>00936 <span class="keywordtype">void</span> CBitDepth16ColorType6Decoder::DoDecode(TUint8* aDataPtr,<span class="keyword">const</span> TUint8* aDataPtrLimit)
<a name="l00937"></a>00937 {
<a name="l00938"></a>00938 <span class="keywordflow">if</span> (iMaskProc)
<a name="l00939"></a>00939 {
<a name="l00940"></a>00940 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00941"></a>00941 {
<a name="l00942"></a>00942 WritePixel(TRgb(aDataPtr[0],aDataPtr[2],aDataPtr[4]),aDataPtr[6]);
<a name="l00943"></a>00943 aDataPtr += 8;
<a name="l00944"></a>00944 }
<a name="l00945"></a>00945 }
<a name="l00946"></a>00946 <span class="keywordflow">else</span>
<a name="l00947"></a>00947 {
<a name="l00948"></a>00948 <span class="keywordflow">while</span> (aDataPtr < aDataPtrLimit)
<a name="l00949"></a>00949 {
<a name="l00950"></a>00950 WritePixel(TRgb(aDataPtr[0],aDataPtr[2],aDataPtr[4]));
<a name="l00951"></a>00951 aDataPtr += 8;
<a name="l00952"></a>00952 }
<a name="l00953"></a>00953 }
<a name="l00954"></a>00954 }
<a name="l00955"></a>00955
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