LCOV - code coverage report
Current view: directory - image/decoders - nsBMPDecoder.h (source / functions) Found Hit Coverage
Test: app.info Lines: 14 6 42.9 %
Date: 2012-06-02 Functions: 3 2 66.7 %

       1                 : /* vim:set tw=80 expandtab softtabstop=4 ts=4 sw=4: */
       2                 : /* ***** BEGIN LICENSE BLOCK *****
       3                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       4                 :  *
       5                 :  * The contents of this file are subject to the Mozilla Public License Version
       6                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       7                 :  * the License. You may obtain a copy of the License at
       8                 :  * http://www.mozilla.org/MPL/
       9                 :  *
      10                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      11                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      12                 :  * for the specific language governing rights and limitations under the
      13                 :  * License.
      14                 :  *
      15                 :  * The Original Code is the Mozilla BMP Decoder.
      16                 :  *
      17                 :  * The Initial Developer of the Original Code is
      18                 :  * Christian Biesinger <cbiesinger@web.de>.
      19                 :  * Portions created by the Initial Developer are Copyright (C) 2001
      20                 :  * the Initial Developer. All Rights Reserved.
      21                 :  *
      22                 :  * Contributor(s):
      23                 :  *   Bobby Holley <bobbyholley@gmail.com>
      24                 :  *   Brian R. Bondy <netzen@gmail.com>
      25                 :  *
      26                 :  * Alternatively, the contents of this file may be used under the terms of
      27                 :  * either the GNU General Public License Version 2 or later (the "GPL"), or
      28                 :  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      29                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      30                 :  * of those above. If you wish to allow use of your version of this file only
      31                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      32                 :  * use your version of this file under the terms of the MPL, indicate your
      33                 :  * decision by deleting the provisions above and replace them with the notice
      34                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      35                 :  * the provisions above, a recipient may use your version of this file under
      36                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      37                 :  *
      38                 :  * ***** END LICENSE BLOCK ***** */
      39                 : 
      40                 : 
      41                 : #ifndef _nsBMPDecoder_h
      42                 : #define _nsBMPDecoder_h
      43                 : 
      44                 : #include "nsAutoPtr.h"
      45                 : #include "imgIDecoderObserver.h"
      46                 : #include "gfxColor.h"
      47                 : #include "Decoder.h"
      48                 : #include "BMPFileHeaders.h"
      49                 : 
      50                 : namespace mozilla {
      51                 : namespace image {
      52                 : 
      53                 : class RasterImage;
      54                 : 
      55                 : /**
      56                 :  * Decoder for BMP-Files, as used by Windows and OS/2
      57                 :  */
      58                 : class nsBMPDecoder : public Decoder
      59                 : {
      60                 : public:
      61                 : 
      62                 :     nsBMPDecoder(RasterImage &aImage, imgIDecoderObserver* aObserver);
      63                 :     ~nsBMPDecoder();
      64                 : 
      65                 :     // Specifies whether or not the BMP file will contain alpha data
      66                 :     // If set to true and the BMP is 32BPP, the alpha data will be
      67                 :     // retrieved from the 4th byte of image data per pixel 
      68                 :     void SetUseAlphaData(bool useAlphaData);
      69                 :     // Obtains the bits per pixel from the internal BIH header
      70                 :     PRInt32 GetBitsPerPixel() const;
      71                 :     // Obtains the width from the internal BIH header
      72                 :     PRInt32 GetWidth() const;
      73                 :     // Obtains the height from the internal BIH header
      74                 :     PRInt32 GetHeight() const;
      75                 :     // Obtains the internal output image buffer
      76                 :     PRUint32* GetImageData();
      77                 :     // Obtains the size of the compressed image resource
      78                 :     PRInt32 GetCompressedImageSize() const;
      79                 :     // Obtains whether or not a BMP file had alpha data in its 4th byte
      80                 :     // for 32BPP bitmaps.  Only use after the bitmap has been processed.
      81                 :     bool HasAlphaData() const;
      82                 : 
      83                 :     virtual void WriteInternal(const char* aBuffer, PRUint32 aCount);
      84                 :     virtual void FinishInternal();
      85                 : 
      86                 : private:
      87                 : 
      88                 :     /** Calculates the red-, green- and blueshift in mBitFields using
      89                 :      * the bitmasks from mBitFields */
      90                 :     NS_METHOD CalcBitShift();
      91                 : 
      92                 :     PRUint32 mPos;
      93                 : 
      94                 :     BMPFILEHEADER mBFH;
      95                 :     BMPINFOHEADER mBIH;
      96                 :     char mRawBuf[36];
      97                 : 
      98                 :     PRUint32 mLOH; ///< Length of the header
      99                 : 
     100                 :     PRUint32 mNumColors; ///< The number of used colors, i.e. the number of entries in mColors
     101                 :     colorTable *mColors;
     102                 : 
     103                 :     bitFields mBitFields;
     104                 : 
     105                 :     PRUint32 *mImageData; ///< Pointer to the image data for the frame
     106                 :     PRUint8 *mRow;      ///< Holds one raw line of the image
     107                 :     PRUint32 mRowBytes; ///< How many bytes of the row were already received
     108                 :     PRInt32 mCurLine;   ///< Index of the line of the image that's currently being decoded
     109                 :     PRInt32 mOldLine;   ///< Previous index of the line 
     110                 :     PRInt32 mCurPos;    ///< Index in the current line of the image
     111                 : 
     112                 :     ERLEState mState;   ///< Maintains the current state of the RLE decoding
     113                 :     PRUint32 mStateData;///< Decoding information that is needed depending on mState
     114                 : 
     115                 :     /** Set mBFH from the raw data in mRawBuf, converting from little-endian
     116                 :      * data to native data as necessary */
     117                 :     void ProcessFileHeader();
     118                 :     /** Set mBIH from the raw data in mRawBuf, converting from little-endian
     119                 :      * data to native data as necessary */
     120                 :     void ProcessInfoHeader();
     121                 : 
     122                 :     // Stores whether the image data may store alpha data, or if
     123                 :     // the alpha data is unspecified and filled with a padding byte of 0. 
     124                 :     // When a 32BPP bitmap is stored in an ICO or CUR file, its 4th byte
     125                 :     // is used for alpha transparency.  When it is stored in a BMP, its
     126                 :     // 4th byte is reserved and is always 0.
     127                 :     // Reference: 
     128                 :     // http://en.wikipedia.org/wiki/ICO_(file_format)#cite_note-9
     129                 :     // Bitmaps where the alpha bytes are all 0 should be fully visible.
     130                 :     bool mUseAlphaData;
     131                 :     // Whether the 4th byte alpha data was found to be non zero and hence used.
     132                 :     bool mHaveAlphaData;
     133                 : };
     134                 : 
     135                 : /** Sets the pixel data in aDecoded to the given values.
     136                 :  * @param aDecoded pointer to pixel to be set, will be incremented to point to the next pixel.
     137                 :  */
     138            1024 : static inline void SetPixel(PRUint32*& aDecoded, PRUint8 aRed, PRUint8 aGreen, PRUint8 aBlue, PRUint8 aAlpha = 0xFF)
     139                 : {
     140            1024 :     *aDecoded++ = GFX_PACKED_PIXEL(aAlpha, aRed, aGreen, aBlue);
     141            1024 : }
     142                 : 
     143             768 : static inline void SetPixel(PRUint32*& aDecoded, PRUint8 idx, colorTable* aColors)
     144                 : {
     145             768 :     SetPixel(aDecoded, aColors[idx].red, aColors[idx].green, aColors[idx].blue);
     146             768 : }
     147                 : 
     148                 : /** Sets two (or one if aCount = 1) pixels
     149                 :  * @param aDecoded where the data is stored. Will be moved 4 resp 8 bytes
     150                 :  * depending on whether one or two pixels are written.
     151                 :  * @param aData The values for the two pixels
     152                 :  * @param aCount Current count. Is decremented by one or two.
     153                 :  */
     154               0 : inline void Set4BitPixel(PRUint32*& aDecoded, PRUint8 aData,
     155                 :                          PRUint32& aCount, colorTable* aColors)
     156                 : {
     157               0 :     PRUint8 idx = aData >> 4;
     158               0 :     SetPixel(aDecoded, idx, aColors);
     159               0 :     if (--aCount > 0) {
     160               0 :         idx = aData & 0xF;
     161               0 :         SetPixel(aDecoded, idx, aColors);
     162               0 :         --aCount;
     163                 :     }
     164               0 : }
     165                 : 
     166                 : } // namespace image
     167                 : } // namespace mozilla
     168                 : 
     169                 : 
     170                 : #endif
     171                 : 

Generated by: LCOV version 1.7