/* vim:set tw=80 expandtab softtabstop=4 ts=4 sw=4: */ /* ***** BEGIN LICENSE BLOCK ***** * Version: MPL 1.1/GPL 2.0/LGPL 2.1 * * The contents of this file are subject to the Mozilla Public License Version * 1.1 (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the * License. * * The Original Code is the Mozilla BMP Decoder. * * The Initial Developer of the Original Code is * Christian Biesinger . * Portions created by the Initial Developer are Copyright (C) 2001 * the Initial Developer. All Rights Reserved. * * Contributor(s): * * Alternatively, the contents of this file may be used under the terms of * either the GNU General Public License Version 2 or later (the "GPL"), or * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"), * in which case the provisions of the GPL or the LGPL are applicable instead * of those above. If you wish to allow use of your version of this file only * under the terms of either the GPL or the LGPL, and not to allow others to * use your version of this file under the terms of the MPL, indicate your * decision by deleting the provisions above and replace them with the notice * and other provisions required by the GPL or the LGPL. If you do not delete * the provisions above, a recipient may use your version of this file under * the terms of any one of the MPL, the GPL or the LGPL. * * ***** END LICENSE BLOCK ***** */ #ifndef _nsBMPDecoder_h #define _nsBMPDecoder_h #include "nsCOMPtr.h" #include "imgIDecoder.h" #include "imgIContainer.h" #include "imgIDecoderObserver.h" #include "gfxIImageFrame.h" #define NS_BMPDECODER_CID \ { /* {78c61626-4d1f-4843-9364-4652d98ff6e1} */ \ 0x78c61626, \ 0x4d1f, \ 0x4843, \ { 0x93, 0x64, 0x46, 0x52, 0xd9, 0x8f, 0xf6, 0xe1 } \ } struct BMPFILEHEADER { char signature[2]; // String "BM" PRUint32 filesize; PRInt32 reserved; // Zero PRUint32 dataoffset; // Offset to raster data PRUint32 bihsize; }; #define BFH_LENGTH 18 // Note: For our purposes, we include bihsize in the BFH #define OS2_BIH_LENGTH 12 // This is the real BIH size (as contained in the bihsize field of BMPFILEHEADER) #define OS2_HEADER_LENGTH (BFH_LENGTH + 8) #define WIN_HEADER_LENGTH (BFH_LENGTH + 36) struct BMPINFOHEADER { PRInt32 width; // Uint16 in OS/2 BMPs PRInt32 height; // Uint16 in OS/2 BMPs PRUint16 planes; // =1 PRUint16 bpp; // Bits per pixel. // The rest of the header is not available in OS/2 BMP Files PRUint32 compression; // 0=no compression 1=8bit RLE 2=4bit RLE PRUint32 image_size; // (compressed) image size. Can be 0 if compression==0 PRUint32 xppm; // Pixels per meter, horizontal PRUint32 yppm; // Pixels per meter, vertical PRUint32 colors; // Used Colors PRUint32 important_colors; // Number of important colors. 0=all }; struct colorTable { PRUint8 red; PRUint8 green; PRUint8 blue; }; struct bitFields { PRUint32 red; PRUint32 green; PRUint32 blue; PRUint8 redLeftShift; PRUint8 redRightShift; PRUint8 greenLeftShift; PRUint8 greenRightShift; PRUint8 blueLeftShift; PRUint8 blueRightShift; }; #define BITFIELD_LENGTH 12 // Length of the bitfields structure in the bmp file #if defined WORDS_BIGENDIAN || defined IS_BIG_ENDIAN // We must ensure that the entity is unsigned // otherwise, if it is signed/negative, the MSB will be // propagated when we shift #define LITTLE_TO_NATIVE16(x) (((((PRUint16) x) & 0xFF) << 8) | \ (((PRUint16) x) >> 8)) #define LITTLE_TO_NATIVE32(x) (((((PRUint32) x) & 0xFF) << 24) | \ (((((PRUint32) x) >> 8) & 0xFF) << 16) | \ (((((PRUint32) x) >> 16) & 0xFF) << 8) | \ (((PRUint32) x) >> 24)) #else #define LITTLE_TO_NATIVE16(x) x #define LITTLE_TO_NATIVE32(x) x #endif #if defined(XP_WIN) || defined(XP_OS2) || defined(XP_BEOS) || defined(MOZ_WIDGET_PHOTON) #define BMP_GFXFORMAT gfxIFormats::BGR #define RLE_GFXFORMAT_ALPHA gfxIFormats::BGR_A1 #else #define USE_RGB #define BMP_GFXFORMAT gfxIFormats::RGB #define RLE_GFXFORMAT_ALPHA gfxIFormats::RGB_A1 #endif #if defined(XP_MAC) || defined(XP_MACOSX) #define GFXBYTESPERPIXEL 4 #else #define GFXBYTESPERPIXEL 3 #endif // BMPINFOHEADER.compression defines #define BI_RLE8 1 #define BI_RLE4 2 #define BI_BITFIELDS 3 // RLE Escape codes #define RLE_ESCAPE 0 #define RLE_ESCAPE_EOL 0 #define RLE_ESCAPE_EOF 1 #define RLE_ESCAPE_DELTA 2 /// enums for mState enum ERLEState { eRLEStateInitial, eRLEStateNeedSecondEscapeByte, eRLEStateNeedXDelta, eRLEStateNeedYDelta, ///< mStateData will hold x delta eRLEStateAbsoluteMode, ///< mStateData will hold count of existing data to read eRLEStateAbsoluteModePadded ///< As above, but another byte of data has to be read as padding }; /** * Decoder for BMP-Files, as used by Windows and OS/2 */ class nsBMPDecoder : public imgIDecoder { public: NS_DECL_ISUPPORTS NS_DECL_IMGIDECODER nsBMPDecoder(); ~nsBMPDecoder(); private: /** Callback for ReadSegments to avoid copying the data */ static NS_METHOD ReadSegCb(nsIInputStream* aIn, void* aClosure, const char* aFromRawSegment, PRUint32 aToOffset, PRUint32 aCount, PRUint32 *aWriteCount); /** Processes the data. * @param aBuffer Data to process. * @oaram count Number of bytes in mBuffer */ NS_METHOD ProcessData(const char* aBuffer, PRUint32 aCount); /** Calculates the red-, green- and blueshift in mBitFields using * the bitmasks from mBitFields */ NS_METHOD CalcBitShift(); /** Sets the image data. mCurLine is used to get the row, * mDecoded is used to get the data */ nsresult SetData(); /** Sets the rle data. mCurLine is used to get the row, * mDecoded is used to get the data for the first row, * all subsequent rows are blank. * @param rows Number of rows of data to set */ nsresult WriteRLERows(PRUint32 rows); nsCOMPtr mObserver; nsCOMPtr mImage; nsCOMPtr mFrame; PRUint32 mPos; BMPFILEHEADER mBFH; BMPINFOHEADER mBIH; char mRawBuf[36]; PRUint32 mLOH; ///< Length of the header PRUint32 mNumColors; ///< The number of used colors, i.e. the number of entries in mColors colorTable *mColors; bitFields mBitFields; PRUint8 *mRow; ///< Holds one raw line of the image PRUint32 mRowBytes; ///< How many bytes of the row were already received PRInt32 mCurLine; ///< Index of the line of the image that's currently being decoded PRUint8 *mAlpha; ///< Holds one line of unpacked alpha data PRUint8 *mAlphaPtr; ///< Pointer within unpacked alpha data PRUint8 *mDecoded; ///< Holds one line of color image data PRUint8 *mDecoding; ///< Pointer within image data ERLEState mState; ///< Maintains the current state of the RLE decoding PRUint32 mStateData;///< Decoding information that is needed depending on mState PRUint32 mBpr; ///< Cached image bytes per row /** Set mBFH from the raw data in mRawBuf, converting from little-endian * data to native data as necessary */ void ProcessFileHeader(); /** Set mBIH from the raw data in mRawBuf, converting from little-endian * data to native data as necessary */ void ProcessInfoHeader(); }; /** Sets the pixel data in aDecoded to the given values. * The variable passed in as aDecoded will be moved on 3 bytes! */ inline void SetPixel(PRUint8*& aDecoded, PRUint8 aRed, PRUint8 aGreen, PRUint8 aBlue) { #if defined(XP_MAC) || defined(XP_MACOSX) *aDecoded++ = 0; // Mac needs this padding byte #endif #ifdef USE_RGB *aDecoded++ = aRed; *aDecoded++ = aGreen; *aDecoded++ = aBlue; #else *aDecoded++ = aBlue; *aDecoded++ = aGreen; *aDecoded++ = aRed; #endif } inline void SetPixel(PRUint8*& aDecoded, PRUint8 idx, colorTable* aColors) { PRUint8 red, green, blue; red = aColors[idx].red; green = aColors[idx].green; blue = aColors[idx].blue; SetPixel(aDecoded, red, green, blue); } /** Sets two (or one if aCount = 1) pixels * @param aDecoded where the data is stored. Will be moved 3 or 6 bytes, * depending on whether one or two pixels are written. * @param aData The values for the two pixels * @param aCount Current count. Is decremented by one or two. */ inline void Set4BitPixel(PRUint8*& aDecoded, PRUint8 aData, PRUint32& aCount, colorTable* aColors) { PRUint8 idx = aData >> 4; SetPixel(aDecoded, idx, aColors); if (--aCount > 0) { idx = aData & 0xF; SetPixel(aDecoded, idx, aColors); --aCount; } } #endif