src/gui/image/qbmphandler.cpp
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     1 /****************************************************************************
       
     2 **
       
     3 ** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
       
     4 ** All rights reserved.
       
     5 ** Contact: Nokia Corporation (qt-info@nokia.com)
       
     6 **
       
     7 ** This file is part of the QtGui module of the Qt Toolkit.
       
     8 **
       
     9 ** $QT_BEGIN_LICENSE:LGPL$
       
    10 ** No Commercial Usage
       
    11 ** This file contains pre-release code and may not be distributed.
       
    12 ** You may use this file in accordance with the terms and conditions
       
    13 ** contained in the Technology Preview License Agreement accompanying
       
    14 ** this package.
       
    15 **
       
    16 ** GNU Lesser General Public License Usage
       
    17 ** Alternatively, this file may be used under the terms of the GNU Lesser
       
    18 ** General Public License version 2.1 as published by the Free Software
       
    19 ** Foundation and appearing in the file LICENSE.LGPL included in the
       
    20 ** packaging of this file.  Please review the following information to
       
    21 ** ensure the GNU Lesser General Public License version 2.1 requirements
       
    22 ** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
       
    23 **
       
    24 ** In addition, as a special exception, Nokia gives you certain additional
       
    25 ** rights.  These rights are described in the Nokia Qt LGPL Exception
       
    26 ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
       
    27 **
       
    28 ** If you have questions regarding the use of this file, please contact
       
    29 ** Nokia at qt-info@nokia.com.
       
    30 **
       
    31 **
       
    32 **
       
    33 **
       
    34 **
       
    35 **
       
    36 **
       
    37 **
       
    38 ** $QT_END_LICENSE$
       
    39 **
       
    40 ****************************************************************************/
       
    41 
       
    42 #include "private/qbmphandler_p.h"
       
    43 
       
    44 #ifndef QT_NO_IMAGEFORMAT_BMP
       
    45 
       
    46 #include <qimage.h>
       
    47 #include <qvariant.h>
       
    48 #include <qvector.h>
       
    49 
       
    50 QT_BEGIN_NAMESPACE
       
    51 
       
    52 static void swapPixel01(QImage *image)        // 1-bpp: swap 0 and 1 pixels
       
    53 {
       
    54     int i;
       
    55     if (image->depth() == 1 && image->numColors() == 2) {
       
    56         register uint *p = (uint *)image->bits();
       
    57         int nbytes = image->numBytes();
       
    58         for (i=0; i<nbytes/4; i++) {
       
    59             *p = ~*p;
       
    60             p++;
       
    61         }
       
    62         uchar *p2 = (uchar *)p;
       
    63         for (i=0; i<(nbytes&3); i++) {
       
    64             *p2 = ~*p2;
       
    65             p2++;
       
    66         }
       
    67         QRgb t = image->color(0);                // swap color 0 and 1
       
    68         image->setColor(0, image->color(1));
       
    69         image->setColor(1, t);
       
    70     }
       
    71 }
       
    72 
       
    73 /*
       
    74     QImageIO::defineIOHandler("BMP", "^BM", 0,
       
    75                                read_bmp_image, write_bmp_image);
       
    76 */
       
    77 
       
    78 /*****************************************************************************
       
    79   BMP (DIB) image read/write functions
       
    80  *****************************************************************************/
       
    81 
       
    82 const int BMP_FILEHDR_SIZE = 14;                // size of BMP_FILEHDR data
       
    83 
       
    84 static QDataStream &operator>>(QDataStream &s, BMP_FILEHDR &bf)
       
    85 {                                                // read file header
       
    86     s.readRawData(bf.bfType, 2);
       
    87     s >> bf.bfSize >> bf.bfReserved1 >> bf.bfReserved2 >> bf.bfOffBits;
       
    88     return s;
       
    89 }
       
    90 
       
    91 static QDataStream &operator<<(QDataStream &s, const BMP_FILEHDR &bf)
       
    92 {                                                // write file header
       
    93     s.writeRawData(bf.bfType, 2);
       
    94     s << bf.bfSize << bf.bfReserved1 << bf.bfReserved2 << bf.bfOffBits;
       
    95     return s;
       
    96 }
       
    97 
       
    98 
       
    99 const int BMP_OLD  = 12;                        // old Windows/OS2 BMP size
       
   100 const int BMP_WIN  = 40;                        // new Windows BMP size
       
   101 const int BMP_OS2  = 64;                        // new OS/2 BMP size
       
   102 
       
   103 const int BMP_RGB  = 0;                                // no compression
       
   104 const int BMP_RLE8 = 1;                                // run-length encoded, 8 bits
       
   105 const int BMP_RLE4 = 2;                                // run-length encoded, 4 bits
       
   106 const int BMP_BITFIELDS = 3;                        // RGB values encoded in data as bit-fields
       
   107 
       
   108 
       
   109 static QDataStream &operator>>(QDataStream &s, BMP_INFOHDR &bi)
       
   110 {
       
   111     s >> bi.biSize;
       
   112     if (bi.biSize == BMP_WIN || bi.biSize == BMP_OS2) {
       
   113         s >> bi.biWidth >> bi.biHeight >> bi.biPlanes >> bi.biBitCount;
       
   114         s >> bi.biCompression >> bi.biSizeImage;
       
   115         s >> bi.biXPelsPerMeter >> bi.biYPelsPerMeter;
       
   116         s >> bi.biClrUsed >> bi.biClrImportant;
       
   117     }
       
   118     else {                                        // probably old Windows format
       
   119         qint16 w, h;
       
   120         s >> w >> h >> bi.biPlanes >> bi.biBitCount;
       
   121         bi.biWidth  = w;
       
   122         bi.biHeight = h;
       
   123         bi.biCompression = BMP_RGB;                // no compression
       
   124         bi.biSizeImage = 0;
       
   125         bi.biXPelsPerMeter = bi.biYPelsPerMeter = 0;
       
   126         bi.biClrUsed = bi.biClrImportant = 0;
       
   127     }
       
   128     return s;
       
   129 }
       
   130 
       
   131 static QDataStream &operator<<(QDataStream &s, const BMP_INFOHDR &bi)
       
   132 {
       
   133     s << bi.biSize;
       
   134     s << bi.biWidth << bi.biHeight;
       
   135     s << bi.biPlanes;
       
   136     s << bi.biBitCount;
       
   137     s << bi.biCompression;
       
   138     s << bi.biSizeImage;
       
   139     s << bi.biXPelsPerMeter << bi.biYPelsPerMeter;
       
   140     s << bi.biClrUsed << bi.biClrImportant;
       
   141     return s;
       
   142 }
       
   143 
       
   144 static int calc_shift(int mask)
       
   145 {
       
   146     int result = 0;
       
   147     while (!(mask & 1)) {
       
   148         result++;
       
   149         mask >>= 1;
       
   150     }
       
   151     return result;
       
   152 }
       
   153 
       
   154 static bool read_dib_fileheader(QDataStream &s, BMP_FILEHDR &bf)
       
   155 {
       
   156     // read BMP file header
       
   157     s >> bf;
       
   158     if (s.status() != QDataStream::Ok)
       
   159         return false;
       
   160 
       
   161     // check header
       
   162     if (qstrncmp(bf.bfType,"BM",2) != 0)
       
   163         return false;
       
   164 
       
   165     return true;
       
   166 }
       
   167 
       
   168 static bool read_dib_infoheader(QDataStream &s, BMP_INFOHDR &bi)
       
   169 {
       
   170     s >> bi;                                        // read BMP info header
       
   171     if (s.status() != QDataStream::Ok)
       
   172         return false;
       
   173 
       
   174     int nbits = bi.biBitCount;
       
   175     int comp = bi.biCompression;
       
   176     if (!(nbits == 1 || nbits == 4 || nbits == 8 || nbits == 16 || nbits == 24 || nbits == 32) ||
       
   177         bi.biPlanes != 1 || comp > BMP_BITFIELDS)
       
   178         return false;                                        // weird BMP image
       
   179     if (!(comp == BMP_RGB || (nbits == 4 && comp == BMP_RLE4) ||
       
   180         (nbits == 8 && comp == BMP_RLE8) || ((nbits == 16 || nbits == 32) && comp == BMP_BITFIELDS)))
       
   181          return false;                                // weird compression type
       
   182 
       
   183     return true;
       
   184 }
       
   185 
       
   186 static bool read_dib_body(QDataStream &s, const BMP_INFOHDR &bi, int offset, int startpos, QImage &image)
       
   187 {
       
   188     QIODevice* d = s.device();
       
   189     if (d->atEnd())                                // end of stream/file
       
   190         return false;
       
   191 #if 0
       
   192     qDebug("offset...........%d", offset);
       
   193     qDebug("startpos.........%d", startpos);
       
   194     qDebug("biSize...........%d", bi.biSize);
       
   195     qDebug("biWidth..........%d", bi.biWidth);
       
   196     qDebug("biHeight.........%d", bi.biHeight);
       
   197     qDebug("biPlanes.........%d", bi.biPlanes);
       
   198     qDebug("biBitCount.......%d", bi.biBitCount);
       
   199     qDebug("biCompression....%d", bi.biCompression);
       
   200     qDebug("biSizeImage......%d", bi.biSizeImage);
       
   201     qDebug("biXPelsPerMeter..%d", bi.biXPelsPerMeter);
       
   202     qDebug("biYPelsPerMeter..%d", bi.biYPelsPerMeter);
       
   203     qDebug("biClrUsed........%d", bi.biClrUsed);
       
   204     qDebug("biClrImportant...%d", bi.biClrImportant);
       
   205 #endif
       
   206     int w = bi.biWidth,         h = bi.biHeight,  nbits = bi.biBitCount;
       
   207     int t = bi.biSize,         comp = bi.biCompression;
       
   208     int red_mask = 0;
       
   209     int green_mask = 0;
       
   210     int blue_mask = 0;
       
   211     int red_shift = 0;
       
   212     int green_shift = 0;
       
   213     int blue_shift = 0;
       
   214     int red_scale = 0;
       
   215     int green_scale = 0;
       
   216     int blue_scale = 0;
       
   217 
       
   218     int ncols = 0;
       
   219     int depth = 0;
       
   220     QImage::Format format;
       
   221     switch (nbits) {
       
   222         case 32:
       
   223         case 24:
       
   224         case 16:
       
   225             depth = 32;
       
   226             format = QImage::Format_RGB32;
       
   227             break;
       
   228         case 8:
       
   229         case 4:
       
   230             depth = 8;
       
   231             format = QImage::Format_Indexed8;
       
   232             break;
       
   233         default:
       
   234             depth = 1;
       
   235             format = QImage::Format_Mono;
       
   236     }
       
   237 
       
   238     if (bi.biHeight < 0)
       
   239         h = -h;                  // support images with negative height
       
   240 
       
   241     if (image.size() != QSize(w, h) || image.format() != format) {
       
   242         image = QImage(w, h, format);
       
   243         if (image.isNull())                        // could not create image
       
   244             return false;
       
   245     }
       
   246 
       
   247     if (depth != 32) {
       
   248         ncols = bi.biClrUsed ? bi.biClrUsed : 1 << nbits;
       
   249         image.setNumColors(ncols);
       
   250     }
       
   251 
       
   252     image.setDotsPerMeterX(bi.biXPelsPerMeter);
       
   253     image.setDotsPerMeterY(bi.biYPelsPerMeter);
       
   254 
       
   255     if (!d->isSequential())
       
   256         d->seek(startpos + BMP_FILEHDR_SIZE + bi.biSize); // goto start of colormap
       
   257 
       
   258     if (ncols > 0) {                                // read color table
       
   259         uchar rgb[4];
       
   260         int   rgb_len = t == BMP_OLD ? 3 : 4;
       
   261         for (int i=0; i<ncols; i++) {
       
   262             if (d->read((char *)rgb, rgb_len) != rgb_len)
       
   263                 return false;
       
   264             image.setColor(i, qRgb(rgb[2],rgb[1],rgb[0]));
       
   265             if (d->atEnd())                        // truncated file
       
   266                 return false;
       
   267         }
       
   268     } else if (comp == BMP_BITFIELDS && (nbits == 16 || nbits == 32)) {
       
   269         if (d->read((char *)&red_mask, sizeof(red_mask)) != sizeof(red_mask))
       
   270             return false;
       
   271         if (d->read((char *)&green_mask, sizeof(green_mask)) != sizeof(green_mask))
       
   272             return false;
       
   273         if (d->read((char *)&blue_mask, sizeof(blue_mask)) != sizeof(blue_mask))
       
   274             return false;
       
   275         red_shift = calc_shift(red_mask);
       
   276         red_scale = 256 / ((red_mask >> red_shift) + 1);
       
   277         green_shift = calc_shift(green_mask);
       
   278         green_scale = 256 / ((green_mask >> green_shift) + 1);
       
   279         blue_shift = calc_shift(blue_mask);
       
   280         blue_scale = 256 / ((blue_mask >> blue_shift) + 1);
       
   281     } else if (comp == BMP_RGB && (nbits == 24 || nbits == 32)) {
       
   282         blue_mask = 0x000000ff;
       
   283         green_mask = 0x0000ff00;
       
   284         red_mask = 0x00ff0000;
       
   285         blue_shift = 0;
       
   286         green_shift = 8;
       
   287         red_shift = 16;
       
   288         blue_scale = green_scale = red_scale = 1;
       
   289     } else if (comp == BMP_RGB && nbits == 16) {
       
   290         blue_mask = 0x001f;
       
   291         green_mask = 0x03e0;
       
   292         red_mask = 0x7c00;
       
   293         blue_shift = 0;
       
   294         green_shift = 2;
       
   295         red_shift = 7;
       
   296         red_scale = 1;
       
   297         green_scale = 1;
       
   298         blue_scale = 8;
       
   299     }
       
   300 
       
   301     // offset can be bogus, be careful
       
   302     if (offset>=0 && startpos + offset > d->pos()) {
       
   303         if (!d->isSequential())
       
   304             d->seek(startpos + offset);                // start of image data
       
   305     }
       
   306 
       
   307     int             bpl = image.bytesPerLine();
       
   308     uchar *data = image.bits();
       
   309 
       
   310     if (nbits == 1) {                                // 1 bit BMP image
       
   311         while (--h >= 0) {
       
   312             if (d->read((char*)(data + h*bpl), bpl) != bpl)
       
   313                 break;
       
   314         }
       
   315         if (ncols == 2 && qGray(image.color(0)) < qGray(image.color(1)))
       
   316             swapPixel01(&image);                // pixel 0 is white!
       
   317     }
       
   318 
       
   319     else if (nbits == 4) {                        // 4 bit BMP image
       
   320         int    buflen = ((w+7)/8)*4;
       
   321         uchar *buf    = new uchar[buflen];
       
   322         if (comp == BMP_RLE4) {                // run length compression
       
   323             int x=0, y=0, c, i;
       
   324             quint8 b;
       
   325             register uchar *p = data + (h-1)*bpl;
       
   326             const uchar *endp = p + w;
       
   327             while (y < h) {
       
   328                 if (!d->getChar((char *)&b))
       
   329                     break;
       
   330                 if (b == 0) {                        // escape code
       
   331                     if (!d->getChar((char *)&b) || b == 1) {
       
   332                         y = h;                // exit loop
       
   333                     } else switch (b) {
       
   334                         case 0:                        // end of line
       
   335                             x = 0;
       
   336                             y++;
       
   337                             p = data + (h-y-1)*bpl;
       
   338                             break;
       
   339                         case 2:                        // delta (jump)
       
   340                         {
       
   341                             quint8 tmp;
       
   342                             d->getChar((char *)&tmp);
       
   343                             x += tmp;
       
   344                             d->getChar((char *)&tmp);
       
   345                             y += tmp;
       
   346                         }
       
   347 
       
   348                             // Protection
       
   349                             if ((uint)x >= (uint)w)
       
   350                                 x = w-1;
       
   351                             if ((uint)y >= (uint)h)
       
   352                                 y = h-1;
       
   353 
       
   354                             p = data + (h-y-1)*bpl + x;
       
   355                             break;
       
   356                         default:                // absolute mode
       
   357                             // Protection
       
   358                             if (p + b > endp)
       
   359                                 b = endp-p;
       
   360 
       
   361                             i = (c = b)/2;
       
   362                             while (i--) {
       
   363                                 d->getChar((char *)&b);
       
   364                                 *p++ = b >> 4;
       
   365                                 *p++ = b & 0x0f;
       
   366                             }
       
   367                             if (c & 1) {
       
   368                                 unsigned char tmp;
       
   369                                 d->getChar((char *)&tmp);
       
   370                                 *p++ = tmp >> 4;
       
   371                             }
       
   372                             if ((((c & 3) + 1) & 2) == 2)
       
   373                                 d->getChar(0);        // align on word boundary
       
   374                             x += c;
       
   375                     }
       
   376                 } else {                        // encoded mode
       
   377                     // Protection
       
   378                     if (p + b > endp)
       
   379                         b = endp-p;
       
   380 
       
   381                     i = (c = b)/2;
       
   382                     d->getChar((char *)&b);                // 2 pixels to be repeated
       
   383                     while (i--) {
       
   384                         *p++ = b >> 4;
       
   385                         *p++ = b & 0x0f;
       
   386                     }
       
   387                     if (c & 1)
       
   388                         *p++ = b >> 4;
       
   389                     x += c;
       
   390                 }
       
   391             }
       
   392         } else if (comp == BMP_RGB) {                // no compression
       
   393             memset(data, 0, h*bpl);
       
   394             while (--h >= 0) {
       
   395                 if (d->read((char*)buf,buflen) != buflen)
       
   396                     break;
       
   397                 register uchar *p = data + h*bpl;
       
   398                 uchar *b = buf;
       
   399                 for (int i=0; i<w/2; i++) {        // convert nibbles to bytes
       
   400                     *p++ = *b >> 4;
       
   401                     *p++ = *b++ & 0x0f;
       
   402                 }
       
   403                 if (w & 1)                        // the last nibble
       
   404                     *p = *b >> 4;
       
   405             }
       
   406         }
       
   407         delete [] buf;
       
   408     }
       
   409 
       
   410     else if (nbits == 8) {                        // 8 bit BMP image
       
   411         if (comp == BMP_RLE8) {                // run length compression
       
   412             int x=0, y=0;
       
   413             quint8 b;
       
   414             register uchar *p = data + (h-1)*bpl;
       
   415             const uchar *endp = p + w;
       
   416             while (y < h) {
       
   417                 if (!d->getChar((char *)&b))
       
   418                     break;
       
   419                 if (b == 0) {                        // escape code
       
   420                     if (!d->getChar((char *)&b) || b == 1) {
       
   421                             y = h;                // exit loop
       
   422                     } else switch (b) {
       
   423                         case 0:                        // end of line
       
   424                             x = 0;
       
   425                             y++;
       
   426                             p = data + (h-y-1)*bpl;
       
   427                             break;
       
   428                         case 2:                        // delta (jump)
       
   429                             // Protection
       
   430                             if ((uint)x >= (uint)w)
       
   431                                 x = w-1;
       
   432                             if ((uint)y >= (uint)h)
       
   433                                 y = h-1;
       
   434 
       
   435                             {
       
   436                                 quint8 tmp;
       
   437                                 d->getChar((char *)&tmp);
       
   438                                 x += tmp;
       
   439                                 d->getChar((char *)&tmp);
       
   440                                 y += tmp;
       
   441                             }
       
   442                             p = data + (h-y-1)*bpl + x;
       
   443                             break;
       
   444                         default:                // absolute mode
       
   445                             // Protection
       
   446                             if (p + b > endp)
       
   447                                 b = endp-p;
       
   448 
       
   449                             if (d->read((char *)p, b) != b)
       
   450                                 return false;
       
   451                             if ((b & 1) == 1)
       
   452                                 d->getChar(0);        // align on word boundary
       
   453                             x += b;
       
   454                             p += b;
       
   455                     }
       
   456                 } else {                        // encoded mode
       
   457                     // Protection
       
   458                     if (p + b > endp)
       
   459                         b = endp-p;
       
   460 
       
   461                     char tmp;
       
   462                     d->getChar(&tmp);
       
   463                     memset(p, tmp, b); // repeat pixel
       
   464                     x += b;
       
   465                     p += b;
       
   466                 }
       
   467             }
       
   468         } else if (comp == BMP_RGB) {                // uncompressed
       
   469             while (--h >= 0) {
       
   470                 if (d->read((char *)data + h*bpl, bpl) != bpl)
       
   471                     break;
       
   472             }
       
   473         }
       
   474     }
       
   475 
       
   476     else if (nbits == 16 || nbits == 24 || nbits == 32) { // 16,24,32 bit BMP image
       
   477         register QRgb *p;
       
   478         QRgb  *end;
       
   479         uchar *buf24 = new uchar[bpl];
       
   480         int    bpl24 = ((w*nbits+31)/32)*4;
       
   481         uchar *b;
       
   482         int c;
       
   483 
       
   484         while (--h >= 0) {
       
   485             p = (QRgb *)(data + h*bpl);
       
   486             end = p + w;
       
   487             if (d->read((char *)buf24,bpl24) != bpl24)
       
   488                 break;
       
   489             b = buf24;
       
   490             while (p < end) {
       
   491                 c = *(uchar*)b | (*(uchar*)(b+1)<<8);
       
   492                 if (nbits != 16)
       
   493                     c |= *(uchar*)(b+2)<<16;
       
   494                 *p++ = qRgb(((c & red_mask) >> red_shift) * red_scale,
       
   495                                         ((c & green_mask) >> green_shift) * green_scale,
       
   496                                         ((c & blue_mask) >> blue_shift) * blue_scale);
       
   497                 b += nbits/8;
       
   498             }
       
   499         }
       
   500         delete[] buf24;
       
   501     }
       
   502 
       
   503     if (bi.biHeight < 0) {
       
   504         // Flip the image
       
   505         uchar *buf = new uchar[bpl];
       
   506         h = -bi.biHeight;
       
   507         for (int y = 0; y < h/2; ++y) {
       
   508             memcpy(buf, data + y*bpl, bpl);
       
   509             memcpy(data + y*bpl, data + (h-y-1)*bpl, bpl);
       
   510             memcpy(data + (h-y-1)*bpl, buf, bpl);
       
   511         }
       
   512         delete [] buf;
       
   513     }
       
   514 
       
   515     return true;
       
   516 }
       
   517 
       
   518 // this is also used in qmime_win.cpp
       
   519 bool qt_write_dib(QDataStream &s, QImage image)
       
   520 {
       
   521     int        nbits;
       
   522     int        bpl_bmp;
       
   523     int        bpl = image.bytesPerLine();
       
   524 
       
   525     QIODevice* d = s.device();
       
   526     if (!d->isWritable())
       
   527         return false;
       
   528 
       
   529     if (image.depth() == 8 && image.numColors() <= 16) {
       
   530         bpl_bmp = (((bpl+1)/2+3)/4)*4;
       
   531         nbits = 4;
       
   532     } else if (image.depth() == 32) {
       
   533         bpl_bmp = ((image.width()*24+31)/32)*4;
       
   534         nbits = 24;
       
   535 #ifdef Q_WS_QWS
       
   536     } else if (image.depth() == 1 || image.depth() == 8) {
       
   537         // Qt for Embedded Linux doesn't word align.
       
   538         bpl_bmp = ((image.width()*image.depth()+31)/32)*4;
       
   539         nbits = image.depth();
       
   540 #endif
       
   541     } else {
       
   542         bpl_bmp = bpl;
       
   543         nbits = image.depth();
       
   544     }
       
   545 
       
   546     BMP_INFOHDR bi;
       
   547     bi.biSize               = BMP_WIN;                // build info header
       
   548     bi.biWidth               = image.width();
       
   549     bi.biHeight               = image.height();
       
   550     bi.biPlanes               = 1;
       
   551     bi.biBitCount      = nbits;
       
   552     bi.biCompression   = BMP_RGB;
       
   553     bi.biSizeImage     = bpl_bmp*image.height();
       
   554     bi.biXPelsPerMeter = image.dotsPerMeterX() ? image.dotsPerMeterX()
       
   555                                                 : 2834; // 72 dpi default
       
   556     bi.biYPelsPerMeter = image.dotsPerMeterY() ? image.dotsPerMeterY() : 2834;
       
   557     bi.biClrUsed       = image.numColors();
       
   558     bi.biClrImportant  = image.numColors();
       
   559     s << bi;                                        // write info header
       
   560     if (s.status() != QDataStream::Ok)
       
   561         return false;
       
   562 
       
   563     if (image.depth() != 32) {                // write color table
       
   564         uchar *color_table = new uchar[4*image.numColors()];
       
   565         uchar *rgb = color_table;
       
   566         QVector<QRgb> c = image.colorTable();
       
   567         for (int i=0; i<image.numColors(); i++) {
       
   568             *rgb++ = qBlue (c[i]);
       
   569             *rgb++ = qGreen(c[i]);
       
   570             *rgb++ = qRed  (c[i]);
       
   571             *rgb++ = 0;
       
   572         }
       
   573         if (d->write((char *)color_table, 4*image.numColors()) == -1) {
       
   574             delete [] color_table;
       
   575             return false;
       
   576         }
       
   577         delete [] color_table;
       
   578     }
       
   579 
       
   580     if (image.format() == QImage::Format_MonoLSB)
       
   581         image = image.convertToFormat(QImage::Format_Mono);
       
   582 
       
   583     int y;
       
   584 
       
   585     if (nbits == 1 || nbits == 8) {                // direct output
       
   586 #ifdef Q_WS_QWS
       
   587         // Qt for Embedded Linux doesn't word align.
       
   588         int pad = bpl_bmp - bpl;
       
   589         char padding[4];
       
   590 #endif
       
   591         for (y=image.height()-1; y>=0; y--) {
       
   592             if (d->write((char*)image.scanLine(y), bpl) == -1)
       
   593                 return false;
       
   594 #ifdef Q_WS_QWS
       
   595             if (d->write(padding, pad) == -1)
       
   596                 return false;
       
   597 #endif
       
   598         }
       
   599         return true;
       
   600     }
       
   601 
       
   602     uchar *buf        = new uchar[bpl_bmp];
       
   603     uchar *b, *end;
       
   604     register uchar *p;
       
   605 
       
   606     memset(buf, 0, bpl_bmp);
       
   607     for (y=image.height()-1; y>=0; y--) {        // write the image bits
       
   608         if (nbits == 4) {                        // convert 8 -> 4 bits
       
   609             p = image.scanLine(y);
       
   610             b = buf;
       
   611             end = b + image.width()/2;
       
   612             while (b < end) {
       
   613                 *b++ = (*p << 4) | (*(p+1) & 0x0f);
       
   614                 p += 2;
       
   615             }
       
   616             if (image.width() & 1)
       
   617                 *b = *p << 4;
       
   618         } else {                                // 32 bits
       
   619             QRgb *p   = (QRgb *)image.scanLine(y);
       
   620             QRgb *end = p + image.width();
       
   621             b = buf;
       
   622             while (p < end) {
       
   623                 *b++ = qBlue(*p);
       
   624                 *b++ = qGreen(*p);
       
   625                 *b++ = qRed(*p);
       
   626                 p++;
       
   627             }
       
   628         }
       
   629         if (bpl_bmp != d->write((char*)buf, bpl_bmp)) {
       
   630             delete[] buf;
       
   631             return false;
       
   632         }
       
   633     }
       
   634     delete[] buf;
       
   635     return true;
       
   636 }
       
   637 
       
   638 // this is also used in qmime_win.cpp
       
   639 bool qt_read_dib(QDataStream &s, QImage &image)
       
   640 {
       
   641     BMP_INFOHDR bi;
       
   642     if (!read_dib_infoheader(s, bi))
       
   643         return false;
       
   644     return read_dib_body(s, bi, -1, -BMP_FILEHDR_SIZE, image);
       
   645 }
       
   646 
       
   647 QBmpHandler::QBmpHandler()
       
   648     : state(Ready)
       
   649 {
       
   650 }
       
   651 
       
   652 bool QBmpHandler::readHeader()
       
   653 {
       
   654     state = Error;
       
   655 
       
   656     QIODevice *d = device();
       
   657     QDataStream s(d);
       
   658     startpos = d->pos();
       
   659 
       
   660     // Intel byte order
       
   661     s.setByteOrder(QDataStream::LittleEndian);
       
   662 
       
   663     // read BMP file header
       
   664     if (!read_dib_fileheader(s, fileHeader))
       
   665         return false;
       
   666 
       
   667     // read BMP info header
       
   668     if (!read_dib_infoheader(s, infoHeader))
       
   669         return false;
       
   670 
       
   671     state = ReadHeader;
       
   672     return true;
       
   673 }
       
   674 
       
   675 bool QBmpHandler::canRead() const
       
   676 {
       
   677     if (state == Ready) {
       
   678         if (!canRead(device()))
       
   679             return false;
       
   680         setFormat("bmp");
       
   681         return true;
       
   682     }
       
   683     return state != Error;
       
   684 }
       
   685 
       
   686 bool QBmpHandler::canRead(QIODevice *device)
       
   687 {
       
   688     if (!device) {
       
   689         qWarning("QBmpHandler::canRead() called with 0 pointer");
       
   690         return false;
       
   691     }
       
   692 
       
   693     char head[2];
       
   694     if (device->peek(head, sizeof(head)) != sizeof(head))
       
   695         return false;
       
   696 
       
   697     return (qstrncmp(head, "BM", 2) == 0);
       
   698 }
       
   699 
       
   700 bool QBmpHandler::read(QImage *image)
       
   701 {
       
   702     if (state == Error)
       
   703         return false;
       
   704 
       
   705     if (!image) {
       
   706         qWarning("QBmpHandler::read: cannot read into null pointer");
       
   707         return false;
       
   708     }
       
   709 
       
   710     if (state == Ready && !readHeader()) {
       
   711         state = Error;
       
   712         return false;
       
   713     }
       
   714 
       
   715     QIODevice *d = device();
       
   716     QDataStream s(d);
       
   717 
       
   718     // Intel byte order
       
   719     s.setByteOrder(QDataStream::LittleEndian);
       
   720 
       
   721     // read image
       
   722     if (!read_dib_body(s, infoHeader, fileHeader.bfOffBits, startpos, *image))
       
   723         return false;
       
   724 
       
   725     state = Ready;
       
   726     return true;
       
   727 }
       
   728 
       
   729 bool QBmpHandler::write(const QImage &img)
       
   730 {
       
   731     QImage image;
       
   732     switch (img.format()) {
       
   733     case QImage::Format_ARGB8565_Premultiplied:
       
   734     case QImage::Format_ARGB8555_Premultiplied:
       
   735     case QImage::Format_ARGB6666_Premultiplied:
       
   736     case QImage::Format_ARGB4444_Premultiplied:
       
   737         image = img.convertToFormat(QImage::Format_ARGB32);
       
   738         break;
       
   739     case QImage::Format_RGB16:
       
   740     case QImage::Format_RGB888:
       
   741     case QImage::Format_RGB666:
       
   742     case QImage::Format_RGB555:
       
   743     case QImage::Format_RGB444:
       
   744         image = img.convertToFormat(QImage::Format_RGB32);
       
   745         break;
       
   746     default:
       
   747         image = img;
       
   748     }
       
   749 
       
   750     QIODevice *d = device();
       
   751     QDataStream s(d);
       
   752     BMP_FILEHDR bf;
       
   753     int bpl_bmp;
       
   754     int bpl = image.bytesPerLine();
       
   755 
       
   756     // Code partially repeated in qt_write_dib
       
   757     if (image.depth() == 8 && image.numColors() <= 16) {
       
   758         bpl_bmp = (((bpl+1)/2+3)/4)*4;
       
   759     } else if (image.depth() == 32) {
       
   760         bpl_bmp = ((image.width()*24+31)/32)*4;
       
   761     } else {
       
   762         bpl_bmp = bpl;
       
   763     }
       
   764 
       
   765     // Intel byte order
       
   766     s.setByteOrder(QDataStream::LittleEndian);
       
   767 
       
   768     // build file header
       
   769     memcpy(bf.bfType, "BM", 2);
       
   770 
       
   771     // write file header
       
   772     bf.bfReserved1 = 0;
       
   773     bf.bfReserved2 = 0;
       
   774     bf.bfOffBits = BMP_FILEHDR_SIZE + BMP_WIN + image.numColors() * 4;
       
   775     bf.bfSize = bf.bfOffBits + bpl_bmp*image.height();
       
   776     s << bf;
       
   777 
       
   778     // write image
       
   779     return qt_write_dib(s, image);
       
   780 }
       
   781 
       
   782 bool QBmpHandler::supportsOption(ImageOption option) const
       
   783 {
       
   784     return option == Size
       
   785             || option == ImageFormat;
       
   786 }
       
   787 
       
   788 QVariant QBmpHandler::option(ImageOption option) const
       
   789 {
       
   790     if (option == Size) {
       
   791         if (state == Error)
       
   792             return QVariant();
       
   793         if (state == Ready && !const_cast<QBmpHandler*>(this)->readHeader())
       
   794             return QVariant();
       
   795         return QSize(infoHeader.biWidth, infoHeader.biHeight);
       
   796     } else if (option == ImageFormat) {
       
   797         if (state == Error)
       
   798             return QVariant();
       
   799         if (state == Ready && !const_cast<QBmpHandler*>(this)->readHeader())
       
   800             return QVariant();
       
   801         QImage::Format format;
       
   802         switch (infoHeader.biBitCount) {
       
   803             case 32:
       
   804             case 24:
       
   805             case 16:
       
   806                 format = QImage::Format_RGB32;
       
   807                 break;
       
   808             case 8:
       
   809             case 4:
       
   810                 format = QImage::Format_Indexed8;
       
   811                 break;
       
   812             default:
       
   813                 format = QImage::Format_Mono;
       
   814             }
       
   815         return format;
       
   816     }
       
   817     return QVariant();
       
   818 }
       
   819 
       
   820 void QBmpHandler::setOption(ImageOption option, const QVariant &value)
       
   821 {
       
   822     Q_UNUSED(option);
       
   823     Q_UNUSED(value);
       
   824 }
       
   825 
       
   826 QByteArray QBmpHandler::name() const
       
   827 {
       
   828     return "bmp";
       
   829 }
       
   830 
       
   831 QT_END_NAMESPACE
       
   832 
       
   833 #endif // QT_NO_IMAGEFORMAT_BMP