src/common/imagbmp.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        imagbmp.cpp
   3 // Purpose:     wxImage BMP handler
   4 // Author:      Robert Roebling
   5 // RCS-ID:      $Id$
   6 // Copyright:   (c) Robert Roebling
   7 // Licence:     wxWindows licence
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10 /*
  11    We don't put pragma implement in this file because it is already present in
  12    src/common/image.cpp
  13 */
  14
  15 // For compilers that support precompilation, includes "wx.h".
  16 #include "wx/wxprec.h"
  17
  18 #ifdef __BORLANDC__
  19 #pragma hdrstop
  20 #endif
  21
  22 #include "wx/image.h"
  23 #include "wx/bitmap.h"
  24 #include "wx/debug.h"
  25 #include "wx/log.h"
  26 #include "wx/app.h"
  27 #include "wx/filefn.h"
  28 #include "wx/wfstream.h"
  29 #include "wx/intl.h"
  30 #include "wx/module.h"
  31
  32 // For memcpy
  33 #include <string.h>
  34
  35 #ifdef __SALFORDC__
  36 #ifdef FAR
  37 #undef FAR
  38 #endif
  39 #endif
  40
  41 #ifdef __WXMSW__
  42 #include <windows.h>
  43 #endif
  44
  45 //-----------------------------------------------------------------------------
  46 // wxBMPHandler
  47 //-----------------------------------------------------------------------------
  48
  49 #if !USE_SHARED_LIBRARIES
  50 IMPLEMENT_DYNAMIC_CLASS(wxBMPHandler,wxImageHandler)
  51 #endif
  52
  53 #if wxUSE_STREAMS
  54
  55 #ifndef BI_RGB
  56 #define BI_RGB       0
  57 #define BI_RLE8      1
  58 #define BI_RLE4      2
  59 #endif
  60
  61 #ifndef BI_BITFIELDS
  62 #define BI_BITFIELDS 3
  63 #endif
  64
  65 #define poffset (line * width * 3 + column * 3)
  66
  67 bool wxBMPHandler::LoadFile( wxImage *image, wxInputStream& stream, bool WXUNUSED(verbose) )
  68 {
  69     int             rshift = 0, gshift = 0, bshift = 0;
  70     wxUint8         aByte;
  71     wxUint16        aWord;
  72     wxInt32         dbuf[4], aDword,
  73                     rmask = 0, gmask = 0, bmask = 0;
  74     wxInt8          bbuf[4];
  75     struct _cmap {
  76         unsigned char r, g, b;
  77     } *cmap = NULL;
  78
  79     off_t start_offset = stream.TellI();
  80
  81     image->Destroy();
  82
  83     /*
  84      * Read the BMP header
  85      */
  86
  87     stream.Read( &bbuf, 2 );
  88     stream.Read( dbuf, 4 * 4 );
  89
  90 #if 0 // unused
  91     wxInt32 size = wxINT32_SWAP_ON_BE( dbuf[0] );
  92 #endif
  93     wxInt32 offset = wxINT32_SWAP_ON_BE( dbuf[2] );
  94
  95     stream.Read(dbuf, 4 * 2);
  96     int width = (int)wxINT32_SWAP_ON_BE( dbuf[0] );
  97     int height = (int)wxINT32_SWAP_ON_BE( dbuf[1] );
  98     if (width > 32767)
  99     {
 100         wxLogError( wxT("Image width > 32767 pixels for file.") );
 101         return FALSE;
 102     }
 103     if (height > 32767)
 104     {
 105         wxLogError( wxT("Image height > 32767 pixels for file.") );
 106         return FALSE;
 107     }
 108
 109     stream.Read( &aWord, 2 );
 110 /*
 111     TODO
 112     int planes = (int)wxUINT16_SWAP_ON_BE( aWord );
 113 */
 114     stream.Read( &aWord, 2 );
 115     int bpp = (int)wxUINT16_SWAP_ON_BE( aWord );
 116     if (bpp != 1 && bpp != 4 && bpp != 8 && bpp != 16 && bpp != 24 && bpp != 32)
 117     {
 118         wxLogError( wxT("unknown bitdepth in file.") );
 119         return FALSE;
 120     }
 121
 122     stream.Read( dbuf, 4 * 4 );
 123     int comp = (int)wxINT32_SWAP_ON_BE( dbuf[0] );
 124     if (comp != BI_RGB && comp != BI_RLE4 && comp != BI_RLE8 && comp != BI_BITFIELDS)
 125     {
 126         wxLogError( wxT("unknown encoding in Windows BMP file.") );
 127         return FALSE;
 128     }
 129
 130     stream.Read( dbuf, 4 * 2 );
 131     int ncolors = (int)wxINT32_SWAP_ON_BE( dbuf[0] );
 132     if (ncolors == 0)
 133         ncolors = 1 << bpp;
 134     /* some more sanity checks */
 135     if (((comp == BI_RLE4) && (bpp != 4)) ||
 136         ((comp == BI_RLE8) && (bpp != 8)) ||
 137         ((comp == BI_BITFIELDS) && (bpp != 16 && bpp != 32)))
 138     {
 139         wxLogError( wxT("encoding of BMP doesn't match bitdepth.") );
 140         return FALSE;
 141     }
 142     if (bpp < 16)
 143     {
 144         cmap = (struct _cmap *)malloc(sizeof(struct _cmap) * ncolors);
 145         if (!cmap)
 146         {
 147             wxLogError( wxT("Cannot allocate RAM for color map in BMP file.") );
 148             return FALSE;
 149         }
 150     }
 151     else
 152         cmap = NULL;
 153
 154     image->Create( width, height );
 155     unsigned char *ptr = image->GetData();
 156     if (!ptr)
 157     {
 158         wxLogError( wxT("Cannot allocate RAM for RGB data in file.") );
 159         if (cmap)
 160             free(cmap);
 161         return FALSE;
 162     }
 163
 164     /*
 165      * Reading the palette, if it exists.
 166      */
 167     if (bpp < 16 && ncolors != 0)
 168     {
 169         for (int j = 0; j < ncolors; j++)
 170         {
 171             stream.Read( bbuf, 4 );
 172             cmap[j].b = bbuf[0];
 173             cmap[j].g = bbuf[1];
 174             cmap[j].r = bbuf[2];
 175         }
 176     }
 177     else if (bpp == 16 || bpp == 32)
 178     {
 179         if (comp == BI_BITFIELDS)
 180         {
 181             int bit = 0;
 182             stream.Read( dbuf, 4 * 3 );
 183             bmask = wxINT32_SWAP_ON_BE( dbuf[0] );
 184             gmask = wxINT32_SWAP_ON_BE( dbuf[1] );
 185             rmask = wxINT32_SWAP_ON_BE( dbuf[2] );
 186             /* find shift amount.. ugly, but i can't think of a better way */
 187             for (bit = 0; bit < bpp; bit++)
 188             {
 189                 if (bmask & (1 << bit))
 190                     bshift = bit;
 191                 if (gmask & (1 << bit))
 192                     gshift = bit;
 193                 if (rmask & (1 << bit))
 194                     rshift = bit;
 195             }
 196         }
 197         else if (bpp == 16)
 198         {
 199             rmask = 0x7C00;
 200             gmask = 0x03E0;
 201             bmask = 0x001F;
 202             rshift = 10;
 203             gshift = 5;
 204             bshift = 0;
 205         }
 206         else if (bpp == 32)
 207         {
 208             rmask = 0x00FF0000;
 209             gmask = 0x0000FF00;
 210             bmask = 0x000000FF;
 211             rshift = 16;
 212             gshift = 8;
 213             bshift = 0;
 214         }
 215     }
 216
 217     /*
 218      * Reading the image data
 219      */
 220     stream.SeekI( start_offset + offset );
 221     unsigned char *data = ptr;
 222
 223     /* set the whole image to the background color */
 224     if (bpp < 16 && (comp == BI_RLE4 || comp == BI_RLE8))
 225     {
 226         for (int i = 0; i < width * height; i++)
 227         {
 228             *ptr++ = cmap[0].r;
 229             *ptr++ = cmap[0].g;
 230             *ptr++ = cmap[0].b;
 231         }
 232         ptr = data;
 233     }
 234
 235     int line = 0;
 236     int column = 0;
 237     int linesize = ((width * bpp + 31) / 32) * 4;
 238
 239     /* BMPs are stored upside down */
 240     for (line = (height - 1); line >= 0; line--)
 241     {
 242         int linepos = 0;
 243         for (column = 0; column < width;)
 244         {
 245             if (bpp < 16)
 246             {
 247                 int index = 0;
 248                 linepos++;
 249                 aByte = stream.GetC();
 250                 if (bpp == 1)
 251                 {
 252                     int bit = 0;
 253                     for (bit = 0; bit < 8; bit++)
 254                     {
 255                         index = ((aByte & (0x80 >> bit)) ? 1 : 0);
 256                         ptr[poffset] = cmap[index].r;
 257                         ptr[poffset + 1] = cmap[index].g;
 258                         ptr[poffset + 2] = cmap[index].b;
 259                         column++;
 260                     }
 261                 }
 262                 else if (bpp == 4)
 263                 {
 264                     if (comp == BI_RLE4)
 265                     {
 266                         wxLogError( wxT("Can't deal with 4bit encoded yet.") );
 267                         image->Destroy();
 268                         free(cmap);
 269                         return FALSE;
 270                     }
 271                     else
 272                     {
 273                         int nibble = 0;
 274                         for (nibble = 0; nibble < 2; nibble++)
 275                         {
 276                             index = ((aByte & (0xF0 >> nibble * 4)) >> (!nibble * 4));
 277                             if (index >= 16)
 278                                 index = 15;
 279                             ptr[poffset] = cmap[index].r;
 280                             ptr[poffset + 1] = cmap[index].g;
 281                             ptr[poffset + 2] = cmap[index].b;
 282                             column++;
 283                         }
 284                     }
 285                 }
 286                 else if (bpp == 8)
 287                 {
 288                     if (comp == BI_RLE8)
 289                     {
 290                         unsigned char first;
 291                         first = aByte;
 292                         aByte = stream.GetC();
 293                         if (first == 0)
 294                         {
 295                             if (aByte == 0)
 296                             {
 297                                 /* column = width; */
 298                             }
 299                             else if (aByte == 1)
 300                             {
 301                                 column = width;
 302                                 line = -1;
 303                             }
 304                             else if (aByte == 2)
 305                             {
 306                                 aByte = stream.GetC();
 307                                 column += aByte;
 308                                 linepos = column * bpp / 8;
 309                                 aByte = stream.GetC();
 310                                 line += aByte;
 311                             }
 312                             else
 313                             {
 314                                 int absolute = aByte;
 315                                 for (int k = 0; k < absolute; k++)
 316                                 {
 317                                     linepos++;
 318                                     aByte = stream.GetC();
 319                                     ptr[poffset    ] = cmap[aByte].r;
 320                                     ptr[poffset + 1] = cmap[aByte].g;
 321                                     ptr[poffset + 2] = cmap[aByte].b;
 322                                     column++;
 323                                 }
 324                                 if (absolute & 0x01)
 325                                     aByte = stream.GetC();
 326                             }
 327                         }
 328                         else
 329                         {
 330                             for (int l = 0; l < first; l++)
 331                             {
 332                                 ptr[poffset    ] = cmap[aByte].r;
 333                                 ptr[poffset + 1] = cmap[aByte].g;
 334                                 ptr[poffset + 2] = cmap[aByte].b;
 335                                 column++;
 336                                 linepos++;
 337                             }
 338                         }
 339                     }
 340                     else
 341                     {
 342                         ptr[poffset    ] = cmap[aByte].r;
 343                         ptr[poffset + 1] = cmap[aByte].g;
 344                         ptr[poffset + 2] = cmap[aByte].b;
 345                         column++;
 346                         // linepos += size;    seems to be wrong, RR
 347                     }
 348                 }
 349                }
 350                else if (bpp == 24)
 351                {
 352                    stream.Read( &bbuf, 3 );
 353                    linepos += 3;
 354                    ptr[poffset    ] = (unsigned char)bbuf[2];
 355                    ptr[poffset + 1] = (unsigned char)bbuf[1];
 356                    ptr[poffset + 2] = (unsigned char)bbuf[0];
 357                    column++;
 358                }
 359                else if (bpp == 16)
 360                {
 361                    unsigned char temp;
 362                    stream.Read( &aWord, 2 );
 363                    aWord = wxUINT16_SWAP_ON_BE( aWord );
 364                    linepos += 2;
 365                    temp = (aWord & rmask) >> rshift;
 366                    ptr[poffset] = temp;
 367                    temp = (aWord & gmask) >> gshift;
 368                    ptr[poffset + 1] = temp;
 369                    temp = (aWord & bmask) >> bshift;
 370                    ptr[poffset + 2] = temp;
 371                    column++;
 372                }
 373                else
 374                {
 375                    unsigned char temp;
 376                    stream.Read( &aDword, 4 );
 377                    aDword = wxINT32_SWAP_ON_BE( aDword );
 378                    linepos += 4;
 379                    temp = (aDword & rmask) >> rshift;
 380                    ptr[poffset] = temp;
 381                    temp = (aDword & gmask) >> gshift;
 382                    ptr[poffset + 1] = temp;
 383                    temp = (aDword & bmask) >> bshift;
 384                    ptr[poffset + 2] = temp;
 385                    column++;
 386                }
 387           }
 388           while ((linepos < linesize) && (comp != 1) && (comp != 2))
 389           {
 390               stream.Read( &aByte, 1 );
 391               linepos += 1;
 392               if (stream.LastError() != wxStream_NOERROR)
 393                   break;
 394           }
 395      }
 396      if (cmap)
 397        free(cmap);
 398
 399      image->SetMask( FALSE );
 400
 401      return TRUE;
 402 }
 403
 404 bool wxBMPHandler::DoCanRead( wxInputStream& stream )
 405 {
 406     unsigned char hdr[2];
 407
 408     stream.Read(&hdr, 2);
 409     stream.SeekI(-2, wxFromCurrent);
 410     return (hdr[0] == 'B' && hdr[1] == 'M');
 411 }
 412
 413 #endif // wxUSE_STREAMS
 414
 415