src/common/imagiff.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/common/imagiff.h
   3 // Purpose:     wxImage handler for Amiga IFF images
   4 // Author:      Steffen Gutmann, Thomas Meyer
   5 // RCS-ID:      $Id$
   6 // Copyright:   (c) Steffen Gutmann, 2002
   7 // Licence:     wxWindows licence
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10 // Parts of this source are based on the iff loading algorithm found
  11 // in xviff.c.  Permission by the original author, Thomas Meyer, and
  12 // by the author of xv, John Bradley for using the iff loading part
  13 // in wxWidgets has been gratefully given.
  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 #if wxUSE_IMAGE && wxUSE_IFF
  23
  24 #ifndef WX_PRECOMP
  25     #include "wx/log.h"
  26     #include "wx/intl.h"
  27 #endif
  28
  29 #include "wx/imagiff.h"
  30 #include "wx/wfstream.h"
  31
  32 #if wxUSE_PALETTE
  33     #include "wx/palette.h"
  34 #endif // wxUSE_PALETTE
  35
  36 #include <stdlib.h>
  37 #include <string.h>
  38
  39
  40 // --------------------------------------------------------------------------
  41 // Constants
  42 // --------------------------------------------------------------------------
  43
  44 // Error codes:
  45 //  Note that the error code wxIFF_TRUNCATED means that the image itself
  46 //  is most probably OK, but the decoder didn't reach the end of the data
  47 //  stream; this means that if it was not reading directly from file,
  48 //  the stream will not be correctly positioned.
  49 //
  50
  51 enum
  52 {
  53     wxIFF_OK = 0,                   /* everything was OK */
  54     wxIFF_INVFORMAT,                /* error in iff header */
  55     wxIFF_MEMERR,                   /* error allocating memory */
  56     wxIFF_TRUNCATED                 /* file appears to be truncated */
  57 };
  58
  59 // --------------------------------------------------------------------------
  60 // wxIFFDecoder class
  61 // --------------------------------------------------------------------------
  62
  63 // internal class for storing IFF image data
  64 class IFFImage
  65 {
  66 public:
  67     unsigned int w;                 /* width */
  68     unsigned int h;                 /* height */
  69     int transparent;                /* transparent color (-1 = none) */
  70     int colors;                     /* number of colors */
  71     unsigned char *p;               /* bitmap */
  72     unsigned char *pal;             /* palette */
  73
  74     IFFImage() : w(0), h(0), colors(0), p(0), pal(0) {}
  75     ~IFFImage() { delete [] p; delete [] pal; }
  76 };
  77
  78 class WXDLLEXPORT wxIFFDecoder
  79 {
  80 private:
  81     IFFImage *m_image;        // image data
  82     wxInputStream *m_f;       // input stream
  83     unsigned char *databuf;
  84     unsigned char *picptr;
  85     unsigned char *decomp_mem;
  86
  87     void Destroy();
  88
  89 public:
  90     // get data of current frame
  91     unsigned char* GetData() const;
  92     unsigned char* GetPalette() const;
  93     int GetNumColors() const;
  94     unsigned int GetWidth() const;
  95     unsigned int GetHeight() const;
  96     int GetTransparentColour() const;
  97
  98     // constructor, destructor, etc.
  99     wxIFFDecoder(wxInputStream *s);
 100     ~wxIFFDecoder() { Destroy(); }
 101     bool CanRead();
 102     int ReadIFF();
 103     bool ConvertToImage(wxImage *image) const;
 104 };
 105
 106
 107 //---------------------------------------------------------------------------
 108 // wxIFFDecoder constructor and destructor
 109 //---------------------------------------------------------------------------
 110
 111 wxIFFDecoder::wxIFFDecoder(wxInputStream *s)
 112 {
 113     m_f = s;
 114     m_image = 0;
 115     databuf = 0;
 116     decomp_mem = 0;
 117 }
 118
 119 void wxIFFDecoder::Destroy()
 120 {
 121     delete m_image;
 122     m_image = 0;
 123     delete [] databuf;
 124     databuf = 0;
 125     delete [] decomp_mem;
 126     decomp_mem = 0;
 127 }
 128
 129 //---------------------------------------------------------------------------
 130 // Convert this image to a wxImage object
 131 //---------------------------------------------------------------------------
 132
 133 // This function was designed by Vaclav Slavik
 134
 135 bool wxIFFDecoder::ConvertToImage(wxImage *image) const
 136 {
 137     // just in case...
 138     image->Destroy();
 139
 140     // create the image
 141     image->Create(GetWidth(), GetHeight());
 142
 143     if (!image->Ok())
 144         return false;
 145
 146     unsigned char *pal = GetPalette();
 147     unsigned char *src = GetData();
 148     unsigned char *dst = image->GetData();
 149     int colors = GetNumColors();
 150     int transparent = GetTransparentColour();
 151     long i;
 152
 153     // set transparent colour mask
 154     if (transparent != -1)
 155     {
 156         for (i = 0; i < colors; i++)
 157         {
 158             if ((pal[3 * i + 0] == 255) &&
 159                 (pal[3 * i + 1] == 0) &&
 160                 (pal[3 * i + 2] == 255))
 161             {
 162                 pal[3 * i + 2] = 254;
 163             }
 164         }
 165
 166         pal[3 * transparent + 0] = 255,
 167         pal[3 * transparent + 1] = 0,
 168         pal[3 * transparent + 2] = 255;
 169
 170         image->SetMaskColour(255, 0, 255);
 171     }
 172     else
 173         image->SetMask(false);
 174
 175 #if wxUSE_PALETTE
 176     if (pal && colors > 0)
 177     {
 178         unsigned char* r = new unsigned char[colors];
 179         unsigned char* g = new unsigned char[colors];
 180         unsigned char* b = new unsigned char[colors];
 181
 182         for (i = 0; i < colors; i++)
 183         {
 184             r[i] = pal[3*i + 0];
 185             g[i] = pal[3*i + 1];
 186             b[i] = pal[3*i + 2];
 187         }
 188
 189         image->SetPalette(wxPalette(colors, r, g, b));
 190
 191         delete [] r;
 192         delete [] g;
 193         delete [] b;
 194     }
 195 #endif // wxUSE_PALETTE
 196
 197     // copy image data
 198     for (i = 0; i < (long)(GetWidth() * GetHeight()); i++, src += 3, dst += 3)
 199     {
 200     dst[0] = src[0];
 201     dst[1] = src[1];
 202     dst[2] = src[2];
 203     }
 204
 205     return true;
 206 }
 207
 208
 209 //---------------------------------------------------------------------------
 210 // Data accessors
 211 //---------------------------------------------------------------------------
 212
 213 // Get data for current frame
 214
 215 unsigned char* wxIFFDecoder::GetData() const    { return (m_image->p); }
 216 unsigned char* wxIFFDecoder::GetPalette() const { return (m_image->pal); }
 217 int wxIFFDecoder::GetNumColors() const          { return m_image->colors; }
 218 unsigned int wxIFFDecoder::GetWidth() const     { return (m_image->w); }
 219 unsigned int wxIFFDecoder::GetHeight() const    { return (m_image->h); }
 220 int wxIFFDecoder::GetTransparentColour() const { return m_image->transparent; }
 221
 222 //---------------------------------------------------------------------------
 223 // IFF reading and decoding
 224 //---------------------------------------------------------------------------
 225
 226 //
 227 // CanRead:
 228 //  Returns true if the file looks like a valid IFF, false otherwise.
 229 //
 230 bool wxIFFDecoder::CanRead()
 231 {
 232     unsigned char buf[12];
 233
 234     if ( !m_f->Read(buf, WXSIZEOF(buf)) )
 235         return false;
 236
 237     m_f->SeekI(-(wxFileOffset)WXSIZEOF(buf), wxFromCurrent);
 238
 239     return (memcmp(buf, "FORM", 4) == 0) && (memcmp(buf+8, "ILBM", 4) == 0);
 240 }
 241
 242
 243 // ReadIFF:
 244 // Based on xv source code by Thomas Meyer
 245 // Permission for use in wxWidgets has been gratefully given.
 246
 247 typedef unsigned char byte;
 248 #define IFFDEBUG 0
 249
 250 /*************************************************************************
 251   void decomprle(source, destination, source length, buffer size)
 252
 253   Decompress run-length encoded data from source to destination. Terminates
 254   when source is decoded completely or destination buffer is full.
 255
 256   The decruncher is as optimized as I could make it, without risking
 257   safety in case of corrupt BODY chunks.
 258 **************************************************************************/
 259
 260 static void decomprle(const byte *sptr, byte *dptr, long slen, long dlen)
 261 {
 262     byte codeByte, dataByte;
 263
 264     while ((slen > 0) && (dlen > 0)) {
 265     // read control byte
 266     codeByte = *sptr++;
 267
 268     if (codeByte < 0x80) {
 269         codeByte++;
 270         if ((slen > (long) codeByte) && (dlen >= (long) codeByte)) {
 271         slen -= codeByte + 1;
 272         dlen -= codeByte;
 273         while (codeByte > 0) {
 274             *dptr++ = *sptr++;
 275             codeByte--;
 276         }
 277         }
 278         else slen = 0;
 279     }
 280
 281     else if (codeByte > 0x80) {
 282         codeByte = 0x81 - (codeByte & 0x7f);
 283         if ((slen > (long) 0) && (dlen >= (long) codeByte)) {
 284         dataByte = *sptr++;
 285         slen -= 2;
 286         dlen -= codeByte;
 287         while (codeByte > 0) {
 288             *dptr++ = dataByte;
 289             codeByte--;
 290         }
 291         }
 292         else slen = 0;
 293     }
 294     }
 295 }
 296
 297 /******************************************/
 298 static unsigned int iff_getword(const byte *ptr)
 299 {
 300     unsigned int v;
 301
 302     v = *ptr++;
 303     v = (v << 8) + *ptr;
 304     return v;
 305 }
 306
 307 /******************************************/
 308 static unsigned long iff_getlong(const byte *ptr)
 309 {
 310     unsigned long l;
 311
 312     l = *ptr++;
 313     l = (l << 8) + *ptr++;
 314     l = (l << 8) + *ptr++;
 315     l = (l << 8) + *ptr;
 316     return l;
 317 }
 318
 319 // Define internal ILBM types
 320 #define ILBM_NORMAL     0
 321 #define ILBM_EHB        1
 322 #define ILBM_HAM        2
 323 #define ILBM_HAM8       3
 324 #define ILBM_24BIT      4
 325
 326 int wxIFFDecoder::ReadIFF()
 327 {
 328     Destroy();
 329
 330     m_image = new IFFImage();
 331     if (m_image == 0) {
 332     Destroy();
 333     return wxIFF_MEMERR;
 334     }
 335
 336     // compute file length
 337     wxFileOffset currentPos = m_f->TellI();
 338     m_f->SeekI(0, wxFromEnd);
 339     long filesize = m_f->TellI();
 340     m_f->SeekI(currentPos, wxFromStart);
 341
 342     // allocate memory for complete file
 343     if ((databuf = new byte[filesize]) == 0) {
 344     Destroy();
 345     return wxIFF_MEMERR;
 346     }
 347
 348     m_f->Read(databuf, filesize);
 349     const byte *dataend = databuf + filesize;
 350
 351     // initialize work pointer. used to trace the buffer for IFF chunks
 352     const byte *dataptr = databuf;
 353
 354     // check for minmal size
 355     if (dataptr + 12 > dataend) {
 356     Destroy();
 357     return wxIFF_INVFORMAT;
 358     }
 359
 360     // check if we really got an IFF file
 361     if (strncmp((char *)dataptr, "FORM", 4) != 0) {
 362     Destroy();
 363     return wxIFF_INVFORMAT;
 364     }
 365
 366     dataptr = dataptr + 8;                  // skip ID and length of FORM
 367
 368     // check if the IFF file is an ILBM (picture) file
 369     if (strncmp((char *) dataptr, "ILBM", 4) != 0) {
 370     Destroy();
 371     return wxIFF_INVFORMAT;
 372     }
 373
 374     wxLogTrace(_T("iff"), _T("IFF ILBM file recognized"));
 375
 376     dataptr = dataptr + 4;                                // skip ID
 377
 378     //
 379     // main decoding loop. searches IFF chunks and handles them.
 380     // terminates when BODY chunk was found or dataptr ran over end of file
 381     //
 382     bool BMHDok = false, CMAPok = false, CAMGok = false;
 383     int bmhd_width = 0, bmhd_height = 0, bmhd_bitplanes = 0, bmhd_transcol = -1;
 384     byte bmhd_masking = 0, bmhd_compression = 0;
 385     long camg_viewmode = 0;
 386     int colors = 0;
 387     while (dataptr + 8 <= dataend) {
 388     // get chunk length and make even
 389     size_t chunkLen = (iff_getlong(dataptr + 4) + 1) & 0xfffffffe;
 390 #ifdef __VMS
 391        // Silence compiler warning
 392        int chunkLen_;
 393        chunkLen_ = chunkLen;
 394        if (chunkLen_ < 0) {     // format error?
 395 #else
 396        if (chunkLen < 0) {     // format error?
 397 #endif
 398          break;
 399     }
 400     bool truncated = (dataptr + 8 + chunkLen > dataend);
 401
 402     if (strncmp((char *)dataptr, "BMHD", 4) == 0) { // BMHD chunk?
 403         if (chunkLen < 12 + 2 || truncated) {
 404         break;
 405         }
 406         bmhd_width = iff_getword(dataptr + 8);      // width of picture
 407         bmhd_height= iff_getword(dataptr + 8 + 2);  // height of picture
 408         bmhd_bitplanes = *(dataptr + 8 + 8);        // # of bitplanes
 409         bmhd_masking  = *(dataptr + 8 + 9);
 410         bmhd_compression = *(dataptr + 8 + 10);     // get compression
 411         bmhd_transcol    = iff_getword(dataptr + 8 + 12);
 412         BMHDok = true;                              // got BMHD
 413         dataptr += 8 + chunkLen;                    // to next chunk
 414     }
 415     else if (strncmp((char *)dataptr, "CMAP", 4) == 0) { // CMAP ?
 416         if (truncated) {
 417         break;
 418         }
 419         const byte *cmapptr = dataptr + 8;
 420         colors = chunkLen / 3;                  // calc no of colors
 421
 422         delete m_image->pal;
 423         m_image->pal = 0;
 424         m_image->colors = colors;
 425         if (colors > 0) {
 426         m_image->pal = new byte[3*colors];
 427         if (!m_image->pal) {
 428             Destroy();
 429             return wxIFF_MEMERR;
 430         }
 431
 432         // copy colors to color map
 433         for (int i=0; i < colors; i++) {
 434             m_image->pal[3*i + 0] = *cmapptr++;
 435             m_image->pal[3*i + 1] = *cmapptr++;
 436             m_image->pal[3*i + 2] = *cmapptr++;
 437         }
 438         }
 439
 440         wxLogTrace(_T("iff"), _T("Read %d colors from IFF file."),
 441             colors);
 442
 443         CMAPok = true;                              // got CMAP
 444         dataptr += 8 + chunkLen;                    // to next chunk
 445     } else if (strncmp((char *)dataptr, "CAMG", 4) == 0) { // CAMG ?
 446         if (chunkLen < 4 || truncated) {
 447         break;
 448         }
 449         camg_viewmode = iff_getlong(dataptr + 8);   // get viewmodes
 450         CAMGok = true;                              // got CAMG
 451         dataptr += 8 + chunkLen;                    // to next chunk
 452     }
 453     else if (strncmp((char *)dataptr, "BODY", 4) == 0) { // BODY ?
 454         if (!BMHDok) {                              // BMHD found?
 455         break;
 456         }
 457         const byte *bodyptr = dataptr + 8;          // -> BODY data
 458
 459         if (truncated) {
 460         chunkLen = dataend - dataptr;
 461         }
 462
 463         //
 464             // if BODY is compressed, allocate buffer for decrunched BODY
 465         // and decompress it (run length encoding)
 466         //
 467         if (bmhd_compression == 1) {
 468         // calc size of decrunch buffer - (size of the actual pic.
 469         // decompressed in interleaved Amiga bitplane format)
 470
 471         size_t decomp_bufsize = (((bmhd_width + 15) >> 4) << 1)
 472             * bmhd_height * bmhd_bitplanes;
 473
 474         if ((decomp_mem = new byte[decomp_bufsize]) == 0) {
 475             Destroy();
 476             return wxIFF_MEMERR;
 477         }
 478
 479         decomprle(bodyptr, decomp_mem, chunkLen, decomp_bufsize);
 480         bodyptr = decomp_mem;                 // -> uncompressed BODY
 481         chunkLen = decomp_bufsize;
 482         delete [] databuf;
 483         databuf = 0;
 484         }
 485
 486         // the following determines the type of the ILBM file.
 487         // it's either NORMAL, EHB, HAM, HAM8 or 24BIT
 488
 489         int fmt = ILBM_NORMAL;                 // assume normal ILBM
 490         if (bmhd_bitplanes == 24) {
 491         fmt = ILBM_24BIT;
 492         } else if (bmhd_bitplanes == 8) {
 493         if (CAMGok && (camg_viewmode & 0x800)) {
 494             fmt = ILBM_HAM8;
 495         }
 496         } else if ((bmhd_bitplanes > 5) && CAMGok) {
 497         if (camg_viewmode & 0x80) {
 498             fmt = ILBM_EHB;
 499         } else if (camg_viewmode & 0x800) {
 500             fmt = ILBM_HAM;
 501         }
 502         }
 503
 504         wxLogTrace(_T("iff"),
 505             _T("LoadIFF: %s %dx%d, planes=%d (%d cols), comp=%d"),
 506             (fmt==ILBM_NORMAL) ? "Normal ILBM" :
 507             (fmt==ILBM_HAM)    ? "HAM ILBM" :
 508             (fmt==ILBM_HAM8)   ? "HAM8 ILBM" :
 509             (fmt==ILBM_EHB)    ? "EHB ILBM" :
 510             (fmt==ILBM_24BIT)  ? "24BIT ILBM" : "unknown ILBM",
 511             bmhd_width, bmhd_height, bmhd_bitplanes,
 512             1<<bmhd_bitplanes, bmhd_compression);
 513
 514         if ((fmt==ILBM_NORMAL) || (fmt==ILBM_EHB) || (fmt==ILBM_HAM)) {
 515         wxLogTrace(_T("iff"),
 516             _T("Converting CMAP from normal ILBM CMAP"));
 517
 518         switch(fmt) {
 519             case ILBM_NORMAL: colors = 1 << bmhd_bitplanes; break;
 520             case ILBM_EHB:    colors = 32*2; break;
 521             case ILBM_HAM:    colors = 16; break;
 522         }
 523
 524         if (colors > m_image->colors) {
 525             byte *pal = new byte[colors*3];
 526             if (!pal) {
 527             Destroy();
 528             return wxIFF_MEMERR;
 529             }
 530             int i;
 531             for (i = 0; i < m_image->colors; i++) {
 532             pal[3*i + 0] = m_image->pal[3*i + 0];
 533             pal[3*i + 1] = m_image->pal[3*i + 1];
 534             pal[3*i + 2] = m_image->pal[3*i + 2];
 535             }
 536             for (; i < colors; i++) {
 537             pal[3*i + 0] = 0;
 538             pal[3*i + 1] = 0;
 539             pal[3*i + 2] = 0;
 540             }
 541             delete m_image->pal;
 542             m_image->pal = pal;
 543             m_image->colors = colors;
 544         }
 545
 546             for (int i=0; i < colors; i++) {
 547             m_image->pal[3*i + 0] = (m_image->pal[3*i + 0] >> 4) * 17;
 548             m_image->pal[3*i + 1] = (m_image->pal[3*i + 1] >> 4) * 17;
 549             m_image->pal[3*i + 2] = (m_image->pal[3*i + 2] >> 4) * 17;
 550         }
 551         }
 552
 553         m_image->p = new byte[bmhd_width * bmhd_height * 3];
 554             byte *picptr = m_image->p;
 555         if (!picptr) {
 556         Destroy();
 557         return wxIFF_MEMERR;
 558         }
 559
 560         byte *pal = m_image->pal;
 561         int lineskip = ((bmhd_width + 15) >> 4) << 1;
 562             int height = chunkLen / (lineskip * bmhd_bitplanes);
 563
 564         if (bmhd_height < height) {
 565             height = bmhd_height;
 566         }
 567
 568         if (fmt == ILBM_HAM || fmt == ILBM_HAM8 || fmt == ILBM_24BIT) {
 569         byte *pic = picptr;
 570         const byte *workptr = bodyptr;
 571
 572         for (int i=0; i < height; i++) {
 573             byte bitmsk = 0x80;
 574             const byte *workptr2 = workptr;
 575
 576             // at start of each line, init RGB values to background
 577             byte rval = pal[0];
 578             byte gval = pal[1];
 579             byte bval = pal[2];
 580
 581             for (int j=0; j < bmhd_width; j++) {
 582             long col = 0;
 583             long colbit = 1;
 584             const byte *workptr3 = workptr2;
 585             for (int k=0; k < bmhd_bitplanes; k++) {
 586                 if (*workptr3 & bitmsk) {
 587                 col += colbit;
 588                 }
 589                 workptr3 += lineskip;
 590                 colbit <<= 1;
 591             }
 592
 593             if (fmt==ILBM_HAM) {
 594                 int c = (col & 0x0f);
 595                 switch (col & 0x30) {
 596                 case 0x00: if (c >= 0 && c < colors) {
 597                            rval = pal[3*c + 0];
 598                            gval = pal[3*c + 1];
 599                            bval = pal[3*c + 2];
 600                        }
 601                        break;
 602
 603                 case 0x10: bval = c * 17;
 604                        break;
 605
 606                 case 0x20: rval = c * 17;
 607                        break;
 608
 609                 case 0x30: gval = c * 17;
 610                        break;
 611                 }
 612             } else if (fmt == ILBM_HAM8) {
 613                 int c = (col & 0x3f);
 614                 switch(col & 0xc0) {
 615                 case 0x00: if (c >= 0 && c < colors) {
 616                            rval = pal[3*c + 0];
 617                            gval = pal[3*c + 1];
 618                            bval = pal[3*c + 2];
 619                        }
 620                        break;
 621
 622                 case 0x40: bval = (bval & 3) | (c << 2);
 623                        break;
 624
 625                 case 0x80: rval = (rval & 3) | (c << 2);
 626                        break;
 627
 628                 case 0xc0: gval = (rval & 3) | (c << 2);
 629                 }
 630             } else {
 631                 rval = col & 0xff;
 632                 gval = (col >> 8) & 0xff;
 633                 bval = (col >> 16) & 0xff;
 634             }
 635
 636             *pic++ = rval;
 637             *pic++ = gval;
 638             *pic++ = bval;
 639
 640             bitmsk = bitmsk >> 1;
 641             if (bitmsk == 0) {
 642                 bitmsk = 0x80;
 643                 workptr2++;
 644             }
 645             }
 646             workptr += lineskip * bmhd_bitplanes;
 647         }
 648         }  else if ((fmt == ILBM_NORMAL) || (fmt == ILBM_EHB)) {
 649         if (fmt == ILBM_EHB) {
 650             wxLogTrace(_T("iff"), _T("Doubling CMAP for EHB mode"));
 651
 652             for (int i=0; i<32; i++) {
 653             pal[3*(i + 32) + 0] = pal[3*i + 0] >> 1;
 654             pal[3*(i + 32) + 1] = pal[3*i + 1] >> 1;
 655             pal[3*(i + 32) + 2] = pal[3*i + 2] >> 1;
 656             }
 657         }
 658
 659         byte *pic = picptr;         // ptr to buffer
 660         const byte *workptr = bodyptr;  // ptr to pic, planar format
 661
 662         if (bmhd_height < height) {
 663             height = bmhd_height;
 664         }
 665
 666         for (int i=0; i < height; i++) {
 667             byte bitmsk = 0x80;                 // left most bit (mask)
 668             const byte *workptr2 = workptr;     // work ptr to source
 669             for (int j=0; j < bmhd_width; j++) {
 670             long col = 0;
 671             long colbit = 1;
 672             const byte *workptr3 = workptr2;  // 1st byte in 1st pln
 673
 674             for (int k=0; k < bmhd_bitplanes; k++) {
 675                 if (*workptr3 & bitmsk) { // if bit set in this pln
 676                 col = col + colbit; // add bit to chunky byte
 677                 }
 678                 workptr3 += lineskip;   // go to next line
 679                 colbit <<= 1;           // shift color bit
 680             }
 681
 682             if (col >= 0 && col < colors) {
 683                 pic[0] = pal[3*col + 0];
 684                 pic[1] = pal[3*col + 1];
 685                 pic[2] = pal[3*col + 2];
 686             } else {
 687                 pic[0] = pic[1] = pic[2] = 0;
 688             }
 689             pic += 3;
 690             bitmsk = bitmsk >> 1;   // shift mask to next bit
 691             if (bitmsk == 0) {      // if mask is zero
 692                 bitmsk = 0x80;      // reset mask
 693                 workptr2++;         // mv ptr to next byte
 694             }
 695             }
 696
 697             workptr += lineskip * bmhd_bitplanes;  // to next line
 698         }
 699         } else {
 700         break;      // unknown format
 701         }
 702
 703         m_image->w = bmhd_width;
 704         m_image->h = height;
 705         m_image->transparent = bmhd_transcol;
 706
 707         wxLogTrace(_T("iff"), _T("Loaded IFF picture %s"),
 708             truncated? "truncated" : "completely");
 709
 710         return (truncated? wxIFF_TRUNCATED : wxIFF_OK);
 711     } else {
 712         wxLogTrace(_T("iff"), _T("Skipping unknown chunk '%c%c%c%c'"),
 713                 *dataptr, *(dataptr+1), *(dataptr+2), *(dataptr+3));
 714
 715         dataptr = dataptr + 8 + chunkLen;      // skip unknown chunk
 716     }
 717     }
 718
 719     Destroy();
 720     return wxIFF_INVFORMAT;
 721 }
 722
 723
 724
 725 //-----------------------------------------------------------------------------
 726 // wxIFFHandler
 727 //-----------------------------------------------------------------------------
 728
 729 IMPLEMENT_DYNAMIC_CLASS(wxIFFHandler, wxImageHandler)
 730
 731 #if wxUSE_STREAMS
 732
 733 bool wxIFFHandler::LoadFile(wxImage *image, wxInputStream& stream,
 734                             bool verbose, int WXUNUSED(index))
 735 {
 736     wxIFFDecoder *decod;
 737     int error;
 738     bool ok;
 739
 740     decod = new wxIFFDecoder(&stream);
 741     error = decod->ReadIFF();
 742
 743     if ((error != wxIFF_OK) && (error != wxIFF_TRUNCATED))
 744     {
 745         if (verbose)
 746         {
 747             switch (error)
 748             {
 749                 case wxIFF_INVFORMAT:
 750                     wxLogError(_("IFF: error in IFF image format."));
 751                     break;
 752                 case wxIFF_MEMERR:
 753                     wxLogError(_("IFF: not enough memory."));
 754                     break;
 755                 default:
 756                     wxLogError(_("IFF: unknown error!!!"));
 757                     break;
 758             }
 759         }
 760         delete decod;
 761         return false;
 762     }
 763
 764     if ((error == wxIFF_TRUNCATED) && verbose)
 765     {
 766         wxLogError(_("IFF: data stream seems to be truncated."));
 767         /* go on; image data is OK */
 768     }
 769
 770     ok = decod->ConvertToImage(image);
 771     delete decod;
 772
 773     return ok;
 774 }
 775
 776 bool wxIFFHandler::SaveFile(wxImage * WXUNUSED(image),
 777                             wxOutputStream& WXUNUSED(stream), bool verbose)
 778 {
 779     if (verbose)
 780         wxLogDebug(wxT("IFF: the handler is read-only!!"));
 781
 782     return false;
 783 }
 784
 785 bool wxIFFHandler::DoCanRead(wxInputStream& stream)
 786 {
 787     wxIFFDecoder decod(&stream);
 788
 789     return decod.CanRead();
 790 }
 791
 792 #endif // wxUSE_STREAMS
 793
 794 #endif // wxUSE_IFF