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
 102     // NOTE: this function modifies the current stream position
 103     bool CanRead();
 104
 105     int ReadIFF();
 106     bool ConvertToImage(wxImage *image) const;
 107 };
 108
 109
 110 //---------------------------------------------------------------------------
 111 // wxIFFDecoder constructor and destructor
 112 //---------------------------------------------------------------------------
 113
 114 wxIFFDecoder::wxIFFDecoder(wxInputStream *s)
 115 {
 116     m_f = s;
 117     m_image = 0;
 118     databuf = 0;
 119     decomp_mem = 0;
 120 }
 121
 122 void wxIFFDecoder::Destroy()
 123 {
 124     delete m_image;
 125     m_image = 0;
 126     delete [] databuf;
 127     databuf = 0;
 128     delete [] decomp_mem;
 129     decomp_mem = 0;
 130 }
 131
 132 //---------------------------------------------------------------------------
 133 // Convert this image to a wxImage object
 134 //---------------------------------------------------------------------------
 135
 136 // This function was designed by Vaclav Slavik
 137
 138 bool wxIFFDecoder::ConvertToImage(wxImage *image) const
 139 {
 140     // just in case...
 141     image->Destroy();
 142
 143     // create the image
 144     image->Create(GetWidth(), GetHeight());
 145
 146     if (!image->Ok())
 147         return false;
 148
 149     unsigned char *pal = GetPalette();
 150     unsigned char *src = GetData();
 151     unsigned char *dst = image->GetData();
 152     int colors = GetNumColors();
 153     int transparent = GetTransparentColour();
 154     long i;
 155
 156     // set transparent colour mask
 157     if (transparent != -1)
 158     {
 159         for (i = 0; i < colors; i++)
 160         {
 161             if ((pal[3 * i + 0] == 255) &&
 162                 (pal[3 * i + 1] == 0) &&
 163                 (pal[3 * i + 2] == 255))
 164             {
 165                 pal[3 * i + 2] = 254;
 166             }
 167         }
 168
 169         pal[3 * transparent + 0] = 255,
 170         pal[3 * transparent + 1] = 0,
 171         pal[3 * transparent + 2] = 255;
 172
 173         image->SetMaskColour(255, 0, 255);
 174     }
 175     else
 176         image->SetMask(false);
 177
 178 #if wxUSE_PALETTE
 179     if (pal && colors > 0)
 180     {
 181         unsigned char* r = new unsigned char[colors];
 182         unsigned char* g = new unsigned char[colors];
 183         unsigned char* b = new unsigned char[colors];
 184
 185         for (i = 0; i < colors; i++)
 186         {
 187             r[i] = pal[3*i + 0];
 188             g[i] = pal[3*i + 1];
 189             b[i] = pal[3*i + 2];
 190         }
 191
 192         image->SetPalette(wxPalette(colors, r, g, b));
 193
 194         delete [] r;
 195         delete [] g;
 196         delete [] b;
 197     }
 198 #endif // wxUSE_PALETTE
 199
 200     // copy image data
 201     for (i = 0; i < (long)(GetWidth() * GetHeight()); i++, src += 3, dst += 3)
 202     {
 203     dst[0] = src[0];
 204     dst[1] = src[1];
 205     dst[2] = src[2];
 206     }
 207
 208     return true;
 209 }
 210
 211
 212 //---------------------------------------------------------------------------
 213 // Data accessors
 214 //---------------------------------------------------------------------------
 215
 216 // Get data for current frame
 217
 218 unsigned char* wxIFFDecoder::GetData() const    { return (m_image->p); }
 219 unsigned char* wxIFFDecoder::GetPalette() const { return (m_image->pal); }
 220 int wxIFFDecoder::GetNumColors() const          { return m_image->colors; }
 221 unsigned int wxIFFDecoder::GetWidth() const     { return (m_image->w); }
 222 unsigned int wxIFFDecoder::GetHeight() const    { return (m_image->h); }
 223 int wxIFFDecoder::GetTransparentColour() const { return m_image->transparent; }
 224
 225 //---------------------------------------------------------------------------
 226 // IFF reading and decoding
 227 //---------------------------------------------------------------------------
 228
 229 //
 230 // CanRead:
 231 //  Returns true if the file looks like a valid IFF, false otherwise.
 232 //
 233 bool wxIFFDecoder::CanRead()
 234 {
 235     unsigned char buf[12];
 236
 237     if ( !m_f->Read(buf, WXSIZEOF(buf)) )
 238         return false;
 239
 240     return (memcmp(buf, "FORM", 4) == 0) && (memcmp(buf+8, "ILBM", 4) == 0);
 241 }
 242
 243
 244 // ReadIFF:
 245 // Based on xv source code by Thomas Meyer
 246 // Permission for use in wxWidgets has been gratefully given.
 247
 248 typedef unsigned char byte;
 249 #define IFFDEBUG 0
 250
 251 /*************************************************************************
 252 void decomprle(source, destination, source length, buffer size)
 253
 254 Decompress run-length encoded data from source to destination. Terminates
 255 when source is decoded completely or destination buffer is full.
 256
 257 The decruncher is as optimized as I could make it, without risking
 258 safety in case of corrupt BODY chunks.
 259 **************************************************************************/
 260
 261 static void decomprle(const byte *sptr, byte *dptr, long slen, long dlen)
 262 {
 263     byte codeByte, dataByte;
 264
 265     while ((slen > 0) && (dlen > 0)) {
 266     // read control byte
 267     codeByte = *sptr++;
 268
 269     if (codeByte < 0x80) {
 270         codeByte++;
 271         if ((slen > (long) codeByte) && (dlen >= (long) codeByte)) {
 272         slen -= codeByte + 1;
 273         dlen -= codeByte;
 274         while (codeByte > 0) {
 275             *dptr++ = *sptr++;
 276             codeByte--;
 277         }
 278         }
 279         else slen = 0;
 280     }
 281
 282     else if (codeByte > 0x80) {
 283         codeByte = 0x81 - (codeByte & 0x7f);
 284         if ((slen > (long) 0) && (dlen >= (long) codeByte)) {
 285         dataByte = *sptr++;
 286         slen -= 2;
 287         dlen -= codeByte;
 288         while (codeByte > 0) {
 289             *dptr++ = dataByte;
 290             codeByte--;
 291         }
 292         }
 293         else slen = 0;
 294     }
 295     }
 296 }
 297
 298 /******************************************/
 299 static unsigned int iff_getword(const byte *ptr)
 300 {
 301     unsigned int v;
 302
 303     v = *ptr++;
 304     v = (v << 8) + *ptr;
 305     return v;
 306 }
 307
 308 /******************************************/
 309 static unsigned long iff_getlong(const byte *ptr)
 310 {
 311     unsigned long l;
 312
 313     l = *ptr++;
 314     l = (l << 8) + *ptr++;
 315     l = (l << 8) + *ptr++;
 316     l = (l << 8) + *ptr;
 317     return l;
 318 }
 319
 320 // Define internal ILBM types
 321 #define ILBM_NORMAL     0
 322 #define ILBM_EHB        1
 323 #define ILBM_HAM        2
 324 #define ILBM_HAM8       3
 325 #define ILBM_24BIT      4
 326
 327 int wxIFFDecoder::ReadIFF()
 328 {
 329     Destroy();
 330
 331     m_image = new IFFImage();
 332     if (m_image == 0) {
 333         Destroy();
 334         return wxIFF_MEMERR;
 335     }
 336
 337     // compute file length
 338     wxFileOffset currentPos = m_f->TellI();
 339     if (m_f->SeekI(0, wxFromEnd) == wxInvalidOffset) {
 340         Destroy();
 341         return wxIFF_MEMERR;
 342     }
 343
 344     long filesize = m_f->TellI();
 345     if (m_f->SeekI(currentPos, wxFromStart) == wxInvalidOffset) {
 346         Destroy();
 347         return wxIFF_MEMERR;
 348     }
 349
 350     // allocate memory for complete file
 351     if ((databuf = new byte[filesize]) == 0) {
 352         Destroy();
 353         return wxIFF_MEMERR;
 354     }
 355
 356     m_f->Read(databuf, filesize);
 357     const byte *dataend = databuf + filesize;
 358
 359     // initialize work pointer. used to trace the buffer for IFF chunks
 360     const byte *dataptr = databuf;
 361
 362     // check for minmal size
 363     if (dataptr + 12 > dataend) {
 364         Destroy();
 365         return wxIFF_INVFORMAT;
 366     }
 367
 368     // check if we really got an IFF file
 369     if (strncmp((char *)dataptr, "FORM", 4) != 0) {
 370         Destroy();
 371         return wxIFF_INVFORMAT;
 372     }
 373
 374     dataptr = dataptr + 8;                  // skip ID and length of FORM
 375
 376     // check if the IFF file is an ILBM (picture) file
 377     if (strncmp((char *) dataptr, "ILBM", 4) != 0) {
 378         Destroy();
 379         return wxIFF_INVFORMAT;
 380     }
 381
 382     wxLogTrace(_T("iff"), _T("IFF ILBM file recognized"));
 383
 384     dataptr = dataptr + 4;                                // skip ID
 385
 386     //
 387     // main decoding loop. searches IFF chunks and handles them.
 388     // terminates when BODY chunk was found or dataptr ran over end of file
 389     //
 390     bool BMHDok = false, CAMGok = false;
 391     int bmhd_width = 0, bmhd_height = 0, bmhd_bitplanes = 0, bmhd_transcol = -1;
 392     byte bmhd_compression = 0;
 393     long camg_viewmode = 0;
 394     int colors = 0;
 395     while (dataptr + 8 <= dataend) {
 396     // get chunk length and make even
 397     long chunkLen = (iff_getlong(dataptr + 4) + 1) & 0xfffffffe;
 398     if (chunkLen < 0) {     // format error?
 399         break;
 400     }
 401     bool truncated = (dataptr + 8 + chunkLen > dataend);
 402
 403     if (strncmp((char *)dataptr, "BMHD", 4) == 0) { // BMHD chunk?
 404         if (chunkLen < 12 + 2 || truncated) {
 405         break;
 406         }
 407         bmhd_width = iff_getword(dataptr + 8);      // width of picture
 408         bmhd_height= iff_getword(dataptr + 8 + 2);  // height of picture
 409         bmhd_bitplanes = *(dataptr + 8 + 8);        // # of bitplanes
 410         // bmhd_masking  = *(dataptr + 8 + 9); -- unused currently
 411         bmhd_compression = *(dataptr + 8 + 10);     // get compression
 412         bmhd_transcol    = iff_getword(dataptr + 8 + 12);
 413         BMHDok = true;                              // got BMHD
 414         dataptr += 8 + chunkLen;                    // to next chunk
 415     }
 416     else if (strncmp((char *)dataptr, "CMAP", 4) == 0) { // CMAP ?
 417         if (truncated) {
 418         break;
 419         }
 420         const byte *cmapptr = dataptr + 8;
 421         colors = chunkLen / 3;                  // calc no of colors
 422
 423         delete m_image->pal;
 424         m_image->pal = 0;
 425         m_image->colors = colors;
 426         if (colors > 0) {
 427         m_image->pal = new byte[3*colors];
 428         if (!m_image->pal) {
 429             Destroy();
 430             return wxIFF_MEMERR;
 431         }
 432
 433         // copy colors to color map
 434         for (int i=0; i < colors; i++) {
 435             m_image->pal[3*i + 0] = *cmapptr++;
 436             m_image->pal[3*i + 1] = *cmapptr++;
 437             m_image->pal[3*i + 2] = *cmapptr++;
 438         }
 439         }
 440
 441         wxLogTrace(_T("iff"), _T("Read %d colors from IFF file."),
 442             colors);
 443
 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     {
 781         wxLogDebug(wxT("IFF: the handler is read-only!!"));
 782     }
 783
 784     return false;
 785 }
 786
 787 bool wxIFFHandler::DoCanRead(wxInputStream& stream)
 788 {
 789     wxIFFDecoder decod(&stream);
 790
 791     return decod.CanRead();
 792          // it's ok to modify the stream position here
 793 }
 794
 795 #endif // wxUSE_STREAMS
 796
 797 #endif // wxUSE_IFF