src/common/imagiff.cpp

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