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     wxDELETE(m_image);
 125     wxDELETEA(databuf);
 126     wxDELETEA(decomp_mem);
 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     return (memcmp(buf, "FORM", 4) == 0) && (memcmp(buf+8, "ILBM", 4) == 0);
 238 }
 239
 240
 241 // ReadIFF:
 242 // Based on xv source code by Thomas Meyer
 243 // Permission for use in wxWidgets has been gratefully given.
 244
 245 typedef unsigned char byte;
 246 #define IFFDEBUG 0
 247
 248 /*************************************************************************
 249 void decomprle(source, destination, source length, buffer size)
 250
 251 Decompress run-length encoded data from source to destination. Terminates
 252 when source is decoded completely or destination buffer is full.
 253
 254 The decruncher is as optimized as I could make it, without risking
 255 safety in case of corrupt BODY chunks.
 256 **************************************************************************/
 257
 258 static void decomprle(const byte *sptr, byte *dptr, long slen, long dlen)
 259 {
 260     byte codeByte, dataByte;
 261
 262     while ((slen > 0) && (dlen > 0)) {
 263     // read control byte
 264     codeByte = *sptr++;
 265
 266     if (codeByte < 0x80) {
 267         codeByte++;
 268         if ((slen > (long) codeByte) && (dlen >= (long) codeByte)) {
 269         slen -= codeByte + 1;
 270         dlen -= codeByte;
 271         while (codeByte > 0) {
 272             *dptr++ = *sptr++;
 273             codeByte--;
 274         }
 275         }
 276         else slen = 0;
 277     }
 278
 279     else if (codeByte > 0x80) {
 280         codeByte = 0x81 - (codeByte & 0x7f);
 281         if ((slen > (long) 0) && (dlen >= (long) codeByte)) {
 282         dataByte = *sptr++;
 283         slen -= 2;
 284         dlen -= codeByte;
 285         while (codeByte > 0) {
 286             *dptr++ = dataByte;
 287             codeByte--;
 288         }
 289         }
 290         else slen = 0;
 291     }
 292     }
 293 }
 294
 295 /******************************************/
 296 static unsigned int iff_getword(const byte *ptr)
 297 {
 298     unsigned int v;
 299
 300     v = *ptr++;
 301     v = (v << 8) + *ptr;
 302     return v;
 303 }
 304
 305 /******************************************/
 306 static unsigned long iff_getlong(const byte *ptr)
 307 {
 308     unsigned long l;
 309
 310     l = *ptr++;
 311     l = (l << 8) + *ptr++;
 312     l = (l << 8) + *ptr++;
 313     l = (l << 8) + *ptr;
 314     return l;
 315 }
 316
 317 // Define internal ILBM types
 318 #define ILBM_NORMAL     0
 319 #define ILBM_EHB        1
 320 #define ILBM_HAM        2
 321 #define ILBM_HAM8       3
 322 #define ILBM_24BIT      4
 323
 324 int wxIFFDecoder::ReadIFF()
 325 {
 326     Destroy();
 327
 328     m_image = new IFFImage();
 329     if (m_image == 0) {
 330         Destroy();
 331         return wxIFF_MEMERR;
 332     }
 333
 334     // compute file length
 335     wxFileOffset currentPos = m_f->TellI();
 336     if (m_f->SeekI(0, wxFromEnd) == wxInvalidOffset) {
 337         Destroy();
 338         return wxIFF_MEMERR;
 339     }
 340
 341     long filesize = m_f->TellI();
 342     if (m_f->SeekI(currentPos, wxFromStart) == wxInvalidOffset) {
 343         Destroy();
 344         return wxIFF_MEMERR;
 345     }
 346
 347     // allocate memory for complete file
 348     if ((databuf = new byte[filesize]) == 0) {
 349         Destroy();
 350         return wxIFF_MEMERR;
 351     }
 352
 353     m_f->Read(databuf, filesize);
 354     const byte *dataend = databuf + filesize;
 355
 356     // initialize work pointer. used to trace the buffer for IFF chunks
 357     const byte *dataptr = databuf;
 358
 359     // check for minmal size
 360     if (dataptr + 12 > dataend) {
 361         Destroy();
 362         return wxIFF_INVFORMAT;
 363     }
 364
 365     // check if we really got an IFF file
 366     if (strncmp((char *)dataptr, "FORM", 4) != 0) {
 367         Destroy();
 368         return wxIFF_INVFORMAT;
 369     }
 370
 371     dataptr = dataptr + 8;                  // skip ID and length of FORM
 372
 373     // check if the IFF file is an ILBM (picture) file
 374     if (strncmp((char *) dataptr, "ILBM", 4) != 0) {
 375         Destroy();
 376         return wxIFF_INVFORMAT;
 377     }
 378
 379     wxLogTrace(wxT("iff"), wxT("IFF ILBM file recognized"));
 380
 381     dataptr = dataptr + 4;                                // skip ID
 382
 383     //
 384     // main decoding loop. searches IFF chunks and handles them.
 385     // terminates when BODY chunk was found or dataptr ran over end of file
 386     //
 387     bool BMHDok = false, CAMGok = false;
 388     int bmhd_width = 0, bmhd_height = 0, bmhd_bitplanes = 0, bmhd_transcol = -1;
 389     byte bmhd_compression = 0;
 390     long camg_viewmode = 0;
 391     int colors = 0;
 392     while (dataptr + 8 <= dataend) {
 393     // get chunk length and make even
 394     long chunkLen = (iff_getlong(dataptr + 4) + 1) & 0xfffffffe;
 395     if (chunkLen < 0) {     // format error?
 396         break;
 397     }
 398     bool truncated = (dataptr + 8 + chunkLen > dataend);
 399
 400     if (strncmp((char *)dataptr, "BMHD", 4) == 0) { // BMHD chunk?
 401         if (chunkLen < 12 + 2 || truncated) {
 402         break;
 403         }
 404         bmhd_width = iff_getword(dataptr + 8);      // width of picture
 405         bmhd_height= iff_getword(dataptr + 8 + 2);  // height of picture
 406         bmhd_bitplanes = *(dataptr + 8 + 8);        // # of bitplanes
 407         // bmhd_masking  = *(dataptr + 8 + 9); -- unused currently
 408         bmhd_compression = *(dataptr + 8 + 10);     // get compression
 409         bmhd_transcol    = iff_getword(dataptr + 8 + 12);
 410         BMHDok = true;                              // got BMHD
 411         dataptr += 8 + chunkLen;                    // to next chunk
 412     }
 413     else if (strncmp((char *)dataptr, "CMAP", 4) == 0) { // CMAP ?
 414         if (truncated) {
 415         break;
 416         }
 417         const byte *cmapptr = dataptr + 8;
 418         colors = chunkLen / 3;                  // calc no of colors
 419
 420         wxDELETE(m_image->pal);
 421         m_image->colors = colors;
 422         if (colors > 0) {
 423         m_image->pal = new byte[3*colors];
 424         if (!m_image->pal) {
 425             Destroy();
 426             return wxIFF_MEMERR;
 427         }
 428
 429         // copy colors to color map
 430         for (int i=0; i < colors; i++) {
 431             m_image->pal[3*i + 0] = *cmapptr++;
 432             m_image->pal[3*i + 1] = *cmapptr++;
 433             m_image->pal[3*i + 2] = *cmapptr++;
 434         }
 435         }
 436
 437         wxLogTrace(wxT("iff"), wxT("Read %d colors from IFF file."),
 438             colors);
 439
 440         dataptr += 8 + chunkLen;                    // to next chunk
 441     } else if (strncmp((char *)dataptr, "CAMG", 4) == 0) { // CAMG ?
 442         if (chunkLen < 4 || truncated) {
 443         break;
 444         }
 445         camg_viewmode = iff_getlong(dataptr + 8);   // get viewmodes
 446         CAMGok = true;                              // got CAMG
 447         dataptr += 8 + chunkLen;                    // to next chunk
 448     }
 449     else if (strncmp((char *)dataptr, "BODY", 4) == 0) { // BODY ?
 450         if (!BMHDok) {                              // BMHD found?
 451         break;
 452         }
 453         const byte *bodyptr = dataptr + 8;          // -> BODY data
 454
 455         if (truncated) {
 456         chunkLen = dataend - dataptr;
 457         }
 458
 459         //
 460             // if BODY is compressed, allocate buffer for decrunched BODY
 461         // and decompress it (run length encoding)
 462         //
 463         if (bmhd_compression == 1) {
 464         // calc size of decrunch buffer - (size of the actual pic.
 465         // decompressed in interleaved Amiga bitplane format)
 466
 467         size_t decomp_bufsize = (((bmhd_width + 15) >> 4) << 1)
 468             * bmhd_height * bmhd_bitplanes;
 469
 470         if ((decomp_mem = new byte[decomp_bufsize]) == 0) {
 471             Destroy();
 472             return wxIFF_MEMERR;
 473         }
 474
 475         decomprle(bodyptr, decomp_mem, chunkLen, decomp_bufsize);
 476         bodyptr = decomp_mem;                 // -> uncompressed BODY
 477         chunkLen = decomp_bufsize;
 478         wxDELETEA(databuf);
 479         }
 480
 481         // the following determines the type of the ILBM file.
 482         // it's either NORMAL, EHB, HAM, HAM8 or 24BIT
 483
 484         int fmt = ILBM_NORMAL;                 // assume normal ILBM
 485         if (bmhd_bitplanes == 24) {
 486         fmt = ILBM_24BIT;
 487         } else if (bmhd_bitplanes == 8) {
 488         if (CAMGok && (camg_viewmode & 0x800)) {
 489             fmt = ILBM_HAM8;
 490         }
 491         } else if ((bmhd_bitplanes > 5) && CAMGok) {
 492         if (camg_viewmode & 0x80) {
 493             fmt = ILBM_EHB;
 494         } else if (camg_viewmode & 0x800) {
 495             fmt = ILBM_HAM;
 496         }
 497         }
 498
 499         wxLogTrace(wxT("iff"),
 500             wxT("LoadIFF: %s %dx%d, planes=%d (%d cols), comp=%d"),
 501             (fmt==ILBM_NORMAL) ? "Normal ILBM" :
 502             (fmt==ILBM_HAM)    ? "HAM ILBM" :
 503             (fmt==ILBM_HAM8)   ? "HAM8 ILBM" :
 504             (fmt==ILBM_EHB)    ? "EHB ILBM" :
 505             (fmt==ILBM_24BIT)  ? "24BIT ILBM" : "unknown ILBM",
 506             bmhd_width, bmhd_height, bmhd_bitplanes,
 507             1<<bmhd_bitplanes, bmhd_compression);
 508
 509         if ((fmt==ILBM_NORMAL) || (fmt==ILBM_EHB) || (fmt==ILBM_HAM)) {
 510         wxLogTrace(wxT("iff"),
 511             wxT("Converting CMAP from normal ILBM CMAP"));
 512
 513         switch(fmt) {
 514             case ILBM_NORMAL: colors = 1 << bmhd_bitplanes; break;
 515             case ILBM_EHB:    colors = 32*2; break;
 516             case ILBM_HAM:    colors = 16; break;
 517         }
 518
 519         if (colors > m_image->colors) {
 520             byte *pal = new byte[colors*3];
 521             if (!pal) {
 522             Destroy();
 523             return wxIFF_MEMERR;
 524             }
 525             int i;
 526             for (i = 0; i < m_image->colors; i++) {
 527             pal[3*i + 0] = m_image->pal[3*i + 0];
 528             pal[3*i + 1] = m_image->pal[3*i + 1];
 529             pal[3*i + 2] = m_image->pal[3*i + 2];
 530             }
 531             for (; i < colors; i++) {
 532             pal[3*i + 0] = 0;
 533             pal[3*i + 1] = 0;
 534             pal[3*i + 2] = 0;
 535             }
 536             delete m_image->pal;
 537             m_image->pal = pal;
 538             m_image->colors = colors;
 539         }
 540
 541             for (int i=0; i < colors; i++) {
 542             m_image->pal[3*i + 0] = (m_image->pal[3*i + 0] >> 4) * 17;
 543             m_image->pal[3*i + 1] = (m_image->pal[3*i + 1] >> 4) * 17;
 544             m_image->pal[3*i + 2] = (m_image->pal[3*i + 2] >> 4) * 17;
 545         }
 546         }
 547
 548         m_image->p = new byte[bmhd_width * bmhd_height * 3];
 549             byte *picptr = m_image->p;
 550         if (!picptr) {
 551         Destroy();
 552         return wxIFF_MEMERR;
 553         }
 554
 555         byte *pal = m_image->pal;
 556         int lineskip = ((bmhd_width + 15) >> 4) << 1;
 557             int height = chunkLen / (lineskip * bmhd_bitplanes);
 558
 559         if (bmhd_height < height) {
 560             height = bmhd_height;
 561         }
 562
 563         if (fmt == ILBM_HAM || fmt == ILBM_HAM8 || fmt == ILBM_24BIT) {
 564         byte *pic = picptr;
 565         const byte *workptr = bodyptr;
 566
 567         for (int i=0; i < height; i++) {
 568             byte bitmsk = 0x80;
 569             const byte *workptr2 = workptr;
 570
 571             // at start of each line, init RGB values to background
 572             byte rval = pal[0];
 573             byte gval = pal[1];
 574             byte bval = pal[2];
 575
 576             for (int j=0; j < bmhd_width; j++) {
 577             long col = 0;
 578             long colbit = 1;
 579             const byte *workptr3 = workptr2;
 580             for (int k=0; k < bmhd_bitplanes; k++) {
 581                 if (*workptr3 & bitmsk) {
 582                 col += colbit;
 583                 }
 584                 workptr3 += lineskip;
 585                 colbit <<= 1;
 586             }
 587
 588             if (fmt==ILBM_HAM) {
 589                 int c = (col & 0x0f);
 590                 switch (col & 0x30) {
 591                 case 0x00: if (c >= 0 && c < colors) {
 592                         rval = pal[3*c + 0];
 593                         gval = pal[3*c + 1];
 594                         bval = pal[3*c + 2];
 595                     }
 596                     break;
 597
 598                 case 0x10: bval = c * 17;
 599                     break;
 600
 601                 case 0x20: rval = c * 17;
 602                     break;
 603
 604                 case 0x30: gval = c * 17;
 605                     break;
 606                 }
 607             } else if (fmt == ILBM_HAM8) {
 608                 int c = (col & 0x3f);
 609                 switch(col & 0xc0) {
 610                 case 0x00: if (c >= 0 && c < colors) {
 611                         rval = pal[3*c + 0];
 612                         gval = pal[3*c + 1];
 613                         bval = pal[3*c + 2];
 614                     }
 615                     break;
 616
 617                 case 0x40: bval = (bval & 3) | (c << 2);
 618                     break;
 619
 620                 case 0x80: rval = (rval & 3) | (c << 2);
 621                     break;
 622
 623                 case 0xc0: gval = (rval & 3) | (c << 2);
 624                 }
 625             } else {
 626                 rval = col & 0xff;
 627                 gval = (col >> 8) & 0xff;
 628                 bval = (col >> 16) & 0xff;
 629             }
 630
 631             *pic++ = rval;
 632             *pic++ = gval;
 633             *pic++ = bval;
 634
 635             bitmsk = bitmsk >> 1;
 636             if (bitmsk == 0) {
 637                 bitmsk = 0x80;
 638                 workptr2++;
 639             }
 640             }
 641             workptr += lineskip * bmhd_bitplanes;
 642         }
 643         }  else if ((fmt == ILBM_NORMAL) || (fmt == ILBM_EHB)) {
 644         if (fmt == ILBM_EHB) {
 645             wxLogTrace(wxT("iff"), wxT("Doubling CMAP for EHB mode"));
 646
 647             for (int i=0; i<32; i++) {
 648             pal[3*(i + 32) + 0] = pal[3*i + 0] >> 1;
 649             pal[3*(i + 32) + 1] = pal[3*i + 1] >> 1;
 650             pal[3*(i + 32) + 2] = pal[3*i + 2] >> 1;
 651             }
 652         }
 653
 654         byte *pic = picptr;         // ptr to buffer
 655         const byte *workptr = bodyptr;  // ptr to pic, planar format
 656
 657         if (bmhd_height < height) {
 658             height = bmhd_height;
 659         }
 660
 661         for (int i=0; i < height; i++) {
 662             byte bitmsk = 0x80;                 // left most bit (mask)
 663             const byte *workptr2 = workptr;     // work ptr to source
 664             for (int j=0; j < bmhd_width; j++) {
 665             long col = 0;
 666             long colbit = 1;
 667             const byte *workptr3 = workptr2;  // 1st byte in 1st pln
 668
 669             for (int k=0; k < bmhd_bitplanes; k++) {
 670                 if (*workptr3 & bitmsk) { // if bit set in this pln
 671                 col = col + colbit; // add bit to chunky byte
 672                 }
 673                 workptr3 += lineskip;   // go to next line
 674                 colbit <<= 1;           // shift color bit
 675             }
 676
 677             if (col >= 0 && col < colors) {
 678                 pic[0] = pal[3*col + 0];
 679                 pic[1] = pal[3*col + 1];
 680                 pic[2] = pal[3*col + 2];
 681             } else {
 682                 pic[0] = pic[1] = pic[2] = 0;
 683             }
 684             pic += 3;
 685             bitmsk = bitmsk >> 1;   // shift mask to next bit
 686             if (bitmsk == 0) {      // if mask is zero
 687                 bitmsk = 0x80;      // reset mask
 688                 workptr2++;         // mv ptr to next byte
 689             }
 690             }
 691
 692             workptr += lineskip * bmhd_bitplanes;  // to next line
 693         }
 694         } else {
 695         break;      // unknown format
 696         }
 697
 698         m_image->w = bmhd_width;
 699         m_image->h = height;
 700         m_image->transparent = bmhd_transcol;
 701
 702         wxLogTrace(wxT("iff"), wxT("Loaded IFF picture %s"),
 703             truncated? "truncated" : "completely");
 704
 705         return (truncated? wxIFF_TRUNCATED : wxIFF_OK);
 706     } else {
 707         wxLogTrace(wxT("iff"), wxT("Skipping unknown chunk '%c%c%c%c'"),
 708                 *dataptr, *(dataptr+1), *(dataptr+2), *(dataptr+3));
 709
 710         dataptr = dataptr + 8 + chunkLen;      // skip unknown chunk
 711     }
 712     }
 713
 714     Destroy();
 715     return wxIFF_INVFORMAT;
 716 }
 717
 718
 719
 720 //-----------------------------------------------------------------------------
 721 // wxIFFHandler
 722 //-----------------------------------------------------------------------------
 723
 724 IMPLEMENT_DYNAMIC_CLASS(wxIFFHandler, wxImageHandler)
 725
 726 #if wxUSE_STREAMS
 727
 728 bool wxIFFHandler::LoadFile(wxImage *image, wxInputStream& stream,
 729                             bool verbose, int WXUNUSED(index))
 730 {
 731     wxIFFDecoder *decod;
 732     int error;
 733     bool ok;
 734
 735     decod = new wxIFFDecoder(&stream);
 736     error = decod->ReadIFF();
 737
 738     if ((error != wxIFF_OK) && (error != wxIFF_TRUNCATED))
 739     {
 740         if (verbose)
 741         {
 742             switch (error)
 743             {
 744                 case wxIFF_INVFORMAT:
 745                     wxLogError(_("IFF: error in IFF image format."));
 746                     break;
 747                 case wxIFF_MEMERR:
 748                     wxLogError(_("IFF: not enough memory."));
 749                     break;
 750                 default:
 751                     wxLogError(_("IFF: unknown error!!!"));
 752                     break;
 753             }
 754         }
 755         delete decod;
 756         return false;
 757     }
 758
 759     if ((error == wxIFF_TRUNCATED) && verbose)
 760     {
 761         wxLogError(_("IFF: data stream seems to be truncated."));
 762         /* go on; image data is OK */
 763     }
 764
 765     ok = decod->ConvertToImage(image);
 766     delete decod;
 767
 768     return ok;
 769 }
 770
 771 bool wxIFFHandler::SaveFile(wxImage * WXUNUSED(image),
 772                             wxOutputStream& WXUNUSED(stream), bool verbose)
 773 {
 774     if (verbose)
 775     {
 776         wxLogDebug(wxT("IFF: the handler is read-only!!"));
 777     }
 778
 779     return false;
 780 }
 781
 782 bool wxIFFHandler::DoCanRead(wxInputStream& stream)
 783 {
 784     wxIFFDecoder decod(&stream);
 785
 786     return decod.CanRead();
 787          // it's ok to modify the stream position here
 788 }
 789
 790 #endif // wxUSE_STREAMS
 791
 792 #endif // wxUSE_IFF