src/os2/pngread.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        pnghand.cpp
   3 // Purpose:     Implements a PNG reader class + handler
   4 // Author:      David Webster
   5 // Modified by:
   6 // Created:     10/10/99
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) David Webster
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // For compilers that support precompilation, includes "wx.h".
  13 #include "wx/wxprec.h"
  14
  15 #include <stdlib.h>
  16 #include <stdio.h>
  17 #include <string.h>
  18
  19 #if wxUSE_IOSTREAMH
  20 #   include <fstream.h>
  21 #else
  22 #   include <fstream>
  23 #endif
  24
  25 #define INCL_DOS
  26 #define INCL_PM
  27 #define INCL_GPI
  28 #include <os2.h>
  29 #include "wx/palette.h"
  30 #include "wx/bitmap.h"
  31 #include "wx/utils.h"
  32 #include "wx/msw/pngread.h"
  33 #include "wx/msw/dibutils.h"
  34
  35 extern "C" {
  36 #include "../png/png.h"
  37 }
  38
  39 extern "C" void png_read_init PNGARG((png_structp png_ptr));
  40 extern "C" void png_write_init PNGARG((png_structp png_ptr));
  41
  42 #ifndef GlobalAllocPtr
  43 #define     GlobalPtrHandle(lp)         \
  44                 ((HGLOBAL)GlobalHandle(lp))
  45
  46 #define     GlobalLockPtr(lp)                \
  47                 ((BOOL)GlobalLock(GlobalPtrHandle(lp)))
  48 #define     GlobalUnlockPtr(lp)      \
  49                 GlobalUnlock(GlobalPtrHandle(lp))
  50
  51 #define     GlobalAllocPtr(flags, cb)        \
  52                 (GlobalLock(GlobalAlloc((flags), (cb))))
  53 #define     GlobalReAllocPtr(lp, cbNew, flags)       \
  54                 (GlobalUnlockPtr(lp), GlobalLock(GlobalReAlloc(GlobalPtrHandle(lp) , (cbNew), (flags))))
  55 #define     GlobalFreePtr(lp)                \
  56                 (GlobalUnlockPtr(lp), (BOOL)GlobalFree(GlobalPtrHandle(lp)))
  57 #endif
  58
  59
  60 void
  61 ima_png_error(png_struct *png_ptr, char *message)
  62 {
  63 //        wxMessageBox(message, "PNG error");
  64
  65   longjmp(png_ptr->jmpbuf, 1);
  66 }
  67
  68
  69 // static wxGifReaderIter* iter;
  70 wxPalette *wxCopyPalette(const wxPalette *cmap);
  71
  72 wxPNGReader::wxPNGReader()
  73 {
  74   filetype = 0;
  75   RawImage = NULL;      //  Image data
  76
  77   Width = 0; Height = 0;       //  Dimensions
  78   Depth = 0;           // (bits x pixel)
  79   ColorType = 0;        // Bit 1 = Palette used
  80                   // Bit 2 = Color used
  81                   // Bit 3 = Alpha used
  82
  83   EfeWidth = 0;         // Efective Width
  84
  85   lpbi = NULL;
  86   bgindex = -1;
  87   Palette = 0;
  88   imageOK = FALSE;
  89 }
  90
  91 wxPNGReader::wxPNGReader ( wxChar* ImageFileName )
  92 {
  93   imageOK = FALSE;
  94   filetype = 0;
  95   RawImage = NULL;      //  Image data
  96
  97   Width = 0; Height = 0;       //  Dimensions
  98   Depth = 0;           // (bits x pixel)
  99   ColorType = 0;        // Bit 1 = Palette used
 100                   // Bit 2 = Color used
 101                   // Bit 3 = Alpha used
 102
 103   EfeWidth = 0;         // Efective Width
 104
 105   lpbi = NULL;
 106   bgindex = -1;
 107   Palette = 0;
 108
 109   imageOK = ReadFile (ImageFileName);
 110 }
 111
 112 void
 113 wxPNGReader::Create(int width, int height, int depth, int colortype)
 114 {
 115   Width = width; Height = height; Depth = depth;
 116   ColorType = (colortype>=0) ? colortype: ((Depth>8) ? COLORTYPE_COLOR: 0);
 117
 118   if (lpbi)  {
 119 #ifdef __WIN16__
 120    GlobalFreePtr((unsigned int) lpbi);
 121 #else
 122    GlobalFreePtr(lpbi);
 123 #endif
 124 //   delete Palette;
 125   }
 126   RawImage = 0;
 127   Palette = 0;
 128   lpbi = wxDibCreate(Depth, Width, Height);
 129   if (lpbi)  {
 130     RawImage = (ImagePointerType)wxDibPtr(lpbi);
 131     EfeWidth = (long)(((long)Width*Depth + 31) / 32) * 4;
 132         imageOK = TRUE;
 133   }
 134 }
 135
 136 wxPNGReader::~wxPNGReader ( )
 137 {
 138   if (lpbi)  {
 139 #ifdef __WIN16__
 140    GlobalFreePtr((unsigned int) lpbi);
 141 #else
 142    GlobalFreePtr(lpbi);
 143 #endif
 144    delete Palette;
 145   }
 146 }
 147
 148
 149 int wxPNGReader::GetIndex(int x, int y)
 150 {
 151   if (!Inside(x, y) || (Depth>8)) return -1;
 152
 153   ImagePointerType ImagePointer = RawImage + EfeWidth*y + (x*Depth >> 3);
 154   int index = (int)(*ImagePointer);
 155   return index;
 156 }
 157
 158 bool wxPNGReader::GetRGB(int x, int y, byte* r, byte* g, byte* b)
 159 {
 160   if (!Inside(x, y)) return FALSE;
 161
 162   if (Palette) {
 163    return Palette->GetRGB(GetIndex(x, y), r, g, b);
 164 /*   PALETTEENTRY entry;
 165    ::GetPaletteEntries((HPALETTE) Palette->GetHPALETTE(), GetIndex(x, y), 1, &entry);
 166    *r = entry.peRed;
 167    *g = entry.peGreen;
 168    *b = entry.peBlue;  */
 169   } else {
 170    ImagePointerType ImagePointer = RawImage + EfeWidth*y + (x*Depth >> 3);
 171    *b = ImagePointer[0];
 172    *g = ImagePointer[1];
 173    *r = ImagePointer[2];
 174   }
 175   return TRUE;
 176 }
 177
 178
 179 bool wxPNGReader::SetIndex(int x, int y, int index)
 180 {
 181   if (!Inside(x, y) || (Depth>8)) return FALSE;
 182
 183   ImagePointerType ImagePointer = RawImage + EfeWidth*y + (x*Depth >> 3);
 184   *ImagePointer = index;
 185
 186   return TRUE;
 187 }
 188
 189 bool wxPNGReader::SetRGB(int x, int y, byte r, byte g, byte b)
 190 {
 191   if (!Inside(x, y)) return FALSE;
 192
 193   if (ColorType & COLORTYPE_PALETTE)
 194   {
 195    if (!Palette) return FALSE;
 196    SetIndex(x, y, Palette->GetPixel(r, g, b));
 197
 198   } else {
 199    ImagePointerType ImagePointer = RawImage + EfeWidth*y + (x*Depth >> 3);
 200    ImagePointer[0] = b;
 201    ImagePointer[1] = g;
 202    ImagePointer[2] = r;
 203   }
 204
 205   return TRUE;
 206 }
 207
 208 bool wxPNGReader::SetPalette(wxPalette* colourmap)
 209 {
 210   if (!colourmap)
 211    return FALSE;
 212   ColorType |= (COLORTYPE_PALETTE | COLORTYPE_COLOR);
 213   Palette = colourmap;
 214   return (wxDibSetUsage(lpbi, (HPALETTE) Palette->GetHPALETTE(), WXIMA_COLORS ) != 0);
 215 }
 216
 217 bool
 218 wxPNGReader::SetPalette(int n, byte *r, byte *g, byte *b)
 219 {
 220   Palette = new wxPalette();
 221   if (!Palette)
 222    return FALSE;
 223
 224   if (!g) g = r;
 225   if (!b) b = g;
 226   Palette->Create(n, r, g, b);
 227   ColorType |= (COLORTYPE_PALETTE | COLORTYPE_COLOR);
 228   return (wxDibSetUsage(lpbi, (HPALETTE) Palette->GetHPALETTE(), WXIMA_COLORS ) != 0);
 229 }
 230
 231 bool
 232 wxPNGReader::SetPalette(int n, rgb_color_struct *rgb_struct)
 233 {
 234   Palette = new wxPalette();
 235   if (!Palette)
 236    return FALSE;
 237
 238   byte r[256], g[256], b[256];
 239
 240   for(int i=0; i<n; i++)
 241   {
 242    r[i] = rgb_struct[i].red;
 243    g[i] = rgb_struct[i].green;
 244    b[i] = rgb_struct[i].blue;
 245   }
 246   // Added by JACS copying from Andrew Davison's additions
 247   // to GIF-reading code
 248   // Make transparency colour black...
 249   if (bgindex != -1)
 250     r[bgindex] = g[bgindex] = b[bgindex] = 0;
 251
 252   Palette->Create(n, r, g, b);
 253   ColorType |= (COLORTYPE_PALETTE | COLORTYPE_COLOR);
 254   return (wxDibSetUsage(lpbi, (HPALETTE) Palette->GetHPALETTE(), WXIMA_COLORS ) != 0);
 255 }
 256
 257 void wxPNGReader::NullData()
 258 {
 259   lpbi = NULL;
 260   Palette = NULL;
 261 }
 262
 263 wxBitmap* wxPNGReader::GetBitmap()
 264 {
 265     wxBitmap *bitmap = new wxBitmap;
 266     if ( InstantiateBitmap(bitmap) )
 267         return bitmap;
 268     else
 269     {
 270         delete bitmap;
 271         return NULL;
 272     }
 273 }
 274
 275 bool wxPNGReader::InstantiateBitmap(wxBitmap *bitmap)
 276 {
 277   HDC dc = ::CreateCompatibleDC(NULL);
 278
 279   if (dc)
 280   {
 281         // tmpBitmap is a dummy, to satisfy ::CreateCompatibleDC (it
 282         // is a memory dc that must have a bitmap selected into it)
 283         HDC dc2 = GetDC(NULL);
 284         HBITMAP tmpBitmap = ::CreateCompatibleBitmap(dc2, GetWidth(), GetHeight());
 285         ReleaseDC(NULL, dc2);
 286         HBITMAP oldBitmap = (HBITMAP) ::SelectObject(dc, tmpBitmap);
 287
 288         if ( Palette )
 289         {
 290             ::SelectPalette(dc, (HPALETTE) Palette->GetHPALETTE(), FALSE);
 291         ::RealizePalette(dc);
 292         }
 293
 294     HBITMAP hBitmap = ::CreateDIBitmap(dc, lpbi,
 295         CBM_INIT, RawImage, (LPBITMAPINFO) lpbi, DIB_PAL_COLORS);
 296
 297         ::SelectPalette(dc, NULL, TRUE);
 298         ::SelectObject(dc, oldBitmap);
 299         ::DeleteObject(tmpBitmap);
 300         ::DeleteDC(dc);
 301
 302         if ( hBitmap )
 303         {
 304           bitmap->SetHBITMAP((WXHBITMAP) hBitmap);
 305           bitmap->SetWidth(GetWidth());
 306           bitmap->SetHeight(GetHeight());
 307           bitmap->SetDepth(GetDepth());
 308           if ( GetDepth() > 1 && Palette )
 309             bitmap->SetPalette(*Palette);
 310           bitmap->SetOk(TRUE);
 311
 312
 313           // Make a mask if appropriate
 314           if ( bgindex > -1 )
 315           {
 316             wxMask *mask = CreateMask();
 317             bitmap->SetMask(mask);
 318           }
 319       return TRUE;
 320         }
 321         else
 322         {
 323           return FALSE;
 324         }
 325   }
 326   else
 327     {
 328     return FALSE;
 329     }
 330 }
 331
 332 wxPalette *wxCopyPalette(const wxPalette *cmap)
 333 {
 334   // To get number of entries...
 335   WORD count = 0;
 336   ::GetObject((HPALETTE) cmap->GetHPALETTE(), sizeof(WORD), &count);
 337
 338   LOGPALETTE* logPal = (LOGPALETTE*)
 339      new BYTE[sizeof(LOGPALETTE) + count*sizeof(PALETTEENTRY)];
 340   logPal->palVersion = 0x300;
 341   logPal->palNumEntries = count;
 342   ::GetPaletteEntries((HPALETTE) cmap->GetHPALETTE(), 0, count, logPal->palPalEntry);
 343
 344   HPALETTE hPalette = ::CreatePalette(logPal);
 345   delete[] logPal;
 346
 347   wxPalette *newCmap = new wxPalette;
 348   newCmap->SetHPALETTE((WXHPALETTE) hPalette);
 349   return newCmap;
 350 }
 351
 352 wxMask *wxPNGReader::CreateMask()
 353 {
 354     HBITMAP hBitmap = ::CreateBitmap(GetWidth(), GetHeight(), 1, 1, NULL);
 355
 356   HDC dc = ::CreateCompatibleDC(NULL);
 357     HBITMAP oldBitmap = (HBITMAP) ::SelectObject(dc, hBitmap);
 358
 359     int bgIndex = GetBGIndex();
 360
 361     int x,y;
 362
 363     for (x=0; x<GetWidth(); x++)
 364     {
 365         for (y=0; y<GetHeight(); y++)
 366         {
 367             int index = GetIndex(x, y);
 368             if ( index == bgIndex )
 369                 ::SetPixel(dc, x, GetHeight() - y - 1, RGB(0, 0, 0));
 370             else
 371                 ::SetPixel(dc, x, GetHeight() - y - 1, RGB(255, 255, 255));
 372
 373       }
 374     }
 375     ::SelectObject(dc, oldBitmap);
 376     wxMask *mask = new wxMask;
 377     mask->SetMaskBitmap((WXHBITMAP) hBitmap);
 378     return mask;
 379 }
 380
 381 bool wxPNGReader::ReadFile(wxChar * ImageFileName)
 382 {
 383     if (ImageFileName)
 384         wxStrcpy(filename, ImageFileName);
 385
 386     /* open the file */
 387     FILE *fp = fopen(wxConvFile.cWX2MB(filename), "rb");
 388     if (!fp)
 389         return FALSE;
 390
 391     /* allocate the necessary structures */
 392     png_struct *png_ptr = new (png_struct);
 393     if (!png_ptr)
 394     {
 395         fclose(fp);
 396         return FALSE;
 397     }
 398
 399     png_info *info_ptr = new (png_info);
 400     if (!info_ptr)
 401     {
 402         fclose(fp);
 403         delete(png_ptr);
 404         return FALSE;
 405     }
 406
 407     /* set error handling */
 408     if (setjmp(png_ptr->jmpbuf))
 409     {
 410         png_read_destroy(png_ptr, info_ptr, (png_info *)0);
 411         fclose(fp);
 412         delete(png_ptr);
 413         delete(info_ptr);
 414
 415         /* If we get here, we had a problem reading the file */
 416         return FALSE;
 417     }
 418     //png_set_error(ima_png_error, NULL);
 419
 420     /* initialize the structures, info first for error handling */
 421     png_info_init(info_ptr);
 422     png_read_init(png_ptr);
 423
 424     /* set up the input control */
 425     png_init_io(png_ptr, fp);
 426
 427     /* read the file information */
 428     png_read_info(png_ptr, info_ptr);
 429
 430     /* allocate the memory to hold the image using the fields
 431        of png_info. */
 432     png_color_16 my_background={ 0, 31, 127, 255, 0 };
 433
 434     if (info_ptr->valid & PNG_INFO_bKGD)
 435     {
 436         png_set_background(png_ptr, &(info_ptr->background),
 437                 PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
 438         if ( info_ptr->num_palette > 0 )
 439             bgindex = info_ptr->background.index;
 440     }
 441     else   {
 442         png_set_background(png_ptr, &my_background,
 443                 PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
 444
 445         // Added by JACS: guesswork!
 446         if ( info_ptr->num_trans != 0 )
 447             bgindex = info_ptr->num_trans - 1 ;
 448     }
 449
 450     /* tell libpng to strip 16 bit depth files down to 8 bits */
 451     if (info_ptr->bit_depth == 16)
 452         png_set_strip_16(png_ptr);
 453
 454     int pixel_depth=(info_ptr->pixel_depth<24) ? info_ptr->pixel_depth: 24;
 455     Create(info_ptr->width, info_ptr->height, pixel_depth,
 456             info_ptr->color_type);
 457
 458     if (info_ptr->num_palette>0)
 459     {
 460         SetPalette((int)info_ptr->num_palette, (rgb_color_struct*)info_ptr->palette);
 461     }
 462
 463     int row_stride = info_ptr->width * ((pixel_depth+7)>>3);
 464     //  printf("P = %d D = %d RS= %d ", info_ptr->num_palette, info_ptr->pixel_depth,row_stride);
 465     //  printf("CT = %d TRS = %d BD= %d ", info_ptr->color_type, info_ptr->valid & PNG_INFO_tRNS,info_ptr->bit_depth);
 466
 467     byte *row_pointers = new byte[row_stride];
 468
 469     /* turn on interlace handling */
 470     int number_passes;
 471     if (info_ptr->interlace_type)
 472         number_passes = png_set_interlace_handling(png_ptr);
 473     else
 474         number_passes = 1;
 475     //  printf("NP = %d ", number_passes);
 476
 477     // don't use the object to prevent warnings from VC++ about "unportable
 478     // interaction between setjmp and C++ object destruction" (this is a correct
 479     // warning, of course!)
 480     wxPNGReaderIter *iter = new wxPNGReaderIter(this);
 481     for (int pass=0; pass< number_passes; pass++)
 482     {
 483         iter->upset();
 484         int y=0;
 485         do  {
 486             //(unsigned char *)iter.GetRow();
 487             if (info_ptr->interlace_type)  {
 488                 if (pass>0)
 489                     iter->GetRow(row_pointers, row_stride);
 490                 png_read_row(png_ptr, row_pointers, NULL);
 491             }
 492             else
 493                 png_read_row(png_ptr, row_pointers, NULL);
 494
 495             iter->SetRow(row_pointers, row_stride);
 496             y++;
 497         } while(iter->PrevRow());
 498         //  printf("Y=%d ",y);
 499     }
 500
 501     delete iter;
 502     delete[] row_pointers;
 503
 504     /* read the rest of the file, getting any additional chunks
 505        in info_ptr */
 506     png_read_end(png_ptr, info_ptr);
 507
 508     /* clean up after the read, and free any memory allocated */
 509     png_read_destroy(png_ptr, info_ptr, (png_info *)0);
 510
 511     /* free the structures */
 512     delete(png_ptr);
 513     delete(info_ptr);
 514
 515     /* close the file */
 516     fclose(fp);
 517
 518     /* that's it */
 519     return TRUE;
 520 }
 521
 522
 523 /* write a png file */
 524
 525 bool wxPNGReader::SaveFile(wxChar * ImageFileName)
 526 {
 527   if (ImageFileName)
 528    wxStrcpy(filename, ImageFileName);
 529
 530   wxPNGReaderIter iter(this);
 531   FILE *fp;
 532    png_struct *png_ptr;
 533   png_info *info_ptr;
 534
 535    /* open the file */
 536   fp = fopen(wxConvFile.cWX2MB(filename), "wb");
 537   if (!fp)
 538     return FALSE;
 539
 540   /* allocate the necessary structures */
 541   png_ptr = new (png_struct);
 542   if (!png_ptr)
 543   {
 544     fclose(fp);
 545     return FALSE;
 546   }
 547
 548   info_ptr = new (png_info);
 549   if (!info_ptr)
 550   {
 551     fclose(fp);
 552     delete(png_ptr);
 553     return FALSE;
 554   }
 555
 556   /* set error handling */
 557   if (setjmp(png_ptr->jmpbuf))
 558   {
 559     png_write_destroy(png_ptr);
 560     fclose(fp);
 561     delete(png_ptr);
 562     delete(info_ptr);
 563
 564     /* If we get here, we had a problem reading the file */
 565     return FALSE;
 566   }
 567         //png_set_error(ima_png_error, NULL);
 568
 569 //  printf("writig pg %s ", filename);
 570    /* initialize the structures */
 571   png_info_init(info_ptr);
 572   png_write_init(png_ptr);
 573
 574   int row_stride = GetWidth() * ((GetDepth()+7)>>3);
 575   /* set up the output control */
 576    png_init_io(png_ptr, fp);
 577
 578   /* set the file information here */
 579   info_ptr->width = GetWidth();
 580   info_ptr->height = GetHeight();
 581   info_ptr->pixel_depth = GetDepth();
 582   info_ptr->channels = (GetDepth()>8) ? 3: 1;
 583   info_ptr->bit_depth = GetDepth()/info_ptr->channels;
 584   info_ptr->color_type = GetColorType();
 585   info_ptr->compression_type = info_ptr->filter_type = info_ptr->interlace_type=0;
 586   info_ptr->valid = 0;
 587   info_ptr->rowbytes = row_stride;
 588
 589
 590 // printf("P = %d D = %d RS= %d GD= %d CH= %d ", info_ptr->pixel_depth, info_ptr->bit_depth, row_stride, GetDepth(), info_ptr->channels);
 591   /* set the palette if there is one */
 592   if ((GetColorType() & COLORTYPE_PALETTE) && GetPalette())
 593   {
 594 //    printf("writing paleta[%d %d %x]",GetColorType() ,COLORTYPE_PALETTE, GetPalette());
 595     info_ptr->valid |= PNG_INFO_PLTE;
 596     info_ptr->palette = new png_color[256];
 597     info_ptr->num_palette = 256;
 598     for (int i=0; i<256; i++)
 599      GetPalette()->GetRGB(i, &info_ptr->palette[i].red, &info_ptr->palette[i].green, &info_ptr->palette[i].blue);
 600   }
 601 //    printf("Paleta [%d %d %x]",GetColorType() ,COLORTYPE_PALETTE, GetPalette());
 602
 603
 604    /* optional significant bit chunk */
 605 //   info_ptr->valid |= PNG_INFO_sBIT;
 606 //   info_ptr->sig_bit = true_bit_depth;
 607
 608   /* optional gamma chunk */
 609 //   info_ptr->valid |= PNG_INFO_gAMA;
 610 //   info_ptr->gamma = gamma;
 611
 612   /* other optional chunks */
 613
 614    /* write the file information */
 615    png_write_info(png_ptr, info_ptr);
 616
 617    /* set up the transformations you want.  Note that these are
 618       all optional.  Only call them if you want them */
 619
 620   /* shift the pixels up to a legal bit depth and fill in
 621       as appropriate to correctly scale the image */
 622 //   png_set_shift(png_ptr, &(info_ptr->sig_bit));
 623
 624   /* pack pixels into bytes */
 625 //   png_set_packing(png_ptr);
 626
 627   /* flip bgr pixels to rgb */
 628 //   png_set_bgr(png_ptr);
 629
 630    /* swap bytes of 16 bit files to most significant bit first */
 631 //   png_set_swap(png_ptr);
 632
 633    /* get rid of filler bytes, pack rgb into 3 bytes */
 634 //   png_set_rgbx(png_ptr);
 635
 636 /* If you are only writing one row at a time, this works */
 637
 638   byte *row_pointers = new byte[row_stride];
 639     iter.upset();
 640   do  {
 641 //    (unsigned char *)iter.GetRow();
 642     iter.GetRow(row_pointers, row_stride);
 643     png_write_row(png_ptr, row_pointers);
 644   } while(iter.PrevRow());
 645
 646         delete[] row_pointers;
 647
 648 /* write the rest of the file */
 649    png_write_end(png_ptr, info_ptr);
 650
 651   /* clean up after the write, and free any memory allocated */
 652    png_write_destroy(png_ptr);
 653
 654    /* if you malloced the palette, free it here */
 655    if (info_ptr->palette)
 656     delete[] (info_ptr->palette);
 657
 658   /* free the structures */
 659   delete(png_ptr);
 660   delete(info_ptr);
 661
 662   /* close the file */
 663   fclose(fp);
 664
 665   /* that's it */
 666   return TRUE;
 667 }
 668
 669 static int Power(int x, int y)
 670 {
 671     int z = 1;
 672     int i;
 673     for ( i = 0; i < y; i++)
 674     {
 675         z *= x;
 676     }
 677     return z;
 678 }
 679
 680 static char hexArray[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B',
 681   'C', 'D', 'E', 'F' };
 682
 683 static void DecToHex(int dec, char *buf)
 684 {
 685   int firstDigit = (int)(dec/16.0);
 686   int secondDigit = (int)(dec - (firstDigit*16.0));
 687   buf[0] = hexArray[firstDigit];
 688   buf[1] = hexArray[secondDigit];
 689   buf[2] = 0;
 690 }
 691
 692
 693 bool wxPNGReader::SaveXPM(wxChar *filename, wxChar *name)
 694 {
 695     wxChar nameStr[256];
 696     if ( name )
 697         wxStrcpy(nameStr, name);
 698     else
 699     {
 700         wxStrcpy(nameStr, filename);
 701         wxStripExtension(nameStr);
 702     }
 703
 704     if ( GetDepth() > 4 )
 705     {
 706         // Only a depth of 4 and below allowed
 707         return FALSE;
 708     }
 709
 710     if ( !GetPalette() )
 711         return FALSE;
 712
 713     ofstream str(wxConvFile.cWX2MB(filename));
 714     if ( str.bad() )
 715         return FALSE;
 716
 717     int noColours = Power(2, GetDepth());
 718
 719     // Output header
 720     str << "/* XPM */\n";
 721     str << "static char * " << nameStr << "_xpm[] = {\n";
 722     str << "\"" << GetWidth() << " " << GetHeight() << " " << noColours << " 1\",\n";
 723
 724     // Output colourmap
 725     int base = 97 ; // start from 'a'
 726
 727     unsigned char red, green, blue;
 728     char hexBuf[4];
 729     int i;
 730     for ( i = 0; i < noColours; i ++)
 731     {
 732         str << "\"" << (char)(base + i) << "      c #";
 733         GetPalette()->GetRGB(i, &red, &green, &blue);
 734         DecToHex(red, hexBuf);
 735         str << hexBuf;
 736         DecToHex(green, hexBuf);
 737         str << hexBuf;
 738         DecToHex(blue, hexBuf);
 739         str << hexBuf;
 740         str << "\",\n";
 741     }
 742
 743     // Output the data
 744     int x, y;
 745     for ( y = 0; y < GetHeight(); y++)
 746     {
 747         str << "\"";
 748         for ( x = 0; x < GetWidth(); x++)
 749         {
 750             int index = GetIndex(x, y);
 751             str << (char)(base + index) ;
 752         }
 753         str << "\",\n";
 754     }
 755
 756     str << "};\n";
 757     str.flush();
 758
 759     return TRUE;
 760 }
 761
 762 #include <wx/os2/pnghand.h>
 763
 764 IMPLEMENT_DYNAMIC_CLASS(wxPNGFileHandler, wxBitmapHandler)
 765
 766 bool wxPNGFileHandler::LoadFile(wxBitmap *bitmap, const wxString& name, long flags,
 767     int desiredWidth, int desiredHeight)
 768 {
 769     wxPNGReader reader;
 770     if (reader.ReadFile(WXSTRINGCAST name))
 771     {
 772         return reader.InstantiateBitmap(bitmap);
 773     }
 774     else
 775         return FALSE;
 776 }
 777
 778 bool wxPNGFileHandler::SaveFile(wxBitmap *bitmap, const wxString& name, int type, const wxPalette *pal)
 779 {
 780     return FALSE;
 781 }
 782
 783