src/msw/pnghand.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        pnghand.cpp
   3 // Purpose:     Implements a PNG reader class + handler
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     04/01/98
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart and Markus Holzem
   9 // Licence:     wxWindows license
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifdef __GNUG__
  13 #pragma implementation "pngread.h"
  14 #pragma implementation "pnghand.h"
  15 #endif
  16
  17 // For compilers that support precompilation, includes "wx.h".
  18 #include "wx/wxprec.h"
  19
  20 #ifdef __BORLANDC__
  21 #pragma hdrstop
  22 #endif
  23
  24 #include <stdlib.h>
  25 #include <stdio.h>
  26 #include <string.h>
  27
  28 #if wxUSE_IOSTREAMH
  29 #   include <fstream.h>
  30 #else
  31 #   include <fstream>
  32 #endif
  33
  34 #include <windows.h>
  35 #include "wx/palette.h"
  36 #include "wx/bitmap.h"
  37 #include "wx/utils.h"
  38 #include "wx/msw/pngread.h"
  39 #include "wx/msw/dibutils.h"
  40
  41 extern "C" {
  42 #include "../png/png.h"
  43 }
  44
  45 extern "C" void png_read_init PNGARG((png_structp png_ptr));
  46 extern "C" void png_write_init PNGARG((png_structp png_ptr));
  47
  48 #ifndef GlobalAllocPtr
  49 #define     GlobalPtrHandle(lp)         \
  50                 ((HGLOBAL)GlobalHandle(lp))
  51
  52 #define     GlobalLockPtr(lp)                \
  53                 ((BOOL)GlobalLock(GlobalPtrHandle(lp)))
  54 #define     GlobalUnlockPtr(lp)      \
  55                 GlobalUnlock(GlobalPtrHandle(lp))
  56
  57 #define     GlobalAllocPtr(flags, cb)        \
  58                 (GlobalLock(GlobalAlloc((flags), (cb))))
  59 #define     GlobalReAllocPtr(lp, cbNew, flags)       \
  60                 (GlobalUnlockPtr(lp), GlobalLock(GlobalReAlloc(GlobalPtrHandle(lp) , (cbNew), (flags))))
  61 #define     GlobalFreePtr(lp)                \
  62                 (GlobalUnlockPtr(lp), (BOOL)GlobalFree(GlobalPtrHandle(lp)))
  63 #endif
  64
  65
  66 void
  67 ima_png_error(png_struct *png_ptr, char *message)
  68 {
  69 //        wxMessageBox(message, "PNG error");
  70
  71   longjmp(png_ptr->jmpbuf, 1);
  72 }
  73
  74
  75 // static wxGifReaderIter* iter;
  76 wxPalette *wxCopyPalette(const wxPalette *cmap);
  77
  78 wxPNGReader::wxPNGReader()
  79 {
  80   filetype = 0;
  81   RawImage = NULL;      //  Image data
  82
  83   Width = 0; Height = 0;       //  Dimensions
  84   Depth = 0;           // (bits x pixel)
  85   ColorType = 0;        // Bit 1 = Palette used
  86                   // Bit 2 = Color used
  87                   // Bit 3 = Alpha used
  88
  89   EfeWidth = 0;         // Efective Width
  90
  91   lpbi = NULL;
  92   bgindex = -1;
  93   Palette = 0;
  94   imageOK = FALSE;
  95 }
  96
  97 wxPNGReader::wxPNGReader ( wxChar* ImageFileName )
  98 {
  99   imageOK = FALSE;
 100   filetype = 0;
 101   RawImage = NULL;      //  Image data
 102
 103   Width = 0; Height = 0;       //  Dimensions
 104   Depth = 0;           // (bits x pixel)
 105   ColorType = 0;        // Bit 1 = Palette used
 106                   // Bit 2 = Color used
 107                   // Bit 3 = Alpha used
 108
 109   EfeWidth = 0;         // Efective Width
 110
 111   lpbi = NULL;
 112   bgindex = -1;
 113   Palette = 0;
 114
 115   imageOK = ReadFile (ImageFileName);
 116 }
 117
 118 void
 119 wxPNGReader::Create(int width, int height, int depth, int colortype)
 120 {
 121   Width = width; Height = height; Depth = depth;
 122   ColorType = (colortype>=0) ? colortype: ((Depth>8) ? COLORTYPE_COLOR: 0);
 123
 124   if (lpbi)  {
 125 #ifdef __WIN16__
 126    GlobalFreePtr((unsigned int) lpbi);
 127 #else
 128    GlobalFreePtr(lpbi);
 129 #endif
 130 //   delete Palette;
 131   }
 132   RawImage = 0;
 133   Palette = 0;
 134   lpbi = wxDibCreate(Depth, Width, Height);
 135   if (lpbi)  {
 136     RawImage = (ImagePointerType)wxDibPtr(lpbi);
 137     EfeWidth = (long)(((long)Width*Depth + 31) / 32) * 4;
 138         imageOK = TRUE;
 139   }
 140 }
 141
 142 wxPNGReader::~wxPNGReader ( )
 143 {
 144   if (lpbi)  {
 145 #ifdef __WIN16__
 146    GlobalFreePtr((unsigned int) lpbi);
 147 #else
 148    GlobalFreePtr(lpbi);
 149 #endif
 150    delete Palette;
 151   }
 152 }
 153
 154
 155 int wxPNGReader::GetIndex(int x, int y)
 156 {
 157   if (!Inside(x, y) || (Depth>8)) return -1;
 158
 159   ImagePointerType ImagePointer = RawImage + EfeWidth*y + (x*Depth >> 3);
 160   int index = (int)(*ImagePointer);
 161   return index;
 162 }
 163
 164 bool wxPNGReader::GetRGB(int x, int y, byte* r, byte* g, byte* b)
 165 {
 166   if (!Inside(x, y)) return FALSE;
 167
 168   if (Palette) {
 169    return Palette->GetRGB(GetIndex(x, y), r, g, b);
 170 /*   PALETTEENTRY entry;
 171    ::GetPaletteEntries((HPALETTE) Palette->GetHPALETTE(), GetIndex(x, y), 1, &entry);
 172    *r = entry.peRed;
 173    *g = entry.peGreen;
 174    *b = entry.peBlue;  */
 175   } else {
 176    ImagePointerType ImagePointer = RawImage + EfeWidth*y + (x*Depth >> 3);
 177    *b = ImagePointer[0];
 178    *g = ImagePointer[1];
 179    *r = ImagePointer[2];
 180   }
 181   return TRUE;
 182 }
 183
 184
 185 bool wxPNGReader::SetIndex(int x, int y, int index)
 186 {
 187   if (!Inside(x, y) || (Depth>8)) return FALSE;
 188
 189   ImagePointerType ImagePointer = RawImage + EfeWidth*y + (x*Depth >> 3);
 190   *ImagePointer = index;
 191
 192   return TRUE;
 193 }
 194
 195 bool wxPNGReader::SetRGB(int x, int y, byte r, byte g, byte b)
 196 {
 197   if (!Inside(x, y)) return FALSE;
 198
 199   if (ColorType & COLORTYPE_PALETTE)
 200   {
 201    if (!Palette) return FALSE;
 202    SetIndex(x, y, Palette->GetPixel(r, g, b));
 203
 204   } else {
 205    ImagePointerType ImagePointer = RawImage + EfeWidth*y + (x*Depth >> 3);
 206    ImagePointer[0] = b;
 207    ImagePointer[1] = g;
 208    ImagePointer[2] = r;
 209   }
 210
 211   return TRUE;
 212 }
 213
 214 bool wxPNGReader::SetPalette(wxPalette* colourmap)
 215 {
 216   if (!colourmap)
 217    return FALSE;
 218   ColorType |= (COLORTYPE_PALETTE | COLORTYPE_COLOR);
 219   Palette = colourmap;
 220   return (wxDibSetUsage(lpbi, (HPALETTE) Palette->GetHPALETTE(), WXIMA_COLORS ) != 0);
 221 }
 222
 223 bool
 224 wxPNGReader::SetPalette(int n, byte *r, byte *g, byte *b)
 225 {
 226   Palette = new wxPalette();
 227   if (!Palette)
 228    return FALSE;
 229
 230   if (!g) g = r;
 231   if (!b) b = g;
 232   Palette->Create(n, r, g, b);
 233   ColorType |= (COLORTYPE_PALETTE | COLORTYPE_COLOR);
 234   return (wxDibSetUsage(lpbi, (HPALETTE) Palette->GetHPALETTE(), WXIMA_COLORS ) != 0);
 235 }
 236
 237 bool
 238 wxPNGReader::SetPalette(int n, rgb_color_struct *rgb_struct)
 239 {
 240   Palette = new wxPalette();
 241   if (!Palette)
 242    return FALSE;
 243
 244   byte r[256], g[256], b[256];
 245
 246   for(int i=0; i<n; i++)
 247   {
 248    r[i] = rgb_struct[i].red;
 249    g[i] = rgb_struct[i].green;
 250    b[i] = rgb_struct[i].blue;
 251   }
 252   // Added by JACS copying from Andrew Davison's additions
 253   // to GIF-reading code
 254   // Make transparency colour black...
 255   if (bgindex != -1)
 256     r[bgindex] = g[bgindex] = b[bgindex] = 0;
 257
 258   Palette->Create(n, r, g, b);
 259   ColorType |= (COLORTYPE_PALETTE | COLORTYPE_COLOR);
 260   return (wxDibSetUsage(lpbi, (HPALETTE) Palette->GetHPALETTE(), WXIMA_COLORS ) != 0);
 261 }
 262
 263 void wxPNGReader::NullData()
 264 {
 265   lpbi = NULL;
 266   Palette = NULL;
 267 }
 268
 269 wxBitmap* wxPNGReader::GetBitmap()
 270 {
 271     wxBitmap *bitmap = new wxBitmap;
 272     if ( InstantiateBitmap(bitmap) )
 273         return bitmap;
 274     else
 275     {
 276         delete bitmap;
 277         return NULL;
 278     }
 279 }
 280
 281 bool wxPNGReader::InstantiateBitmap(wxBitmap *bitmap)
 282 {
 283   HDC dc = ::CreateCompatibleDC(NULL);
 284
 285   if (dc)
 286   {
 287         // tmpBitmap is a dummy, to satisfy ::CreateCompatibleDC (it
 288         // is a memory dc that must have a bitmap selected into it)
 289         HDC dc2 = GetDC(NULL);
 290         HBITMAP tmpBitmap = ::CreateCompatibleBitmap(dc2, GetWidth(), GetHeight());
 291         ReleaseDC(NULL, dc2);
 292         HBITMAP oldBitmap = (HBITMAP) ::SelectObject(dc, tmpBitmap);
 293
 294         if ( Palette )
 295         {
 296             ::SelectPalette(dc, (HPALETTE) Palette->GetHPALETTE(), FALSE);
 297         ::RealizePalette(dc);
 298         }
 299
 300     HBITMAP hBitmap = ::CreateDIBitmap(dc, lpbi,
 301         CBM_INIT, RawImage, (LPBITMAPINFO) lpbi, DIB_PAL_COLORS);
 302
 303         ::SelectPalette(dc, NULL, TRUE);
 304         ::SelectObject(dc, oldBitmap);
 305         ::DeleteObject(tmpBitmap);
 306         ::DeleteDC(dc);
 307
 308         if ( hBitmap )
 309         {
 310           bitmap->SetHBITMAP((WXHBITMAP) hBitmap);
 311           bitmap->SetWidth(GetWidth());
 312           bitmap->SetHeight(GetHeight());
 313           bitmap->SetDepth(GetDepth());
 314           if ( GetDepth() > 1 && Palette )
 315             bitmap->SetPalette(*Palette);
 316           bitmap->SetOk(TRUE);
 317
 318
 319           // Make a mask if appropriate
 320           if ( bgindex > -1 )
 321           {
 322             wxMask *mask = CreateMask();
 323             bitmap->SetMask(mask);
 324           }
 325       return TRUE;
 326         }
 327         else
 328         {
 329           return FALSE;
 330         }
 331   }
 332   else
 333     {
 334     return FALSE;
 335     }
 336 }
 337
 338 wxPalette *wxCopyPalette(const wxPalette *cmap)
 339 {
 340   // To get number of entries...
 341   WORD count = 0;
 342   ::GetObject((HPALETTE) cmap->GetHPALETTE(), sizeof(WORD), &count);
 343
 344   LOGPALETTE* logPal = (LOGPALETTE*)
 345      new BYTE[sizeof(LOGPALETTE) + count*sizeof(PALETTEENTRY)];
 346   logPal->palVersion = 0x300;
 347   logPal->palNumEntries = count;
 348   ::GetPaletteEntries((HPALETTE) cmap->GetHPALETTE(), 0, count, logPal->palPalEntry);
 349
 350   HPALETTE hPalette = ::CreatePalette(logPal);
 351   delete[] logPal;
 352
 353   wxPalette *newCmap = new wxPalette;
 354   newCmap->SetHPALETTE((WXHPALETTE) hPalette);
 355   return newCmap;
 356 }
 357
 358 wxMask *wxPNGReader::CreateMask()
 359 {
 360     HBITMAP hBitmap = ::CreateBitmap(GetWidth(), GetHeight(), 1, 1, NULL);
 361
 362   HDC dc = ::CreateCompatibleDC(NULL);
 363     HBITMAP oldBitmap = (HBITMAP) ::SelectObject(dc, hBitmap);
 364
 365     int bgIndex = GetBGIndex();
 366
 367     int x,y;
 368
 369     for (x=0; x<GetWidth(); x++)
 370     {
 371         for (y=0; y<GetHeight(); y++)
 372         {
 373             int index = GetIndex(x, y);
 374             if ( index == bgIndex )
 375                 ::SetPixel(dc, x, GetHeight() - y - 1, RGB(0, 0, 0));
 376             else
 377                 ::SetPixel(dc, x, GetHeight() - y - 1, RGB(255, 255, 255));
 378
 379       }
 380     }
 381     ::SelectObject(dc, oldBitmap);
 382     wxMask *mask = new wxMask;
 383     mask->SetMaskBitmap((WXHBITMAP) hBitmap);
 384     return mask;
 385 }
 386
 387 bool wxPNGReader::ReadFile(wxChar * ImageFileName)
 388 {
 389     if (ImageFileName)
 390         wxStrcpy(filename, ImageFileName);
 391
 392     /* open the file */
 393     FILE *fp = fopen(wxConvFile.cWX2MB(filename), "rb");
 394     if (!fp)
 395         return FALSE;
 396
 397     /* allocate the necessary structures */
 398     png_struct *png_ptr = new (png_struct);
 399     if (!png_ptr)
 400     {
 401         fclose(fp);
 402         return FALSE;
 403     }
 404
 405     png_info *info_ptr = new (png_info);
 406     if (!info_ptr)
 407     {
 408         fclose(fp);
 409         delete(png_ptr);
 410         return FALSE;
 411     }
 412
 413     /* set error handling */
 414     if (setjmp(png_ptr->jmpbuf))
 415     {
 416         png_read_destroy(png_ptr, info_ptr, (png_info *)0);
 417         fclose(fp);
 418         delete(png_ptr);
 419         delete(info_ptr);
 420
 421         /* If we get here, we had a problem reading the file */
 422         return FALSE;
 423     }
 424     //png_set_error(ima_png_error, NULL);
 425
 426     /* initialize the structures, info first for error handling */
 427     png_info_init(info_ptr);
 428     png_read_init(png_ptr);
 429
 430     /* set up the input control */
 431     png_init_io(png_ptr, fp);
 432
 433     /* read the file information */
 434     png_read_info(png_ptr, info_ptr);
 435
 436     /* allocate the memory to hold the image using the fields
 437        of png_info. */
 438     png_color_16 my_background={ 0, 31, 127, 255, 0 };
 439
 440     if (info_ptr->valid & PNG_INFO_bKGD)
 441     {
 442         png_set_background(png_ptr, &(info_ptr->background),
 443                 PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
 444         if ( info_ptr->num_palette > 0 )
 445             bgindex = info_ptr->background.index;
 446     }
 447     else   {
 448         png_set_background(png_ptr, &my_background,
 449                 PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
 450
 451         // Added by JACS: guesswork!
 452         if ( info_ptr->num_trans != 0 )
 453             bgindex = info_ptr->num_trans - 1 ;
 454     }
 455
 456     /* tell libpng to strip 16 bit depth files down to 8 bits */
 457     if (info_ptr->bit_depth == 16)
 458         png_set_strip_16(png_ptr);
 459
 460     int pixel_depth=(info_ptr->pixel_depth<24) ? info_ptr->pixel_depth: 24;
 461     Create(info_ptr->width, info_ptr->height, pixel_depth,
 462             info_ptr->color_type);
 463
 464     if (info_ptr->num_palette>0)
 465     {
 466         SetPalette((int)info_ptr->num_palette, (rgb_color_struct*)info_ptr->palette);
 467     }
 468
 469     int row_stride = info_ptr->width * ((pixel_depth+7)>>3);
 470     //  printf("P = %d D = %d RS= %d ", info_ptr->num_palette, info_ptr->pixel_depth,row_stride);
 471     //  printf("CT = %d TRS = %d BD= %d ", info_ptr->color_type, info_ptr->valid & PNG_INFO_tRNS,info_ptr->bit_depth);
 472
 473     byte *row_pointers = new byte[row_stride];
 474
 475     /* turn on interlace handling */
 476     int number_passes;
 477     if (info_ptr->interlace_type)
 478         number_passes = png_set_interlace_handling(png_ptr);
 479     else
 480         number_passes = 1;
 481     //  printf("NP = %d ", number_passes);
 482
 483     // don't use the object to prevent warnings from VC++ about "unportable
 484     // interaction between setjmp and C++ object destruction" (this is a correct
 485     // warning, of course!)
 486     wxPNGReaderIter *iter = new wxPNGReaderIter(this);
 487     for (int pass=0; pass< number_passes; pass++)
 488     {
 489         iter->upset();
 490         int y=0;
 491         do  {
 492             //(unsigned char *)iter.GetRow();
 493             if (info_ptr->interlace_type)  {
 494                 if (pass>0)
 495                     iter->GetRow(row_pointers, row_stride);
 496                 png_read_row(png_ptr, row_pointers, NULL);
 497             }
 498             else
 499                 png_read_row(png_ptr, row_pointers, NULL);
 500
 501             iter->SetRow(row_pointers, row_stride);
 502             y++;
 503         } while(iter->PrevRow());
 504         //  printf("Y=%d ",y);
 505     }
 506
 507     delete iter;
 508     delete[] row_pointers;
 509
 510     /* read the rest of the file, getting any additional chunks
 511        in info_ptr */
 512     png_read_end(png_ptr, info_ptr);
 513
 514     /* clean up after the read, and free any memory allocated */
 515     png_read_destroy(png_ptr, info_ptr, (png_info *)0);
 516
 517     /* free the structures */
 518     delete(png_ptr);
 519     delete(info_ptr);
 520
 521     /* close the file */
 522     fclose(fp);
 523
 524     /* that's it */
 525     return TRUE;
 526 }
 527
 528
 529 /* write a png file */
 530
 531 bool wxPNGReader::SaveFile(wxChar * ImageFileName)
 532 {
 533   if (ImageFileName)
 534    wxStrcpy(filename, ImageFileName);
 535
 536   wxPNGReaderIter iter(this);
 537   FILE *fp;
 538    png_struct *png_ptr;
 539   png_info *info_ptr;
 540
 541    /* open the file */
 542   fp = fopen(wxConvFile.cWX2MB(filename), "wb");
 543   if (!fp)
 544     return FALSE;
 545
 546   /* allocate the necessary structures */
 547   png_ptr = new (png_struct);
 548   if (!png_ptr)
 549   {
 550     fclose(fp);
 551     return FALSE;
 552   }
 553
 554   info_ptr = new (png_info);
 555   if (!info_ptr)
 556   {
 557     fclose(fp);
 558     delete(png_ptr);
 559     return FALSE;
 560   }
 561
 562   /* set error handling */
 563   if (setjmp(png_ptr->jmpbuf))
 564   {
 565     png_write_destroy(png_ptr);
 566     fclose(fp);
 567     delete(png_ptr);
 568     delete(info_ptr);
 569
 570     /* If we get here, we had a problem reading the file */
 571     return FALSE;
 572   }
 573         //png_set_error(ima_png_error, NULL);
 574
 575 //  printf("writig pg %s ", filename);
 576    /* initialize the structures */
 577   png_info_init(info_ptr);
 578   png_write_init(png_ptr);
 579
 580   int row_stride = GetWidth() * ((GetDepth()+7)>>3);
 581   /* set up the output control */
 582    png_init_io(png_ptr, fp);
 583
 584   /* set the file information here */
 585   info_ptr->width = GetWidth();
 586   info_ptr->height = GetHeight();
 587   info_ptr->pixel_depth = GetDepth();
 588   info_ptr->channels = (GetDepth()>8) ? 3: 1;
 589   info_ptr->bit_depth = GetDepth()/info_ptr->channels;
 590   info_ptr->color_type = GetColorType();
 591   info_ptr->compression_type = info_ptr->filter_type = info_ptr->interlace_type=0;
 592   info_ptr->valid = 0;
 593   info_ptr->rowbytes = row_stride;
 594
 595
 596 // 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);
 597   /* set the palette if there is one */
 598   if ((GetColorType() & COLORTYPE_PALETTE) && GetPalette())
 599   {
 600 //    printf("writing paleta[%d %d %x]",GetColorType() ,COLORTYPE_PALETTE, GetPalette());
 601     info_ptr->valid |= PNG_INFO_PLTE;
 602     info_ptr->palette = new png_color[256];
 603     info_ptr->num_palette = 256;
 604     for (int i=0; i<256; i++)
 605      GetPalette()->GetRGB(i, &info_ptr->palette[i].red, &info_ptr->palette[i].green, &info_ptr->palette[i].blue);
 606   }
 607 //    printf("Paleta [%d %d %x]",GetColorType() ,COLORTYPE_PALETTE, GetPalette());
 608
 609
 610    /* optional significant bit chunk */
 611 //   info_ptr->valid |= PNG_INFO_sBIT;
 612 //   info_ptr->sig_bit = true_bit_depth;
 613
 614   /* optional gamma chunk */
 615 //   info_ptr->valid |= PNG_INFO_gAMA;
 616 //   info_ptr->gamma = gamma;
 617
 618   /* other optional chunks */
 619
 620    /* write the file information */
 621    png_write_info(png_ptr, info_ptr);
 622
 623    /* set up the transformations you want.  Note that these are
 624       all optional.  Only call them if you want them */
 625
 626   /* shift the pixels up to a legal bit depth and fill in
 627       as appropriate to correctly scale the image */
 628 //   png_set_shift(png_ptr, &(info_ptr->sig_bit));
 629
 630   /* pack pixels into bytes */
 631 //   png_set_packing(png_ptr);
 632
 633   /* flip bgr pixels to rgb */
 634 //   png_set_bgr(png_ptr);
 635
 636    /* swap bytes of 16 bit files to most significant bit first */
 637 //   png_set_swap(png_ptr);
 638
 639    /* get rid of filler bytes, pack rgb into 3 bytes */
 640 //   png_set_rgbx(png_ptr);
 641
 642 /* If you are only writing one row at a time, this works */
 643
 644   byte *row_pointers = new byte[row_stride];
 645     iter.upset();
 646   do  {
 647 //    (unsigned char *)iter.GetRow();
 648     iter.GetRow(row_pointers, row_stride);
 649     png_write_row(png_ptr, row_pointers);
 650   } while(iter.PrevRow());
 651
 652         delete[] row_pointers;
 653
 654 /* write the rest of the file */
 655    png_write_end(png_ptr, info_ptr);
 656
 657   /* clean up after the write, and free any memory allocated */
 658    png_write_destroy(png_ptr);
 659
 660    /* if you malloced the palette, free it here */
 661    if (info_ptr->palette)
 662     delete[] (info_ptr->palette);
 663
 664   /* free the structures */
 665   delete(png_ptr);
 666   delete(info_ptr);
 667
 668   /* close the file */
 669   fclose(fp);
 670
 671   /* that's it */
 672   return TRUE;
 673 }
 674
 675 static int Power(int x, int y)
 676 {
 677     int z = 1;
 678     int i;
 679     for ( i = 0; i < y; i++)
 680     {
 681         z *= x;
 682     }
 683     return z;
 684 }
 685
 686 static char hexArray[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B',
 687   'C', 'D', 'E', 'F' };
 688
 689 static void DecToHex(int dec, char *buf)
 690 {
 691   int firstDigit = (int)(dec/16.0);
 692   int secondDigit = (int)(dec - (firstDigit*16.0));
 693   buf[0] = hexArray[firstDigit];
 694   buf[1] = hexArray[secondDigit];
 695   buf[2] = 0;
 696 }
 697
 698
 699 bool wxPNGReader::SaveXPM(wxChar *filename, wxChar *name)
 700 {
 701     wxChar nameStr[256];
 702     if ( name )
 703         wxStrcpy(nameStr, name);
 704     else
 705     {
 706         wxStrcpy(nameStr, filename);
 707         wxStripExtension(nameStr);
 708     }
 709
 710     if ( GetDepth() > 4 )
 711     {
 712         // Only a depth of 4 and below allowed
 713         return FALSE;
 714     }
 715
 716     if ( !GetPalette() )
 717         return FALSE;
 718
 719     ofstream str(wxConvFile.cWX2MB(filename));
 720     if ( str.bad() )
 721         return FALSE;
 722
 723     int noColours = Power(2, GetDepth());
 724
 725     // Output header
 726     str << "/* XPM */\n";
 727     str << "static char * " << nameStr << "_xpm[] = {\n";
 728     str << "\"" << GetWidth() << " " << GetHeight() << " " << noColours << " 1\",\n";
 729
 730     // Output colourmap
 731     int base = 97 ; // start from 'a'
 732
 733     unsigned char red, green, blue;
 734     char hexBuf[4];
 735     int i;
 736     for ( i = 0; i < noColours; i ++)
 737     {
 738         str << "\"" << (char)(base + i) << "      c #";
 739         GetPalette()->GetRGB(i, &red, &green, &blue);
 740         DecToHex(red, hexBuf);
 741         str << hexBuf;
 742         DecToHex(green, hexBuf);
 743         str << hexBuf;
 744         DecToHex(blue, hexBuf);
 745         str << hexBuf;
 746         str << "\",\n";
 747     }
 748
 749     // Output the data
 750     int x, y;
 751     for ( y = 0; y < GetHeight(); y++)
 752     {
 753         str << "\"";
 754         for ( x = 0; x < GetWidth(); x++)
 755         {
 756             int index = GetIndex(x, y);
 757             str << (char)(base + index) ;
 758         }
 759         str << "\",\n";
 760     }
 761
 762     str << "};\n";
 763     str.flush();
 764
 765     return TRUE;
 766 }
 767
 768 #include <wx/msw/pnghand.h>
 769
 770 IMPLEMENT_DYNAMIC_CLASS(wxPNGFileHandler, wxBitmapHandler)
 771
 772 bool wxPNGFileHandler::LoadFile(wxBitmap *bitmap, const wxString& name, long flags,
 773     int desiredWidth, int desiredHeight)
 774 {
 775     wxPNGReader reader;
 776     if (reader.ReadFile(WXSTRINGCAST name))
 777     {
 778         return reader.InstantiateBitmap(bitmap);
 779     }
 780     else
 781         return FALSE;
 782 }
 783
 784 bool wxPNGFileHandler::SaveFile(wxBitmap *bitmap, const wxString& name, int type, const wxPalette *pal)
 785 {
 786     return FALSE;
 787 }
 788
 789