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