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/msw/pngread.h>
  38 #include <wx/msw/dibutils.h>
  39
  40 extern "C" {
  41 #include "../png/png.h"
  42 }
  43
  44 extern "C" void png_read_init PNGARG((png_structp png_ptr));
  45 extern "C" void png_write_init PNGARG((png_structp png_ptr));
  46
  47 #ifndef GlobalAllocPtr
  48 #define     GlobalPtrHandle(lp)         \
  49                 ((HGLOBAL)GlobalHandle(lp))
  50
  51 #define     GlobalLockPtr(lp)                \
  52                 ((BOOL)GlobalLock(GlobalPtrHandle(lp)))
  53 #define     GlobalUnlockPtr(lp)      \
  54                 GlobalUnlock(GlobalPtrHandle(lp))
  55
  56 #define     GlobalAllocPtr(flags, cb)        \
  57                 (GlobalLock(GlobalAlloc((flags), (cb))))
  58 #define     GlobalReAllocPtr(lp, cbNew, flags)       \
  59                 (GlobalUnlockPtr(lp), GlobalLock(GlobalReAlloc(GlobalPtrHandle(lp) , (cbNew), (flags))))
  60 #define     GlobalFreePtr(lp)                \
  61                 (GlobalUnlockPtr(lp), (BOOL)GlobalFree(GlobalPtrHandle(lp)))
  62 #endif
  63
  64
  65 void
  66 ima_png_error(png_struct *png_ptr, char *message)
  67 {
  68 //        wxMessageBox(message, "PNG error");
  69
  70   longjmp(png_ptr->jmpbuf, 1);
  71 }
  72
  73
  74 // static wxGifReaderIter* iter;
  75 wxPalette *wxCopyPalette(const wxPalette *cmap);
  76
  77 wxPNGReader::wxPNGReader()
  78 {
  79   filetype = 0;
  80   RawImage = NULL;      //  Image data
  81
  82   Width = 0; Height = 0;       //  Dimensions
  83   Depth = 0;           // (bits x pixel)
  84   ColorType = 0;        // Bit 1 = Palette used
  85                   // Bit 2 = Color used
  86                   // Bit 3 = Alpha used
  87
  88   EfeWidth = 0;         // Efective Width
  89
  90   lpbi = NULL;
  91   bgindex = -1;
  92   Palette = 0;
  93   imageOK = FALSE;
  94 }
  95
  96 wxPNGReader::wxPNGReader ( wxChar* ImageFileName )
  97 {
  98   imageOK = FALSE;
  99   filetype = 0;
 100   RawImage = NULL;      //  Image data
 101
 102   Width = 0; Height = 0;       //  Dimensions
 103   Depth = 0;           // (bits x pixel)
 104   ColorType = 0;        // Bit 1 = Palette used
 105                   // Bit 2 = Color used
 106                   // Bit 3 = Alpha used
 107
 108   EfeWidth = 0;         // Efective Width
 109
 110   lpbi = NULL;
 111   bgindex = -1;
 112   Palette = 0;
 113
 114   imageOK = ReadFile (ImageFileName);
 115 }
 116
 117 void
 118 wxPNGReader::Create(int width, int height, int depth, int colortype)
 119 {
 120   Width = width; Height = height; Depth = depth;
 121   ColorType = (colortype>=0) ? colortype: ((Depth>8) ? COLORTYPE_COLOR: 0);
 122
 123   if (lpbi)  {
 124 #ifdef __WIN16__
 125    GlobalFreePtr((unsigned int) lpbi);
 126 #else
 127    GlobalFreePtr(lpbi);
 128 #endif
 129 //   delete Palette;
 130   }
 131   RawImage = 0;
 132   Palette = 0;
 133   lpbi = DibCreate(Depth, Width, Height);
 134   if (lpbi)  {
 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()
 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             ::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()
 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(wxChar * ImageFileName)
 387 {
 388     int number_passes;
 389
 390     if (ImageFileName)
 391         wxStrcpy(filename, ImageFileName);
 392
 393     FILE *fp;
 394     png_struct *png_ptr;
 395     png_info *info_ptr;
 396
 397     /* open the file */
 398     fp = fopen(wxConvFile.cWX2MB(filename), "rb");
 399     if (!fp)
 400         return FALSE;
 401
 402     /* allocate the necessary structures */
 403     png_ptr = new (png_struct);
 404     if (!png_ptr)
 405     {
 406         fclose(fp);
 407         return FALSE;
 408     }
 409
 410     info_ptr = new (png_info);
 411     if (!info_ptr)
 412     {
 413         fclose(fp);
 414         delete(png_ptr);
 415         return FALSE;
 416     }
 417     /* set error handling */
 418     if (setjmp(png_ptr->jmpbuf))
 419     {
 420         png_read_destroy(png_ptr, info_ptr, (png_info *)0);
 421         fclose(fp);
 422         delete(png_ptr);
 423         delete(info_ptr);
 424
 425         /* If we get here, we had a problem reading the file */
 426         return FALSE;
 427     }
 428     //png_set_error(ima_png_error, NULL);
 429
 430     /* initialize the structures, info first for error handling */
 431     png_info_init(info_ptr);
 432     png_read_init(png_ptr);
 433
 434     /* set up the input control */
 435     png_init_io(png_ptr, fp);
 436
 437     /* read the file information */
 438     png_read_info(png_ptr, info_ptr);
 439
 440     /* allocate the memory to hold the image using the fields
 441        of png_info. */
 442     png_color_16 my_background={ 0, 31, 127, 255, 0 };
 443
 444     if (info_ptr->valid & PNG_INFO_bKGD)
 445     {
 446         png_set_background(png_ptr, &(info_ptr->background),
 447                 PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
 448         if ( info_ptr->num_palette > 0 )
 449             bgindex = info_ptr->background.index;
 450     }
 451     else   {
 452         png_set_background(png_ptr, &my_background,
 453                 PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
 454
 455         // Added by JACS: guesswork!
 456         if ( info_ptr->num_trans != 0 )
 457             bgindex = info_ptr->num_trans - 1 ;
 458     }
 459
 460     /* tell libpng to strip 16 bit depth files down to 8 bits */
 461     if (info_ptr->bit_depth == 16)
 462         png_set_strip_16(png_ptr);
 463
 464     int pixel_depth=(info_ptr->pixel_depth<24) ? info_ptr->pixel_depth: 24;
 465     Create(info_ptr->width, info_ptr->height, pixel_depth,
 466             info_ptr->color_type);
 467
 468     if (info_ptr->num_palette>0)
 469     {
 470         SetPalette((int)info_ptr->num_palette, (rgb_color_struct*)info_ptr->palette);
 471     }
 472
 473     int row_stride = info_ptr->width * ((pixel_depth+7)>>3);
 474     //  printf("P = %d D = %d RS= %d ", info_ptr->num_palette, info_ptr->pixel_depth,row_stride);
 475     //  printf("CT = %d TRS = %d BD= %d ", info_ptr->color_type, info_ptr->valid & PNG_INFO_tRNS,info_ptr->bit_depth);
 476
 477     byte *row_pointers = new byte[row_stride];
 478
 479     /* turn on interlace handling */
 480     if (info_ptr->interlace_type)
 481         number_passes = png_set_interlace_handling(png_ptr);
 482     else
 483         number_passes = 1;
 484     //  printf("NP = %d ", number_passes);
 485
 486     // don't use the object to prevent warnings from VC++ about "unportable
 487     // interaction between setjmp and C++ object destruction" (this is a correct
 488     // warning, of course!)
 489     wxPNGReaderIter *iter = new wxPNGReaderIter(this);
 490     for (int pass=0; pass< number_passes; pass++)
 491     {
 492         iter->upset();
 493         int y=0;
 494         do  {
 495             //(unsigned char *)iter.GetRow();
 496             if (info_ptr->interlace_type)  {
 497                 if (pass>0)
 498                     iter->GetRow(row_pointers, row_stride);
 499                 png_read_row(png_ptr, row_pointers, NULL);
 500             }
 501             else
 502                 png_read_row(png_ptr, row_pointers, NULL);
 503
 504             iter->SetRow(row_pointers, row_stride);
 505             y++;
 506         } while(iter->PrevRow());
 507         //  printf("Y=%d ",y);
 508     }
 509
 510     delete iter;
 511     delete[] row_pointers;
 512
 513     /* read the rest of the file, getting any additional chunks
 514        in info_ptr */
 515     png_read_end(png_ptr, info_ptr);
 516
 517     /* clean up after the read, and free any memory allocated */
 518     png_read_destroy(png_ptr, info_ptr, (png_info *)0);
 519
 520     /* free the structures */
 521     delete(png_ptr);
 522     delete(info_ptr);
 523
 524     /* close the file */
 525     fclose(fp);
 526
 527     /* that's it */
 528     return TRUE;
 529 }
 530
 531
 532 /* write a png file */
 533
 534 bool wxPNGReader::SaveFile(wxChar * ImageFileName)
 535 {
 536   if (ImageFileName)
 537    wxStrcpy(filename, ImageFileName);
 538
 539   wxPNGReaderIter iter(this);
 540   FILE *fp;
 541    png_struct *png_ptr;
 542   png_info *info_ptr;
 543
 544    /* open the file */
 545   fp = fopen(wxConvFile.cWX2MB(filename), "wb");
 546   if (!fp)
 547     return FALSE;
 548
 549   /* allocate the necessary structures */
 550   png_ptr = new (png_struct);
 551   if (!png_ptr)
 552   {
 553     fclose(fp);
 554     return FALSE;
 555   }
 556
 557   info_ptr = new (png_info);
 558   if (!info_ptr)
 559   {
 560     fclose(fp);
 561     delete(png_ptr);
 562     return FALSE;
 563   }
 564
 565   /* set error handling */
 566   if (setjmp(png_ptr->jmpbuf))
 567   {
 568     png_write_destroy(png_ptr);
 569     fclose(fp);
 570     delete(png_ptr);
 571     delete(info_ptr);
 572
 573     /* If we get here, we had a problem reading the file */
 574     return FALSE;
 575   }
 576         //png_set_error(ima_png_error, NULL);
 577
 578 //  printf("writig pg %s ", filename);
 579    /* initialize the structures */
 580   png_info_init(info_ptr);
 581   png_write_init(png_ptr);
 582
 583   int row_stride = GetWidth() * ((GetDepth()+7)>>3);
 584   /* set up the output control */
 585    png_init_io(png_ptr, fp);
 586
 587   /* set the file information here */
 588   info_ptr->width = GetWidth();
 589   info_ptr->height = GetHeight();
 590   info_ptr->pixel_depth = GetDepth();
 591   info_ptr->channels = (GetDepth()>8) ? 3: 1;
 592   info_ptr->bit_depth = GetDepth()/info_ptr->channels;
 593   info_ptr->color_type = GetColorType();
 594   info_ptr->compression_type = info_ptr->filter_type = info_ptr->interlace_type=0;
 595   info_ptr->valid = 0;
 596   info_ptr->rowbytes = row_stride;
 597
 598
 599 // 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);
 600   /* set the palette if there is one */
 601   if ((GetColorType() & COLORTYPE_PALETTE) && GetPalette())
 602   {
 603 //    printf("writing paleta[%d %d %x]",GetColorType() ,COLORTYPE_PALETTE, GetPalette());
 604     info_ptr->valid |= PNG_INFO_PLTE;
 605     info_ptr->palette = new png_color[256];
 606     info_ptr->num_palette = 256;
 607     for (int i=0; i<256; i++)
 608      GetPalette()->GetRGB(i, &info_ptr->palette[i].red, &info_ptr->palette[i].green, &info_ptr->palette[i].blue);
 609   }
 610 //    printf("Paleta [%d %d %x]",GetColorType() ,COLORTYPE_PALETTE, GetPalette());
 611
 612
 613    /* optional significant bit chunk */
 614 //   info_ptr->valid |= PNG_INFO_sBIT;
 615 //   info_ptr->sig_bit = true_bit_depth;
 616
 617   /* optional gamma chunk */
 618 //   info_ptr->valid |= PNG_INFO_gAMA;
 619 //   info_ptr->gamma = gamma;
 620
 621   /* other optional chunks */
 622
 623    /* write the file information */
 624    png_write_info(png_ptr, info_ptr);
 625
 626    /* set up the transformations you want.  Note that these are
 627       all optional.  Only call them if you want them */
 628
 629   /* shift the pixels up to a legal bit depth and fill in
 630       as appropriate to correctly scale the image */
 631 //   png_set_shift(png_ptr, &(info_ptr->sig_bit));
 632
 633   /* pack pixels into bytes */
 634 //   png_set_packing(png_ptr);
 635
 636   /* flip bgr pixels to rgb */
 637 //   png_set_bgr(png_ptr);
 638
 639    /* swap bytes of 16 bit files to most significant bit first */
 640 //   png_set_swap(png_ptr);
 641
 642    /* get rid of filler bytes, pack rgb into 3 bytes */
 643 //   png_set_rgbx(png_ptr);
 644
 645 /* If you are only writing one row at a time, this works */
 646
 647   byte *row_pointers = new byte[row_stride];
 648     iter.upset();
 649   do  {
 650 //    (unsigned char *)iter.GetRow();
 651     iter.GetRow(row_pointers, row_stride);
 652     png_write_row(png_ptr, row_pointers);
 653   } while(iter.PrevRow());
 654
 655         delete[] row_pointers;
 656
 657 /* write the rest of the file */
 658    png_write_end(png_ptr, info_ptr);
 659
 660   /* clean up after the write, and free any memory allocated */
 661    png_write_destroy(png_ptr);
 662
 663    /* if you malloced the palette, free it here */
 664    if (info_ptr->palette)
 665     delete[] (info_ptr->palette);
 666
 667   /* free the structures */
 668   delete(png_ptr);
 669   delete(info_ptr);
 670
 671   /* close the file */
 672   fclose(fp);
 673
 674   /* that's it */
 675   return TRUE;
 676 }
 677
 678 static int Power(int x, int y)
 679 {
 680     int z = 1;
 681     int i;
 682     for ( i = 0; i < y; i++)
 683     {
 684         z *= x;
 685     }
 686     return z;
 687 }
 688
 689 static char hexArray[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B',
 690   'C', 'D', 'E', 'F' };
 691
 692 static void DecToHex(int dec, char *buf)
 693 {
 694   int firstDigit = (int)(dec/16.0);
 695   int secondDigit = (int)(dec - (firstDigit*16.0));
 696   buf[0] = hexArray[firstDigit];
 697   buf[1] = hexArray[secondDigit];
 698   buf[2] = 0;
 699 }
 700
 701
 702 bool wxPNGReader::SaveXPM(wxChar *filename, wxChar *name)
 703 {
 704     wxChar nameStr[256];
 705     if ( name )
 706         wxStrcpy(nameStr, name);
 707     else
 708     {
 709         wxStrcpy(nameStr, filename);
 710         wxStripExtension(nameStr);
 711     }
 712
 713     if ( GetDepth() > 4 )
 714     {
 715         // Only a depth of 4 and below allowed
 716         return FALSE;
 717     }
 718
 719     if ( !GetPalette() )
 720         return FALSE;
 721
 722     ofstream str(wxConvFile.cWX2MB(filename));
 723     if ( str.bad() )
 724         return FALSE;
 725
 726     int noColours = Power(2, GetDepth());
 727
 728     // Output header
 729     str << "/* XPM */\n";
 730     str << "static char * " << nameStr << "_xpm[] = {\n";
 731     str << "\"" << GetWidth() << " " << GetHeight() << " " << noColours << " 1\",\n";
 732
 733     // Output colourmap
 734     int base = 97 ; // start from 'a'
 735
 736     unsigned char red, green, blue;
 737     char hexBuf[4];
 738     int i;
 739     for ( i = 0; i < noColours; i ++)
 740     {
 741         str << "\"" << (char)(base + i) << "      c #";
 742         GetPalette()->GetRGB(i, &red, &green, &blue);
 743         DecToHex(red, hexBuf);
 744         str << hexBuf;
 745         DecToHex(green, hexBuf);
 746         str << hexBuf;
 747         DecToHex(blue, hexBuf);
 748         str << hexBuf;
 749         str << "\",\n";
 750     }
 751
 752     // Output the data
 753     int x, y;
 754     for ( y = 0; y < GetHeight(); y++)
 755     {
 756         str << "\"";
 757         for ( x = 0; x < GetWidth(); x++)
 758         {
 759             int index = GetIndex(x, y);
 760             str << (char)(base + index) ;
 761         }
 762         str << "\",\n";
 763     }
 764
 765     str << "};\n";
 766     str.flush();
 767
 768     return TRUE;
 769 }
 770
 771 #include <wx/msw/pnghand.h>
 772
 773 IMPLEMENT_DYNAMIC_CLASS(wxPNGFileHandler, wxBitmapHandler)
 774
 775 bool wxPNGFileHandler::LoadFile(wxBitmap *bitmap, const wxString& name, long flags,
 776     int desiredWidth, int desiredHeight)
 777 {
 778     wxPNGReader reader;
 779     if (reader.ReadFile(WXSTRINGCAST name))
 780     {
 781         return reader.InstantiateBitmap(bitmap);
 782     }
 783     else
 784         return FALSE;
 785 }
 786
 787 bool wxPNGFileHandler::SaveFile(wxBitmap *bitmap, const wxString& name, int type, const wxPalette *pal)
 788 {
 789     return FALSE;
 790 }
 791
 792