src/mac/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
   9 // Licence:     wxWindows licence
  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 #ifndef __DARWIN__
  35 #  include <windows.h>
  36 #endif
  37 #include "wx/msgdlg.h"
  38 #include "wx/palette.h"
  39 #include "wx/bitmap.h"
  40 #include "wx/mac/pnghand.h"
  41 #include "wx/mac/pngread.h"
  42 #include "wx/mac/private.h"
  43
  44 extern "C" {
  45 #include "png.h"
  46 }
  47
  48 extern "C" void png_read_init PNGARG((png_structp png_ptr));
  49 extern "C" void png_write_init PNGARG((png_structp png_ptr));
  50
  51 extern CTabHandle wxMacCreateColorTable( int numColors ) ;
  52 extern void wxMacDestroyColorTable( CTabHandle colors )  ;
  53 extern void wxMacSetColorTableEntry( CTabHandle newColors , int index , int red , int green ,  int blue ) ;
  54 extern GWorldPtr wxMacCreateGWorld( int width , int height , int depth ) ;
  55 extern void wxMacDestroyGWorld( GWorldPtr gw ) ;
  56
  57 void
  58 ima_png_error(png_struct *png_ptr, char *message)
  59 {
  60     wxMessageBox(message, "PNG error");
  61     longjmp(png_ptr->jmpbuf, 1);
  62 }
  63
  64
  65 // static wxGifReaderIter* iter;
  66 wxPalette *wxCopyPalette(const wxPalette *cmap);
  67
  68 wxPNGReader::wxPNGReader(void)
  69 {
  70     filetype = 0;
  71     RawImage = NULL;      //  Image data
  72
  73     Width = 0; Height = 0;       //  Dimensions
  74     Depth = 0;           // (bits x pixel)
  75     ColorType = 0;        // Bit 1 = Palette used
  76     // Bit 2 = Color used
  77     // Bit 3 = Alpha used
  78
  79     EfeWidth = 0;         // Efective Width
  80
  81     lpbi = NULL;
  82     bgindex = -1;
  83     m_palette = 0;
  84     imageOK = FALSE;
  85 }
  86
  87 wxPNGReader::wxPNGReader ( char* ImageFileName )
  88 {
  89     imageOK = FALSE;
  90     filetype = 0;
  91     RawImage = NULL;      //  Image data
  92
  93     Width = 0; Height = 0;       //  Dimensions
  94     Depth = 0;           // (bits x pixel)
  95     ColorType = 0;        // Bit 1 = m_palette used
  96     // Bit 2 = Color used
  97     // Bit 3 = Alpha used
  98
  99     EfeWidth = 0;         // Efective Width
 100
 101     lpbi = NULL;
 102     bgindex = -1;
 103     m_palette = 0;
 104
 105     imageOK = ReadFile (ImageFileName);
 106 }
 107
 108 void
 109 wxPNGReader::Create(int width, int height, int depth, int colortype)
 110 {
 111     Width = width; Height = height; Depth = depth;
 112     ColorType = (colortype>=0) ? colortype: ((Depth>8) ? COLORTYPE_COLOR: 0);
 113     delete m_palette;
 114     m_palette = NULL;
 115     delete[] RawImage;
 116     RawImage = NULL;
 117
 118     if (lpbi) {
 119         wxMacDestroyGWorld( (GWorldPtr) lpbi ) ;
 120     }
 121     lpbi = wxMacCreateGWorld( Width , Height , Depth);
 122     if (lpbi)
 123     {
 124         EfeWidth = (long)(((long)Width*Depth + 31) / 32) * 4;
 125         int bitwidth = width ;
 126         if ( EfeWidth > bitwidth )
 127             bitwidth = EfeWidth ;
 128
 129         RawImage = (byte*) new char[ ( bitwidth * Height * ((Depth+7)>>3) ) ];
 130         imageOK = TRUE;
 131     }
 132 }
 133
 134 wxPNGReader::~wxPNGReader ( )
 135 {
 136     if (RawImage != NULL) {
 137         delete[] RawImage ;
 138         RawImage = NULL;
 139     }
 140     if (lpbi)  {
 141         wxMacDestroyGWorld( (GWorldPtr) lpbi ) ;
 142         lpbi = NULL;
 143     }
 144     if (m_palette != NULL) {
 145         delete m_palette;
 146         m_palette = NULL;
 147     }
 148 }
 149
 150
 151 int wxPNGReader::GetIndex(int x, int y)
 152 {
 153     if (!Inside(x, y) || (Depth>8)) return -1;
 154
 155     ImagePointerType ImagePointer = RawImage + EfeWidth*y + (x*Depth >> 3);
 156     int index = (int)(*ImagePointer);
 157     return index;
 158 }
 159
 160 bool wxPNGReader::GetRGB(int x, int y, byte* r, byte* g, byte* b)
 161 {
 162     if (!Inside(x, y)) return FALSE;
 163
 164     if (m_palette) {
 165         return m_palette->GetRGB(GetIndex(x, y), r, g, b);
 166         /*   PALETTEENTRY entry;
 167         ::GetPaletteEntries((HPALETTE) m_palette->GetHPALETTE(), GetIndex(x, y), 1, &entry);
 168         *r = entry.peRed;
 169         *g = entry.peGreen;
 170         *b = entry.peBlue;  */
 171     } else {
 172         ImagePointerType ImagePointer = RawImage + EfeWidth*y + (x*Depth >> 3);
 173         *b = ImagePointer[0];
 174         *g = ImagePointer[1];
 175         *r = ImagePointer[2];
 176     }
 177     return TRUE;
 178 }
 179
 180
 181 bool wxPNGReader::SetIndex(int x, int y, int index)
 182 {
 183     if (!Inside(x, y) || (Depth>8)) return FALSE;
 184
 185     ImagePointerType ImagePointer = RawImage + EfeWidth*y + (x*Depth >> 3);
 186     *ImagePointer = index;
 187
 188     return TRUE;
 189 }
 190
 191 bool wxPNGReader::SetRGB(int x, int y, byte r, byte g, byte b)
 192 {
 193     if (!Inside(x, y)) return FALSE;
 194
 195     if (ColorType & COLORTYPE_PALETTE)
 196     {
 197         if (!m_palette) return FALSE;
 198         SetIndex(x, y, m_palette->GetPixel(r, g, b));
 199
 200     } else {
 201         ImagePointerType ImagePointer = RawImage + EfeWidth*y + (x*Depth >> 3);
 202         ImagePointer[0] = b;
 203         ImagePointer[1] = g;
 204         ImagePointer[2] = r;
 205     }
 206
 207     return TRUE;
 208 }
 209
 210 bool wxPNGReader::SetPalette(wxPalette* colourmap)
 211 {
 212     delete m_palette ;
 213     if (!colourmap)
 214         return FALSE;
 215     ColorType |= (COLORTYPE_PALETTE | COLORTYPE_COLOR);
 216     m_palette = new wxPalette( *colourmap );
 217     return true ;
 218     //  return (DibSetUsage(lpbi, (HPALETTE) m_palette->GetHPALETTE(), WXIMA_COLORS ) != 0);
 219 }
 220
 221 bool
 222 wxPNGReader::SetPalette(int n, byte *r, byte *g, byte *b)
 223 {
 224     delete m_palette ;
 225     m_palette = new wxPalette();
 226     if (!m_palette)
 227         return FALSE;
 228
 229     if (!g) g = r;
 230     if (!b) b = g;
 231     m_palette->Create(n, r, g, b);
 232     ColorType |= (COLORTYPE_PALETTE | COLORTYPE_COLOR);
 233     return true ;
 234     //    return (DibSetUsage(lpbi, (HPALETTE) m_palette->GetHPALETTE(), WXIMA_COLORS ) != 0);
 235 }
 236
 237 bool
 238 wxPNGReader::SetPalette(int n, rgb_color_struct *rgb_struct)
 239 {
 240     delete m_palette ;
 241     m_palette = new wxPalette();
 242     if (!m_palette)
 243         return FALSE;
 244
 245     byte r[256], g[256], b[256];
 246
 247     for(int i=0; i<n; i++)
 248     {
 249         r[i] = rgb_struct[i].red;
 250         g[i] = rgb_struct[i].green;
 251         b[i] = rgb_struct[i].blue;
 252     }
 253     // Added by JACS copying from Andrew Davison's additions
 254     // to GIF-reading code
 255     // Make transparency colour black...
 256     if (bgindex != -1)
 257         r[bgindex] = g[bgindex] = b[bgindex] = 0;
 258
 259     m_palette->Create(n, r, g, b);
 260     ColorType |= (COLORTYPE_PALETTE | COLORTYPE_COLOR);
 261     return true ;
 262     //    return (DibSetUsage(lpbi, (HPALETTE) m_palette->GetHPALETTE(), WXIMA_COLORS ) != 0);
 263 }
 264
 265 void wxPNGReader::NullData()
 266 {
 267     if (lpbi)  {
 268         wxMacDestroyGWorld( (GWorldPtr) lpbi ) ;
 269         lpbi = NULL;
 270     }
 271     if (m_palette != NULL) {
 272         delete m_palette;
 273         m_palette = NULL;
 274     }
 275 }
 276
 277 wxBitmap* wxPNGReader::GetBitmap(void)
 278 {
 279     wxBitmap *bitmap = new wxBitmap;
 280     if ( InstantiateBitmap(bitmap) )
 281         return bitmap;
 282     else
 283     {
 284         delete bitmap;
 285         return NULL;
 286     }
 287 }
 288
 289 bool wxPNGReader::InstantiateBitmap(wxBitmap *bitmap)
 290 {
 291     if ( lpbi )
 292     {
 293         bitmap->SetHBITMAP((WXHBITMAP) lpbi);
 294         bitmap->SetWidth(GetWidth());
 295         bitmap->SetHeight(GetHeight());
 296         bitmap->SetDepth(GetDepth());
 297         if ( GetDepth() > 1 && m_palette )
 298             bitmap->SetPalette(*m_palette);
 299         bitmap->SetOk(TRUE);
 300
 301
 302         // Make a mask if appropriate
 303         /*
 304         if ( bgindex > -1 )
 305         {
 306         wxMask *mask = CreateMask();
 307         bitmap->SetMask(mask);
 308         }
 309         */
 310         lpbi = NULL ; // bitmap has taken over ownership
 311         return TRUE;
 312     }
 313     else
 314     {
 315         return FALSE;
 316     }
 317     /*
 318     HDC dc = ::CreateCompatibleDC(NULL);
 319
 320       if (dc)
 321       {
 322       // tmpBitmap is a dummy, to satisfy ::CreateCompatibleDC (it
 323       // is a memory dc that must have a bitmap selected into it)
 324       HDC dc2 = GetDC(NULL);
 325       HBITMAP tmpBitmap = ::CreateCompatibleBitmap(dc2, GetWidth(), GetHeight());
 326       ReleaseDC(NULL, dc2);
 327       HBITMAP oldBitmap = (HBITMAP) ::SelectObject(dc, tmpBitmap);
 328
 329         if ( m_palette )
 330         {
 331         HPALETTE oldPal = ::SelectPalette(dc, (HPALETTE) m_palette->GetHPALETTE(), FALSE);
 332         ::RealizePalette(dc);
 333         }
 334
 335           HBITMAP hBitmap = ::CreateDIBitmap(dc, lpbi,
 336           CBM_INIT, RawImage, (LPBITMAPINFO) lpbi, DIB_PAL_COLORS);
 337
 338             ::SelectPalette(dc, NULL, TRUE);
 339             ::SelectObject(dc, oldBitmap);
 340             ::DeleteObject(tmpBitmap);
 341             ::DeleteDC(dc);
 342
 343               if ( hBitmap )
 344               {
 345               bitmap->SetHBITMAP((WXHBITMAP) hBitmap);
 346               bitmap->SetWidth(GetWidth());
 347               bitmap->SetHeight(GetHeight());
 348               bitmap->SetDepth(GetDepth());
 349               if ( GetDepth() > 1 && m_palette )
 350               bitmap->SetPalette(*m_palette);
 351               bitmap->SetOk(TRUE);
 352
 353
 354                   // Make a mask if appropriate
 355                   if ( bgindex > -1 )
 356                   {
 357                   wxMask *mask = CreateMask();
 358                   bitmap->SetMask(mask);
 359                   }
 360                   return TRUE;
 361                   }
 362                   else
 363                   {
 364                   return FALSE;
 365                   }
 366                   }
 367                   else
 368                   {
 369                   return FALSE;
 370                   }
 371     */
 372     return false ;
 373 }
 374
 375 wxPalette *wxCopyPalette(const wxPalette *cmap)
 376 {
 377     wxPalette *newCmap = new wxPalette( *cmap ) ;
 378     return newCmap;
 379 }
 380
 381 wxMask *wxPNGReader::CreateMask(void)
 382 {
 383 /*
 384 HBITMAP hBitmap = ::CreateBitmap(GetWidth(), GetHeight(), 1, 1, NULL);
 385
 386   HDC dc = ::CreateCompatibleDC(NULL);
 387   HBITMAP oldBitmap = (HBITMAP) ::SelectObject(dc, hBitmap);
 388
 389     int bgIndex = GetBGIndex();
 390
 391       int x,y;
 392
 393         for (x=0; x<GetWidth(); x++)
 394         {
 395         for (y=0; y<GetHeight(); y++)
 396         {
 397         int index = GetIndex(x, y);
 398         if ( index == bgIndex )
 399         ::SetPixel(dc, x, GetHeight() - y - 1, RGB(0, 0, 0));
 400         else
 401         ::SetPixel(dc, x, GetHeight() - y - 1, RGB(255, 255, 255));
 402
 403           }
 404           }
 405           ::SelectObject(dc, oldBitmap);
 406           wxMask *mask = new wxMask;
 407           mask->SetMaskBitmap((WXHBITMAP) hBitmap);
 408           return mask;
 409     */
 410     return NULL ;
 411 }
 412
 413 bool wxPNGReader::ReadFile(char * ImageFileName)
 414 {
 415     int number_passes;
 416
 417     if (ImageFileName)
 418         strcpy(filename, ImageFileName);
 419
 420     FILE *fp;
 421     png_struct *png_ptr;
 422     png_info *info_ptr;
 423     wxPNGReaderIter iter(this);
 424
 425     /* open the file */
 426     fp = fopen( ImageFileName , "rb" );
 427
 428     if (!fp)
 429         return FALSE;
 430
 431     /* allocate the necessary structures */
 432     png_ptr = new (png_struct);
 433     if (!png_ptr)
 434     {
 435         fclose(fp);
 436         return FALSE;
 437     }
 438
 439     info_ptr = new (png_info);
 440     if (!info_ptr)
 441     {
 442         fclose(fp);
 443         delete png_ptr;
 444         return FALSE;
 445     }
 446     /* set error handling */
 447     if (setjmp(png_ptr->jmpbuf))
 448     {
 449         png_read_destroy(png_ptr, info_ptr, (png_info *)0);
 450         fclose(fp);
 451         delete png_ptr;
 452         delete info_ptr;
 453
 454         /* If we get here, we had a problem reading the file */
 455         return FALSE;
 456     }
 457     //png_set_error(ima_png_error, NULL);
 458
 459     /* initialize the structures, info first for error handling */
 460     png_info_init(info_ptr);
 461     png_read_init(png_ptr);
 462
 463     /* set up the input control */
 464     png_init_io(png_ptr, fp);
 465
 466     /* read the file information */
 467     png_read_info(png_ptr, info_ptr);
 468
 469     /* allocate the memory to hold the image using the fields
 470     of png_info. */
 471     png_color_16 my_background={ 0, 31, 127, 255, 0 };
 472
 473     if (info_ptr->valid & PNG_INFO_bKGD)
 474     {
 475         png_set_background(png_ptr, &(info_ptr->background),
 476             PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
 477         if ( info_ptr->num_palette > 0 )
 478             bgindex = info_ptr->background.index;
 479     }
 480     else   {
 481         png_set_background(png_ptr, &my_background,
 482             PNG_BACKGROUND_GAMMA_SCREEN, 0, 1.0);
 483
 484         // Added by JACS: guesswork!
 485         if ( info_ptr->num_trans != 0 )
 486             bgindex = info_ptr->num_trans - 1 ;
 487     }
 488
 489     /* tell libpng to strip 16 bit depth files down to 8 bits */
 490     if (info_ptr->bit_depth == 16)
 491         png_set_strip_16(png_ptr);
 492
 493     int pixel_depth=(info_ptr->pixel_depth<24) ? info_ptr->pixel_depth: 24;
 494     Create(info_ptr->width, info_ptr->height, pixel_depth,
 495         info_ptr->color_type);
 496
 497     if (info_ptr->num_palette>0)
 498     {
 499         SetPalette((int)info_ptr->num_palette, (rgb_color_struct*)info_ptr->palette);
 500     }
 501
 502     int row_stride = info_ptr->width * ((pixel_depth+7)>>3);
 503     //  printf("P = %d D = %d RS= %d ", info_ptr->num_palette, info_ptr->pixel_depth,row_stride);
 504     //  printf("CT = %d TRS = %d BD= %d ", info_ptr->color_type, info_ptr->valid & PNG_INFO_tRNS,info_ptr->bit_depth);
 505
 506     byte *row_pointers = new byte[row_stride];
 507
 508     /* turn on interlace handling */
 509     if (info_ptr->interlace_type)
 510         number_passes = png_set_interlace_handling(png_ptr);
 511     else
 512         number_passes = 1;
 513     //  printf("NP = %d ", number_passes);
 514
 515     for (int pass=0; pass< number_passes; pass++)
 516     {
 517         iter.upset();
 518         int y=0;
 519         CGrafPtr     origPort ;
 520         GDHandle    origDevice ;
 521
 522         GetGWorld( &origPort , &origDevice ) ;
 523         // ignore shapedc
 524         SetGWorld( (GWorldPtr) lpbi , NULL ) ;
 525         do
 526         {
 527             //    (unsigned char *)iter.GetRow();
 528             if (info_ptr->interlace_type)
 529             {
 530                 if (pass>0)
 531                     iter.GetRow(row_pointers, row_stride);
 532                 png_read_row(png_ptr, row_pointers, NULL);
 533             }
 534             else
 535                 png_read_row(png_ptr, row_pointers, NULL);
 536
 537             if ( info_ptr->palette )
 538             {
 539                 if ( pixel_depth == 8 )
 540                 {
 541                     for ( size_t i = 0 ; i < info_ptr->width ; ++i )
 542                     {
 543                         png_color_struct* color ;
 544                         RGBColor col ;
 545
 546                         int index = row_pointers[i] ;
 547                         color = &info_ptr->palette[index] ;
 548                         col.red = (((int)color->red) << 8) | ((int)color->red) ;
 549                         col.green = (((int)color->green) << 8) | ((int)color->green) ;
 550                         col.blue = (((int)color->blue) << 8) | ((int)color->blue) ;
 551                         SetCPixel( i, y, &col);
 552                     }
 553                     /*
 554                     png_color_struct* color ;
 555                     RGBColor col ;
 556                     unsigned char* p = &row_pointers[0] ;
 557                     PenNormal() ;
 558                     MoveTo( 0 , y ) ;
 559                     int index = *p ;
 560                     color = &info_ptr->palette[index] ;
 561                     col.red = (color->red << 8) | color->red ;
 562                     col.green = (color->green << 8) | color->green ;
 563                     col.blue = (color->blue << 8) | color->blue ;
 564                     RGBForeColor( &col ) ;
 565                     col.red = col.green = col.blue = 0xFFFF ;
 566                     RGBBackColor( &col ) ;
 567                     for ( int i = 0 ; i < info_ptr->width ; ++i , ++p)
 568                     {
 569                     if ( *p != index )
 570                     {
 571                     LineTo( i , y ) ;
 572                     index = *p ;
 573                     color = &info_ptr->palette[index] ;
 574                     col.red = (((int)color->red) << 8) | ((int)color->red) ;
 575                     col.green = (((int)color->green) << 8) | ((int)color->green) ;
 576                     col.blue = (((int)color->blue) << 8) | ((int)color->blue) ;
 577                     RGBForeColor( &col ) ;
 578                     }
 579                     }
 580                     LineTo( info_ptr->width  , y ) ;
 581                     */
 582                 }
 583                 else
 584                 {
 585                     for ( size_t i = 0 ; i < info_ptr->width ; ++i )
 586                     {
 587                         png_color_struct* color ;
 588                         RGBColor col ;
 589
 590                         int byte = ( i * pixel_depth ) / 8 ;
 591                         int offset = ( 8 - pixel_depth ) - ( i * pixel_depth ) % 8 ;
 592
 593                         int index = ( row_pointers[byte] >> offset ) & ( 0xFF >> ( 8 - pixel_depth ) );
 594                         color = &info_ptr->palette[index] ;
 595                         col.red = (((int)color->red) << 8) | ((int)color->red) ;
 596                         col.green = (((int)color->green) << 8) | ((int)color->green) ;
 597                         col.blue = (((int)color->blue) << 8) | ((int)color->blue) ;
 598                         SetCPixel( i, y, &col);
 599                     }
 600                 }
 601             }
 602             else
 603             {
 604                 for ( size_t i = 0 ; i < info_ptr->width ; ++i )
 605                 {
 606                     png_color_struct* color ;
 607                     RGBColor col ;
 608                     color =(png_color_struct*) (&row_pointers[i*3]) ;
 609                     col.red = (((int)color->red) << 8) | ((int)color->red) ;
 610                     col.green = (((int)color->green) << 8) | ((int)color->green) ;
 611                     col.blue = (((int)color->blue) << 8) | ((int)color->blue) ;
 612                     SetCPixel( i, y, &col);
 613                 }
 614             }
 615             if (number_passes)
 616                 iter.SetRow(row_pointers, row_stride);
 617             y++;
 618         }
 619         while(iter.PrevRow());
 620         SetGWorld( origPort , origDevice ) ;
 621
 622         //  printf("Y=%d ",y);
 623   }
 624   delete[] row_pointers;
 625
 626   /* read the rest of the file, getting any additional chunks
 627   in info_ptr */
 628   png_read_end(png_ptr, info_ptr);
 629
 630   /* clean up after the read, and free any memory allocated */
 631   png_read_destroy(png_ptr, info_ptr, (png_info *)0);
 632
 633   /* free the structures */
 634   delete png_ptr;
 635   delete info_ptr;
 636
 637   /* close the file */
 638   fclose(fp);
 639
 640   /* that's it */
 641   return TRUE;
 642 }
 643
 644
 645 /* write a png file */
 646
 647 bool wxPNGReader::SaveFile(char * ImageFileName)
 648 {
 649     if (ImageFileName)
 650         strcpy(filename, ImageFileName);
 651
 652     wxPNGReaderIter iter(this);
 653     FILE *fp;
 654     png_struct *png_ptr;
 655     png_info *info_ptr;
 656
 657     /* open the file */
 658     fp = fopen(filename, "wb");
 659     if (!fp)
 660         return FALSE;
 661
 662     /* allocate the necessary structures */
 663     png_ptr = new (png_struct);
 664     if (!png_ptr)
 665     {
 666         fclose(fp);
 667         return FALSE;
 668     }
 669
 670     info_ptr = new (png_info);
 671     if (!info_ptr)
 672     {
 673         fclose(fp);
 674         delete png_ptr;
 675         return FALSE;
 676     }
 677
 678     /* set error handling */
 679     if (setjmp(png_ptr->jmpbuf))
 680     {
 681         png_write_destroy(png_ptr);
 682         fclose(fp);
 683         delete png_ptr;
 684         delete info_ptr;
 685
 686         /* If we get here, we had a problem reading the file */
 687         return FALSE;
 688     }
 689     //png_set_error(ima_png_error, NULL);
 690
 691     //  printf("writig pg %s ", filename);
 692     /* initialize the structures */
 693     png_info_init(info_ptr);
 694     png_write_init(png_ptr);
 695
 696     int row_stride = GetWidth() * ((GetDepth()+7)>>3);
 697     /* set up the output control */
 698     png_init_io(png_ptr, fp);
 699
 700     /* set the file information here */
 701     info_ptr->width = GetWidth();
 702     info_ptr->height = GetHeight();
 703     info_ptr->pixel_depth = GetDepth();
 704     info_ptr->channels = (GetDepth()>8) ? 3: 1;
 705     info_ptr->bit_depth = GetDepth()/info_ptr->channels;
 706     info_ptr->color_type = GetColorType();
 707     info_ptr->compression_type = info_ptr->filter_type = info_ptr->interlace_type=0;
 708     info_ptr->valid = 0;
 709     info_ptr->rowbytes = row_stride;
 710
 711
 712     // 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);
 713     /* set the palette if there is one */
 714     if ((GetColorType() & COLORTYPE_PALETTE) && GetPalette())
 715     {
 716         //    printf("writing paleta[%d %d %x]",GetColorType() ,COLORTYPE_PALETTE, GetPalette());
 717         info_ptr->valid |= PNG_INFO_PLTE;
 718         info_ptr->palette = new png_color[256];
 719         info_ptr->num_palette = 256;
 720         for (int i=0; i<256; i++)
 721             GetPalette()->GetRGB(i, &info_ptr->palette[i].red, &info_ptr->palette[i].green, &info_ptr->palette[i].blue);
 722     }
 723     //    printf("Paleta [%d %d %x]",GetColorType() ,COLORTYPE_PALETTE, GetPalette());
 724
 725
 726     /* optional significant bit chunk */
 727     //   info_ptr->valid |= PNG_INFO_sBIT;
 728     //   info_ptr->sig_bit = true_bit_depth;
 729
 730     /* optional gamma chunk */
 731     //   info_ptr->valid |= PNG_INFO_gAMA;
 732     //   info_ptr->gamma = gamma;
 733
 734     /* other optional chunks */
 735
 736     /* write the file information */
 737     png_write_info(png_ptr, info_ptr);
 738
 739     /* set up the transformations you want.  Note that these are
 740     all optional.  Only call them if you want them */
 741
 742     /* shift the pixels up to a legal bit depth and fill in
 743     as appropriate to correctly scale the image */
 744     //   png_set_shift(png_ptr, &(info_ptr->sig_bit));
 745
 746     /* pack pixels into bytes */
 747     //   png_set_packing(png_ptr);
 748
 749     /* flip bgr pixels to rgb */
 750     //   png_set_bgr(png_ptr);
 751
 752     /* swap bytes of 16 bit files to most significant bit first */
 753     //   png_set_swap(png_ptr);
 754
 755     /* get rid of filler bytes, pack rgb into 3 bytes */
 756     //   png_set_rgbx(png_ptr);
 757
 758     /* If you are only writing one row at a time, this works */
 759
 760     byte *row_pointers = new byte[row_stride];
 761     iter.upset();
 762     do  {
 763         //    (unsigned char *)iter.GetRow();
 764         iter.GetRow(row_pointers, row_stride);
 765         png_write_row(png_ptr, row_pointers);
 766     } while(iter.PrevRow());
 767
 768     delete[] row_pointers;
 769
 770     /* write the rest of the file */
 771     png_write_end(png_ptr, info_ptr);
 772
 773     /* clean up after the write, and free any memory allocated */
 774     png_write_destroy(png_ptr);
 775
 776     /* if you malloced the palette, free it here */
 777     if (info_ptr->palette)
 778         delete[] (info_ptr->palette);
 779
 780     /* free the structures */
 781     delete png_ptr;
 782     delete info_ptr;
 783
 784     /* close the file */
 785     fclose(fp);
 786
 787     /* that's it */
 788     return TRUE;
 789 }
 790
 791 static int Power(int x, int y)
 792 {
 793     int z = 1;
 794     int i;
 795     for ( i = 0; i < y; i++)
 796     {
 797         z *= x;
 798     }
 799     return z;
 800 }
 801
 802 static char hexArray[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B',
 803 'C', 'D', 'E', 'F' };
 804
 805 static void DecToHex(int dec, char *buf)
 806 {
 807     int firstDigit = (int)(dec/16.0);
 808     int secondDigit = (int)(dec - (firstDigit*16.0));
 809     buf[0] = hexArray[firstDigit];
 810     buf[1] = hexArray[secondDigit];
 811     buf[2] = 0;
 812 }
 813
 814
 815 bool wxPNGReader::SaveXPM(char *filename, char *name)
 816 {
 817     char nameStr[256];
 818     if ( name )
 819         strcpy(nameStr, name);
 820     else
 821     {
 822         strcpy(nameStr, filename);
 823         wxStripExtension(nameStr);
 824     }
 825
 826     if ( GetDepth() > 4 )
 827     {
 828         // Only a depth of 4 and below allowed
 829         return FALSE;
 830     }
 831
 832     if ( !GetPalette() )
 833         return FALSE;
 834
 835     wxSTD ofstream str(filename);
 836     if ( str.bad() )
 837         return FALSE;
 838
 839     int noColours = Power(2, GetDepth());
 840
 841     // Output header
 842     str << "/* XPM */\n";
 843     str << "static char * " << nameStr << "_xpm[] = {\n";
 844     str << "\"" << GetWidth() << " " << GetHeight() << " " << noColours << " 1\",\n";
 845
 846     // Output colourmap
 847     int base = 97 ; // start from 'a'
 848
 849     unsigned char red, green, blue;
 850     char hexBuf[4];
 851     int i;
 852     for ( i = 0; i < noColours; i ++)
 853     {
 854         str << "\"" << (char)(base + i) << "      c #";
 855         GetPalette()->GetRGB(i, &red, &green, &blue);
 856         DecToHex(red, hexBuf);
 857         str << hexBuf;
 858         DecToHex(green, hexBuf);
 859         str << hexBuf;
 860         DecToHex(blue, hexBuf);
 861         str << hexBuf;
 862         str << "\",\n";
 863     }
 864
 865     // Output the data
 866     int x, y;
 867     for ( y = 0; y < GetHeight(); y++)
 868     {
 869         str << "\"";
 870         for ( x = 0; x < GetWidth(); x++)
 871         {
 872             int index = GetIndex(x, y);
 873             str << (char)(base + index) ;
 874         }
 875         str << "\",\n";
 876     }
 877
 878     str << "};\n";
 879     str.flush();
 880
 881     return TRUE;
 882 }
 883
 884
 885 IMPLEMENT_DYNAMIC_CLASS(wxPNGFileHandler, wxBitmapHandler)
 886
 887 bool wxPNGFileHandler::LoadFile(wxBitmap *bitmap, const wxString& name, long flags,
 888                                 int desiredWidth, int desiredHeight)
 889 {
 890     wxPNGReader reader;
 891     if (reader.ReadFile((char*) (const char*) name))
 892     {
 893         return reader.InstantiateBitmap(bitmap);
 894     }
 895     else
 896         return FALSE;
 897 }
 898
 899 bool wxPNGFileHandler::SaveFile(const wxBitmap *bitmap, const wxString& name, int type, const wxPalette *pal)
 900 {
 901     return FALSE;
 902 }
 903
 904