src/common/imagpng.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        imagepng.cpp
   3 // Purpose:     wxImage PNG handler
   4 // Author:      Robert Roebling
   5 // RCS-ID:      $Id$
   6 // Copyright:   (c) Robert Roebling
   7 // Licence:     wxWindows licence
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10 #ifdef __GNUG__
  11 #pragma implementation "imagpng.h"
  12 #endif
  13
  14 // For compilers that support precompilation, includes "wx.h".
  15 #include "wx/wxprec.h"
  16
  17 #ifdef __BORLANDC__
  18   #pragma hdrstop
  19 #endif
  20
  21 #ifndef WX_PRECOMP
  22   #include "wx/defs.h"
  23 #endif
  24
  25 #if wxUSE_LIBPNG
  26
  27 #include "wx/imagpng.h"
  28 #include "wx/bitmap.h"
  29 #include "wx/debug.h"
  30 #include "wx/log.h"
  31 #include "wx/app.h"
  32 #include "png.h"
  33 #include "wx/filefn.h"
  34 #include "wx/wfstream.h"
  35 #include "wx/intl.h"
  36 #include "wx/module.h"
  37
  38 // For memcpy
  39 #include <string.h>
  40
  41 #ifdef __SALFORDC__
  42 #ifdef FAR
  43 #undef FAR
  44 #endif
  45 #endif
  46
  47 #ifdef __WXMSW__
  48 #include <windows.h>
  49 #endif
  50
  51 //-----------------------------------------------------------------------------
  52 // wxPNGHandler
  53 //-----------------------------------------------------------------------------
  54
  55 IMPLEMENT_DYNAMIC_CLASS(wxPNGHandler,wxImageHandler)
  56
  57 #if wxUSE_LIBPNG
  58
  59 #if defined(__VISAGECPP__)
  60 #define LINKAGEMODE _Optlink
  61 #else
  62 #define LINKAGEMODE
  63 #endif
  64
  65 static void LINKAGEMODE _PNG_stream_reader( png_structp png_ptr, png_bytep data, png_size_t length )
  66 {
  67     ((wxInputStream*) png_get_io_ptr( png_ptr )) -> Read(data, length);
  68 }
  69
  70 static void LINKAGEMODE _PNG_stream_writer( png_structp png_ptr, png_bytep data, png_size_t length )
  71 {
  72     ((wxOutputStream*) png_get_io_ptr( png_ptr )) -> Write(data, length);
  73 }
  74
  75 // from pngerror.c
  76 // so that the libpng doesn't send anything on stderr
  77 void
  78 LINKAGEMODE png_silent_error(png_structp png_ptr, png_const_charp WXUNUSED(message))
  79 {
  80 #ifdef USE_FAR_KEYWORD
  81    {
  82       jmp_buf jmpbuf;
  83       png_memcpy(jmpbuf,png_ptr->jmpbuf,sizeof(jmp_buf));
  84       longjmp(jmpbuf, 1);
  85    }
  86 #else
  87    longjmp(png_ptr->jmpbuf, 1);
  88 #endif
  89 }
  90
  91 void
  92 LINKAGEMODE png_silent_warning(png_structp WXUNUSED(png_ptr), png_const_charp WXUNUSED(message))
  93 {
  94 }
  95
  96 // temporarily disable the warning C4611 (interaction between '_setjmp' and
  97 // C++ object destruction is non-portable) - I don't see any dtors here
  98 #ifdef __VISUALC__
  99     #pragma warning(disable:4611)
 100 #endif /* VC++ */
 101
 102 bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream, bool verbose, int WXUNUSED(index) )
 103 {
 104     // VZ: as this function uses setjmp() the only fool proof error handling
 105     //     method is to use goto (setjmp is not really C++ dtors friendly...)
 106
 107     unsigned char **lines;
 108     unsigned int i;
 109     png_infop info_ptr = (png_infop) NULL;
 110
 111     image->Destroy();
 112
 113     png_structp png_ptr = png_create_read_struct( PNG_LIBPNG_VER_STRING,
 114         (voidp) NULL,
 115         (png_error_ptr) NULL,
 116         (png_error_ptr) NULL );
 117     if (!png_ptr)
 118         goto error_nolines;
 119
 120     // the file example.c explain how to guess if the stream is a png image
 121     if (!verbose) png_set_error_fn(png_ptr, (png_voidp)NULL, png_silent_error, png_silent_warning);
 122
 123     info_ptr = png_create_info_struct( png_ptr );
 124     if (!info_ptr)
 125         goto error_nolines;
 126
 127     if (setjmp(png_ptr->jmpbuf))
 128         goto error_nolines;
 129
 130     if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
 131         goto error_nolines;
 132
 133     png_set_read_fn( png_ptr, &stream, _PNG_stream_reader);
 134
 135     png_uint_32 width,height;
 136     int bit_depth,color_type,interlace_type;
 137
 138     png_read_info( png_ptr, info_ptr );
 139     png_get_IHDR( png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, (int*) NULL, (int*) NULL );
 140
 141     if (color_type == PNG_COLOR_TYPE_PALETTE)
 142         png_set_expand( png_ptr );
 143
 144     png_set_strip_16( png_ptr );
 145     png_set_packing( png_ptr );
 146     if (png_get_valid( png_ptr, info_ptr, PNG_INFO_tRNS))
 147         png_set_expand( png_ptr );
 148     png_set_filler( png_ptr, 0xff, PNG_FILLER_AFTER );
 149
 150     image->Create( (int)width, (int)height );
 151
 152     if (!image->Ok())
 153         goto error_nolines;
 154
 155     lines = (unsigned char **)malloc( (size_t)(height * sizeof(unsigned char *)) );
 156     if (lines == NULL)
 157         goto error_nolines;
 158
 159     for (i = 0; i < height; i++)
 160     {
 161         if ((lines[i] = (unsigned char *)malloc( (size_t)(width * (sizeof(unsigned char) * 4)))) == NULL)
 162         {
 163             for ( unsigned int n = 0; n < i; n++ )
 164                 free( lines[n] );
 165             goto error;
 166         }
 167     }
 168
 169     // loaded successfully!
 170     {
 171         int transp = 0;
 172         png_read_image( png_ptr, lines );
 173         png_read_end( png_ptr, info_ptr );
 174         png_destroy_read_struct( &png_ptr, &info_ptr, (png_infopp) NULL );
 175         unsigned char *ptr = image->GetData();
 176         if ((color_type == PNG_COLOR_TYPE_GRAY) ||
 177             (color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
 178         {
 179             for (unsigned int y = 0; y < height; y++)
 180             {
 181                 unsigned char *ptr2 = lines[y];
 182                 for (unsigned int x = 0; x < width; x++)
 183                 {
 184                     unsigned char r = *ptr2++;
 185                     unsigned char a = *ptr2++;
 186                     if (a < 128)
 187                     {
 188                         *ptr++ = 255;
 189                         *ptr++ = 0;
 190                         *ptr++ = 255;
 191                         transp = 1;
 192                     }
 193                     else
 194                     {
 195                         *ptr++ = r;
 196                         *ptr++ = r;
 197                         *ptr++ = r;
 198                     }
 199                 }
 200             }
 201         }
 202         else
 203         {
 204             for (unsigned int y = 0; y < height; y++)
 205             {
 206                 unsigned char *ptr2 = lines[y];
 207                 for (unsigned int x = 0; x < width; x++)
 208                 {
 209                     unsigned char r = *ptr2++;
 210                     unsigned char g = *ptr2++;
 211                     unsigned char b = *ptr2++;
 212                     unsigned char a = *ptr2++;
 213                     if (a < 128)
 214                     {
 215                         *ptr++ = 255;
 216                         *ptr++ = 0;
 217                         *ptr++ = 255;
 218                         transp = 1;
 219                     }
 220                     else
 221                     {
 222                         if ((r == 255) && (g == 0) && (b == 255)) r = 254;
 223                         *ptr++ = r;
 224                         *ptr++ = g;
 225                         *ptr++ = b;
 226                     }
 227                 }
 228             }
 229         }
 230
 231         for ( unsigned int j = 0; j < height; j++ )
 232             free( lines[j] );
 233         free( lines );
 234
 235         if (transp)
 236         {
 237             image->SetMaskColour( 255, 0, 255 );
 238         }
 239         else
 240         {
 241             image->SetMask( FALSE );
 242         }
 243     }
 244
 245     return TRUE;
 246
 247  error_nolines:
 248     lines = NULL; // called from before it was set
 249  error:
 250     if (verbose)
 251        wxLogError(_("Couldn't load a PNG image - file is corrupted or not enough memory."));
 252
 253     if ( image->Ok() )
 254     {
 255         image->Destroy();
 256     }
 257
 258     if ( lines )
 259     {
 260         free( lines );
 261     }
 262
 263     if ( png_ptr )
 264     {
 265         if ( info_ptr )
 266         {
 267             png_destroy_read_struct( &png_ptr, &info_ptr, (png_infopp) NULL );
 268             free(info_ptr);
 269         }
 270         else
 271             png_destroy_read_struct( &png_ptr, (png_infopp) NULL, (png_infopp) NULL );
 272     }
 273     return FALSE;
 274 }
 275
 276 bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool verbose )
 277 {
 278     {
 279         png_structp png_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 280         if (!png_ptr)
 281         {
 282             return FALSE;
 283         }
 284
 285         if (!verbose) png_set_error_fn(png_ptr, (png_voidp)NULL, png_silent_error, png_silent_warning);
 286
 287         png_infop info_ptr = png_create_info_struct(png_ptr);
 288         if (info_ptr == NULL)
 289         {
 290             png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
 291             return FALSE;
 292         }
 293
 294         if (setjmp(png_ptr->jmpbuf))
 295         {
 296             png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
 297             return FALSE;
 298         }
 299
 300         png_set_write_fn( png_ptr, &stream, _PNG_stream_writer, NULL);
 301
 302         png_set_IHDR( png_ptr, info_ptr, image->GetWidth(), image->GetHeight(), 8,
 303             PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
 304             PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 305
 306         png_color_8 sig_bit;
 307         sig_bit.red = 8;
 308         sig_bit.green = 8;
 309         sig_bit.blue = 8;
 310         sig_bit.alpha = 8;
 311         png_set_sBIT( png_ptr, info_ptr, &sig_bit );
 312         png_write_info( png_ptr, info_ptr );
 313         png_set_shift( png_ptr, &sig_bit );
 314         png_set_packing( png_ptr );
 315
 316         unsigned char *data = (unsigned char *)malloc( image->GetWidth()*4 );
 317         if (!data)
 318         {
 319             png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
 320             return FALSE;
 321         }
 322
 323         for (int y = 0; y < image->GetHeight(); y++)
 324         {
 325             unsigned char *ptr = image->GetData() + (y * image->GetWidth() * 3);
 326             for (int x = 0; x < image->GetWidth(); x++)
 327             {
 328                 data[(x << 2) + 0] = *ptr++;
 329                 data[(x << 2) + 1] = *ptr++;
 330                 data[(x << 2) + 2] = *ptr++;
 331                 if (( !image->HasMask() ) || \
 332                     (data[(x << 2) + 0] != image->GetMaskRed()) || \
 333                     (data[(x << 2) + 1] != image->GetMaskGreen()) || \
 334                     (data[(x << 2) + 2] != image->GetMaskBlue()))
 335                 {
 336                     data[(x << 2) + 3] = 255;
 337                 }
 338                 else
 339                 {
 340                     data[(x << 2) + 3] = 0;
 341                 }
 342             }
 343             png_bytep row_ptr = data;
 344             png_write_rows( png_ptr, &row_ptr, 1 );
 345         }
 346
 347         free(data);
 348         png_write_end( png_ptr, info_ptr );
 349         png_destroy_write_struct( &png_ptr, (png_infopp)&info_ptr );
 350     }
 351     return TRUE;
 352 }
 353
 354 #ifdef __VISUALC__
 355     #pragma warning(default:4611)
 356 #endif /* VC++ */
 357
 358 bool wxPNGHandler::DoCanRead( wxInputStream& stream )
 359 {
 360     unsigned char hdr[4];
 361
 362     stream.Read(&hdr, 4);
 363     stream.SeekI(-4, wxFromCurrent);
 364     return (hdr[0] == 0x89 && hdr[1] == 'P' && hdr[2] == 'N' && hdr[3] == 'G');
 365 }
 366
 367 #endif  // wxUSE_STREAMS
 368
 369 #endif  // wxUSE_LIBPNG