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 /*
  11    We don't put pragma implement in this file because it is already present in
  12    src/common/image.cpp
  13
  14 #ifdef __GNUG__
  15 #pragma implementation "image.h"
  16 #endif
  17 */
  18
  19 // For compilers that support precompilation, includes "wx.h".
  20 #include "wx/wxprec.h"
  21
  22 #ifdef __BORLANDC__
  23 #pragma hdrstop
  24 #endif
  25
  26 #include "wx/image.h"
  27 #include "wx/bitmap.h"
  28 #include "wx/debug.h"
  29 #include "wx/log.h"
  30 #include "wx/app.h"
  31 #if wxUSE_LIBPNG
  32 #include "../png/png.h"
  33 #endif
  34 #include "wx/filefn.h"
  35 #include "wx/wfstream.h"
  36 #include "wx/intl.h"
  37 #include "wx/module.h"
  38
  39 // For memcpy
  40 #include <string.h>
  41
  42 #ifdef __SALFORDC__
  43 #ifdef FAR
  44 #undef FAR
  45 #endif
  46 #endif
  47
  48 #ifdef __WXMSW__
  49 #include <windows.h>
  50 #endif
  51
  52 //-----------------------------------------------------------------------------
  53 // wxPNGHandler
  54 //-----------------------------------------------------------------------------
  55
  56 #if wxUSE_LIBPNG
  57
  58 #if !USE_SHARED_LIBRARIES
  59 IMPLEMENT_DYNAMIC_CLASS(wxPNGHandler,wxImageHandler)
  60 #endif
  61
  62
  63 #if wxUSE_STREAMS
  64 static void _PNG_stream_reader( png_structp png_ptr, png_bytep data, png_size_t length )
  65 {
  66     ((wxInputStream*) png_get_io_ptr( png_ptr )) -> Read(data, length);
  67 }
  68
  69 static void _PNG_stream_writer( png_structp png_ptr, png_bytep data, png_size_t length )
  70 {
  71     ((wxOutputStream*) png_get_io_ptr( png_ptr )) -> Write(data, length);
  72 }
  73
  74 bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream )
  75 {
  76     // VZ: as this function uses setjmp() the only fool proof error handling
  77     //     method is to use goto (setjmp is not really C++ dtors friendly...)
  78
  79     unsigned char **lines = (unsigned char **) NULL;
  80     unsigned int i;
  81     png_infop info_ptr = (png_infop) NULL;
  82
  83     image->Destroy();
  84
  85     png_structp png_ptr = png_create_read_struct( PNG_LIBPNG_VER_STRING,
  86         (voidp) NULL,
  87         (png_error_ptr) NULL,
  88         (png_error_ptr) NULL );
  89     if (!png_ptr)
  90         goto error;
  91
  92     info_ptr = png_create_info_struct( png_ptr );
  93     if (!info_ptr)
  94         goto error;
  95
  96     if (setjmp(png_ptr->jmpbuf))
  97         goto error;
  98
  99     if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
 100         goto error;
 101
 102     png_set_read_fn( png_ptr, &stream, _PNG_stream_reader);
 103
 104     png_uint_32 width,height;
 105     int bit_depth,color_type,interlace_type;
 106
 107     png_read_info( png_ptr, info_ptr );
 108     png_get_IHDR( png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, (int*) NULL, (int*) NULL );
 109
 110     if (color_type == PNG_COLOR_TYPE_PALETTE)
 111         png_set_expand( png_ptr );
 112
 113     png_set_strip_16( png_ptr );
 114     png_set_packing( png_ptr );
 115     if (png_get_valid( png_ptr, info_ptr, PNG_INFO_tRNS))
 116         png_set_expand( png_ptr );
 117     png_set_filler( png_ptr, 0xff, PNG_FILLER_AFTER );
 118
 119     image->Create( width, height );
 120
 121     if (!image->Ok())
 122         goto error;
 123
 124     lines = (unsigned char **)malloc( height * sizeof(unsigned char *) );
 125     if (lines == NULL)
 126         goto error;
 127
 128     for (i = 0; i < height; i++)
 129     {
 130         if ((lines[i] = (unsigned char *)malloc(width * (sizeof(unsigned char) * 4))) == NULL)
 131         {
 132             for ( unsigned int n = 0; n < i; n++ )
 133                 free( lines[n] );
 134             goto error;
 135         }
 136     }
 137
 138     // loaded successfully!
 139     {
 140         int transp = 0;
 141         png_read_image( png_ptr, lines );
 142         png_destroy_read_struct( &png_ptr, &info_ptr, (png_infopp) NULL );
 143         unsigned char *ptr = image->GetData();
 144         if ((color_type == PNG_COLOR_TYPE_GRAY) ||
 145             (color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
 146         {
 147             for (unsigned int y = 0; y < height; y++)
 148             {
 149                 unsigned char *ptr2 = lines[y];
 150                 for (unsigned int x = 0; x < width; x++)
 151                 {
 152                     unsigned char r = *ptr2++;
 153                     unsigned char a = *ptr2++;
 154                     if (a < 128)
 155                     {
 156                         *ptr++ = 255;
 157                         *ptr++ = 0;
 158                         *ptr++ = 255;
 159                         transp = 1;
 160                     }
 161                     else
 162                     {
 163                         *ptr++ = r;
 164                         *ptr++ = r;
 165                         *ptr++ = r;
 166                     }
 167                 }
 168             }
 169         }
 170         else
 171         {
 172             for (unsigned int y = 0; y < height; y++)
 173             {
 174                 unsigned char *ptr2 = lines[y];
 175                 for (unsigned int x = 0; x < width; x++)
 176                 {
 177                     unsigned char r = *ptr2++;
 178                     unsigned char g = *ptr2++;
 179                     unsigned char b = *ptr2++;
 180                     unsigned char a = *ptr2++;
 181                     if (a < 128)
 182                     {
 183                         *ptr++ = 255;
 184                         *ptr++ = 0;
 185                         *ptr++ = 255;
 186                         transp = 1;
 187                     }
 188                     else
 189                     {
 190                         if ((r == 255) && (g == 0) && (b == 255)) r = 254;
 191                         *ptr++ = r;
 192                         *ptr++ = g;
 193                         *ptr++ = b;
 194                     }
 195                 }
 196             }
 197         }
 198
 199         for ( unsigned int j = 0; j < height; j++ )
 200             free( lines[j] );
 201         free( lines );
 202
 203         if (transp)
 204         {
 205             image->SetMaskColour( 255, 0, 255 );
 206         }
 207         else
 208         {
 209             image->SetMask( FALSE );
 210         }
 211     }
 212
 213     return TRUE;
 214
 215 error:
 216     wxLogError(_("Couldn't load a PNG image - probably file is corrupted."));
 217
 218     if ( image->Ok() )
 219     {
 220         image->Destroy();
 221     }
 222
 223     if ( lines )
 224     {
 225         free( lines );
 226     }
 227
 228     if ( png_ptr )
 229     {
 230         if ( info_ptr )
 231         {
 232             png_destroy_read_struct( &png_ptr, &info_ptr, (png_infopp) NULL );
 233             free(info_ptr);
 234         }
 235         else
 236             png_destroy_read_struct( &png_ptr, (png_infopp) NULL, (png_infopp) NULL );
 237     }
 238     return FALSE;
 239 }
 240
 241
 242 bool wxPNGHandler::SaveFile( wxImage *image, wxOutputStream& stream )
 243 {
 244     {
 245         png_structp png_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
 246         if (!png_ptr)
 247         {
 248             return FALSE;
 249         }
 250
 251         png_infop info_ptr = png_create_info_struct(png_ptr);
 252         if (info_ptr == NULL)
 253         {
 254             png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
 255             return FALSE;
 256         }
 257
 258         if (setjmp(png_ptr->jmpbuf))
 259         {
 260             png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
 261             return FALSE;
 262         }
 263
 264         png_set_write_fn( png_ptr, &stream, _PNG_stream_writer, NULL);
 265
 266         png_set_IHDR( png_ptr, info_ptr, image->GetWidth(), image->GetHeight(), 8,
 267             PNG_COLOR_TYPE_RGB_ALPHA, PNG_INTERLACE_NONE,
 268             PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE);
 269
 270         png_color_8 sig_bit;
 271         sig_bit.red = 8;
 272         sig_bit.green = 8;
 273         sig_bit.blue = 8;
 274         sig_bit.alpha = 8;
 275         png_set_sBIT( png_ptr, info_ptr, &sig_bit );
 276         png_write_info( png_ptr, info_ptr );
 277         png_set_shift( png_ptr, &sig_bit );
 278         png_set_packing( png_ptr );
 279
 280         unsigned char *data = (unsigned char *)malloc( image->GetWidth()*4 );
 281         if (!data)
 282         {
 283             png_destroy_write_struct( &png_ptr, (png_infopp)NULL );
 284             return FALSE;
 285         }
 286
 287         for (int y = 0; y < image->GetHeight(); y++)
 288         {
 289             unsigned char *ptr = image->GetData() + (y * image->GetWidth() * 3);
 290             for (int x = 0; x < image->GetWidth(); x++)
 291             {
 292                 data[(x << 2) + 0] = *ptr++;
 293                 data[(x << 2) + 1] = *ptr++;
 294                 data[(x << 2) + 2] = *ptr++;
 295                 if ((data[(x << 2) + 0] == image->GetMaskRed()) &&
 296                     (data[(x << 2) + 1] == image->GetMaskGreen()) &&
 297                     (data[(x << 2) + 2] == image->GetMaskBlue()))
 298                 {
 299                     data[(x << 2) + 3] = 0;
 300                 }
 301                 else
 302                 {
 303                     data[(x << 2) + 3] = 255;
 304                 }
 305             }
 306             png_bytep row_ptr = data;
 307             png_write_rows( png_ptr, &row_ptr, 1 );
 308         }
 309
 310         free(data);
 311         png_write_end( png_ptr, info_ptr );
 312         png_destroy_write_struct( &png_ptr, (png_infopp)&info_ptr );
 313     }
 314     return TRUE;
 315 }
 316 #endif // wxUSE_STREAMS
 317
 318 #endif
 319
 320 // wxUSE_LIBPNG
 321