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
  15 // For compilers that support precompilation, includes "wx.h".
  16 #include "wx/wxprec.h"
  17
  18 #ifdef __BORLANDC__
  19   #pragma hdrstop
  20 #endif
  21
  22 #ifndef WX_PRECOMP
  23   #include "wx/defs.h"
  24 #endif
  25
  26 #if wxUSE_LIBPNG
  27
  28 #include "wx/image.h"
  29 #include "wx/bitmap.h"
  30 #include "wx/debug.h"
  31 #include "wx/log.h"
  32 #include "wx/app.h"
  33 #include "png.h"
  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 !USE_SHARED_LIBRARIES
  57 IMPLEMENT_DYNAMIC_CLASS(wxPNGHandler,wxImageHandler)
  58 #endif
  59
  60 #if wxUSE_STREAMS
  61
  62 static void _PNG_stream_reader( png_structp png_ptr, png_bytep data, png_size_t length )
  63 {
  64     ((wxInputStream*) png_get_io_ptr( png_ptr )) -> Read(data, length);
  65 }
  66
  67 static void _PNG_stream_writer( png_structp png_ptr, png_bytep data, png_size_t length )
  68 {
  69     ((wxOutputStream*) png_get_io_ptr( png_ptr )) -> Write(data, length);
  70 }
  71
  72 bool wxPNGHandler::LoadFile( wxImage *image, wxInputStream& stream )
  73 {
  74     // VZ: as this function uses setjmp() the only fool proof error handling
  75     //     method is to use goto (setjmp is not really C++ dtors friendly...)
  76
  77     unsigned char **lines;
  78     unsigned int i;
  79     png_infop info_ptr = (png_infop) NULL;
  80
  81     image->Destroy();
  82
  83     png_structp png_ptr = png_create_read_struct( PNG_LIBPNG_VER_STRING,
  84         (voidp) NULL,
  85         (png_error_ptr) NULL,
  86         (png_error_ptr) NULL );
  87     if (!png_ptr)
  88         goto error_nolines;
  89
  90     info_ptr = png_create_info_struct( png_ptr );
  91     if (!info_ptr)
  92         goto error_nolines;
  93
  94     if (setjmp(png_ptr->jmpbuf))
  95         goto error_nolines;
  96
  97     if (info_ptr->color_type == PNG_COLOR_TYPE_RGB_ALPHA)
  98         goto error_nolines;
  99
 100     png_set_read_fn( png_ptr, &stream, _PNG_stream_reader);
 101
 102     png_uint_32 width,height;
 103     int bit_depth,color_type,interlace_type;
 104
 105     png_read_info( png_ptr, info_ptr );
 106     png_get_IHDR( png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_type, (int*) NULL, (int*) NULL );
 107
 108     if (color_type == PNG_COLOR_TYPE_PALETTE)
 109         png_set_expand( png_ptr );
 110
 111     png_set_strip_16( png_ptr );
 112     png_set_packing( png_ptr );
 113     if (png_get_valid( png_ptr, info_ptr, PNG_INFO_tRNS))
 114         png_set_expand( png_ptr );
 115     png_set_filler( png_ptr, 0xff, PNG_FILLER_AFTER );
 116
 117     image->Create( width, height );
 118
 119     if (!image->Ok())
 120         goto error_nolines;
 121
 122     lines = (unsigned char **)malloc( height * sizeof(unsigned char *) );
 123     if (lines == NULL)
 124         goto error_nolines;
 125
 126     for (i = 0; i < height; i++)
 127     {
 128         if ((lines[i] = (unsigned char *)malloc(width * (sizeof(unsigned char) * 4))) == NULL)
 129         {
 130             for ( unsigned int n = 0; n < i; n++ )
 131                 free( lines[n] );
 132             goto error;
 133         }
 134     }
 135
 136     // loaded successfully!
 137     {
 138         int transp = 0;
 139         png_read_image( png_ptr, lines );
 140         png_destroy_read_struct( &png_ptr, &info_ptr, (png_infopp) NULL );
 141         unsigned char *ptr = image->GetData();
 142         if ((color_type == PNG_COLOR_TYPE_GRAY) ||
 143             (color_type == PNG_COLOR_TYPE_GRAY_ALPHA))
 144         {
 145             for (unsigned int y = 0; y < height; y++)
 146             {
 147                 unsigned char *ptr2 = lines[y];
 148                 for (unsigned int x = 0; x < width; x++)
 149                 {
 150                     unsigned char r = *ptr2++;
 151                     unsigned char a = *ptr2++;
 152                     if (a < 128)
 153                     {
 154                         *ptr++ = 255;
 155                         *ptr++ = 0;
 156                         *ptr++ = 255;
 157                         transp = 1;
 158                     }
 159                     else
 160                     {
 161                         *ptr++ = r;
 162                         *ptr++ = r;
 163                         *ptr++ = r;
 164                     }
 165                 }
 166             }
 167         }
 168         else
 169         {
 170             for (unsigned int y = 0; y < height; y++)
 171             {
 172                 unsigned char *ptr2 = lines[y];
 173                 for (unsigned int x = 0; x < width; x++)
 174                 {
 175                     unsigned char r = *ptr2++;
 176                     unsigned char g = *ptr2++;
 177                     unsigned char b = *ptr2++;
 178                     unsigned char a = *ptr2++;
 179                     if (a < 128)
 180                     {
 181                         *ptr++ = 255;
 182                         *ptr++ = 0;
 183                         *ptr++ = 255;
 184                         transp = 1;
 185                     }
 186                     else
 187                     {
 188                         if ((r == 255) && (g == 0) && (b == 255)) r = 254;
 189                         *ptr++ = r;
 190                         *ptr++ = g;
 191                         *ptr++ = b;
 192                     }
 193                 }
 194             }
 195         }
 196
 197         for ( unsigned int j = 0; j < height; j++ )
 198             free( lines[j] );
 199         free( lines );
 200
 201         if (transp)
 202         {
 203             image->SetMaskColour( 255, 0, 255 );
 204         }
 205         else
 206         {
 207             image->SetMask( FALSE );
 208         }
 209     }
 210
 211     return TRUE;
 212
 213  error_nolines:
 214     lines = NULL; // called from before it was set
 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
 317 #endif
 318   // wxUSE_STREAMS
 319
 320 #endif
 321   // wxUSE_LIBPNG
 322