src/common/imagpnm.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        imagpnm.cpp
   3 // Purpose:     wxImage PNM handler
   4 // Author:      Sylvain Bougnoux
   5 // RCS-ID:      $Id$
   6 // Copyright:   (c) Sylvain Bougnoux
   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/setup.h"
  24 #endif
  25
  26 #if wxUSE_PNM
  27
  28 #include "wx/image.h"
  29 #include "wx/log.h"
  30 #include "wx/txtstrm.h"
  31
  32 //-----------------------------------------------------------------------------
  33 // wxBMPHandler
  34 //-----------------------------------------------------------------------------
  35
  36 #if !USE_SHARED_LIBRARIES
  37 IMPLEMENT_DYNAMIC_CLASS(wxPNMHandler,wxImageHandler)
  38 #endif
  39
  40 #if wxUSE_STREAMS
  41
  42 void Skip_Comment(wxInputStream &stream)
  43 {
  44   wxTextInputStream text_stream(stream);
  45
  46   if (stream.Peek()==wxT('#'))
  47     {
  48       text_stream.ReadLine();
  49       Skip_Comment(stream);
  50     }
  51 }
  52
  53 bool wxPNMHandler::LoadFile( wxImage *image, wxInputStream& stream, bool WXUNUSED(verbose) )
  54 {
  55     wxUint32  width, height;
  56     wxUint16  maxval;
  57     char      c(0);
  58
  59     image->Destroy();
  60
  61     /*
  62      * Read the PNM header
  63      */
  64
  65     wxBufferedInputStream buf_stream(stream);
  66     wxTextInputStream text_stream(buf_stream);
  67
  68     Skip_Comment(buf_stream);
  69     if (buf_stream.GetC()==wxT('P')) c=buf_stream.GetC();
  70
  71     switch (c)
  72       {
  73       case wxT('2'):
  74         wxLogError(wxT("Loading Grey Ascii PNM image is not yet implemented."));
  75         return FALSE;
  76       case wxT('5'):
  77         wxLogError(wxT("Loading Grey Raw PNM image is not yet implemented."));
  78         return FALSE;
  79       case wxT('3'): case wxT('6'): break;
  80         default :
  81         wxLogError(wxT("Loading PNM image : file not recognized."));
  82         return FALSE;
  83       }
  84
  85     text_stream.ReadLine(); // for the \n
  86     Skip_Comment(buf_stream);
  87     text_stream >> width >> height ;
  88     Skip_Comment(buf_stream);
  89     text_stream >> maxval;
  90
  91     //cout << line << " " << width << " " << height << " " << maxval << endl;
  92     image->Create( width, height );
  93     unsigned char *ptr = image->GetData();
  94     if (!ptr)
  95     {
  96         wxLogError( wxT("Cannot allocate RAM for RGB data in PNM file.") );
  97         return FALSE;
  98     }
  99
 100    if (c=='3') // Ascii RBG
 101       {
 102         wxUint32 value, size=3*width*height;
 103         for (wxUint32 i=0; i<size; ++i)
 104           {
 105             //this is very slow !!!
 106             //I wonder how we can make any better ?
 107             value=text_stream.Read32();
 108             *ptr++=(unsigned char)value;
 109
 110             if (buf_stream.LastError()!=wxSTREAM_NOERROR)
 111               {
 112                 wxLogError(wxT("Loading PNM image : file seems truncated."));
 113                 return FALSE;
 114               }
 115           }
 116       }
 117     if (c=='6') // Raw RGB
 118       buf_stream.Read( ptr, 3*width*height );
 119
 120     image->SetMask( FALSE );
 121
 122     return (buf_stream.LastError()==wxStream_NOERROR || buf_stream.LastError()==wxStream_EOF);
 123 }
 124
 125 bool wxPNMHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool WXUNUSED(verbose) )
 126 {
 127     wxTextOutputStream text_stream(stream);
 128
 129     //text_stream << "P6" << endl
 130     //<< image->GetWidth() << " " << image->GetHeight() << endl
 131     //<< "255" << endl;
 132     text_stream << "P6\n" << image->GetWidth() << " " << image->GetHeight() << "\n255\n";
 133     stream.Write(image->GetData(),3*image->GetWidth()*image->GetHeight());
 134
 135     return (stream.LastError()==wxStream_NOERROR);
 136 }
 137
 138 bool wxPNMHandler::DoCanRead( wxInputStream& stream )
 139 {
 140     off_t pos = stream.TellI();
 141
 142     Skip_Comment(stream);
 143
 144     if ( stream.GetC() == 'P' )
 145     {
 146         switch (stream.GetC())
 147         {
 148             case '3':
 149             case '6':
 150                 stream.SeekI(pos);
 151                 return TRUE;
 152         }
 153     }
 154
 155     stream.SeekI(pos);
 156     return FALSE;
 157 }
 158
 159
 160 #endif // wxUSE_STREAMS
 161
 162 #endif // wxUSE_PNM