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