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_STREAMS && 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
  41 void Skip_Comment(wxInputStream &stream)
  42 {
  43   wxString line;
  44   wxTextInputStream text_stream(stream);
  45
  46   if (stream.Peek()==_T('#'))
  47     {
  48       text_stream >> line;
  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     wxString  line;
  58     char      c(0);
  59
  60     image->Destroy();
  61
  62     /*
  63      * Read the PNM header
  64      */
  65
  66     wxBufferedInputStream buf_stream(stream);
  67     wxTextInputStream text_stream(buf_stream);
  68
  69     Skip_Comment(buf_stream);
  70     if (buf_stream.GetC()==_T('P')) c=buf_stream.GetC();
  71
  72     switch (c)
  73       {
  74       case _T('2'):
  75         wxLogError(_T("Loading Grey Ascii PNM image is not yet implemented."));
  76         return FALSE;
  77       case _T('5'):
  78         wxLogError(_T("Loading Grey Raw PNM image is not yet implemented."));
  79         return FALSE;
  80       case _T('3'): case _T('6'): break;
  81         default :
  82         wxLogError(_T("Loading PNM image : file not recognized."));
  83         return FALSE;
  84       }
  85
  86     text_stream >> line; // for the \n
  87     Skip_Comment(buf_stream);
  88     text_stream >> width >> height ;
  89     Skip_Comment(buf_stream);
  90     text_stream >> maxval;
  91
  92     //cout << line << " " << width << " " << height << " " << maxval << endl;
  93     image->Create( width, height );
  94     unsigned char *ptr = image->GetData();
  95     if (!ptr)
  96     {
  97         wxLogError( _T("Cannot allocate RAM for RGB data in PNM file.") );
  98         return FALSE;
  99     }
 100
 101    if (c=='3') // Ascii RBG
 102       {
 103         wxUint32 value, size=3*width*height;
 104         for (wxUint32 i=0; i<size; ++i)
 105           {
 106             //this is very slow !!!
 107             //I wonder how we can make any better ?
 108             value=text_stream.Read32();
 109             *ptr++=(unsigned char)value;
 110
 111             if (buf_stream.LastError()!=wxSTREAM_NOERROR)
 112               {
 113                 wxLogError(_T("Loading PNM image : file seems truncated."));
 114                 return FALSE;
 115               }
 116           }
 117       }
 118     if (c=='6') // Raw RGB
 119       buf_stream.Read( ptr, 3*width*height );
 120
 121     image->SetMask( FALSE );
 122
 123     return (buf_stream.LastError()==wxStream_NOERROR || buf_stream.LastError()==wxStream_EOF);
 124 }
 125
 126 bool wxPNMHandler::SaveFile( wxImage *image, wxOutputStream& stream, bool WXUNUSED(verbose) )
 127 {
 128     wxTextOutputStream text_stream(stream);
 129
 130     //text_stream << "P6" << endl
 131     //<< image->GetWidth() << " " << image->GetHeight() << endl
 132     //<< "255" << endl;
 133     text_stream << "P6\n" << image->GetWidth() << " " << image->GetHeight() << "\n255\n";
 134     stream.Write(image->GetData(),3*image->GetWidth()*image->GetHeight());
 135
 136     return (stream.LastError()==wxStream_NOERROR);
 137 }
 138
 139 bool wxPNMHandler::CanRead( wxInputStream& stream )
 140 {
 141     off_t pos=stream.TellI();
 142
 143     Skip_Comment(stream);
 144
 145     if (stream.GetC()==_T('P'))
 146       switch (stream.GetC())
 147         {
 148         case _T('3'): case _T('6'):
 149           stream.SeekI(pos);
 150           return TRUE;
 151         }
 152
 153     stream.SeekI(pos);
 154     return FALSE;
 155 }
 156
 157
 158 #endif // wxUSE_STREAMS && wxUSE_PNM
 159