src/common/anidecod.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        src/common/anidecod.cpp
   3 // Purpose:     wxANIDecoder, ANI reader for wxImage and wxAnimation
   4 // Author:      Francesco Montorsi
   5 // RCS-ID:      $Id$
   6 // Copyright:   (c) Francesco Montorsi
   7 // Licence:     wxWindows licence
   8 /////////////////////////////////////////////////////////////////////////////
   9
  10 // For compilers that support precompilation, includes "wx.h".
  11 #include "wx/wxprec.h"
  12
  13 #ifdef __BORLANDC__
  14     #pragma hdrstop
  15 #endif
  16
  17 #if wxUSE_STREAMS && wxUSE_GIF
  18
  19 #ifndef WX_PRECOMP
  20     #include "wx/palette.h"
  21 #endif
  22
  23 #include <stdlib.h>
  24 #include <string.h>
  25 #include "wx/anidecod.h"
  26
  27 // static
  28 wxCURHandler wxANIDecoder::sm_handler;
  29
  30
  31
  32 //---------------------------------------------------------------------------
  33 // wxANIFrameInfo
  34 //---------------------------------------------------------------------------
  35
  36 class wxANIFrameInfo
  37 {
  38 public:
  39     wxANIFrameInfo(size_t delay = 0, int idx = -1)
  40         { m_delay=delay; m_imageIndex=idx; }
  41
  42     size_t m_delay;
  43     int m_imageIndex;
  44 };
  45
  46 #include <wx/arrimpl.cpp> // this is a magic incantation which must be done!
  47 WX_DEFINE_OBJARRAY(wxImageArray);
  48
  49 #include <wx/arrimpl.cpp> // this is a magic incantation which must be done!
  50 WX_DEFINE_OBJARRAY(wxANIFrameInfoArray);
  51
  52
  53
  54
  55 //---------------------------------------------------------------------------
  56 // wxANIDecoder
  57 //---------------------------------------------------------------------------
  58
  59 wxANIDecoder::wxANIDecoder()
  60 {
  61 }
  62
  63 wxANIDecoder::~wxANIDecoder()
  64 {
  65 }
  66
  67 bool wxANIDecoder::ConvertToImage(size_t frame, wxImage *image) const
  68 {
  69     size_t idx = m_info[frame].m_imageIndex;
  70     *image = m_images[idx];       // copy
  71     return image->Ok();
  72 }
  73
  74
  75 //---------------------------------------------------------------------------
  76 // Data accessors
  77 //---------------------------------------------------------------------------
  78
  79 wxSize wxANIDecoder::GetFrameSize(size_t WXUNUSED(frame)) const
  80 {
  81     // all frames are of the same size...
  82     return m_szAnimation;
  83 }
  84
  85 wxPoint wxANIDecoder::GetFramePosition(size_t WXUNUSED(frame)) const
  86 {
  87     // all frames are of the same size...
  88     return wxPoint(0,0);
  89 }
  90
  91 wxAnimationDisposal wxANIDecoder::GetDisposalMethod(size_t WXUNUSED(frame)) const
  92 {
  93     // this disposal is implicit for all frames inside an ANI file
  94     return wxANIM_TOBACKGROUND;
  95 }
  96
  97 long wxANIDecoder::GetDelay(size_t frame) const
  98 {
  99     return m_info[frame].m_delay;
 100 }
 101
 102
 103 //---------------------------------------------------------------------------
 104 // ANI reading and decoding
 105 //---------------------------------------------------------------------------
 106
 107 bool wxANIDecoder::CanRead(wxInputStream& stream) const
 108 {
 109     wxInt32 FCC1, FCC2;
 110     wxUint32 datalen ;
 111
 112     wxInt32 riff32;
 113     memcpy( &riff32, "RIFF", 4 );
 114     wxInt32 list32;
 115     memcpy( &list32, "LIST", 4 );
 116     wxInt32 ico32;
 117     memcpy( &ico32, "icon", 4 );
 118     wxInt32 anih32;
 119     memcpy( &anih32, "anih", 4 );
 120
 121     stream.SeekI(0);
 122     if ( !stream.Read(&FCC1, 4) )
 123         return false;
 124
 125     if ( FCC1 != riff32 )
 126         return false;
 127
 128     // we have a riff file:
 129     while ( stream.IsOk() )
 130     {
 131         if ( FCC1 == anih32 )
 132             return true;        // found the ANIH chunk - this should be an ANI file
 133
 134         // we always have a data size:
 135         stream.Read(&datalen, 4);
 136         datalen = wxINT32_SWAP_ON_BE(datalen) ;
 137
 138         // data should be padded to make even number of bytes
 139         if (datalen % 2 == 1) datalen ++ ;
 140
 141         // now either data or a FCC:
 142         if ( (FCC1 == riff32) || (FCC1 == list32) )
 143         {
 144             stream.Read(&FCC2, 4);
 145         }
 146         else
 147         {
 148             stream.SeekI(stream.TellI() + datalen);
 149         }
 150
 151         // try to read next data chunk:
 152         if ( !stream.Read(&FCC1, 4) )
 153         {
 154             // reading failed -- either EOF or IO error, bail out anyhow
 155             return false;
 156         }
 157     }
 158
 159     return false;
 160 }
 161
 162 // the "anih" RIFF chunk
 163 struct wxANIHeader
 164 {
 165     wxInt32 cbSizeOf;     // Num bytes in AniHeader (36 bytes)
 166     wxInt32 cFrames;      // Number of unique Icons in this cursor
 167     wxInt32 cSteps;       // Number of Blits before the animation cycles
 168     wxInt32 cx;           // width of the frames
 169     wxInt32 cy;           // height of the frames
 170     wxInt32 cBitCount;    // bit depth
 171     wxInt32 cPlanes;      // 1
 172     wxInt32 JifRate;      // Default Jiffies (1/60th of a second) if rate chunk not present.
 173     wxInt32 flags;        // Animation Flag (see AF_ constants)
 174 };
 175
 176 bool wxANIDecoder::Load( wxInputStream& stream )
 177 {
 178     wxInt32 FCC1, FCC2;
 179     wxUint32 datalen;
 180     size_t globaldelay=0;
 181
 182     wxInt32 riff32;
 183     memcpy( &riff32, "RIFF", 4 );
 184     wxInt32 list32;
 185     memcpy( &list32, "LIST", 4 );
 186     wxInt32 ico32;
 187     memcpy( &ico32, "icon", 4 );
 188     wxInt32 anih32;
 189     memcpy( &anih32, "anih", 4 );
 190     wxInt32 rate32;
 191     memcpy( &rate32, "rate", 4 );
 192     wxInt32 seq32;
 193     memcpy( &seq32, "seq ", 4 );
 194
 195     stream.SeekI(0);
 196     stream.Read(&FCC1, 4);
 197     if ( FCC1 != riff32 )
 198         return false;
 199
 200     m_nFrames = 0;
 201     m_szAnimation = wxDefaultSize;
 202
 203     m_images.Clear();
 204     m_info.Clear();
 205
 206     // we have a riff file:
 207     while ( stream.IsOk() )
 208     {
 209         // we always have a data size:
 210         stream.Read(&datalen, 4);
 211         datalen = wxINT32_SWAP_ON_BE(datalen);
 212
 213         //data should be padded to make even number of bytes
 214         if (datalen % 2 == 1) datalen++;
 215
 216         // now either data or a FCC:
 217         if ( (FCC1 == riff32) || (FCC1 == list32) )
 218         {
 219             stream.Read(&FCC2, 4);
 220         }
 221         else if ( FCC1 == anih32 )
 222         {
 223             if ( datalen != sizeof(wxANIHeader) )
 224                 return false;
 225
 226             if (m_nFrames > 0)
 227                 return false;       // already parsed an ani header?
 228
 229             struct wxANIHeader header;
 230             stream.Read(&header, sizeof(wxANIHeader));
 231
 232             // we should have a global frame size
 233             m_szAnimation = wxSize(header.cx, header.cy);
 234
 235             // save interesting info from the header
 236             m_nFrames = header.cSteps;   // NB: not cFrames!!
 237             if (m_nFrames==0)
 238                 return false;
 239
 240             globaldelay = wxINT32_SWAP_ON_BE(header.JifRate) * 1000 / 60;
 241
 242             m_images.Alloc(header.cFrames);
 243             m_info.Add(wxANIFrameInfo(), m_nFrames);
 244         }
 245         else if ( FCC1 == rate32 )
 246         {
 247             // did we already process the anih32 chunk?
 248             if (m_nFrames == 0)
 249                 return false;       // rate chunks should always be placed after anih chunk
 250
 251             wxASSERT(m_info.GetCount() == m_nFrames);
 252             for (size_t i=0; i<m_nFrames; i++)
 253             {
 254                 stream.Read(&FCC2, 4);
 255                 m_info[i].m_delay = wxINT32_SWAP_ON_BE(FCC2) * 1000 / 60;
 256             }
 257         }
 258         else if ( FCC1 == seq32 )
 259         {
 260             // did we already process the anih32 chunk?
 261             if (m_nFrames == 0)
 262                 return false;       // seq chunks should always be placed after anih chunk
 263
 264             wxASSERT(m_info.GetCount() == m_nFrames);
 265             for (size_t i=0; i<m_nFrames; i++)
 266             {
 267                 stream.Read(&FCC2, 4);
 268                 m_info[i].m_imageIndex = wxINT32_SWAP_ON_BE(FCC2);
 269             }
 270         }
 271         else if ( FCC1 == ico32 )
 272         {
 273             // use DoLoadFile() and not LoadFile()!
 274             wxImage image;
 275             if (!sm_handler.DoLoadFile(&image, stream, false /* verbose */, -1))
 276                 return false;
 277
 278             m_images.Add(image);
 279         }
 280         else
 281             stream.SeekI(stream.TellI() + datalen);
 282
 283         // try to read next data chunk:
 284         stream.Read(&FCC1, 4);
 285     }
 286
 287     if (m_nFrames==0)
 288         return false;
 289
 290     if (m_nFrames==m_images.GetCount())
 291     {
 292         // if no SEQ chunk is available, display the frames in the order
 293         // they were loaded
 294         for (size_t i=0; i<m_nFrames; i++)
 295             if (m_info[i].m_imageIndex == -1)
 296                 m_info[i].m_imageIndex = i;
 297     }
 298
 299     // if some frame has an invalid delay, use the global delay given in the
 300     // ANI header
 301     for (size_t i=0; i<m_nFrames; i++)
 302         if (m_info[i].m_delay == 0)
 303             m_info[i].m_delay = globaldelay;
 304
 305     // if the header did not contain a valid frame size, try to grab
 306     // it from the size of the first frame (all frames are of the same size)
 307     if (m_szAnimation.GetWidth() == 0 ||
 308         m_szAnimation.GetHeight() == 0)
 309         m_szAnimation = wxSize(m_images[0].GetWidth(), m_images[0].GetHeight());
 310
 311     return m_szAnimation!=wxDefaultSize;
 312 }
 313
 314 #endif // wxUSE_STREAMS && wxUSE_GIF