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 #include "wx/anidecod.h"
  20
  21 #ifndef WX_PRECOMP
  22     #include "wx/palette.h"
  23 #endif
  24
  25 #include <stdlib.h>
  26 #include <string.h>
  27
  28 // static
  29 wxCURHandler wxANIDecoder::sm_handler;
  30
  31 //---------------------------------------------------------------------------
  32 // wxANIFrameInfo
  33 //---------------------------------------------------------------------------
  34
  35 class wxANIFrameInfo
  36 {
  37 public:
  38     wxANIFrameInfo(size_t delay = 0, int idx = -1)
  39         { m_delay=delay; m_imageIndex=idx; }
  40
  41     size_t m_delay;
  42     int m_imageIndex;
  43 };
  44
  45 #include "wx/arrimpl.cpp" // this is a magic incantation which must be done!
  46 WX_DEFINE_OBJARRAY(wxImageArray)
  47
  48 #include "wx/arrimpl.cpp" // this is a magic incantation which must be done!
  49 WX_DEFINE_OBJARRAY(wxANIFrameInfoArray)
  50
  51
  52 //---------------------------------------------------------------------------
  53 // wxANIDecoder
  54 //---------------------------------------------------------------------------
  55
  56 wxANIDecoder::wxANIDecoder()
  57 {
  58 }
  59
  60 wxANIDecoder::~wxANIDecoder()
  61 {
  62 }
  63
  64 bool wxANIDecoder::ConvertToImage(size_t frame, wxImage *image) const
  65 {
  66     size_t idx = m_info[frame].m_imageIndex;
  67     *image = m_images[idx];       // copy
  68     return image->IsOk();
  69 }
  70
  71
  72 //---------------------------------------------------------------------------
  73 // Data accessors
  74 //---------------------------------------------------------------------------
  75
  76 wxSize wxANIDecoder::GetFrameSize(size_t WXUNUSED(frame)) const
  77 {
  78     // all frames are of the same size...
  79     return m_szAnimation;
  80 }
  81
  82 wxPoint wxANIDecoder::GetFramePosition(size_t WXUNUSED(frame)) const
  83 {
  84     // all frames are of the same size...
  85     return wxPoint(0,0);
  86 }
  87
  88 wxAnimationDisposal wxANIDecoder::GetDisposalMethod(size_t WXUNUSED(frame)) const
  89 {
  90     // this disposal is implicit for all frames inside an ANI file
  91     return wxANIM_TOBACKGROUND;
  92 }
  93
  94 long wxANIDecoder::GetDelay(size_t frame) const
  95 {
  96     return m_info[frame].m_delay;
  97 }
  98
  99
 100 //---------------------------------------------------------------------------
 101 // ANI reading and decoding
 102 //---------------------------------------------------------------------------
 103
 104 bool wxANIDecoder::CanRead(wxInputStream& stream) const
 105 {
 106     wxInt32 FCC1, FCC2;
 107     wxUint32 datalen ;
 108
 109     wxInt32 riff32;
 110     memcpy( &riff32, "RIFF", 4 );
 111     wxInt32 list32;
 112     memcpy( &list32, "LIST", 4 );
 113     wxInt32 ico32;
 114     memcpy( &ico32, "icon", 4 );
 115     wxInt32 anih32;
 116     memcpy( &anih32, "anih", 4 );
 117
 118     stream.SeekI(0);
 119     if ( !stream.Read(&FCC1, 4) )
 120         return false;
 121
 122     if ( FCC1 != riff32 )
 123         return false;
 124
 125     // we have a riff file:
 126     while ( stream.IsOk() )
 127     {
 128         if ( FCC1 == anih32 )
 129             return true;        // found the ANIH chunk - this should be an ANI file
 130
 131         // we always have a data size:
 132         stream.Read(&datalen, 4);
 133         datalen = wxINT32_SWAP_ON_BE(datalen) ;
 134
 135         // data should be padded to make even number of bytes
 136         if (datalen % 2 == 1) datalen ++ ;
 137
 138         // now either data or a FCC:
 139         if ( (FCC1 == riff32) || (FCC1 == list32) )
 140         {
 141             stream.Read(&FCC2, 4);
 142         }
 143         else
 144         {
 145             stream.SeekI(stream.TellI() + datalen);
 146         }
 147
 148         // try to read next data chunk:
 149         if ( !stream.Read(&FCC1, 4) )
 150         {
 151             // reading failed -- either EOF or IO error, bail out anyhow
 152             return false;
 153         }
 154     }
 155
 156     return false;
 157 }
 158
 159 // the "anih" RIFF chunk
 160 struct wxANIHeader
 161 {
 162     wxInt32 cbSizeOf;     // Num bytes in AniHeader (36 bytes)
 163     wxInt32 cFrames;      // Number of unique Icons in this cursor
 164     wxInt32 cSteps;       // Number of Blits before the animation cycles
 165     wxInt32 cx;           // width of the frames
 166     wxInt32 cy;           // height of the frames
 167     wxInt32 cBitCount;    // bit depth
 168     wxInt32 cPlanes;      // 1
 169     wxInt32 JifRate;      // Default Jiffies (1/60th of a second) if rate chunk not present.
 170     wxInt32 flags;        // Animation Flag (see AF_ constants)
 171
 172     // ANI files are always little endian so we need to swap bytes on big
 173     // endian architectures
 174 #ifdef WORDS_BIGENDIAN
 175     void AdjustEndianness()
 176     {
 177         // this works because all our fields are wxInt32 and they must be
 178         // packed without holes between them (if they're not, they wouldn't map
 179         // to the file header!)
 180         wxInt32 * const start = (wxInt32 *)this;
 181         wxInt32 * const end = start + sizeof(wxANIHeader)/sizeof(wxInt32);
 182         for ( wxInt32 *p = start; p != end; p++ )
 183         {
 184             *p = wxINT32_SWAP_ALWAYS(*p);
 185         }
 186     }
 187 #else
 188     void AdjustEndianness() { }
 189 #endif
 190 };
 191
 192 bool wxANIDecoder::Load( wxInputStream& stream )
 193 {
 194     wxInt32 FCC1, FCC2;
 195     wxUint32 datalen;
 196     size_t globaldelay=0;
 197
 198     wxInt32 riff32;
 199     memcpy( &riff32, "RIFF", 4 );
 200     wxInt32 list32;
 201     memcpy( &list32, "LIST", 4 );
 202     wxInt32 ico32;
 203     memcpy( &ico32, "icon", 4 );
 204     wxInt32 anih32;
 205     memcpy( &anih32, "anih", 4 );
 206     wxInt32 rate32;
 207     memcpy( &rate32, "rate", 4 );
 208     wxInt32 seq32;
 209     memcpy( &seq32, "seq ", 4 );
 210
 211     stream.SeekI(0);
 212     stream.Read(&FCC1, 4);
 213     if ( FCC1 != riff32 )
 214         return false;
 215
 216     m_nFrames = 0;
 217     m_szAnimation = wxDefaultSize;
 218
 219     m_images.Clear();
 220     m_info.Clear();
 221
 222     // we have a riff file:
 223     while ( stream.IsOk() )
 224     {
 225         // we always have a data size:
 226         stream.Read(&datalen, 4);
 227         datalen = wxINT32_SWAP_ON_BE(datalen);
 228
 229         //data should be padded to make even number of bytes
 230         if (datalen % 2 == 1) datalen++;
 231
 232         // now either data or a FCC:
 233         if ( (FCC1 == riff32) || (FCC1 == list32) )
 234         {
 235             stream.Read(&FCC2, 4);
 236         }
 237         else if ( FCC1 == anih32 )
 238         {
 239             if ( datalen != sizeof(wxANIHeader) )
 240                 return false;
 241
 242             if (m_nFrames > 0)
 243                 return false;       // already parsed an ani header?
 244
 245             struct wxANIHeader header;
 246             stream.Read(&header, sizeof(wxANIHeader));
 247             header.AdjustEndianness();
 248
 249             // we should have a global frame size
 250             m_szAnimation = wxSize(header.cx, header.cy);
 251
 252             // save interesting info from the header
 253             m_nFrames = header.cSteps;   // NB: not cFrames!!
 254             if ( m_nFrames == 0 )
 255                 return false;
 256
 257             globaldelay = header.JifRate * 1000 / 60;
 258
 259             m_images.Alloc(header.cFrames);
 260             m_info.Add(wxANIFrameInfo(), m_nFrames);
 261         }
 262         else if ( FCC1 == rate32 )
 263         {
 264             // did we already process the anih32 chunk?
 265             if (m_nFrames == 0)
 266                 return false;       // rate chunks should always be placed after anih chunk
 267
 268             wxASSERT(m_info.GetCount() == m_nFrames);
 269             for (size_t i=0; i<m_nFrames; i++)
 270             {
 271                 stream.Read(&FCC2, 4);
 272                 m_info[i].m_delay = wxINT32_SWAP_ON_BE(FCC2) * 1000 / 60;
 273             }
 274         }
 275         else if ( FCC1 == seq32 )
 276         {
 277             // did we already process the anih32 chunk?
 278             if (m_nFrames == 0)
 279                 return false;       // seq chunks should always be placed after anih chunk
 280
 281             wxASSERT(m_info.GetCount() == m_nFrames);
 282             for (size_t i=0; i<m_nFrames; i++)
 283             {
 284                 stream.Read(&FCC2, 4);
 285                 m_info[i].m_imageIndex = wxINT32_SWAP_ON_BE(FCC2);
 286             }
 287         }
 288         else if ( FCC1 == ico32 )
 289         {
 290             // use DoLoadFile() and not LoadFile()!
 291             wxImage image;
 292             if (!sm_handler.DoLoadFile(&image, stream, false /* verbose */, -1))
 293                 return false;
 294
 295             m_images.Add(image);
 296         }
 297         else
 298         {
 299             stream.SeekI(stream.TellI() + datalen);
 300         }
 301
 302         // try to read next data chunk:
 303         stream.Read(&FCC1, 4);
 304     }
 305
 306     if (m_nFrames==0)
 307         return false;
 308
 309     if (m_nFrames==m_images.GetCount())
 310     {
 311         // if no SEQ chunk is available, display the frames in the order
 312         // they were loaded
 313         for (size_t i=0; i<m_nFrames; i++)
 314             if (m_info[i].m_imageIndex == -1)
 315                 m_info[i].m_imageIndex = i;
 316     }
 317
 318     // if some frame has an invalid delay, use the global delay given in the
 319     // ANI header
 320     for (size_t i=0; i<m_nFrames; i++)
 321         if (m_info[i].m_delay == 0)
 322             m_info[i].m_delay = globaldelay;
 323
 324     // if the header did not contain a valid frame size, try to grab
 325     // it from the size of the first frame (all frames are of the same size)
 326     if (m_szAnimation.GetWidth() == 0 ||
 327         m_szAnimation.GetHeight() == 0)
 328         m_szAnimation = wxSize(m_images[0].GetWidth(), m_images[0].GetHeight());
 329
 330     return m_szAnimation != wxDefaultSize;
 331 }
 332
 333 #endif // wxUSE_STREAMS && wxUSE_GIF