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_ICO_CUR
  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(unsigned int delay = 0, int idx = -1)
  39         { m_delay=delay; m_imageIndex=idx; }
  40
  41     unsigned int 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(unsigned int frame, wxImage *image) const
  65 {
  66     unsigned int 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(unsigned int WXUNUSED(frame)) const
  77 {
  78     // all frames are of the same size...
  79     return m_szAnimation;
  80 }
  81
  82 wxPoint wxANIDecoder::GetFramePosition(unsigned int WXUNUSED(frame)) const
  83 {
  84     // all frames are of the same size...
  85     return wxPoint(0,0);
  86 }
  87
  88 wxAnimationDisposal wxANIDecoder::GetDisposalMethod(unsigned int 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(unsigned int frame) const
  95 {
  96     return m_info[frame].m_delay;
  97 }
  98
  99 wxColour wxANIDecoder::GetTransparentColour(unsigned int frame) const
 100 {
 101     unsigned int idx = m_info[frame].m_imageIndex;
 102
 103     if (!m_images[idx].HasMask())
 104         return wxNullColour;
 105
 106     return wxColour(m_images[idx].GetMaskRed(),
 107                     m_images[idx].GetMaskGreen(),
 108                     m_images[idx].GetMaskBlue());
 109 }
 110
 111
 112 //---------------------------------------------------------------------------
 113 // ANI reading and decoding
 114 //---------------------------------------------------------------------------
 115
 116 bool wxANIDecoder::CanRead(wxInputStream& stream) const
 117 {
 118     wxInt32 FCC1, FCC2;
 119     wxUint32 datalen ;
 120
 121     wxInt32 riff32;
 122     memcpy( &riff32, "RIFF", 4 );
 123     wxInt32 list32;
 124     memcpy( &list32, "LIST", 4 );
 125     wxInt32 ico32;
 126     memcpy( &ico32, "icon", 4 );
 127     wxInt32 anih32;
 128     memcpy( &anih32, "anih", 4 );
 129
 130     if ( stream.SeekI(0) == wxInvalidOffset )
 131         return false;
 132     if ( !stream.Read(&FCC1, 4) )
 133         return false;
 134
 135     if ( FCC1 != riff32 )
 136         return false;
 137
 138     // we have a riff file:
 139     while ( stream.IsOk() )
 140     {
 141         if ( FCC1 == anih32 )
 142             return true;        // found the ANIH chunk - this should be an ANI file
 143
 144         // we always have a data size:
 145         stream.Read(&datalen, 4);
 146         datalen = wxINT32_SWAP_ON_BE(datalen) ;
 147
 148         // data should be padded to make even number of bytes
 149         if (datalen % 2 == 1) datalen ++ ;
 150
 151         // now either data or a FCC:
 152         if ( (FCC1 == riff32) || (FCC1 == list32) )
 153         {
 154             stream.Read(&FCC2, 4);
 155         }
 156         else
 157         {
 158             if ( stream.SeekI(stream.TellI() + datalen) == wxInvalidOffset )
 159                 return false;
 160         }
 161
 162         // try to read next data chunk:
 163         if ( !stream.Read(&FCC1, 4) )
 164         {
 165             // reading failed -- either EOF or IO error, bail out anyhow
 166             return false;
 167         }
 168     }
 169
 170     return false;
 171 }
 172
 173 // the "anih" RIFF chunk
 174 struct wxANIHeader
 175 {
 176     wxInt32 cbSizeOf;     // Num bytes in AniHeader (36 bytes)
 177     wxInt32 cFrames;      // Number of unique Icons in this cursor
 178     wxInt32 cSteps;       // Number of Blits before the animation cycles
 179     wxInt32 cx;           // width of the frames
 180     wxInt32 cy;           // height of the frames
 181     wxInt32 cBitCount;    // bit depth
 182     wxInt32 cPlanes;      // 1
 183     wxInt32 JifRate;      // Default Jiffies (1/60th of a second) if rate chunk not present.
 184     wxInt32 flags;        // Animation Flag (see AF_ constants)
 185
 186     // ANI files are always little endian so we need to swap bytes on big
 187     // endian architectures
 188 #ifdef WORDS_BIGENDIAN
 189     void AdjustEndianness()
 190     {
 191         // this works because all our fields are wxInt32 and they must be
 192         // packed without holes between them (if they're not, they wouldn't map
 193         // to the file header!)
 194         wxInt32 * const start = (wxInt32 *)this;
 195         wxInt32 * const end = start + sizeof(wxANIHeader)/sizeof(wxInt32);
 196         for ( wxInt32 *p = start; p != end; p++ )
 197         {
 198             *p = wxINT32_SWAP_ALWAYS(*p);
 199         }
 200     }
 201 #else
 202     void AdjustEndianness() { }
 203 #endif
 204 };
 205
 206 bool wxANIDecoder::Load( wxInputStream& stream )
 207 {
 208     wxInt32 FCC1, FCC2;
 209     wxUint32 datalen;
 210     unsigned int globaldelay=0;
 211
 212     wxInt32 riff32;
 213     memcpy( &riff32, "RIFF", 4 );
 214     wxInt32 list32;
 215     memcpy( &list32, "LIST", 4 );
 216     wxInt32 ico32;
 217     memcpy( &ico32, "icon", 4 );
 218     wxInt32 anih32;
 219     memcpy( &anih32, "anih", 4 );
 220     wxInt32 rate32;
 221     memcpy( &rate32, "rate", 4 );
 222     wxInt32 seq32;
 223     memcpy( &seq32, "seq ", 4 );
 224
 225     if ( stream.SeekI(0) == wxInvalidOffset)
 226         return false;
 227     if ( !stream.Read(&FCC1, 4) )
 228         return false;
 229     if ( FCC1 != riff32 )
 230         return false;
 231
 232     m_nFrames = 0;
 233     m_szAnimation = wxDefaultSize;
 234
 235     m_images.Clear();
 236     m_info.Clear();
 237
 238     // we have a riff file:
 239     while ( !stream.Eof() )
 240     {
 241         // we always have a data size:
 242         if (!stream.Read(&datalen, 4))
 243             return false;
 244
 245         datalen = wxINT32_SWAP_ON_BE(datalen);
 246
 247         //data should be padded to make even number of bytes
 248         if (datalen % 2 == 1) datalen++;
 249
 250         // now either data or a FCC:
 251         if ( (FCC1 == riff32) || (FCC1 == list32) )
 252         {
 253             if (!stream.Read(&FCC2, 4))
 254                 return false;
 255         }
 256         else if ( FCC1 == anih32 )
 257         {
 258             if ( datalen != sizeof(wxANIHeader) )
 259                 return false;
 260
 261             if (m_nFrames > 0)
 262                 return false;       // already parsed an ani header?
 263
 264             struct wxANIHeader header;
 265             if (!stream.Read(&header, sizeof(wxANIHeader)))
 266                 return false;
 267             header.AdjustEndianness();
 268
 269             // we should have a global frame size
 270             m_szAnimation = wxSize(header.cx, header.cy);
 271
 272             // save interesting info from the header
 273             m_nFrames = header.cSteps;   // NB: not cFrames!!
 274             if ( m_nFrames == 0 )
 275                 return false;
 276
 277             globaldelay = header.JifRate * 1000 / 60;
 278
 279             m_images.Alloc(header.cFrames);
 280             m_info.Add(wxANIFrameInfo(), m_nFrames);
 281         }
 282         else if ( FCC1 == rate32 )
 283         {
 284             // did we already process the anih32 chunk?
 285             if (m_nFrames == 0)
 286                 return false;       // rate chunks should always be placed after anih chunk
 287
 288             wxASSERT(m_info.GetCount() == m_nFrames);
 289             for (unsigned int i=0; i<m_nFrames; i++)
 290             {
 291                 if (!stream.Read(&FCC2, 4))
 292                     return false;
 293                 m_info[i].m_delay = wxINT32_SWAP_ON_BE(FCC2) * 1000 / 60;
 294             }
 295         }
 296         else if ( FCC1 == seq32 )
 297         {
 298             // did we already process the anih32 chunk?
 299             if (m_nFrames == 0)
 300                 return false;       // seq chunks should always be placed after anih chunk
 301
 302             wxASSERT(m_info.GetCount() == m_nFrames);
 303             for (unsigned int i=0; i<m_nFrames; i++)
 304             {
 305                 if (!stream.Read(&FCC2, 4))
 306                     return false;
 307                 m_info[i].m_imageIndex = wxINT32_SWAP_ON_BE(FCC2);
 308             }
 309         }
 310         else if ( FCC1 == ico32 )
 311         {
 312             // use DoLoadFile() and not LoadFile()!
 313             wxImage image;
 314             if (!sm_handler.DoLoadFile(&image, stream, false /* verbose */, -1))
 315                 return false;
 316
 317             image.SetType(wxBITMAP_TYPE_ANI);
 318             m_images.Add(image);
 319         }
 320         else
 321         {
 322             if ( stream.SeekI(stream.TellI() + datalen) == wxInvalidOffset )
 323                 return false;
 324         }
 325
 326         // try to read next data chunk:
 327         if ( !stream.Read(&FCC1, 4) && !stream.Eof())
 328         {
 329             // we didn't reach the EOF! An other kind of error has occurred...
 330             return false;
 331         }
 332         //else: proceed with the parsing of the next header block or
 333         //      exiting this loop (if stream.Eof() == true)
 334     }
 335
 336     if (m_nFrames==0)
 337         return false;
 338
 339     if (m_nFrames==m_images.GetCount())
 340     {
 341         // if no SEQ chunk is available, display the frames in the order
 342         // they were loaded
 343         for (unsigned int i=0; i<m_nFrames; i++)
 344             if (m_info[i].m_imageIndex == -1)
 345                 m_info[i].m_imageIndex = i;
 346     }
 347
 348     // if some frame has an invalid delay, use the global delay given in the
 349     // ANI header
 350     for (unsigned int i=0; i<m_nFrames; i++)
 351         if (m_info[i].m_delay == 0)
 352             m_info[i].m_delay = globaldelay;
 353
 354     // if the header did not contain a valid frame size, try to grab
 355     // it from the size of the first frame (all frames are of the same size)
 356     if (m_szAnimation.GetWidth() == 0 ||
 357         m_szAnimation.GetHeight() == 0)
 358         m_szAnimation = wxSize(m_images[0].GetWidth(), m_images[0].GetHeight());
 359
 360     return m_szAnimation != wxDefaultSize;
 361 }
 362
 363 #endif // wxUSE_STREAMS && wxUSE_ICO_CUR