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