// Purpose: wxGIFDecoder, GIF reader for wxImage and wxAnimation
// Author: Guillermo Rodriguez Garcia <guille@iies.es>
// Version: 3.04
-// RCS-ID: $Id$
// Copyright: (c) Guillermo Rodriguez Garcia
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#include "wx/scopedptr.h"
#include "wx/scopeguard.h"
+enum
+{
+ GIF_MARKER_EXT = '!', // 0x21
+ GIF_MARKER_SEP = ',', // 0x2C
+ GIF_MARKER_ENDOFDATA = ';', // 0x3B
+
+ GIF_MARKER_EXT_GRAPHICS_CONTROL = 0xF9,
+ GIF_MARKER_EXT_COMMENT = 0xFE,
+ GIF_MARKER_EXT_APP = 0xFF
+};
+#define GetFrame(n) ((GIFImage*)m_frames[n])
//---------------------------------------------------------------------------
// GIFImage
unsigned char *p; // bitmap
unsigned char *pal; // palette
unsigned int ncolours; // number of colours
+ wxString comment;
wxDECLARE_NO_COPY_CLASS(GIFImage);
};
image->Create(sz.GetWidth(), sz.GetHeight());
image->SetType(wxBITMAP_TYPE_GIF);
- if (!image->Ok())
+ if (!image->IsOk())
return false;
pal = GetPalette(frame);
*(dst++) = pal[3 * (*src) + 2];
}
+ wxString comment = GetFrame(frame)->comment;
+ if ( !comment.empty() )
+ {
+ image->SetOption(wxIMAGE_OPTION_GIF_COMMENT, comment);
+ }
+
return true;
}
// Data accessors
//---------------------------------------------------------------------------
-#define GetFrame(n) ((GIFImage*)m_frames[n])
-
-
// Get data for current frame
wxSize wxGIFDecoder::GetFrameSize(unsigned int frame) const
// if no bytes left in this block, read the next block
if (m_restbyte == 0)
{
- m_restbyte = (unsigned char)stream.GetC();
+ m_restbyte = stream.GetC();
/* Some encoders are a bit broken: instead of issuing
* an end-of-image symbol (ab_fin) they come up with
ab_clr = (1 << bits);
ab_fin = (1 << bits) + 1;
- // these will change through the decompression proccess
+ // these will change through the decompression process
ab_bits = bits + 1;
ab_free = (1 << bits) + 2;
ab_max = (1 << ab_bits) - 1;
// CanRead:
// Returns true if the file looks like a valid GIF, false otherwise.
//
-bool wxGIFDecoder::CanRead(wxInputStream &stream) const
+bool wxGIFDecoder::DoCanRead(wxInputStream &stream) const
{
unsigned char buf[3];
if ( !stream.Read(buf, WXSIZEOF(buf)) )
return false;
- if (stream.SeekI(-(wxFileOffset)WXSIZEOF(buf), wxFromCurrent) == wxInvalidOffset)
- return false; // this happens e.g. for non-seekable streams
-
return memcmp(buf, "GIF", WXSIZEOF(buf)) == 0;
}
int transparent = -1;
disposal = wxANIM_UNSPECIFIED;
delay = -1;
+ wxString comment;
bool done = false;
while (!done)
{
- type = (unsigned char)stream.GetC();
+ type = stream.GetC();
/*
If the end of file has been reached (or an error) and a ";"
- (0x3B) hasn't been encountered yet, exit the loop. (Without this
+ (GIF_MARKER_ENDOFDATA) hasn't been encountered yet, exit the loop. (Without this
check the while loop would loop endlessly.) Later on, in the next while
loop, the file will be treated as being truncated (But still
be decoded as far as possible). returning wxGIF_TRUNCATED is not
break; // Alternative : "return wxGIF_INVFORMAT;"
}
- // end of data?
- if (type == 0x3B)
+ switch (type)
{
- done = true;
- }
- else
- // extension block?
- if (type == 0x21)
- {
- if (((unsigned char)stream.GetC()) == 0xF9)
- // graphics control extension, parse it
- {
- static const unsigned int gceSize = 6;
- stream.Read(buf, gceSize);
- if (stream.LastRead() != gceSize)
+ case GIF_MARKER_ENDOFDATA:
+ done = true;
+ break;
+ case GIF_MARKER_EXT:
+ switch (stream.GetC())
{
- Destroy();
- return wxGIF_INVFORMAT;
- }
+ case GIF_MARKER_EXT_GRAPHICS_CONTROL:
+ {
+ // graphics control extension, parse it
- // read delay and convert from 1/100 of a second to ms
- delay = 10 * (buf[2] + 256 * buf[3]);
+ static const unsigned int gceSize = 6;
+ stream.Read(buf, gceSize);
+ if (stream.LastRead() != gceSize)
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
- // read transparent colour index, if used
- transparent = buf[1] & 0x01 ? buf[4] : -1;
+ // read delay and convert from 1/100 of a second to ms
+ delay = 10 * (buf[2] + 256 * buf[3]);
- // read disposal method
- disposal = (wxAnimationDisposal)(((buf[1] & 0x1C) >> 2) - 1);
- }
- else
- // other extension, skip
- {
- while ((i = (unsigned char)stream.GetC()) != 0)
- {
- if (stream.Eof() || (stream.LastRead() == 0) ||
- stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+ // read transparent colour index, if used
+ transparent = buf[1] & 0x01 ? buf[4] : -1;
+
+ // read disposal method
+ disposal = (wxAnimationDisposal)(((buf[1] & 0x1C) >> 2) - 1);
+ break;
+ }
+ case GIF_MARKER_EXT_COMMENT:
{
- done = true;
+ int len = stream.GetC();
+ while (len)
+ {
+ if ( stream.Eof() )
+ {
+ done = true;
+ break;
+ }
+
+ wxCharBuffer charbuf(len);
+ stream.Read(charbuf.data(), len);
+ if ( (int) stream.LastRead() != len )
+ {
+ done = true;
+ break;
+ }
+
+ comment += wxConvertMB2WX(charbuf.data());
+
+ len = stream.GetC();
+ }
+
break;
}
+ default:
+ // other extension, skip
+ while ((i = stream.GetC()) != 0)
+ {
+ if (stream.Eof() || (stream.LastRead() == 0) ||
+ stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+ {
+ done = true;
+ break;
+ }
+ }
+ break;
}
- }
- }
- else
- // image descriptor block?
- if (type == 0x2C)
- {
- // allocate memory for IMAGEN struct
- GIFImagePtr pimg(new GIFImage());
-
- wxScopeGuard guardDestroy = wxMakeObjGuard(*this, &wxGIFDecoder::Destroy);
+ break;
+ case GIF_MARKER_SEP:
+ {
+ // allocate memory for IMAGEN struct
+ GIFImagePtr pimg(new GIFImage());
- if ( !pimg.get() )
- return wxGIF_MEMERR;
+ wxScopeGuard guardDestroy = wxMakeObjGuard(*this, &wxGIFDecoder::Destroy);
- // fill in the data
- static const unsigned int idbSize = (2 + 2 + 2 + 2 + 1);
- stream.Read(buf, idbSize);
- if (stream.LastRead() != idbSize)
- return wxGIF_INVFORMAT;
+ if ( !pimg.get() )
+ return wxGIF_MEMERR;
- pimg->left = buf[0] + 256 * buf[1];
- pimg->top = buf[2] + 256 * buf[3];
-/*
- pimg->left = buf[4] + 256 * buf[5];
- pimg->top = buf[4] + 256 * buf[5];
-*/
- pimg->w = buf[4] + 256 * buf[5];
- pimg->h = buf[6] + 256 * buf[7];
+ // fill in the data
+ static const unsigned int idbSize = (2 + 2 + 2 + 2 + 1);
+ stream.Read(buf, idbSize);
+ if (stream.LastRead() != idbSize)
+ return wxGIF_INVFORMAT;
- if ( anim )
- {
- // some GIF images specify incorrect animation size but we can
- // still open them if we fix up the animation size, see #9465
- if ( m_nFrames == 0 )
- {
- if ( pimg->w > (unsigned)m_szAnimation.x )
- m_szAnimation.x = pimg->w;
- if ( pimg->h > (unsigned)m_szAnimation.y )
- m_szAnimation.y = pimg->h;
- }
- else // subsequent frames
+ pimg->comment = comment;
+ comment.clear();
+ pimg->left = buf[0] + 256 * buf[1];
+ pimg->top = buf[2] + 256 * buf[3];
+ /*
+ pimg->left = buf[4] + 256 * buf[5];
+ pimg->top = buf[4] + 256 * buf[5];
+ */
+ pimg->w = buf[4] + 256 * buf[5];
+ pimg->h = buf[6] + 256 * buf[7];
+
+ if ( anim )
{
- // check that we have valid size
- if ( (!pimg->w || pimg->w > (unsigned)m_szAnimation.x) ||
- (!pimg->h || pimg->h > (unsigned)m_szAnimation.y) )
+ // some GIF images specify incorrect animation size but we can
+ // still open them if we fix up the animation size, see #9465
+ if ( m_nFrames == 0 )
{
- wxLogError(_("Incorrect GIF frame size (%u, %d) for "
- "the frame #%u"),
- pimg->w, pimg->h, m_nFrames);
- return wxGIF_INVFORMAT;
+ if ( pimg->w > (unsigned)m_szAnimation.x )
+ m_szAnimation.x = pimg->w;
+ if ( pimg->h > (unsigned)m_szAnimation.y )
+ m_szAnimation.y = pimg->h;
+ }
+ else // subsequent frames
+ {
+ // check that we have valid size
+ if ( (!pimg->w || pimg->w > (unsigned)m_szAnimation.x) ||
+ (!pimg->h || pimg->h > (unsigned)m_szAnimation.y) )
+ {
+ wxLogError(_("Incorrect GIF frame size (%u, %d) for "
+ "the frame #%u"),
+ pimg->w, pimg->h, m_nFrames);
+ return wxGIF_INVFORMAT;
+ }
}
}
- }
- interl = ((buf[8] & 0x40)? 1 : 0);
- size = pimg->w * pimg->h;
+ interl = ((buf[8] & 0x40)? 1 : 0);
+ size = pimg->w * pimg->h;
- pimg->transparent = transparent;
- pimg->disposal = disposal;
- pimg->delay = delay;
+ pimg->transparent = transparent;
+ pimg->disposal = disposal;
+ pimg->delay = delay;
- // allocate memory for image and palette
- pimg->p = (unsigned char *) malloc((unsigned int)size);
- pimg->pal = (unsigned char *) malloc(768);
+ // allocate memory for image and palette
+ pimg->p = (unsigned char *) malloc((unsigned int)size);
+ pimg->pal = (unsigned char *) malloc(768);
- if ((!pimg->p) || (!pimg->pal))
- return wxGIF_MEMERR;
+ if ((!pimg->p) || (!pimg->pal))
+ return wxGIF_MEMERR;
- // load local color map if available, else use global map
- if ((buf[8] & 0x80) == 0x80)
- {
- unsigned int local_ncolors = 2 << (buf[8] & 0x07);
- unsigned int numBytes = 3 * local_ncolors;
- stream.Read(pimg->pal, numBytes);
- pimg->ncolours = local_ncolors;
- if (stream.LastRead() != numBytes)
- return wxGIF_INVFORMAT;
- }
- else
- {
- memcpy(pimg->pal, pal, 768);
- pimg->ncolours = global_ncolors;
- }
+ // load local color map if available, else use global map
+ if ((buf[8] & 0x80) == 0x80)
+ {
+ unsigned int local_ncolors = 2 << (buf[8] & 0x07);
+ unsigned int numBytes = 3 * local_ncolors;
+ stream.Read(pimg->pal, numBytes);
+ pimg->ncolours = local_ncolors;
+ if (stream.LastRead() != numBytes)
+ return wxGIF_INVFORMAT;
+ }
+ else
+ {
+ memcpy(pimg->pal, pal, 768);
+ pimg->ncolours = global_ncolors;
+ }
- // get initial code size from first byte in raster data
- bits = (unsigned char)stream.GetC();
- if (bits == 0)
- return wxGIF_INVFORMAT;
+ // get initial code size from first byte in raster data
+ bits = stream.GetC();
+ if (bits == 0)
+ return wxGIF_INVFORMAT;
- // decode image
- wxGIFErrorCode result = dgif(stream, pimg.get(), interl, bits);
- if (result != wxGIF_OK)
- return result;
+ // decode image
+ wxGIFErrorCode result = dgif(stream, pimg.get(), interl, bits);
+ if (result != wxGIF_OK)
+ return result;
- guardDestroy.Dismiss();
+ guardDestroy.Dismiss();
- // add the image to our frame array
- m_frames.Add(pimg.release());
- m_nFrames++;
+ // add the image to our frame array
+ m_frames.Add(pimg.release());
+ m_nFrames++;
- // if this is not an animated GIF, exit after first image
- if (!anim)
- done = true;
+ // if this is not an animated GIF, exit after first image
+ if (!anim)
+ done = true;
+ break;
+ }
}
}
}
// try to read to the end of the stream
- while (type != 0x3B)
+ while (type != GIF_MARKER_ENDOFDATA)
{
if (!stream.IsOk())
return wxGIF_TRUNCATED;
- type = (unsigned char)stream.GetC();
+ type = stream.GetC();
- if (type == 0x21)
+ switch (type)
{
- // extension type
- (void) stream.GetC();
+ case GIF_MARKER_EXT:
+ // extension type
+ (void) stream.GetC();
- // skip all data
- while ((i = (unsigned char)stream.GetC()) != 0)
- {
- if (stream.Eof() || (stream.LastRead() == 0) ||
- stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+ // skip all data
+ while ((i = stream.GetC()) != 0)
{
- Destroy();
- return wxGIF_INVFORMAT;
+ if (stream.Eof() || (stream.LastRead() == 0) ||
+ stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
}
- }
- }
- else if (type == 0x2C)
- {
- // image descriptor block
- static const unsigned int idbSize = (2 + 2 + 2 + 2 + 1);
- stream.Read(buf, idbSize);
- if (stream.LastRead() != idbSize)
- {
- Destroy();
- return wxGIF_INVFORMAT;
- }
-
- // local color map
- if ((buf[8] & 0x80) == 0x80)
+ break;
+ case GIF_MARKER_SEP:
{
- unsigned int local_ncolors = 2 << (buf[8] & 0x07);
- wxFileOffset numBytes = 3 * local_ncolors;
- if (stream.SeekI(numBytes, wxFromCurrent) == wxInvalidOffset)
+ // image descriptor block
+ static const unsigned int idbSize = (2 + 2 + 2 + 2 + 1);
+ stream.Read(buf, idbSize);
+ if (stream.LastRead() != idbSize)
{
Destroy();
return wxGIF_INVFORMAT;
}
- }
- // initial code size
- (void) stream.GetC();
- if (stream.Eof() || (stream.LastRead() == 0))
- {
- Destroy();
- return wxGIF_INVFORMAT;
- }
+ // local color map
+ if ((buf[8] & 0x80) == 0x80)
+ {
+ unsigned int local_ncolors = 2 << (buf[8] & 0x07);
+ wxFileOffset numBytes = 3 * local_ncolors;
+ if (stream.SeekI(numBytes, wxFromCurrent) == wxInvalidOffset)
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
+ }
- // skip all data
- while ((i = (unsigned char)stream.GetC()) != 0)
- {
- if (stream.Eof() || (stream.LastRead() == 0) ||
- stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+ // initial code size
+ (void) stream.GetC();
+ if (stream.Eof() || (stream.LastRead() == 0))
{
Destroy();
return wxGIF_INVFORMAT;
}
+
+ // skip all data
+ while ((i = stream.GetC()) != 0)
+ {
+ if (stream.Eof() || (stream.LastRead() == 0) ||
+ stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
+ }
+ break;
}
- }
- else if ((type != 0x3B) && (type != 00)) // testing
- {
- // images are OK, but couldn't read to the end of the stream
- return wxGIF_TRUNCATED;
+ default:
+ if ((type != GIF_MARKER_ENDOFDATA) && (type != 00)) // testing
+ {
+ // images are OK, but couldn't read to the end of the stream
+ return wxGIF_TRUNCATED;
+ }
+ break;
}
}
projects / wxWidgets.git / blobdiff