/////////////////////////////////////////////////////////////////////////////
-// Name: gifdecod.cpp
+// Name: src/common/gifdecod.cpp
// Purpose: wxGIFDecoder, GIF reader for wxImage and wxAnimation
// Author: Guillermo Rodriguez Garcia <guille@iies.es>
// Version: 3.04
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
-#ifdef __GNUG__
-#pragma implementation "gifdecod.h"
-#endif
-
// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"
#ifdef __BORLANDC__
-# pragma hdrstop
+ #pragma hdrstop
#endif
+#if wxUSE_STREAMS && wxUSE_GIF
+
#ifndef WX_PRECOMP
-# include "wx/defs.h"
+ #include "wx/palette.h"
+ #include "wx/intl.h"
+ #include "wx/log.h"
#endif
-#if wxUSE_STREAMS && wxUSE_GIF
-
#include <stdlib.h>
#include <string.h>
#include "wx/gifdecod.h"
+#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
+//---------------------------------------------------------------------------
+
+// internal class for storing GIF image data
+class GIFImage
+{
+public:
+ // def ctor
+ GIFImage();
+
+ unsigned int w; // width
+ unsigned int h; // height
+ unsigned int left; // x coord (in logical screen)
+ unsigned int top; // y coord (in logical screen)
+ int transparent; // transparent color index (-1 = none)
+ wxAnimationDisposal disposal; // disposal method
+ long delay; // delay in ms (-1 = unused)
+ unsigned char *p; // bitmap
+ unsigned char *pal; // palette
+ unsigned int ncolours; // number of colours
+ wxString comment;
+
+ wxDECLARE_NO_COPY_CLASS(GIFImage);
+};
+
+wxDECLARE_SCOPED_PTR(GIFImage, GIFImagePtr)
+wxDEFINE_SCOPED_PTR(GIFImage, GIFImagePtr)
//---------------------------------------------------------------------------
left = 0;
top = 0;
transparent = 0;
- disposal = 0;
+ disposal = wxANIM_DONOTREMOVE;
delay = -1;
p = (unsigned char *) NULL;
pal = (unsigned char *) NULL;
- next = (GIFImage *) NULL;
- prev = (GIFImage *) NULL;
+ ncolours = 0;
}
//---------------------------------------------------------------------------
// wxGIFDecoder constructor and destructor
//---------------------------------------------------------------------------
-wxGIFDecoder::wxGIFDecoder(wxInputStream *s, bool anim)
+wxGIFDecoder::wxGIFDecoder()
{
- m_f = s;
- m_anim = anim;
-
- m_background = -1;
- m_screenw = 0;
- m_screenh = 0;
-
- m_pimage = NULL;
- m_pfirst = NULL;
- m_plast = NULL;
- m_image = 0;
- m_nimages = 0;
}
wxGIFDecoder::~wxGIFDecoder()
void wxGIFDecoder::Destroy()
{
- GIFImage *pimg, *paux;
-
- pimg = m_pfirst;
-
- while (pimg != NULL)
+ wxASSERT(m_nFrames==m_frames.GetCount());
+ for (unsigned int i=0; i<m_nFrames; i++)
{
- paux = pimg->next;
- free(pimg->p);
- free(pimg->pal);
- delete pimg;
- pimg = paux;
+ GIFImage *f = (GIFImage*)m_frames[i];
+ free(f->p);
+ free(f->pal);
+ delete f;
}
- m_pimage = NULL;
- m_pfirst = NULL;
- m_plast = NULL;
- m_image = 0;
- m_nimages = 0;
+ m_frames.Clear();
+ m_nFrames = 0;
}
// This function was designed by Vaclav Slavik
-bool wxGIFDecoder::ConvertToImage(wxImage *image) const
+bool wxGIFDecoder::ConvertToImage(unsigned int frame, wxImage *image) const
{
unsigned char *src, *dst, *pal;
unsigned long i;
int transparent;
- /* just in case... */
+ // just in case...
image->Destroy();
- /* create the image */
- image->Create(GetWidth(), GetHeight());
+ // create the image
+ wxSize sz = GetFrameSize(frame);
+ image->Create(sz.GetWidth(), sz.GetHeight());
+ image->SetType(wxBITMAP_TYPE_GIF);
- if (!image->Ok())
- return FALSE;
+ if (!image->IsOk())
+ return false;
- pal = GetPalette();
- src = GetData();
+ pal = GetPalette(frame);
+ src = GetData(frame);
dst = image->GetData();
- transparent = GetTransparentColour();
+ transparent = GetTransparentColourIndex(frame);
- /* set transparent colour mask */
+ // set transparent colour mask
if (transparent != -1)
{
- for (i = 0; i < 256; i++)
+ for (i = 0; i < GetNcolours(frame); i++)
{
if ((pal[3 * i + 0] == 255) &&
(pal[3 * i + 1] == 0) &&
image->SetMaskColour(255, 0, 255);
}
else
- image->SetMask(FALSE);
+ image->SetMask(false);
#if wxUSE_PALETTE
- if (pal)
- {
- unsigned char r[256];
- unsigned char g[256];
- unsigned char b[256];
-
- for (i = 0; i < 256; i++)
- {
- r[i] = pal[3*i + 0];
- g[i] = pal[3*i + 1];
- b[i] = pal[3*i + 2];
- }
+ unsigned char r[256];
+ unsigned char g[256];
+ unsigned char b[256];
- image->SetPalette(wxPalette(256, r, g, b));
+ for (i = 0; i < 256; i++)
+ {
+ r[i] = pal[3*i + 0];
+ g[i] = pal[3*i + 1];
+ b[i] = pal[3*i + 2];
}
+
+ image->SetPalette(wxPalette(GetNcolours(frame), r, g, b));
#endif // wxUSE_PALETTE
- /* copy image data */
- for (i = 0; i < (GetWidth() * GetHeight()); i++, src++)
+ // copy image data
+ unsigned long npixel = sz.GetWidth() * sz.GetHeight();
+ for (i = 0; i < npixel; i++, src++)
{
*(dst++) = pal[3 * (*src) + 0];
*(dst++) = pal[3 * (*src) + 1];
*(dst++) = pal[3 * (*src) + 2];
}
- return TRUE;
+ wxString comment = GetFrame(frame)->comment;
+ if ( !comment.empty() )
+ {
+ image->SetOption(wxIMAGE_OPTION_GIF_COMMENT, comment);
+ }
+
+ return true;
}
// Get data for current frame
-int wxGIFDecoder::GetFrameIndex() const { return m_image; }
-unsigned char* wxGIFDecoder::GetData() const { return (m_pimage->p); }
-unsigned char* wxGIFDecoder::GetPalette() const { return (m_pimage->pal); }
-unsigned int wxGIFDecoder::GetWidth() const { return (m_pimage->w); }
-unsigned int wxGIFDecoder::GetHeight() const { return (m_pimage->h); }
-unsigned int wxGIFDecoder::GetTop() const { return (m_pimage->top); }
-unsigned int wxGIFDecoder::GetLeft() const { return (m_pimage->left); }
-int wxGIFDecoder::GetTransparentColour() const { return (m_pimage->transparent); }
-int wxGIFDecoder::GetDisposalMethod() const { return (m_pimage->disposal); }
-long wxGIFDecoder::GetDelay() const { return (m_pimage->delay); }
-
-// Get global data
-
-unsigned int wxGIFDecoder::GetLogicalScreenWidth() const { return m_screenw; }
-unsigned int wxGIFDecoder::GetLogicalScreenHeight() const { return m_screenh; }
-int wxGIFDecoder::GetBackgroundColour() const { return m_background; }
-int wxGIFDecoder::GetNumberOfFrames() const { return m_nimages; }
-bool wxGIFDecoder::IsAnimation() const { return (m_nimages > 1); }
-
-
-//---------------------------------------------------------------------------
-// Functions to move through the animation
-//---------------------------------------------------------------------------
-
-bool wxGIFDecoder::GoFirstFrame()
+wxSize wxGIFDecoder::GetFrameSize(unsigned int frame) const
{
- if (!IsAnimation())
- return FALSE;
-
- m_image = 1;
- m_pimage = m_pfirst;
- return TRUE;
+ return wxSize(GetFrame(frame)->w, GetFrame(frame)->h);
}
-bool wxGIFDecoder::GoLastFrame()
+wxPoint wxGIFDecoder::GetFramePosition(unsigned int frame) const
{
- if (!IsAnimation())
- return FALSE;
-
- m_image = m_nimages;
- m_pimage = m_plast;
- return TRUE;
+ return wxPoint(GetFrame(frame)->left, GetFrame(frame)->top);
}
-bool wxGIFDecoder::GoNextFrame(bool cyclic)
+wxAnimationDisposal wxGIFDecoder::GetDisposalMethod(unsigned int frame) const
{
- if (!IsAnimation())
- return FALSE;
-
- if ((m_image < m_nimages) || (cyclic))
- {
- m_pimage = m_pimage->next;
- m_image++;
-
- if (!m_pimage)
- {
- m_image = 1;
- m_pimage = m_pfirst;
- }
-
- return TRUE;
- }
- else
- return FALSE;
+ return GetFrame(frame)->disposal;
}
-bool wxGIFDecoder::GoPrevFrame(bool cyclic)
+long wxGIFDecoder::GetDelay(unsigned int frame) const
{
- if (!IsAnimation())
- return FALSE;
-
- if ((m_image > 1) || (cyclic))
- {
- m_pimage = m_pimage->prev;
- m_image--;
-
- if (!m_pimage)
- {
- m_image = m_nimages;
- m_pimage = m_plast;
- }
-
- return TRUE;
- }
- else
- return FALSE;
+ return GetFrame(frame)->delay;
}
-bool wxGIFDecoder::GoFrame(int which)
+wxColour wxGIFDecoder::GetTransparentColour(unsigned int frame) const
{
- int i;
-
- if (!IsAnimation())
- return FALSE;
-
- if ((which >= 1) && (which <= m_nimages))
- {
- m_pimage = m_pfirst;
+ unsigned char *pal = GetFrame(frame)->pal;
+ int n = GetFrame(frame)->transparent;
+ if (n == -1)
+ return wxNullColour;
+
+ return wxColour(pal[n*3 + 0],
+ pal[n*3 + 1],
+ pal[n*3 + 2]);
+}
- for (i = 1; i < which; i++)
- m_pimage = m_pimage->next;
+unsigned char* wxGIFDecoder::GetData(unsigned int frame) const { return (GetFrame(frame)->p); }
+unsigned char* wxGIFDecoder::GetPalette(unsigned int frame) const { return (GetFrame(frame)->pal); }
+unsigned int wxGIFDecoder::GetNcolours(unsigned int frame) const { return (GetFrame(frame)->ncolours); }
+int wxGIFDecoder::GetTransparentColourIndex(unsigned int frame) const { return (GetFrame(frame)->transparent); }
- return TRUE;
- }
- else
- return FALSE;
-}
//---------------------------------------------------------------------------
// getcode:
// Reads the next code from the file stream, with size 'bits'
//
-int wxGIFDecoder::getcode(int bits, int ab_fin)
+int wxGIFDecoder::getcode(wxInputStream& stream, int bits, int ab_fin)
{
- unsigned int mask; /* bit mask */
- unsigned int code; /* code (result) */
-
+ unsigned int mask; // bit mask
+ unsigned int code; // code (result)
- /* get remaining bits from last byte read */
+ // get remaining bits from last byte read
mask = (1 << bits) - 1;
code = (m_lastbyte >> (8 - m_restbits)) & mask;
- /* keep reading new bytes while needed */
+ // keep reading new bytes while needed
while (bits > m_restbits)
{
- /* if no bytes left in this block, read the next block */
+ // if no bytes left in this block, read the next block
if (m_restbyte == 0)
{
- m_restbyte = (unsigned char)m_f->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
break;
}
- /* prefetch data */
- m_f->Read((void *) m_buffer, m_restbyte);
- if (m_f->LastRead() != m_restbyte)
+ // prefetch data
+ stream.Read((void *) m_buffer, m_restbyte);
+ if (stream.LastRead() != m_restbyte)
{
code = ab_fin;
return code;
m_bufp = m_buffer;
}
- /* read next byte and isolate the bits we need */
+ // read next byte and isolate the bits we need
m_lastbyte = (unsigned char) (*m_bufp++);
mask = (1 << (bits - m_restbits)) - 1;
code = code + ((m_lastbyte & mask) << m_restbits);
m_restbyte--;
- /* adjust total number of bits extracted from the buffer */
+ // adjust total number of bits extracted from the buffer
m_restbits = m_restbits + 8;
}
- /* find number of bits remaining for next code */
+ // find number of bits remaining for next code
m_restbits = (m_restbits - bits);
return code;
// is 'bits'. Supports interlaced images (interl == 1).
// Returns wxGIF_OK (== 0) on success, or an error code if something
// fails (see header file for details)
-int wxGIFDecoder::dgif(GIFImage *img, int interl, int bits)
+wxGIFErrorCode
+wxGIFDecoder::dgif(wxInputStream& stream, GIFImage *img, int interl, int bits)
{
static const int allocSize = 4096 + 1;
- int *ab_prefix = new int[allocSize]; /* alphabet (prefixes) */
+ int *ab_prefix = new int[allocSize]; // alphabet (prefixes)
if (ab_prefix == NULL)
{
return wxGIF_MEMERR;
}
- int *ab_tail = new int[allocSize]; /* alphabet (tails) */
+ int *ab_tail = new int[allocSize]; // alphabet (tails)
if (ab_tail == NULL)
{
delete[] ab_prefix;
return wxGIF_MEMERR;
}
- int *stack = new int[allocSize]; /* decompression stack */
+ int *stack = new int[allocSize]; // decompression stack
if (stack == NULL)
{
delete[] ab_prefix;
return wxGIF_MEMERR;
}
- int ab_clr; /* clear code */
- int ab_fin; /* end of info code */
- int ab_bits; /* actual symbol width, in bits */
- int ab_free; /* first free position in alphabet */
- int ab_max; /* last possible character in alphabet */
- int pass; /* pass number in interlaced images */
- int pos; /* index into decompresion stack */
- unsigned int x, y; /* position in image buffer */
+ int ab_clr; // clear code
+ int ab_fin; // end of info code
+ int ab_bits; // actual symbol width, in bits
+ int ab_free; // first free position in alphabet
+ int ab_max; // last possible character in alphabet
+ int pass; // pass number in interlaced images
+ int pos; // index into decompresion stack
+ unsigned int x, y; // position in image buffer
int code, readcode, lastcode, abcabca;
- /* these won't change */
+ // these won't change
ab_clr = (1 << bits);
ab_fin = (1 << bits) + 1;
- /* these will change through the decompression proccess */
+ // these will change through the decompression proccess
ab_bits = bits + 1;
ab_free = (1 << bits) + 2;
ab_max = (1 << ab_bits) - 1;
pass = 1;
pos = x = y = 0;
- /* reset decoder vars */
+ // reset decoder vars
m_restbits = 0;
m_restbyte = 0;
m_lastbyte = 0;
do
{
- /* get next code */
- readcode = code = getcode(ab_bits, ab_fin);
+ // get next code
+ readcode = code = getcode(stream, ab_bits, ab_fin);
- /* end of image? */
+ // end of image?
if (code == ab_fin) break;
- /* reset alphabet? */
+ // reset alphabet?
if (code == ab_clr)
{
- /* reset main variables */
+ // reset main variables
ab_bits = bits + 1;
ab_free = (1 << bits) + 2;
ab_max = (1 << ab_bits) - 1;
lastcode = -1;
abcabca = -1;
- /* skip to next code */
+ // skip to next code
continue;
}
- /* unknown code: special case (like in ABCABCA) */
+ // unknown code: special case (like in ABCABCA)
if (code >= ab_free)
{
- code = lastcode; /* take last string */
- stack[pos++] = abcabca; /* add first character */
+ code = lastcode; // take last string
+ stack[pos++] = abcabca; // add first character
}
- /* build the string for this code in the stack */
+ // build the string for this code in the stack
while (code > ab_clr)
{
stack[pos++] = ab_tail[code];
return wxGIF_INVFORMAT;
}
}
- stack[pos] = code; /* push last code into the stack */
- abcabca = code; /* save for special case */
- /* make new entry in alphabet (only if NOT just cleared) */
+ if (pos >= allocSize)
+ {
+ delete[] ab_prefix;
+ delete[] ab_tail;
+ delete[] stack;
+ return wxGIF_INVFORMAT;
+ }
+
+ stack[pos] = code; // push last code into the stack
+ abcabca = code; // save for special case
+
+ // make new entry in alphabet (only if NOT just cleared)
if (lastcode != -1)
{
+ // Normally, after the alphabet is full and can't grow any
+ // further (ab_free == 4096), encoder should (must?) emit CLEAR
+ // to reset it. This checks whether we really got it, otherwise
+ // the GIF is damaged.
+ if (ab_free > ab_max)
+ {
+ delete[] ab_prefix;
+ delete[] ab_tail;
+ delete[] stack;
+ return wxGIF_INVFORMAT;
+ }
+
+ // This assert seems unnecessary since the condition above
+ // eliminates the only case in which it went false. But I really
+ // don't like being forced to ask "Who in .text could have
+ // written there?!" And I wouldn't have been forced to ask if
+ // this line had already been here.
+ wxASSERT(ab_free < allocSize);
+
ab_prefix[ab_free] = lastcode;
ab_tail[ab_free] = code;
ab_free++;
}
}
- /* dump stack data to the buffer */
+ // dump stack data to the image buffer
while (pos >= 0)
{
- if (pos >= allocSize)
- {
- delete[] ab_prefix;
- delete[] ab_tail;
- delete[] stack;
- return wxGIF_INVFORMAT;
- }
-
- (img->p)[x + (y * (img->w))] = (char)stack[pos--];
+ (img->p)[x + (y * (img->w))] = (char) stack[pos];
+ pos--;
if (++x >= (img->w))
{
if (interl)
{
- /* support for interlaced images */
+ // support for interlaced images
switch (pass)
{
case 1: y += 8; break;
case 3: y += 4; break;
case 4: y += 2; break;
}
- if (y >= (img->h))
+
+ /* loop until a valid y coordinate has been
+ found, Or if the maximum number of passes has
+ been reached, exit the loop, and stop image
+ decoding (At this point the image is successfully
+ decoded).
+ If we don't loop, but merely set y to some other
+ value, that new value might still be invalid depending
+ on the height of the image. This would cause out of
+ bounds writing.
+ */
+ while (y >= (img->h))
{
switch (++pass)
{
case 2: y = 4; break;
case 3: y = 2; break;
case 4: y = 1; break;
+
+ default:
+ /*
+ It's possible we arrive here. For example this
+ happens when the image is interlaced, and the
+ height is 1. Looking at the above cases, the
+ lowest possible y is 1. While the only valid
+ one would be 0 for an image of height 1. So
+ 'eventually' the loop will arrive here.
+ This case makes sure this while loop is
+ exited, as well as the 2 other ones.
+ */
+
+ // Set y to a valid coordinate so the local
+ // while loop will be exited. (y = 0 always
+ // is >= img->h since if img->h == 0 the
+ // image is never decoded)
+ y = 0;
+
+ // This will exit the other outer while loop
+ pos = -1;
+
+ // This will halt image decoding.
+ code = ab_fin;
+
+ break;
}
}
}
else
{
- /* non-interlaced */
+ // non-interlaced
y++;
/*
Normally image decoding is finished when an End of Information code is
// CanRead:
-// Returns TRUE if the file looks like a valid GIF, FALSE otherwise.
+// Returns true if the file looks like a valid GIF, false otherwise.
//
-bool wxGIFDecoder::CanRead()
+bool wxGIFDecoder::DoCanRead(wxInputStream &stream) const
{
unsigned char buf[3];
- m_f->Read(buf, 3);
- m_f->SeekI(-3, wxFromCurrent);
+ if ( !stream.Read(buf, WXSIZEOF(buf)) )
+ return false;
- return (memcmp(buf, "GIF", 3) == 0);
+ return memcmp(buf, "GIF", WXSIZEOF(buf)) == 0;
}
-// ReadGIF:
+// LoadGIF:
// Reads and decodes one or more GIF images, depending on whether
// animated GIF support is enabled. Can read GIFs with any bit
// size (color depth), but the output images are always expanded
// (== 0) on success, or an error code if something fails (see
// header file for details)
//
-int wxGIFDecoder::ReadGIF()
+wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
{
- unsigned int ncolors;
- int bits, interl, transparent, disposal, i;
+ unsigned int global_ncolors = 0;
+ int bits, interl, i;
+ wxAnimationDisposal disposal;
long size;
long delay;
unsigned char type = 0;
unsigned char pal[768];
unsigned char buf[16];
- GIFImage **ppimg;
- GIFImage *pimg, *pprev;
+ bool anim = true;
- /* check GIF signature */
- if (!CanRead())
+ // check GIF signature
+ if (!CanRead(stream))
return wxGIF_INVFORMAT;
- /* check for animated GIF support (ver. >= 89a) */
+ // check for animated GIF support (ver. >= 89a)
- static const size_t headerSize = (3 + 3);
- m_f->Read(buf, headerSize);
- if (m_f->LastRead() != headerSize)
+ static const unsigned int headerSize = (3 + 3);
+ stream.Read(buf, headerSize);
+ if (stream.LastRead() != headerSize)
{
return wxGIF_INVFORMAT;
}
if (memcmp(buf + 3, "89a", 3) < 0)
{
- m_anim = FALSE;
+ anim = false;
}
- /* read logical screen descriptor block (LSDB) */
- static const size_t lsdbSize = (2 + 2 + 1 + 1 + 1);
- m_f->Read(buf, lsdbSize);
- if (m_f->LastRead() != lsdbSize)
+ // read logical screen descriptor block (LSDB)
+ static const unsigned int lsdbSize = (2 + 2 + 1 + 1 + 1);
+ stream.Read(buf, lsdbSize);
+ if (stream.LastRead() != lsdbSize)
{
return wxGIF_INVFORMAT;
}
- m_screenw = buf[0] + 256 * buf[1];
- m_screenh = buf[2] + 256 * buf[3];
+ m_szAnimation.SetWidth( buf[0] + 256 * buf[1] );
+ m_szAnimation.SetHeight( buf[2] + 256 * buf[3] );
+
+ if (anim && ((m_szAnimation.GetWidth() == 0) || (m_szAnimation.GetHeight() == 0)))
+ {
+ return wxGIF_INVFORMAT;
+ }
- /* load global color map if available */
+ // load global color map if available
if ((buf[4] & 0x80) == 0x80)
{
- m_background = buf[5];
+ int backgroundColIndex = buf[5];
- ncolors = 2 << (buf[4] & 0x07);
- size_t numBytes = 3 * ncolors;
- m_f->Read(pal, numBytes);
- if (m_f->LastRead() != numBytes)
+ global_ncolors = 2 << (buf[4] & 0x07);
+ unsigned int numBytes = 3 * global_ncolors;
+ stream.Read(pal, numBytes);
+ if (stream.LastRead() != numBytes)
{
return wxGIF_INVFORMAT;
}
+
+ m_background.Set(pal[backgroundColIndex*3 + 0],
+ pal[backgroundColIndex*3 + 1],
+ pal[backgroundColIndex*3 + 2]);
}
- /* transparent colour, disposal method and delay default to unused */
- transparent = -1;
- disposal = -1;
+ // transparent colour, disposal method and delay default to unused
+ int transparent = -1;
+ disposal = wxANIM_UNSPECIFIED;
delay = -1;
+ wxString comment;
- /* read images */
- ppimg = &m_pfirst;
- pprev = NULL;
- pimg = NULL;
-
- bool done = FALSE;
-
- while(!done)
+ bool done = false;
+ while (!done)
{
- type = (unsigned char)m_f->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
possible here since some init code is done after this loop.
*/
- if (m_f->Eof())// || !m_f->IsOk())
+ if (stream.Eof())// || !stream.IsOk())
{
/*
type is set to some bogus value, so there's no
break; // Alternative : "return wxGIF_INVFORMAT;"
}
- /* end of data? */
- if (type == 0x3B)
- {
- done = TRUE;
- }
- else
- /* extension block? */
- if (type == 0x21)
+ switch (type)
{
- if (((unsigned char)m_f->GetC()) == 0xF9)
- /* graphics control extension, parse it */
- {
- static const size_t gceSize = 6;
- m_f->Read(buf, gceSize);
- if (m_f->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
+
+ static const unsigned int gceSize = 6;
+ stream.Read(buf, gceSize);
+ if (stream.LastRead() != gceSize)
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
- /* read delay and convert from 1/100 of a second to ms */
- delay = 10 * (buf[2] + 256 * buf[3]);
+ // read delay and convert from 1/100 of a second to ms
+ delay = 10 * (buf[2] + 256 * buf[3]);
- /* read transparent colour index, if used */
- if (buf[1] & 0x01)
- transparent = buf[4];
+ // read transparent colour index, if used
+ transparent = buf[1] & 0x01 ? buf[4] : -1;
- /* read disposal method */
- disposal = (buf[1] & 0x1C) - 1;
- }
- else
- /* other extension, skip */
- {
- while ((i = (unsigned char)m_f->GetC()) != 0)
- {
- m_f->SeekI(i, wxFromCurrent);
- if (m_f->Eof())
+ // 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 */
- pimg = (*ppimg) = new GIFImage();
-
- if (pimg == NULL)
+ break;
+ case GIF_MARKER_SEP:
{
- Destroy();
- return wxGIF_MEMERR;
- }
+ // allocate memory for IMAGEN struct
+ GIFImagePtr pimg(new GIFImage());
- /* fill in the data */
- static const size_t idbSize = (2 + 2 + 2 + 2 + 1);
- m_f->Read(buf, idbSize);
- if (m_f->LastRead() != idbSize)
- {
- Destroy();
- return wxGIF_INVFORMAT;
- }
+ wxScopeGuard guardDestroy = wxMakeObjGuard(*this, &wxGIFDecoder::Destroy);
- 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 ( !pimg.get() )
+ return wxGIF_MEMERR;
- if (pimg->w == 0 || pimg->h == 0)
- {
- Destroy();
- return wxGIF_INVFORMAT;
- }
+ // 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;
+
+ 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 )
+ {
+ // 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
+ {
+ // 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->next = NULL;
- pimg->prev = pprev;
- pprev = pimg;
- ppimg = &pimg->next;
+ pimg->transparent = transparent;
+ pimg->disposal = disposal;
+ pimg->delay = delay;
- /* allocate memory for image and palette */
- pimg->p = (unsigned char *) malloc((size_t)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))
- {
- Destroy();
- 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)
- {
- ncolors = 2 << (buf[8] & 0x07);
- size_t numBytes = 3 * ncolors;
- m_f->Read(pimg->pal, numBytes);
- if (m_f->LastRead() != numBytes)
+ // load local color map if available, else use global map
+ if ((buf[8] & 0x80) == 0x80)
{
- Destroy();
- return wxGIF_INVFORMAT;
+ 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);
- }
+ else
+ {
+ memcpy(pimg->pal, pal, 768);
+ pimg->ncolours = global_ncolors;
+ }
+
+ // get initial code size from first byte in raster data
+ bits = stream.GetC();
+ if (bits == 0)
+ return wxGIF_INVFORMAT;
- /* get initial code size from first byte in raster data */
- bits = (unsigned char)m_f->GetC();
+ // decode image
+ wxGIFErrorCode result = dgif(stream, pimg.get(), interl, bits);
+ if (result != wxGIF_OK)
+ return result;
- /* decode image */
- int result = dgif(pimg, interl, bits);
- if (result != wxGIF_OK)
- {
- Destroy();
- return result;
- }
- m_nimages++;
+ guardDestroy.Dismiss();
- /* if this is not an animated GIF, exit after first image */
- if (!m_anim)
- done = TRUE;
+ // 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;
+ break;
+ }
}
}
- if (m_nimages == 0)
+ if (m_nFrames <= 0)
{
Destroy();
return wxGIF_INVFORMAT;
}
- /* setup image pointers */
- m_image = 1;
- m_plast = pimg;
- m_pimage = m_pfirst;
-
- /* try to read to the end of the stream */
- while (type != 0x3B)
+ // try to read to the end of the stream
+ while (type != GIF_MARKER_ENDOFDATA)
{
- if (!m_f->IsOk())
+ if (!stream.IsOk())
return wxGIF_TRUNCATED;
- type = (unsigned char)m_f->GetC();
-
- if (type == 0x21)
- {
- /* extension type */
- (void) m_f->GetC();
+ type = stream.GetC();
- /* skip all data */
- while ((i = (unsigned char)m_f->GetC()) != 0)
- {
- m_f->SeekI(i, wxFromCurrent);
- }
- }
- else if (type == 0x2C)
+ switch (type)
{
- /* image descriptor block */
- static const size_t idbSize = (2 + 2 + 2 + 2 + 1);
- m_f->Read(buf, idbSize);
- if (m_f->LastRead() != idbSize)
- {
- Destroy();
- return wxGIF_INVFORMAT;
- }
+ case GIF_MARKER_EXT:
+ // extension type
+ (void) stream.GetC();
- /* local color map */
- if ((buf[8] & 0x80) == 0x80)
+ // skip all data
+ while ((i = stream.GetC()) != 0)
+ {
+ if (stream.Eof() || (stream.LastRead() == 0) ||
+ stream.SeekI(i, wxFromCurrent) == wxInvalidOffset)
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
+ }
+ break;
+ case GIF_MARKER_SEP:
{
- ncolors = 2 << (buf[8] & 0x07);
- off_t pos = m_f->TellI();
- off_t numBytes = 3 * ncolors;
- m_f->SeekI(numBytes, wxFromCurrent);
- if (m_f->TellI() != (pos + numBytes))
+ // 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) m_f->GetC();
+ // 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)m_f->GetC()) != 0)
- {
- m_f->SeekI(i, wxFromCurrent);
+ // 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