/////////////////////////////////////////////////////////////////////////////
-// 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"
#endif
-#if wxUSE_STREAMS && wxUSE_GIF
-
#include <stdlib.h>
#include <string.h>
#include "wx/gifdecod.h"
+
+//---------------------------------------------------------------------------
+// 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 */
+
+ DECLARE_NO_COPY_CLASS(GIFImage)
+};
+
+
+
+//---------------------------------------------------------------------------
+// GIFImage constructor
+//---------------------------------------------------------------------------
+GIFImage::GIFImage()
+{
+ w = 0;
+ h = 0;
+ left = 0;
+ top = 0;
+ transparent = 0;
+ disposal = wxANIM_DONOTREMOVE;
+ delay = -1;
+ p = (unsigned char *) NULL;
+ pal = (unsigned char *) 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()
{
- IMAGEN *pimg, *paux;
-
- pimg = m_pfirst;
-
- while (pimg != NULL)
+ wxASSERT(m_nFrames==m_frames.GetCount());
+ for (size_t i=0; i<m_nFrames; i++)
{
- paux = pimg->next;
- free(pimg->p);
- free(pimg->pal);
- free(pimg);
- pimg = paux;
+ GIFImage *f = (GIFImage*)m_frames[i];
+ free(f->p);
+ free(f->pal);
+ delete f;
}
+
+ m_frames.Clear();
+ m_nFrames = 0;
}
// This function was designed by Vaclav Slavik
-bool wxGIFDecoder::ConvertToImage(wxImage *image) const
+bool wxGIFDecoder::ConvertToImage(size_t frame, wxImage *image) const
{
unsigned char *src, *dst, *pal;
unsigned long i;
image->Destroy();
/* create the image */
- image->Create(GetWidth(), GetHeight());
+ wxSize sz = GetFrameSize(frame);
+ image->Create(sz.GetWidth(), sz.GetHeight());
if (!image->Ok())
- return FALSE;
+ return false;
- pal = GetPalette();
- src = GetData();
+ pal = GetPalette(frame);
+ src = GetData(frame);
dst = image->GetData();
- transparent = GetTransparentColour();
+ transparent = GetTransparentColourIndex(frame);
/* 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
+ 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];
+ }
+
+ image->SetPalette(wxPalette(GetNcolours(frame), r, g, b));
+#endif // wxUSE_PALETTE
/* copy image data */
- for (i = 0; i < (GetWidth() * GetHeight()); i++, src++)
+ 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;
+ return true;
}
// Data accessors
//---------------------------------------------------------------------------
-// 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); }
+#define GetFrame(n) ((GIFImage*)m_frames[n])
-// 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
-//---------------------------------------------------------------------------
+// Get data for current frame
-bool wxGIFDecoder::GoFirstFrame()
+wxSize wxGIFDecoder::GetFrameSize(size_t 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(size_t 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(size_t 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(size_t 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(size_t 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(size_t frame) const { return (GetFrame(frame)->p); }
+unsigned char* wxGIFDecoder::GetPalette(size_t frame) const { return (GetFrame(frame)->pal); }
+unsigned int wxGIFDecoder::GetNcolours(size_t frame) const { return (GetFrame(frame)->ncolours); }
+int wxGIFDecoder::GetTransparentColourIndex(size_t 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) */
-
/* get remaining bits from last byte read */
mask = (1 << bits) - 1;
code = (m_lastbyte >> (8 - m_restbits)) & mask;
/* if no bytes left in this block, read the next block */
if (m_restbyte == 0)
{
- m_restbyte = (unsigned char)m_f->GetC();
+ m_restbyte = (unsigned char)stream.GetC();
/* Some encoders are a bit broken: instead of issuing
* an end-of-image symbol (ab_fin) they come up with
code = ab_fin;
break;
}
+
+ /* 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 */
- m_lastbyte = (unsigned char)m_f->GetC();
+ m_lastbyte = (unsigned char) (*m_bufp++);
mask = (1 << (bits - m_restbits)) - 1;
code = code + ((m_lastbyte & mask) << m_restbits);
m_restbyte--;
// dgif:
// GIF decoding function. The initial code size (aka root size)
// is 'bits'. Supports interlaced images (interl == 1).
-//
-int wxGIFDecoder::dgif(IMAGEN *img, int interl, int bits)
+// Returns wxGIF_OK (== 0) on success, or an error code if something
+// fails (see header file for details)
+wxGIFErrorCode wxGIFDecoder::dgif(wxInputStream& stream, GIFImage *img, int interl, int bits)
{
- int ab_prefix[4096]; /* alphabet (prefixes) */
- int ab_tail[4096]; /* alphabet (tails) */
- int stack[4096]; /* decompression stack */
-
- 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 */
+ static const int allocSize = 4096 + 1;
+ int *ab_prefix = new int[allocSize]; /* alphabet (prefixes) */
+ if (ab_prefix == NULL)
+ {
+ return wxGIF_MEMERR;
+ }
+
+ 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 */
+ if (stack == NULL)
+ {
+ delete[] ab_prefix;
+ delete[] ab_tail;
+ 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 code, readcode, lastcode, abcabca;
pass = 1;
pos = x = y = 0;
- /* reset static globals */
+ /* reset decoder vars */
m_restbits = 0;
m_restbyte = 0;
m_lastbyte = 0;
do
{
/* get next code */
- readcode = code = getcode(ab_bits, ab_fin);
+ readcode = code = getcode(stream, ab_bits, ab_fin);
/* end of image? */
if (code == ab_fin) break;
{
stack[pos++] = ab_tail[code];
code = ab_prefix[code];
+
+ // Don't overflow. This shouldn't happen with normal
+ // GIF files, the allocSize of 4096+1 is enough. This
+ // will only happen with badly formed GIFs.
+ if (pos >= allocSize)
+ {
+ delete[] ab_prefix;
+ delete[] ab_tail;
+ delete[] stack;
+ return wxGIF_INVFORMAT;
+ }
+ }
+
+ 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)
{
- (img->p)[x + (y * (img->w))] = (char)stack[pos--];
+ (img->p)[x + (y * (img->w))] = (char) stack[pos];
+ pos--;
if (++x >= (img->w))
{
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;
}
}
}
{
/* non-interlaced */
y++;
+/*
+Normally image decoding is finished when an End of Information code is
+encountered (code == ab_fin) however some broken encoders write wrong
+"block byte counts" (The first byte value after the "code size" byte),
+being one value too high. It might very well be possible other variants
+of this problem occur as well. The only sensible solution seems to
+be to check for clipping.
+Example of wrong encoding:
+(1 * 1 B/W image, raster data stream follows in hex bytes)
+
+02 << B/W images have a code size of 2
+02 << Block byte count
+44 << LZW packed
+00 << Zero byte count (terminates data stream)
+
+Because the block byte count is 2, the zero byte count is used in the
+decoding process, and decoding is continued after this byte. (While it
+should signal an end of image)
+
+It should be:
+02
+02
+44
+01 << When decoded this correctly includes the End of Information code
+00
+
+Or (Worse solution):
+02
+01
+44
+00
+(The 44 doesn't include an End of Information code, but at least the
+decoder correctly skips to 00 now after decoding, and signals this
+as an End of Information itself)
+*/
+ if (y >= img->h)
+ {
+ code = ab_fin;
+ break;
+ }
}
}
}
}
while (code != ab_fin);
- return 0;
+ delete [] ab_prefix ;
+ delete [] ab_tail ;
+ delete [] stack ;
+
+ return wxGIF_OK;
}
// 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::CanRead(wxInputStream &stream) const
{
unsigned char buf[3];
- m_f->Read(buf, 3);
- stream.SeekI(-3, wxFromCurrent);
+ if ( !stream.Read(buf, WXSIZEOF(buf)) )
+ return false;
+
+ stream.SeekI(-(wxFileOffset)WXSIZEOF(buf), wxFromCurrent);
- 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
// to 8 bits per pixel. Also, the image palettes always contain
-// 256 colors, although some of them may be unused. Returns E_OK
-// (== 0) on success, or an error code if something fails. Error
-// codes are E_ARCHIVO, E_FORMATO, E_MEMORIA (see header file).
+// 256 colors, although some of them may be unused. Returns wxGIF_OK
+// (== 0) on success, or an error code if something fails (see
+// header file for details)
//
-int wxGIFDecoder::ReadGIF()
+wxGIFErrorCode wxGIFDecoder::LoadGIF(wxInputStream& stream)
{
- int ncolors, bits, interl, transparent, disposal, i;
+ unsigned int global_ncolors = 0;
+ int bits, interl, transparent, i;
+ wxAnimationDisposal disposal;
long size;
long delay;
- unsigned char type;
+ unsigned char type = 0;
unsigned char pal[768];
unsigned char buf[16];
- IMAGEN **ppimg, *pimg, *pprev;
+ bool anim = true;
/* check GIF signature */
- if (!CanRead())
- return E_FORMATO;
+ if (!CanRead(stream))
+ return wxGIF_INVFORMAT;
- /* check for and animated GIF support (ver. >= 89a) */
- m_f->Read(buf, 6);
+ /* check for animated GIF support (ver. >= 89a) */
+
+ static const size_t 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) */
- m_f->Read(buf, 7);
- m_screenw = buf[0] + 256 * buf[1];
- m_screenh = buf[2] + 256 * buf[3];
+ static const size_t lsdbSize = (2 + 2 + 1 + 1 + 1);
+ stream.Read(buf, lsdbSize);
+ if (stream.LastRead() != lsdbSize)
+ {
+ return wxGIF_INVFORMAT;
+ }
+
+ m_szAnimation.SetWidth( buf[0] + 256 * buf[1] );
+ m_szAnimation.SetHeight( buf[2] + 256 * buf[3] );
+
+ if ((m_szAnimation.GetWidth() == 0) || (m_szAnimation.GetHeight() == 0))
+ {
+ return wxGIF_INVFORMAT;
+ }
/* load global color map if available */
if ((buf[4] & 0x80) == 0x80)
{
- m_background = buf[5];
+ int backgroundColIndex = buf[5];
+
+ global_ncolors = 2 << (buf[4] & 0x07);
+ size_t numBytes = 3 * global_ncolors;
+ stream.Read(pal, numBytes);
+ if (stream.LastRead() != numBytes)
+ {
+ return wxGIF_INVFORMAT;
+ }
- ncolors = 2 << (buf[4] & 0x07);
- m_f->Read(pal, 3 * ncolors);
+ 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;
+ disposal = wxANIM_UNSPECIFIED;
delay = -1;
- /* read images */
- ppimg = &m_pfirst;
- pprev = NULL;
- pimg = NULL;
-
-#if defined(__VISAGECPP__)
-// VA just can't stand while(1)
- bool bOs2var = TRUE;
- while(bOs2var)
-#else
- while (1)
-#endif
+ bool done = false;
+ while (!done)
{
- type = (unsigned char)m_f->GetC();
+ type = (unsigned char)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
+ 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 (stream.Eof())// || !stream.IsOk())
+ {
+ /*
+ type is set to some bogus value, so there's no
+ need to continue evaluating it.
+ */
+ break; // Alternative : "return wxGIF_INVFORMAT;"
+ }
/* end of data? */
if (type == 0x3B)
- break;
-
+ {
+ done = true;
+ }
+ else
/* extension block? */
if (type == 0x21)
{
- if (((unsigned char)m_f->GetC()) == 0xF9)
+ if (((unsigned char)stream.GetC()) == 0xF9)
/* graphics control extension, parse it */
{
- m_f->Read(buf, 6);
+ static const size_t 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]);
transparent = buf[4];
/* read disposal method */
- disposal = (buf[1] & 0x1C) - 1;
+ disposal = (wxAnimationDisposal)(((buf[1] & 0x1C) >> 2) - 1);
}
else
/* other extension, skip */
{
- while ((i = (unsigned char)m_f->GetC()) != 0)
+ while ((i = (unsigned char)stream.GetC()) != 0)
{
- /* This line should not be neccessary!
- * Some images are not loaded correctly
- * without it. A bug in wxStream?
- * Yes. Fixed now.
- */
- // m_f->SeekI(m_f->TellI(), wxFromStart);
-
- m_f->SeekI(i, wxFromCurrent);
+ stream.SeekI(i, wxFromCurrent);
+ if (stream.Eof())
+ {
+ done = true;
+ break;
+ }
}
}
}
-
+ else
/* image descriptor block? */
if (type == 0x2C)
{
/* allocate memory for IMAGEN struct */
- pimg = (*ppimg) = (IMAGEN *) malloc(sizeof(IMAGEN));
+ GIFImage *pimg = new GIFImage();
if (pimg == NULL)
{
Destroy();
- return E_MEMORIA;
+ return wxGIF_MEMERR;
}
/* fill in the data */
- m_f->Read(buf, 9);
+ static const size_t idbSize = (2 + 2 + 2 + 2 + 1);
+ stream.Read(buf, idbSize);
+ if (stream.LastRead() != idbSize)
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
+
+ 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->w == 0) || (pimg->w > (unsigned int)m_szAnimation.GetWidth()) ||
+ (pimg->h == 0) || (pimg->h > (unsigned int)m_szAnimation.GetHeight()))
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
+
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;
/* allocate memory for image and palette */
- pimg->p = (unsigned char *) malloc(size);
+ pimg->p = (unsigned char *) malloc((size_t)size);
pimg->pal = (unsigned char *) malloc(768);
if ((!pimg->p) || (!pimg->pal))
{
Destroy();
- return E_MEMORIA;
+ return wxGIF_MEMERR;
}
/* load local color map if available, else use global map */
if ((buf[8] & 0x80) == 0x80)
{
- ncolors = 2 << (buf[8] & 0x07);
- m_f->Read(pimg->pal, 3 * ncolors);
+ unsigned int local_ncolors = 2 << (buf[8] & 0x07);
+ size_t numBytes = 3 * local_ncolors;
+ stream.Read(pimg->pal, numBytes);
+ pimg->ncolours = local_ncolors;
+ if (stream.LastRead() != numBytes)
+ {
+ Destroy();
+ 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)m_f->GetC();
+ bits = (unsigned char)stream.GetC();
+ if (bits == 0)
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
/* decode image */
- dgif(pimg, interl, bits);
+ wxGIFErrorCode result = dgif(stream, pimg, interl, bits);
+ if (result != wxGIF_OK)
+ {
+ Destroy();
+ return result;
+ }
+
+ /* add the image to our frame array */
+ m_frames.Add((void*)pimg);
+ m_nFrames++;
- m_nimages++;
+ /* if this is not an animated GIF, exit after first image */
+ if (!anim)
+ done = true;
}
+ }
- /* if we have one image and no animated GIF support, exit */
- if (m_nimages == 1 && !m_anim)
- break;
+ if (m_nFrames <= 0)
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
}
- /* finish successfully :-) */
- if (m_nimages != 0)
+ /* try to read to the end of the stream */
+ while (type != 0x3B)
{
- m_image = 1;
- m_plast = pimg;
- m_pimage = m_pfirst;
+ if (!stream.IsOk())
+ return wxGIF_TRUNCATED;
+
+ type = (unsigned char)stream.GetC();
+
+ if (type == 0x21)
+ {
+ /* extension type */
+ (void) stream.GetC();
+
+ /* skip all data */
+ while ((i = (unsigned char)stream.GetC()) != 0)
+ {
+ stream.SeekI(i, wxFromCurrent);
+ }
+ }
+ else if (type == 0x2C)
+ {
+ /* image descriptor block */
+ static const size_t 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)
+ {
+ unsigned int local_ncolors = 2 << (buf[8] & 0x07);
+ wxFileOffset pos = stream.TellI();
+ wxFileOffset numBytes = 3 * local_ncolors;
+ stream.SeekI(numBytes, wxFromCurrent);
+ if (stream.TellI() != (pos + numBytes))
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
+ }
+
+ /* initial code size */
+ (void) stream.GetC();
+
+ /* skip all data */
+ while ((i = (unsigned char)stream.GetC()) != 0)
+ {
+ stream.SeekI(i, wxFromCurrent);
+ }
+ }
+ else if ((type != 0x3B) && (type != 00)) /* testing */
+ {
+ /* images are OK, but couldn't read to the end of the stream */
+ return wxGIF_TRUNCATED;
+ }
}
- return E_OK;
+ return wxGIF_OK;
}
#endif // wxUSE_STREAMS && wxUSE_GIF
projects / wxWidgets.git / blobdiff