/////////////////////////////////////////////////////////////////////////////
-// 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
#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/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
//---------------------------------------------------------------------------
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 (size_t 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(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;
- 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->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++)
+ unsigned long npixel = sz.GetWidth() * sz.GetHeight();
+ for (i = 0; i < npixel; i++, src++)
{
*(dst++) = pal[3 * (*src) + 0];
*(dst++) = pal[3 * (*src) + 1];
// 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); }
-
-// 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); }
+#define GetFrame(n) ((GIFImage*)m_frames[n])
-//---------------------------------------------------------------------------
-// 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
{
- if (!IsAnimation())
- return false;
+ 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]);
+}
- if ((which >= 1) && (which <= m_nimages))
- {
- m_image = 1;
- m_pimage = m_pfirst;
+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); }
- while (m_image < which)
- {
- m_image++;
- m_pimage = m_pimage->next;
- }
-
- 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
}
/* prefetch data */
- m_f->Read((void *) m_buffer, m_restbyte);
- if (m_f->LastRead() != m_restbyte)
+ stream.Read((void *) m_buffer, m_restbyte);
+ if (stream.LastRead() != m_restbyte)
{
code = ab_fin;
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) */
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;
/* 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++;
// CanRead:
// 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];
- if ( !m_f->Read(buf, WXSIZEOF(buf)) )
+ if ( !stream.Read(buf, WXSIZEOF(buf)) )
return false;
- m_f->SeekI(-(wxFileOffset)WXSIZEOF(buf), wxFromCurrent);
+ stream.SeekI(-(wxFileOffset)WXSIZEOF(buf), wxFromCurrent);
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, transparent, 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())
+ if (!CanRead(stream))
return wxGIF_INVFORMAT;
/* check for animated GIF support (ver. >= 89a) */
static const size_t headerSize = (3 + 3);
- m_f->Read(buf, headerSize);
- if (m_f->LastRead() != headerSize)
+ 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)
+ 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 */
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);
+ size_t 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;
+ disposal = wxANIM_UNSPECIFIED;
delay = -1;
- /* read images */
- ppimg = &m_pfirst;
- pprev = NULL;
- pimg = NULL;
-
bool done = false;
-
- while(!done)
+ 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 ";"
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
/* extension block? */
if (type == 0x21)
{
- if (((unsigned char)m_f->GetC()) == 0xF9)
+ if (((unsigned char)stream.GetC()) == 0xF9)
/* graphics control extension, parse it */
{
static const size_t gceSize = 6;
- m_f->Read(buf, gceSize);
- if (m_f->LastRead() != gceSize)
+ stream.Read(buf, gceSize);
+ if (stream.LastRead() != gceSize)
{
Destroy();
return wxGIF_INVFORMAT;
transparent = buf[4];
/* read disposal method */
- disposal = ((buf[1] & 0x1C) >> 2) - 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)
{
- m_f->SeekI(i, wxFromCurrent);
- if (m_f->Eof())
+ if (stream.Eof() || (stream.LastRead() == 0))
{
done = true;
break;
}
+ stream.SeekI(i, wxFromCurrent);
}
}
}
if (type == 0x2C)
{
/* allocate memory for IMAGEN struct */
- pimg = (*ppimg) = new GIFImage();
+ GIFImage *pimg = new GIFImage();
if (pimg == NULL)
{
/* fill in the data */
static const size_t idbSize = (2 + 2 + 2 + 2 + 1);
- m_f->Read(buf, idbSize);
- if (m_f->LastRead() != idbSize)
+ stream.Read(buf, idbSize);
+ if (stream.LastRead() != idbSize)
{
Destroy();
return wxGIF_INVFORMAT;
pimg->w = buf[4] + 256 * buf[5];
pimg->h = buf[6] + 256 * buf[7];
- if (pimg->w == 0 || pimg->h == 0)
+ if (anim && ((pimg->w == 0) || (pimg->w > (unsigned int)m_szAnimation.GetWidth()) ||
+ (pimg->h == 0) || (pimg->h > (unsigned int)m_szAnimation.GetHeight())))
{
Destroy();
return wxGIF_INVFORMAT;
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_t)size);
/* 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)
+ 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 */
- int result = dgif(pimg, interl, bits);
+ wxGIFErrorCode result = dgif(stream, pimg, interl, bits);
if (result != wxGIF_OK)
{
Destroy();
return result;
}
- m_nimages++;
+
+ /* add the image to our frame array */
+ m_frames.Add((void*)pimg);
+ m_nFrames++;
/* if this is not an animated GIF, exit after first image */
- if (!m_anim)
+ if (!anim)
done = true;
}
}
- 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)
{
- if (!m_f->IsOk())
+ if (!stream.IsOk())
return wxGIF_TRUNCATED;
- type = (unsigned char)m_f->GetC();
+ type = (unsigned char)stream.GetC();
if (type == 0x21)
{
/* extension type */
- (void) m_f->GetC();
+ (void) stream.GetC();
/* skip all data */
- while ((i = (unsigned char)m_f->GetC()) != 0)
+ while ((i = (unsigned char)stream.GetC()) != 0)
{
- m_f->SeekI(i, wxFromCurrent);
+ if (stream.Eof() || (stream.LastRead() == 0))
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
+ stream.SeekI(i, wxFromCurrent);
}
}
else if (type == 0x2C)
{
/* image descriptor block */
static const size_t idbSize = (2 + 2 + 2 + 2 + 1);
- m_f->Read(buf, idbSize);
- if (m_f->LastRead() != idbSize)
+ stream.Read(buf, idbSize);
+ if (stream.LastRead() != idbSize)
{
Destroy();
return wxGIF_INVFORMAT;
/* local color map */
if ((buf[8] & 0x80) == 0x80)
{
- ncolors = 2 << (buf[8] & 0x07);
- wxFileOffset pos = m_f->TellI();
- wxFileOffset numBytes = 3 * ncolors;
- m_f->SeekI(numBytes, wxFromCurrent);
- if (m_f->TellI() != (pos + numBytes))
- {
- Destroy();
- return wxGIF_INVFORMAT;
- }
+ unsigned int local_ncolors = 2 << (buf[8] & 0x07);
+ wxFileOffset numBytes = 3 * local_ncolors;
+ stream.SeekI(numBytes, wxFromCurrent);
}
/* initial code size */
- (void) m_f->GetC();
+ (void) stream.GetC();
+ if (stream.Eof() || (stream.LastRead() == 0))
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
/* skip all data */
- while ((i = (unsigned char)m_f->GetC()) != 0)
+ while ((i = (unsigned char)stream.GetC()) != 0)
{
- m_f->SeekI(i, wxFromCurrent);
+ if (stream.Eof() || (stream.LastRead() == 0))
+ {
+ Destroy();
+ return wxGIF_INVFORMAT;
+ }
+ stream.SeekI(i, wxFromCurrent);
}
}
else if ((type != 0x3B) && (type != 00)) /* testing */
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