// Name: gifdecod.cpp
// Purpose: wxGIFDecoder, GIF reader for wxImage and wxAnimation
// Author: Guillermo Rodriguez Garcia <guille@iies.es>
-// Version: 3.01
-// Last rev: 1999/08/14
+// Version: 3.04
+// RCS-ID: $Id$
// Copyright: (c) Guillermo Rodriguez Garcia
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#endif
#ifndef WX_PRECOMP
-# include "wx/setup.h"
+# include "wx/defs.h"
#endif
-#if wxUSE_STREAMS
+#if wxUSE_STREAMS && wxUSE_GIF
#include <stdlib.h>
#include <string.h>
-#include "wx/defs.h"
#include "wx/gifdecod.h"
-
+
//---------------------------------------------------------------------------
// wxGIFDecoder constructor and destructor
void wxGIFDecoder::Destroy()
{
- IMAGEN *pimg, *paux;
+ GIFImage *pimg, *paux;
pimg = m_pfirst;
paux = pimg->next;
free(pimg->p);
free(pimg->pal);
- free(pimg);
+ delete pimg;
pimg = paux;
}
}
unsigned long i;
int transparent;
+ /* just in case... */
+ image->Destroy();
+
/* create the image */
image->Create(GetWidth(), GetHeight());
return TRUE;
}
-
+
//---------------------------------------------------------------------------
// Data accessors
//---------------------------------------------------------------------------
}
else
return FALSE;
-}
+}
bool wxGIFDecoder::GoPrevFrame(bool cyclic)
{
code = ab_fin;
break;
}
+
+ /* prefetch data */
+ m_f->Read((void *) m_buffer, m_restbyte);
+ 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--;
/* adjust total number of bits extracted from the buffer */
m_restbits = m_restbits + 8;
}
-
+
/* find number of bits remaining for next code */
m_restbits = (m_restbits - bits);
// 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)
+int wxGIFDecoder::dgif(GIFImage *img, int interl, int bits)
{
int ab_prefix[4096]; /* alphabet (prefixes) */
int ab_tail[4096]; /* alphabet (tails) */
pass = 1;
pos = x = y = 0;
- /* reset static globals */
+ /* reset decoder vars */
m_restbits = 0;
m_restbyte = 0;
m_lastbyte = 0;
}
+// CanRead:
+// Returns TRUE if the file looks like a valid GIF, FALSE otherwise.
+//
+bool wxGIFDecoder::CanRead()
+{
+ unsigned char buf[3];
+
+ m_f->Read(buf, 3);
+ m_f->SeekI(-3, wxFromCurrent);
+
+ return (memcmp(buf, "GIF", 3) == 0);
+}
+
+
// ReadGIF:
// 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 GIF_OK
+// (== 0) on success, or an error code if something fails (see
+// header file for details)
//
int wxGIFDecoder::ReadGIF()
{
unsigned char type;
unsigned char pal[768];
unsigned char buf[16];
- IMAGEN **ppimg, *pimg, *pprev;
+ GIFImage **ppimg, *pimg, *pprev;
+ /* check GIF signature */
+ if (!CanRead())
+ return wxGIF_INVFORMAT;
- /* check GIF signature and animated GIF support (ver. >= 89a) */
+ /* check for and animated GIF support (ver. >= 89a) */
m_f->Read(buf, 6);
- if (memcmp(buf, "GIF", 3) != 0)
- return E_FORMATO;
-
if (memcmp(buf + 3, "89a", 3) < 0)
m_anim = FALSE;
pprev = NULL;
pimg = NULL;
+#if defined(__VISAGECPP__)
+// VA just can't stand while(1)
+ bool bOs2var = TRUE;
+ while(bOs2var)
+#else
while (1)
+#endif
{
type = (unsigned char)m_f->GetC();
}
else
/* other extension, skip */
- {
+ {
while ((i = (unsigned char)m_f->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);
}
}
if (type == 0x2C)
{
/* allocate memory for IMAGEN struct */
- pimg = (*ppimg) = (IMAGEN *) malloc(sizeof(IMAGEN));
+ pimg = (*ppimg) = new GIFImage();
if (pimg == NULL)
{
Destroy();
- return E_MEMORIA;
+ return wxGIF_MEMERR;
}
/* fill in the data */
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 */
m_pimage = m_pfirst;
}
- return E_OK;
+ return wxGIF_OK;
}
-#endif // wxUSE_STREAM
+#endif // wxUSE_STREAMS && wxUSE_GIF
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