changed PPC struct alignement setting

[wxWidgets.git] / src / common / gifdecod.cpp

diff --git a/src/common/gifdecod.cpp b/src/common/gifdecod.cpp
index 39dfd44e8cbdf12ac87a15d5739fcc7098322f9f..f287947799cd8b7538956546883fbadc2eb3c67b 100644 (file)
--- a/src/common/gifdecod.cpp
+++ b/src/common/gifdecod.cpp
@@ -36,7 +36,7 @@
 
 wxGIFDecoder::wxGIFDecoder(wxInputStream *s, bool anim)
 {
 
 wxGIFDecoder::wxGIFDecoder(wxInputStream *s, bool anim)
 {

-    m_f = s;
+    m_f    = s;

     m_anim = anim;
 
     m_background = -1;
     m_anim = anim;
 
     m_background = -1;


@@ -69,6 +69,12 @@ void wxGIFDecoder::Destroy()
         delete pimg;
         pimg = paux;
     }
         delete pimg;
         pimg = paux;
     }

+
+    m_pimage  = NULL;
+    m_pfirst  = NULL;
+    m_plast   = NULL;
+    m_image   = 0;
+    m_nimages = 0;

 }
 
 
 }
 
 


@@ -120,6 +126,24 @@ bool wxGIFDecoder::ConvertToImage(wxImage *image) const
     else
         image->SetMask(FALSE);
 
     else
         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];
+        }
+
+        image->SetPalette(wxPalette(256, r, g, b));
+    }
+#endif // wxUSE_PALETTE
+

     /* copy image data */
     for (i = 0; i < (GetWidth() * GetHeight()); i++, src++)
     {
     /* copy image data */
     for (i = 0; i < (GetWidth() * GetHeight()); i++, src++)
     {


@@ -311,18 +335,17 @@ int wxGIFDecoder::getcode(int bits, int ab_fin)
 //
 int wxGIFDecoder::dgif(GIFImage *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) */
-    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 */
+    int *ab_prefix = new int[4096]; /* alphabet (prefixes) */
+    int *ab_tail = new int[4096];   /* alphabet (tails) */
+    int *stack = new int[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 */

 
     int code, readcode, lastcode, abcabca;
 
 
     int code, readcode, lastcode, abcabca;
 


@@ -429,6 +452,46 @@ int wxGIFDecoder::dgif(GIFImage *img, int interl, int bits)
                 {
                     /* non-interlaced */
                     y++;
                 {
                     /* 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;
+                    }

                 }
             }
         }
                 }
             }
         }


@@ -438,6 +501,10 @@ int wxGIFDecoder::dgif(GIFImage *img, int interl, int bits)
     }
     while (code != ab_fin);
 
     }
     while (code != ab_fin);
 

+    delete [] ab_prefix ;
+    delete [] ab_tail ;
+    delete [] stack ;
+

     return 0;
 }
 
     return 0;
 }
 


@@ -461,7 +528,7 @@ bool wxGIFDecoder::CanRead()
 //  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
 //  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 GIF_OK
+//  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)
 //
 //  (== 0) on success, or an error code if something fails (see
 //  header file for details)
 //


@@ -470,16 +537,17 @@ int wxGIFDecoder::ReadGIF()
     int           ncolors, bits, interl, transparent, disposal, i;
     long          size;
     long          delay;
     int           ncolors, bits, interl, transparent, disposal, i;
     long          size;
     long          delay;

-    unsigned char type;
+    unsigned char type = 0;

     unsigned char pal[768];
     unsigned char buf[16];
     unsigned char pal[768];
     unsigned char buf[16];

-    GIFImage      **ppimg, *pimg, *pprev;
+    GIFImage      **ppimg;
+        GIFImage      *pimg, *pprev;

 
     /* check GIF signature */
     if (!CanRead())
         return wxGIF_INVFORMAT;
 
 
     /* check GIF signature */
     if (!CanRead())
         return wxGIF_INVFORMAT;
 

-    /* check for and animated GIF support (ver. >= 89a) */
+    /* check for animated GIF support (ver. >= 89a) */

     m_f->Read(buf, 6);
 
     if (memcmp(buf + 3, "89a", 3) < 0)
     m_f->Read(buf, 6);
 
     if (memcmp(buf + 3, "89a", 3) < 0)


@@ -509,20 +577,18 @@ int wxGIFDecoder::ReadGIF()
     pprev = NULL;
     pimg  = NULL;
 
     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();
 
         /* end of data? */
         if (type == 0x3B)
     {
         type = (unsigned char)m_f->GetC();
 
         /* end of data? */
         if (type == 0x3B)

-            break;
-
+        {
+            done = TRUE;
+        }
+        else

         /* extension block? */
         if (type == 0x21)
         {
         /* extension block? */
         if (type == 0x21)
         {


@@ -546,18 +612,11 @@ int wxGIFDecoder::ReadGIF()
             {
                 while ((i = (unsigned char)m_f->GetC()) != 0)
                 {
             {
                 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);
                 }
             }
         }
                     m_f->SeekI(i, wxFromCurrent);
                 }
             }
         }

-
+        else

         /* image descriptor block? */
         if (type == 0x2C)
         {
         /* image descriptor block? */
         if (type == 0x2C)
         {


@@ -572,8 +631,12 @@ int wxGIFDecoder::ReadGIF()
 
             /* fill in the data */
             m_f->Read(buf, 9);
 
             /* fill in the data */
             m_f->Read(buf, 9);

+            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->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];
             interl = ((buf[8] & 0x40)? 1 : 0);
             pimg->w = buf[4] + 256 * buf[5];
             pimg->h = buf[6] + 256 * buf[7];
             interl = ((buf[8] & 0x40)? 1 : 0);


@@ -588,7 +651,7 @@ int wxGIFDecoder::ReadGIF()
             ppimg = &pimg->next;
 
             /* allocate memory for image and palette */
             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))
             pimg->pal = (unsigned char *) malloc(768);
 
             if ((!pimg->p) || (!pimg->pal))


@@ -611,16 +674,15 @@ int wxGIFDecoder::ReadGIF()
 
             /* decode image */
             dgif(pimg, interl, bits);
 
             /* decode image */
             dgif(pimg, interl, bits);

-

             m_nimages++;
             m_nimages++;

-        }

 
 

-        /* if we have one image and no animated GIF support, exit */
-        if (m_nimages == 1 && !m_anim)
-            break;
+            /* if this is not an animated GIF, exit after first image */
+            if (!m_anim)
+                done = TRUE;
+        }

     }
 
     }
 

-    /* finish successfully :-) */
+    /* setup image pointers */

     if (m_nimages != 0)
     {
         m_image = 1;
     if (m_nimages != 0)
     {
         m_image = 1;


@@ -628,6 +690,53 @@ int wxGIFDecoder::ReadGIF()
         m_pimage = m_pfirst;
     }
 
         m_pimage = m_pfirst;
     }
 

+    /* try to read to the end of the stream */
+    while (type != 0x3B)
+    {
+        if (!m_f->IsOk())
+            return wxGIF_TRUNCATED;
+            
+        type = (unsigned char)m_f->GetC();
+
+        if (type == 0x21)
+        {
+            /* extension type */
+            (void) m_f->GetC();
+
+            /* skip all data */
+            while ((i = (unsigned char)m_f->GetC()) != 0)
+            {
+                m_f->SeekI(i, wxFromCurrent);
+            }
+        }
+        else if (type == 0x2C)
+        {
+            /* image descriptor block */
+            m_f->Read(buf, 9);
+
+            /* local color map */
+            if ((buf[8] & 0x80) == 0x80)
+            {
+                ncolors = 2 << (buf[8] & 0x07);
+                m_f->SeekI(3 * ncolors, wxFromCurrent);
+            }
+
+            /* initial code size */
+            (void) m_f->GetC();
+
+            /* skip all data */
+            while ((i = (unsigned char)m_f->GetC()) != 0)
+            {
+                m_f->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 wxGIF_OK;
 }
 
     return wxGIF_OK;
 }