fingers crossed..

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

diff --git a/src/common/gifdecod.cpp b/src/common/gifdecod.cpp
index 66c9aad915b90b6f252fc7553e6c5c9eb3e51c66..828afb82c8e864ac7c115a3c29499e905205b97e 100644 (file)
--- a/src/common/gifdecod.cpp
+++ b/src/common/gifdecod.cpp
@@ -36,7 +36,7 @@
 
 wxGIFDecoder::wxGIFDecoder(wxInputStream *s, bool anim)
 {
-    m_f = s;
+    m_f    = s;
     m_anim = anim;
 
     m_background = -1;
@@ -69,6 +69,12 @@ void wxGIFDecoder::Destroy()
         delete pimg;
         pimg = paux;
     }
+
+    m_pimage  = NULL;
+    m_pfirst  = NULL;
+    m_plast   = NULL;
+    m_image   = 0;
+    m_nimages = 0;
 }
 
 
@@ -120,6 +126,21 @@ bool wxGIFDecoder::ConvertToImage(wxImage *image) const
     else
         image->SetMask(FALSE);
 
+    if (pal)
+    {
+        unsigned char* r = new unsigned char[256];
+        unsigned char* g = new unsigned char[256];
+        unsigned char* b = new unsigned char[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));
+        delete[] r; delete[] g; delete[] b;
+    }
+
     /* copy image data */
     for (i = 0; i < (GetWidth() * GetHeight()); i++, src++)
     {
@@ -311,10 +332,15 @@ int wxGIFDecoder::getcode(int bits, int ab_fin)
 //
 int wxGIFDecoder::dgif(GIFImage *img, int interl, int bits)
 {
+#ifdef __WXMAC__
+    int *ab_prefix = new int[4096];        /* alphabet (prefixes) */
+    int *ab_tail = new int[4096];          /* alphabet (tails) */
+    int *stack = new int[4096];            /* decompression stack */
+#else
     int ab_prefix[4096];        /* alphabet (prefixes) */
     int ab_tail[4096];          /* alphabet (tails) */
     int stack[4096];            /* decompression stack */
-
+#endif
     int ab_clr;                 /* clear code */
     int ab_fin;                 /* end of info code */
     int ab_bits;                /* actual symbol width, in bits */
@@ -438,6 +464,11 @@ int wxGIFDecoder::dgif(GIFImage *img, int interl, int bits)
     }
     while (code != ab_fin);
 
+#ifdef __WXMAC__
+    delete [] ab_prefix ;
+    delete [] ab_tail ;
+    delete [] stack ;
+#endif
     return 0;
 }
 
@@ -461,7 +492,7 @@ 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
-//  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)
 //
@@ -470,16 +501,17 @@ int wxGIFDecoder::ReadGIF()
     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];
-    GIFImage      **ppimg, *pimg, *pprev;
+    GIFImage      **ppimg;
+       GIFImage      *pimg, *pprev;
 
     /* 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)
@@ -509,20 +541,18 @@ int wxGIFDecoder::ReadGIF()
     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)
-            break;
-
+        {
+            done = TRUE;
+        }
+        else
         /* extension block? */
         if (type == 0x21)
         {
@@ -546,18 +576,11 @@ int wxGIFDecoder::ReadGIF()
             {
                 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);
                 }
             }
         }
-
+        else
         /* image descriptor block? */
         if (type == 0x2C)
         {
@@ -611,16 +634,15 @@ int wxGIFDecoder::ReadGIF()
 
             /* decode image */
             dgif(pimg, interl, bits);
-
             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;
@@ -628,6 +650,50 @@ int wxGIFDecoder::ReadGIF()
         m_pimage = m_pfirst;
     }
 
+    /* try to read to the end of the stream */
+    while (type != 0x3B)
+    {
+        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;
 }