Document wxDocument::DeleteContents().

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

diff --git a/src/common/imaggif.cpp b/src/common/imaggif.cpp
index a4ac73ba758d210578a8ebe9f899584f523fec6d..fdb9a4971d1af78c4521d8d47c9fe2bb64c1d961 100644 (file)
--- a/src/common/imaggif.cpp
+++ b/src/common/imaggif.cpp
@@ -1,426 +1,121 @@
 /////////////////////////////////////////////////////////////////////////////
 /////////////////////////////////////////////////////////////////////////////

-// Name:        imaggif.cpp
+// Name:        src/common/imaggif.cpp

 // Purpose:     wxGIFHandler
 // Purpose:     wxGIFHandler

-// Author:      Guillermo Rodriguez Garcia
-//              wxWindows adaptation by Vaclav Slavik
+// Author:      Vaclav Slavik & Guillermo Rodriguez Garcia
+// RCS-ID:      $Id$
+// Copyright:   (c) 1999 Vaclav Slavik & Guillermo Rodriguez Garcia

 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 

-#ifdef __GNUG__
-#pragma implementation "imaggif.h"
-#endif
-

 // For compilers that support precompilation, includes "wx.h".
 // For compilers that support precompilation, includes "wx.h".

-#include <wx/wxprec.h>
+#include "wx/wxprec.h"

 
 #ifdef __BORLANDC__
 
 #ifdef __BORLANDC__

-#pragma hdrstop
+    #pragma hdrstop

 #endif
 
 #endif
 

-#include <wx/wx.h>
-
-#include <wx/image.h>
-#include <wx/wfstream.h>
-#include <wx/module.h>
-
-#include <wx/imaggif.h>
-
-/*
-
-FOLLOWING CODE IS BY G.R.G. :
-(except wxInputStream stuff)
-
-*/
-
-/************************************************************************
-  READGIF.H - Reads a GIF file
- ------------------------------------------------------------------------
-  Guillermo Rodriguez Garcia
-  <guille@iies.es>
-
-  Version: 2.1
-*************************************************************************/
-
-
-typedef struct
-{
-    int w;                  /* width */
-    int h;                  /* height */
-    int transparent;        /* transparent color (-1 = none) */
-    unsigned char *p;       /* bitmap */
-    unsigned char *pal;     /* palette */
-} IMAGEN;
-
-
-
-/************************************************************************
-  READGIF.C - Reads a GIF file
- ------------------------------------------------------------------------
-  Guillermo Rodriguez Garcia
-  <guille@iies.es>
-
-  Version: 2.1
-*************************************************************************/
-
-
-#include <stdlib.h>
-#include <string.h>
-
-
-/* error codes */
-#define E_OK        0               /* everything was OK */
-#define E_ARCHIVO   -1              /* error opening file */
-#define E_FORMATO   -2              /* error in gif header */
-#define E_MEMORIA   -3              /* error allocating memory */
-
-
-/* This class binding is by VS, so all bugs in it are mine ;-) */
-
-class gifDecoder
-{
-    private:
-        /* globals */
-        int            restbits;            /* remaining valid bits */
-        unsigned int   restbyte;            /* remaining bytes in this block */
-        unsigned int   lastbyte;            /* last byte read */
-
-        wxInputStream  *f;                  /* input file */
-
-       public:
-               gifDecoder(wxInputStream *s) { f = s; }
-               int getcode(int bits);
-               int dgif(IMAGEN *img, int interl, int bits);
-               int readgif(IMAGEN *img);
-};
-
-
+#if wxUSE_IMAGE && wxUSE_GIF

 
 

-/* getcode:
- *  Reads the next code from the file, with size 'bits'
- */
-int gifDecoder::getcode(int bits)
-{
-    unsigned int    mask;           /* bit mask */
-    unsigned int    code;           /* code (result) */
-
-
-    /* get remaining bits from last byte read */
-    mask = (1 << bits) - 1;
-    code = (lastbyte >> (8 - restbits)) & mask;
-
-    /* keep reading new bytes while needed */
-    while (bits > restbits)
-    {
-        /* if no bytes left in this block, read the next block */
-        if (restbyte == 0)
-            restbyte = (unsigned char)f->GetC();
-
-        /* read next byte and isolate the bits we need */
-        lastbyte = (unsigned char)f->GetC();
-        mask     = (1 << (bits - restbits)) - 1;
-        code     = code + ((lastbyte & mask) << restbits);
-        restbyte--;
+#ifndef WX_PRECOMP
+    #include "wx/intl.h"
+    #include "wx/log.h"
+#endif

 
 

-        /* adjust total number of bits extracted from the buffer */
-        restbits = restbits + 8;
-    }
-    
-    /* find number of bits reamining for next code */
-    restbits = (restbits - bits);
+#include "wx/imaggif.h"
+#include "wx/gifdecod.h"
+#include "wx/wfstream.h"

 
 

-    return code;
-}
+IMPLEMENT_DYNAMIC_CLASS(wxGIFHandler,wxImageHandler)

 
 

+//-----------------------------------------------------------------------------
+// wxGIFHandler
+//-----------------------------------------------------------------------------

 
 

+#if wxUSE_STREAMS

 
 

-/* dgif:
- *  GIF decoding function. The initial code size (aka root size)
- *  is 'bits'. Supports interlaced images (interl == 1).
- */
-int gifDecoder::dgif(IMAGEN *img, int interl, int bits)
+bool wxGIFHandler::LoadFile(wxImage *image, wxInputStream& stream,
+                            bool verbose, int index)

 {
 {

-    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 */
-    int x, y;                   /* position in image buffer */
+    wxGIFDecoder *decod;
+    wxGIFErrorCode error;
+    bool ok = true;

 
 

-    int code, readcode, lastcode, abcabca;
+//    image->Destroy();
+    decod = new wxGIFDecoder();
+    error = decod->LoadGIF(stream);

 
 

-    /* these won't change */
-    ab_clr  = (1 << bits);
-    ab_fin  = (1 << bits) + 1;
-
-    /* these will change through the decompression proccess */
-    ab_bits  = bits + 1;
-    ab_free  = (1 << bits) + 2;
-    ab_max   = (1 << ab_bits) - 1;
-    lastcode = -1;
-    abcabca  = -1;
-    pass     = 1;
-    pos = x = y = 0;
-
-    /* reset static globals */
-    restbits = 0;
-    restbyte = 0;
-    lastbyte = 0;
-
-    do
+    if ((error != wxGIF_OK) && (error != wxGIF_TRUNCATED))

     {
     {

-        /* get next code */
-        readcode = code = getcode(ab_bits);
-
-        /* end of image? */
-        if (code == ab_fin) break;
-
-        /* reset alphabet? */
-        if (code == ab_clr)
-        {
-            /* reset main variables */
-            ab_bits  = bits + 1;
-            ab_free  = (1 << bits) + 2;
-            ab_max   = (1 << ab_bits) - 1;
-            lastcode = -1;
-            abcabca  = -1;
-
-            /* skip to next code */
-            continue;
-        }
-
-        /* unknown code: special case (like in ABCABCA) */
-        if (code >= ab_free)
-        {
-            code = lastcode;            /* take last string */
-            stack[pos++] = abcabca;     /* add first character */
-        }
-
-        /* build the string for this code in the stack */
-        while (code > ab_clr)
-        {
-            stack[pos++] = ab_tail[code];
-            code         = ab_prefix[code];
-        }
-        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)
-        {
-            ab_prefix[ab_free] = lastcode;
-            ab_tail[ab_free]   = code;
-            ab_free++;
-
-            if ((ab_free > ab_max) && (ab_bits < 12))
-            {
-                ab_bits++;
-                ab_max = (1 << ab_bits) - 1;
-            }
-        }
-
-        /* dump stack data to the buffer */
-        while (pos >= 0)
+        if (verbose)

         {
         {

-            (img->p)[x + (y * (img->w))] = (char)stack[pos--];
-
-            if (++x >= (img->w))
+            switch (error)

             {
             {

-                x = 0;
-
-                if (interl)
-                {
-                    /* support for interlaced images */
-                    switch (pass)
-                    {
-                        case 1: y += 8; break;
-                        case 2: y += 8; break;
-                        case 3: y += 4; break;
-                        case 4: y += 2; break;
-                    }
-                    if (y >= (img->h))
-                    {
-                        switch (++pass)
-                        {
-                            case 2: y = 4; break;
-                            case 3: y = 2; break;
-                            case 4: y = 1; break;
-                        }
-                    }
-                }
-                else
-                {
-                    /* non-interlaced */
-                    y++;
-                }
+                case wxGIF_INVFORMAT:
+                    wxLogError(_("GIF: error in GIF image format."));
+                    break;
+                case wxGIF_MEMERR:
+                    wxLogError(_("GIF: not enough memory."));
+                    break;
+                default:
+                    wxLogError(_("GIF: unknown error!!!"));
+                    break;

             }
         }
             }
         }

-
-        pos = 0;
-        lastcode = readcode;
+        delete decod;
+        return false;

     }
     }

-    while (code != ab_fin);
-
-    return 0;
-}
-

 
 

-
-/* readgif:
- *  Reads a GIF image from the file with filename 'nombre' in the
- *  IMAGEN structure pointed by 'img'. Can read GIFs with any bit
- *  size (color depth), but the output image is always expanded
- *  to 8 bits per pixel. Also, the image palette always contains
- *  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 above).
- */
-int gifDecoder::readgif(IMAGEN *img)
-{
-    int             size, ncolors, bits, interl, i;
-    unsigned char   pal[768];
-    unsigned char   buf[16];
-
-
-    /* read header and logical screen descriptor block (LSDB) */
-    f->Read(buf, 13);
-
-    /* check GIF signature */
-    if (memcmp(buf, "GIF", 3) != 0) return E_FORMATO;
-
-    /* load global color map if available */
-    if ((buf[10] & 0x80) == 0x80)
+    if ((error == wxGIF_TRUNCATED) && verbose)

     {
     {

-        ncolors = 2 << (buf[10] & 0x07);
-        f->Read(pal, 3 * ncolors);
+        wxLogError(_("GIF: data stream seems to be truncated."));
+        /* go on; image data is OK */

     }
 
     }
 

-    /* assume no transparent color */
-    img->transparent = -1;
-
-    /* skip most extensions */
-    while (((unsigned char)f->GetC()) == 0x21)               /* separator */
+    if (ok)

     {
     {

-        if (((unsigned char)f->GetC()) == 0xF9)              /* graphic control ext. */
-        {
-            f->Read(buf, 6);
-            if (buf[1] & 0x01)
-                img->transparent = buf[4];
-        }
-        else
-            while ((i = (unsigned char)f->GetC()) != 0)    /* byte count */
-                f->SeekI(i, wxFromCurrent);
+        ok = decod->ConvertToImage(index != -1 ? (size_t)index : 0, image);

     }
     }

-
-    /* read image descriptor block (IDB) */
-    f->Read(buf, 9);
-    img->w = buf[4] + 256 * buf[5];
-    img->h = buf[6] + 256 * buf[7];
-    size   = img->w * img->h;
-    interl = ((buf[8] & 0x40)? 1 : 0);
-
-    /* load local color map if available */
-    if ((buf[8] & 0x80) == 0x80)
+    else

     {
     {

-        ncolors = 2 << (buf[8] & 0x07);
-        f->Read(pal, 3 * ncolors);
+        wxLogError(_("GIF: Invalid gif index."));

     }
 
     }
 

-    /* get initial code size from first byte in raster data */
-    bits = (unsigned char)f->GetC();
-
-    /* allocate memory for image and palette */
-    if ((img->p   = (unsigned char*) malloc(size)) == NULL) return E_MEMORIA;
-    if ((img->pal = (unsigned char*) malloc(768))  == NULL) return E_MEMORIA;
-
-    /* shift palette to fit VGA 6-bit format */
-    for (i = 0; i < 768; i++)
-        (img->pal)[i] = (unsigned char)pal[i]; /* >> 2 not in wxWin */
-
-    /* decode GIF */
-    dgif(img, interl, bits);
+    delete decod;

 
 

-    /* finish successfully :-) */
-    return E_OK;
+    return ok;

 }
 
 }
 

-
-
-/*
-
-FOLLOWING CODE IS BY V.S. :
-
-*/
-
-//-----------------------------------------------------------------------------
-// wxGIFHandler
-//-----------------------------------------------------------------------------
-
-IMPLEMENT_DYNAMIC_CLASS(wxGIFHandler,wxImageHandler)
-
-bool wxGIFHandler::LoadFile( wxImage *image, wxInputStream& stream )
+bool wxGIFHandler::SaveFile( wxImage * WXUNUSED(image),
+                             wxOutputStream& WXUNUSED(stream), bool verbose )

 {
 {

-    unsigned char *ptr, *src, *pal;
-    IMAGEN igif;
-    int i;
-    gifDecoder *decod;
-
-    image->Destroy();
-
-    decod = new gifDecoder(&stream);
-
-    if (decod->readgif(&igif) != E_OK) {
-        wxLogDebug("Error reading GIF");
-        delete decod;
-        return FALSE;
-    }
-    delete decod;
-
-    image->Create(igif.w, igif.h);
-    if (!image->Ok()) {
-        free(igif.pal);
-        free(igif.p);
-        return FALSE;
-    }
-
-    ptr = image->GetData();
-    src = igif.p;
-    pal = igif.pal;
-
-    if (igif.transparent != -1) {
-        for (i = 0; i < 256; i++)
-            if ((pal[3 * i + 0] == 255) && (pal[3 * i + 1] == 0) && (pal[3 * i + 2] == 255)) pal[3 * i + 2] = 254;
-        pal[3 * (igif.transparent) + 0] = 255,
-        pal[3 * (igif.transparent) + 1] = 0,
-        pal[3 * (igif.transparent) + 2] = 255;
-        image->SetMaskColour(255, 0, 255);
-    }
-    else image->SetMask(FALSE);
-
-    for (i = 0; i < igif.w * igif.h; i++, src++) {
-        *(ptr++) = pal[3 * (*src) + 0];
-        *(ptr++) = pal[3 * (*src) + 1];
-        *(ptr++) = pal[3 * (*src) + 2];
+    if (verbose)
+    {
+        wxLogDebug(wxT("GIF: the handler is read-only!!"));

     }
 
     }
 

-    free(igif.pal);
-    free(igif.p);
-    return TRUE;
+    return false;

 }
 
 }
 

-bool wxGIFHandler::SaveFile( wxImage *image, wxOutputStream& stream )
+bool wxGIFHandler::DoCanRead( wxInputStream& stream )

 {
 {

-    wxLogDebug("wxGIFHandler is read-only!!");
-    return FALSE;
+    wxGIFDecoder decod;
+    return decod.CanRead(stream);
+         // it's ok to modify the stream position here

 }
 
 }
 

+int wxGIFHandler::DoGetImageCount( wxInputStream& stream )
+{
+    wxGIFDecoder decod;
+    wxGIFErrorCode error = decod.LoadGIF(stream);
+    if ( (error != wxGIF_OK) && (error != wxGIF_TRUNCATED) )
+        return -1;

 
 

+    // NOTE: this function modifies the current stream position but it's ok
+    //       (see wxImageHandler::GetImageCount)

 
 

+    return decod.GetFrameCount();
+}

 
 

+#endif  // wxUSE_STREAMS

 
 

-
+#endif  // wxUSE_GIF