/////////////////////////////////////////////////////////////////////////////
// Name: imaggif.cpp
// 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
/////////////////////////////////////////////////////////////////////////////
#endif
// For compilers that support precompilation, includes "wx.h".
-#include <wx/wxprec.h>
+#include "wx/wxprec.h"
#ifdef __BORLANDC__
-#pragma hdrstop
+# pragma hdrstop
#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 - Leer un archivo GIF de 8 bits
- ------------------------------------------------------------------------
- Tratamiento Digital de la Imagen
- ------------------------------------------------------------------------
- Guillermo Rodriguez Garcia
- <guille@iies.es>
-
- Version: 2.0
-*************************************************************************/
-
-typedef struct
-{
- int w; /* width */
- int h; /* height */
- unsigned char *p; /* bitmap */
- unsigned char *pal; /* palette */
-} IMAGEN;
-
-
-/************************************************************************
- READGIF.C - Lee un archivo GIF de 256 colores
- ------------------------------------------------------------------------
- Tratamiento Digital de la Imagen
- ------------------------------------------------------------------------
- Guillermo Rodriguez Garcia
- <guille@iies.es>
-
- Version: 2.0
-*************************************************************************/
-
-
-#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);
-
- private:
- int mygetc() {return (unsigned char)f -> GetC();}
- // This is NEEDED! GetC is char (signed) why we need unsigned value
- // from here
-};
-
-
-
-/* getcode:
- * Reads the next code from the file, with size 'bits'
- * v2.0 - changed to support 'bits' values < 8
- */
-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 until needed */
- while (bits > restbits)
- {
- /* if no bytes left in this block, read the next block */
- if (restbyte == 0)
- restbyte = mygetc();
+#ifndef WX_PRECOMP
+# include "wx/defs.h"
+#endif
- /* read next byte and isolate the bits we need */
- lastbyte = mygetc();
- mask = (1 << (bits - restbits)) - 1;
- code = code + ((lastbyte & mask) << restbits);
- restbyte--;
+#if wxUSE_IMAGE && wxUSE_GIF
- /* adjust total number of bits extracted from the buffer */
- restbits = restbits + 8;
- }
+#include "wx/imaggif.h"
+#include "wx/gifdecod.h"
+#include "wx/wfstream.h"
+#include "wx/log.h"
+#include "wx/intl.h"
- /* find number of bits reamining for next code */
- restbits = (restbits - bits);
+IMPLEMENT_DYNAMIC_CLASS(wxGIFHandler,wxImageHandler)
- return code;
-}
+//-----------------------------------------------------------------------------
+// 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 */
-
- int code, readcode, lastcode, abcabca;
+ wxGIFDecoder *decod;
+ int error;
+ bool ok = TRUE;
- /* these won't change */
- ab_clr = (1 << bits);
- ab_fin = (1 << bits) + 1;
+// image->Destroy();
+ decod = new wxGIFDecoder(&stream, TRUE);
+ error = decod->ReadGIF();
- /* 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)
+ if (verbose)
{
- ab_prefix[ab_free] = lastcode;
- ab_tail[ab_free] = code;
- ab_free++;
-
- if ((ab_free > ab_max) && (ab_bits < 12))
+ switch (error)
{
- ab_bits++;
- ab_max = (1 << ab_bits) - 1;
+ 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;
}
}
-
- /* dump stack data to the buffer */
- while (pos >= 0)
- {
- (img->p)[x + (y * (img->w))] = (char)stack[pos--];
-
- if (++x >= (img->w))
- {
- 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++;
- }
- }
- }
-
- 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 */
}
- /* skip extensions */
- while (mygetc() == 0x21) /* separator */
+ if (index != -1)
{
- mygetc(); /* function code */
-
- while ((i = mygetc()) != 0) /* byte count */
- f -> SeekI(i, wxFromCurrent);
+ // We're already on index = 0 by default. So no need
+ // to call GoFrame(0) then. On top of that GoFrame doesn't
+ // accept an index of 0. (Instead GoFirstFrame() should be used)
+ // Also if the gif image has only one frame, calling GoFrame(0)
+ // fails because GoFrame() only works with gif animations.
+ // (It fails if IsAnimation() returns FALSE)
+ // All valid reasons to NOT call GoFrame when index equals 0.
+ if (index != 0)
+ {
+ ok = decod->GoFrame(index);
+ }
}
- /* 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)
+ if (ok)
{
- ncolors = 2 << (buf[8] & 0x07);
- f -> Read(pal, 3 * ncolors);
+ ok = decod->ConvertToImage(image);
+ }
+ else
+ {
+ wxLogError(_("GIF: Invalid gif index."));
}
- /* get initial code size from first byte in raster data */
- bits = mygetc();
-
- /* 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 needed under 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();
+ if (verbose)
+ wxLogDebug(wxT("GIF: the handler is read-only!!"));
- 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;
- }
- image->SetMask(FALSE);
-
- ptr = image->GetData();
- src = igif.p;
- pal = igif.pal;
- 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];
- }
-
- 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(&stream);
+ return decod.CanRead();
}
+#endif // wxUSE_STREAMS
+#endif // wxUSE_GIF
projects / wxWidgets.git / blobdiff