// Purpose: wxGIFDecoder, GIF reader for wxImage and wxAnimation
// Author: Guillermo Rodriguez Garcia <guille@iies.es>
// Version: 3.02
-// Last rev: 1999/08/18
-// Copyright: (c) Guillermo Rodriguez Garcia
+// CVS-ID: $Id$
+// Copyright: (c) 1999 Guillermo Rodriguez Garcia
// Licence: wxWindows licence
/////////////////////////////////////////////////////////////////////////////
#ifndef _WX_GIFDECOD_H
#define _WX_GIFDECOD_H
-#ifdef __GNUG__
-#pragma interface "gifdecod.h"
-#endif
+#include "wx/defs.h"
-#include "wx/setup.h"
+#if wxUSE_STREAMS && wxUSE_GIF
-#if wxUSE_STREAMS
#include "wx/stream.h"
#include "wx/image.h"
+#include "wx/animdecod.h"
+// internal utility used to store a frame in 8bit-per-pixel format
+class /*WXDLLEXPORT*/ GIFImage;
-typedef struct _IMAGEN
+
+// --------------------------------------------------------------------------
+// Constants
+// --------------------------------------------------------------------------
+
+// Error codes:
+// Note that the error code wxGIF_TRUNCATED means that the image itself
+// is most probably OK, but the decoder didn't reach the end of the data
+// stream; this means that if it was not reading directly from file,
+// the stream will not be correctly positioned. the
+//
+enum wxGIFErrorCode
{
- unsigned int w; /* width */
- unsigned int h; /* height */
- unsigned int left; /* x coord (in logical screen) */
- unsigned int top; /* y coord (in logical screen) */
- int transparent; /* transparent color (-1 = none) */
- int disposal; /* disposal method (-1 = unspecified) */
- long delay; /* delay in ms (-1 = unused) */
- unsigned char *p; /* bitmap */
- unsigned char *pal; /* palette */
- struct _IMAGEN *next; /* next image */
- struct _IMAGEN *prev; /* prev image */
-} IMAGEN;
-
-
-/* disposal method */
-#define D_UNSPECIFIED -1 /* not specified */
-#define D_DONOTDISPOSE 0 /* do not dispose */
-#define D_TOBACKGROUND 1 /* restore to background colour */
-#define D_TOPREVIOUS 2 /* restore to previous image */
-
-/* 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 */
-
-
-class wxGIFDecoder
+ wxGIF_OK = 0, /* everything was OK */
+ wxGIF_INVFORMAT, /* error in gif header */
+ wxGIF_MEMERR, /* error allocating memory */
+ wxGIF_TRUNCATED /* file appears to be truncated */
+};
+
+#define MAX_BLOCK_SIZE 256 /* max. block size */
+
+
+// --------------------------------------------------------------------------
+// wxGIFDecoder class
+// --------------------------------------------------------------------------
+
+class WXDLLEXPORT wxGIFDecoder : public wxAnimationDecoder
{
private:
- /* logical screen */
- unsigned int m_screenw; /* logical screen width */
- unsigned int m_screenh; /* logical screen height */
- int m_background; /* background color (-1 = none) */
-
- /* image data */
- bool m_anim; /* animated GIF */
- int m_nimages; /* number of images */
- int m_image; /* current image */
- IMAGEN *m_pimage; /* pointer to current image */
- IMAGEN *m_pfirst; /* pointer to first image */
- IMAGEN *m_plast; /* pointer to last image */
-
- /* decoder state vars */
+ // a wxArray provides a constant access time rather than a linear time
+ // like for linked lists.
+ wxArrayPtrVoid m_frames;
+
+ // decoder state vars
int m_restbits; /* remaining valid bits */
unsigned int m_restbyte; /* remaining bytes in this block */
unsigned int m_lastbyte; /* last byte read */
-
- wxInputStream *m_f; /* input file */
+ unsigned char m_buffer[MAX_BLOCK_SIZE]; /* buffer for reading */
+ unsigned char *m_bufp; /* pointer to next byte in buffer */
private:
- int getcode(int bits, int abfin);
- int dgif(IMAGEN *img, int interl, int bits);
+ int getcode(wxInputStream& stream, int bits, int abfin);
+ wxGIFErrorCode dgif(wxInputStream& stream, GIFImage *img, int interl, int bits);
+
+public:
+ // get data of current frame
+ unsigned char* GetData(size_t frame) const;
+ unsigned char* GetPalette(size_t frame) const;
+ unsigned int GetNcolours(size_t frame) const;
+ int GetTransparentColourIndex(size_t frame) const;
+ wxColour GetTransparentColour(size_t frame) const;
+
+ virtual wxSize GetFrameSize(size_t frame) const;
+ virtual wxPoint GetFramePosition(size_t frame) const;
+ virtual wxAnimationDisposal GetDisposalMethod(size_t frame) const;
+ virtual long GetDelay(size_t frame) const;
+
+ // GIFs can contain both static images and animations
+ bool IsAnimation() const
+ { return m_nFrames > 1; }
public:
// constructor, destructor, etc.
- wxGIFDecoder(wxInputStream *s, bool anim = FALSE);
+ wxGIFDecoder();
~wxGIFDecoder();
- bool CanRead();
- int ReadGIF();
+
+ // load function which returns more info than just Load():
+ wxGIFErrorCode LoadGIF( wxInputStream& stream );
+
+ // free all internal frames
void Destroy();
- // convert current frame to wxImage
- bool ConvertToImage(wxImage *image) const;
+public: // implementation of wxAnimationDecoder's pure virtuals
- // get data of current frame
- int GetFrameIndex() const;
- unsigned char* GetData() const;
- unsigned char* GetPalette() const;
- unsigned int GetWidth() const;
- unsigned int GetHeight() const;
- unsigned int GetLeft() const;
- unsigned int GetTop() const;
- int GetDisposalMethod() const;
- int GetTransparentColour() const;
- long GetDelay() const;
-
- // get global data
- unsigned int GetLogicalScreenWidth() const;
- unsigned int GetLogicalScreenHeight() const;
- int GetBackgroundColour() const;
- int GetNumberOfFrames() const;
- bool IsAnimation() const;
-
- // move through the animation
- bool GoFirstFrame();
- bool GoLastFrame();
- bool GoNextFrame(bool cyclic = FALSE);
- bool GoPrevFrame(bool cyclic = FALSE);
- bool GoFrame(int which);
+ virtual bool CanRead( wxInputStream& stream ) const;
+ virtual bool Load( wxInputStream& stream )
+ { return LoadGIF(stream) == wxGIF_OK; }
+
+ bool ConvertToImage(size_t frame, wxImage *image) const;
+
+ wxAnimationDecoder *Clone() const
+ { return new wxGIFDecoder; }
+ wxAnimationType GetType() const
+ { return wxANIMATION_TYPE_GIF; }
+
+private:
+ DECLARE_NO_COPY_CLASS(wxGIFDecoder)
};
-#endif // wxUSE_STREAM
+#endif // wxUSE_STREAM && wxUSE_GIF
#endif // _WX_GIFDECOD_H
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