include/wx/gifdecod.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        gifdecod.h
   3 // Purpose:     wxGIFDecoder, GIF reader for wxImage and wxAnimation
   4 // Author:      Guillermo Rodriguez Garcia <guille@iies.es>
   5 // Version:     3.02
   6 // CVS-ID:      $Id$
   7 // Copyright:   (c) 1999 Guillermo Rodriguez Garcia
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef _WX_GIFDECOD_H
  12 #define _WX_GIFDECOD_H
  13
  14 #ifdef __GNUG__
  15 #pragma interface "gifdecod.h"
  16 #endif
  17
  18 #include "wx/setup.h"
  19
  20 #if wxUSE_STREAMS && wxUSE_GIF
  21
  22 #include "wx/stream.h"
  23 #include "wx/image.h"
  24
  25
  26 typedef struct _IMAGEN
  27 {
  28     unsigned int w;                 /* width */
  29     unsigned int h;                 /* height */
  30     unsigned int left;              /* x coord (in logical screen) */
  31     unsigned int top;               /* y coord (in logical screen) */
  32     int transparent;                /* transparent color (-1 = none) */
  33     int disposal;                   /* disposal method (-1 = unspecified) */
  34     long delay;                     /* delay in ms (-1 = unused) */
  35     unsigned char *p;               /* bitmap */
  36     unsigned char *pal;             /* palette */
  37     struct _IMAGEN *next;           /* next image */
  38     struct _IMAGEN *prev;           /* prev image */
  39 } IMAGEN;
  40
  41
  42 /* disposal method */
  43 #define D_UNSPECIFIED   -1          /* not specified */
  44 #define D_DONOTDISPOSE  0           /* do not dispose */
  45 #define D_TOBACKGROUND  1           /* restore to background colour */
  46 #define D_TOPREVIOUS    2           /* restore to previous image */
  47
  48 /* error codes */
  49 #define E_OK            0           /* everything was OK */
  50 #define E_FORMATO       1           /* error in gif header */
  51 #define E_MEMORIA       2           /* error allocating memory */
  52
  53
  54 class wxGIFDecoder
  55 {
  56 private:
  57     /* logical screen */
  58     unsigned int  m_screenw;        /* logical screen width */
  59     unsigned int  m_screenh;        /* logical screen height */
  60     int           m_background;     /* background color (-1 = none) */
  61
  62     /* image data */
  63     bool          m_anim;           /* animated GIF */
  64     int           m_nimages;        /* number of images */
  65     int           m_image;          /* current image */
  66     IMAGEN        *m_pimage;        /* pointer to current image */
  67     IMAGEN        *m_pfirst;        /* pointer to first image */
  68     IMAGEN        *m_plast;         /* pointer to last image */
  69
  70     /* decoder state vars */
  71     int           m_restbits;       /* remaining valid bits */
  72     unsigned int  m_restbyte;       /* remaining bytes in this block */
  73     unsigned int  m_lastbyte;       /* last byte read */
  74
  75     wxInputStream *m_f;             /* input file */
  76
  77 private:
  78     int getcode(int bits, int abfin);
  79     int dgif(IMAGEN *img, int interl, int bits);
  80
  81 public:
  82     // constructor, destructor, etc.
  83     wxGIFDecoder(wxInputStream *s, bool anim = FALSE);
  84     ~wxGIFDecoder();
  85     bool CanRead();
  86     int ReadGIF();
  87     void Destroy();
  88
  89     // convert current frame to wxImage
  90     bool ConvertToImage(wxImage *image) const;
  91
  92     // get data of current frame
  93     int GetFrameIndex() const;
  94     unsigned char* GetData() const;
  95     unsigned char* GetPalette() const;
  96     unsigned int GetWidth() const;
  97     unsigned int GetHeight() const;
  98     unsigned int GetLeft() const;
  99     unsigned int GetTop() const;
 100     int GetDisposalMethod() const;
 101     int GetTransparentColour() const;
 102     long GetDelay() const;
 103
 104     // get global data
 105     unsigned int GetLogicalScreenWidth() const;
 106     unsigned int GetLogicalScreenHeight() const;
 107     int GetBackgroundColour() const;
 108     int GetNumberOfFrames() const;
 109     bool IsAnimation() const;
 110
 111     // move through the animation
 112     bool GoFirstFrame();
 113     bool GoLastFrame();
 114     bool GoNextFrame(bool cyclic = FALSE);
 115     bool GoPrevFrame(bool cyclic = FALSE);
 116     bool GoFrame(int which);
 117 };
 118
 119
 120 #endif  // wxUSE_STREAM && wxUSE_GIF
 121 #endif  // _WX_GIFDECOD_H
 122