///////////////////////////////////////////////////////////////////////////// // Name: gifdecod.h // Purpose: wxGIFDecoder, GIF reader for wxImage and wxAnimation // Author: Guillermo Rodriguez Garcia <guille@iies.es> // Version: 3.02 // CVS-ID: $Id$ // Copyright: (c) 1999 Guillermo Rodriguez Garcia // Licence: wxWindows licence ///////////////////////////////////////////////////////////////////////////// #ifndef _WX_GIFDECOD_H #define _WX_GIFDECOD_H #include "wx/defs.h" #if wxUSE_STREAMS && wxUSE_GIF #include "wx/stream.h" #include "wx/image.h" // -------------------------------------------------------------------------- // 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 { wxGIF_OK = 0, /* everything was OK */ wxGIF_INVFORMAT, /* error in gif header */ wxGIF_MEMERR, /* error allocating memory */ wxGIF_TRUNCATED /* file appears to be truncated */ }; // Disposal method // Experimental; subject to change. // enum { wxGIF_D_UNSPECIFIED = -1, /* not specified */ wxGIF_D_DONOTDISPOSE = 0, /* do not dispose */ wxGIF_D_TOBACKGROUND = 1, /* restore to background colour */ wxGIF_D_TOPREVIOUS = 2 /* restore to previous image */ }; #define MAX_BLOCK_SIZE 256 /* max. block size */ // -------------------------------------------------------------------------- // wxGIFDecoder class // -------------------------------------------------------------------------- // internal class for storing GIF image data class GIFImage { public: // def ctor GIFImage(); 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 */ unsigned int ncolours; /* number of colours */ GIFImage *next; /* next image */ GIFImage *prev; /* prev image */ DECLARE_NO_COPY_CLASS(GIFImage) }; class WXDLLEXPORT wxGIFDecoder { 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 */ GIFImage *m_pimage; /* pointer to current image */ GIFImage *m_pfirst; /* pointer to first image */ GIFImage *m_plast; /* pointer to last image */ // 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 */ unsigned char m_buffer[MAX_BLOCK_SIZE]; /* buffer for reading */ unsigned char *m_bufp; /* pointer to next byte in buffer */ // input stream wxInputStream *m_f; /* input stream */ private: int getcode(int bits, int abfin); int dgif(GIFImage *img, int interl, int bits); public: // get data of current frame int GetFrameIndex() const; unsigned char* GetData() const; unsigned char* GetPalette() const; unsigned int GetNcolours() 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); public: // constructor, destructor, etc. wxGIFDecoder(wxInputStream *s, bool anim = false); ~wxGIFDecoder(); bool CanRead(); int ReadGIF(); void Destroy(); // convert current frame to wxImage bool ConvertToImage(wxImage *image) const; DECLARE_NO_COPY_CLASS(wxGIFDecoder) }; #endif // wxUSE_STREAM && wxUSE_GIF #endif // _WX_GIFDECOD_H