1 ///////////////////////////////////////////////////////////////////////////// 2 // Name: wx/gifdecod.h 3 // Purpose: wxGIFDecoder, GIF reader for wxImage and wxAnimation 4 // Author: Guillermo Rodriguez Garcia <guille@iies.es> 5 // Version: 3.02 6 // Copyright: (c) 1999 Guillermo Rodriguez Garcia 7 // Licence: wxWindows licence 8 ///////////////////////////////////////////////////////////////////////////// 9 10 #ifndef _WX_GIFDECOD_H_ 11 #define _WX_GIFDECOD_H_ 12 13 #include "wx/defs.h" 14 15 #if wxUSE_STREAMS && wxUSE_GIF 16 17 #include "wx/stream.h" 18 #include "wx/image.h" 19 #include "wx/animdecod.h" 20 #include "wx/dynarray.h" 21 22 // internal utility used to store a frame in 8bit-per-pixel format 23 class GIFImage; 24 25 26 // -------------------------------------------------------------------------- 27 // Constants 28 // -------------------------------------------------------------------------- 29 30 // Error codes: 31 // Note that the error code wxGIF_TRUNCATED means that the image itself 32 // is most probably OK, but the decoder didn't reach the end of the data 33 // stream; this means that if it was not reading directly from file, 34 // the stream will not be correctly positioned. 35 // 36 enum wxGIFErrorCode 37 { 38 wxGIF_OK = 0, // everything was OK 39 wxGIF_INVFORMAT, // error in GIF header 40 wxGIF_MEMERR, // error allocating memory 41 wxGIF_TRUNCATED // file appears to be truncated 42 }; 43 44 // -------------------------------------------------------------------------- 45 // wxGIFDecoder class 46 // -------------------------------------------------------------------------- 47 48 class WXDLLIMPEXP_CORE wxGIFDecoder : public wxAnimationDecoder 49 { 50 public: 51 // constructor, destructor, etc. 52 wxGIFDecoder(); 53 ~wxGIFDecoder(); 54 55 // get data of current frame 56 unsigned char* GetData(unsigned int frame) const; 57 unsigned char* GetPalette(unsigned int frame) const; 58 unsigned int GetNcolours(unsigned int frame) const; 59 int GetTransparentColourIndex(unsigned int frame) const; 60 wxColour GetTransparentColour(unsigned int frame) const wxOVERRIDE; 61 62 virtual wxSize GetFrameSize(unsigned int frame) const wxOVERRIDE; 63 virtual wxPoint GetFramePosition(unsigned int frame) const wxOVERRIDE; 64 virtual wxAnimationDisposal GetDisposalMethod(unsigned int frame) const wxOVERRIDE; 65 virtual long GetDelay(unsigned int frame) const wxOVERRIDE; 66 67 // GIFs can contain both static images and animations IsAnimation()68 bool IsAnimation() const 69 { return m_nFrames > 1; } 70 71 // load function which returns more info than just Load(): 72 wxGIFErrorCode LoadGIF( wxInputStream& stream ); 73 74 // free all internal frames 75 void Destroy(); 76 77 // implementation of wxAnimationDecoder's pure virtuals Load(wxInputStream & stream)78 virtual bool Load( wxInputStream& stream ) wxOVERRIDE 79 { return LoadGIF(stream) == wxGIF_OK; } 80 81 bool ConvertToImage(unsigned int frame, wxImage *image) const wxOVERRIDE; 82 Clone()83 wxAnimationDecoder *Clone() const wxOVERRIDE 84 { return new wxGIFDecoder; } GetType()85 wxAnimationType GetType() const wxOVERRIDE 86 { return wxANIMATION_TYPE_GIF; } 87 88 protected: 89 // wxAnimationDecoder pure virtual 90 virtual bool DoCanRead( wxInputStream& stream ) const wxOVERRIDE; 91 // modifies current stream position (see wxAnimationDecoder::CanRead) 92 93 private: 94 int getcode(wxInputStream& stream, int bits, int abfin); 95 wxGIFErrorCode dgif(wxInputStream& stream, 96 GIFImage *img, int interl, int bits); 97 98 99 // array of all frames 100 wxArrayPtrVoid m_frames; 101 102 // decoder state vars 103 int m_restbits; // remaining valid bits 104 unsigned int m_restbyte; // remaining bytes in this block 105 unsigned int m_lastbyte; // last byte read 106 unsigned char m_buffer[256]; // buffer for reading 107 unsigned char *m_bufp; // pointer to next byte in buffer 108 109 wxDECLARE_NO_COPY_CLASS(wxGIFDecoder); 110 }; 111 112 #endif // wxUSE_STREAMS && wxUSE_GIF 113 114 #endif // _WX_GIFDECOD_H_ 115