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Commit	Line	Data
	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	// --------------------------------------------------------------------------
	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. the
	35	//
	36	enum
	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	// Disposal method
	45	// Experimental; subject to change.
	46	//
	47	enum
	48	{
	49	wxGIF_D_UNSPECIFIED = -1, /* not specified */
	50	wxGIF_D_DONOTDISPOSE = 0, /* do not dispose */
	51	wxGIF_D_TOBACKGROUND = 1, /* restore to background colour */
	52	wxGIF_D_TOPREVIOUS = 2 /* restore to previous image */
	53	};
	54
	55
	56	#define MAX_BLOCK_SIZE 256 /* max. block size */
	57
	58
	59	// --------------------------------------------------------------------------
	60	// wxGIFDecoder class
	61	// --------------------------------------------------------------------------
	62
	63	// internal class for storing GIF image data
	64	class GIFImage
	65	{
	66	public:
	67	unsigned int w; /* width */
	68	unsigned int h; /* height */
	69	unsigned int left; /* x coord (in logical screen) */
	70	unsigned int top; /* y coord (in logical screen) */
	71	int transparent; /* transparent color (-1 = none) */
	72	int disposal; /* disposal method (-1 = unspecified) */
	73	long delay; /* delay in ms (-1 = unused) */
	74	unsigned char p; / bitmap */
	75	unsigned char pal; / palette */
	76	GIFImage next; / next image */
	77	GIFImage prev; / prev image */
	78	};
	79
	80
	81	class WXDLLEXPORT wxGIFDecoder
	82	{
	83	private:
	84	// logical screen
	85	unsigned int m_screenw; /* logical screen width */
	86	unsigned int m_screenh; /* logical screen height */
	87	int m_background; /* background color (-1 = none) */
	88
	89	// image data
	90	bool m_anim; /* animated GIF */
	91	int m_nimages; /* number of images */
	92	int m_image; /* current image */
	93	GIFImage m_pimage; / pointer to current image */
	94	GIFImage m_pfirst; / pointer to first image */
	95	GIFImage m_plast; / pointer to last image */
	96
	97	// decoder state vars
	98	int m_restbits; /* remaining valid bits */
	99	unsigned int m_restbyte; /* remaining bytes in this block */
	100	unsigned int m_lastbyte; /* last byte read */
	101	unsigned char m_buffer[MAX_BLOCK_SIZE]; /* buffer for reading */
	102	unsigned char m_bufp; / pointer to next byte in buffer */
	103
	104	// input stream
	105	wxInputStream m_f; / input stream */
	106
	107	private:
	108	int getcode(int bits, int abfin);
	109	int dgif(GIFImage *img, int interl, int bits);
	110
	111	protected:
	112	// get data of current frame
	113	int GetFrameIndex() const;
	114	unsigned char* GetData() const;
	115	unsigned char* GetPalette() const;
	116	unsigned int GetWidth() const;
	117	unsigned int GetHeight() const;
	118	unsigned int GetLeft() const;
	119	unsigned int GetTop() const;
	120	int GetDisposalMethod() const;
	121	int GetTransparentColour() const;
	122	long GetDelay() const;
	123
	124	// get global data
	125	unsigned int GetLogicalScreenWidth() const;
	126	unsigned int GetLogicalScreenHeight() const;
	127	int GetBackgroundColour() const;
	128	int GetNumberOfFrames() const;
	129	bool IsAnimation() const;
	130
	131	// move through the animation
	132	bool GoFirstFrame();
	133	bool GoLastFrame();
	134	bool GoNextFrame(bool cyclic = FALSE);
	135	bool GoPrevFrame(bool cyclic = FALSE);
	136	bool GoFrame(int which);
	137
	138	public:
	139	// constructor, destructor, etc.
	140	wxGIFDecoder(wxInputStream *s, bool anim = FALSE);
	141	~wxGIFDecoder();
	142	bool CanRead();
	143	int ReadGIF();
	144	void Destroy();
	145
	146	// convert current frame to wxImage
	147	bool ConvertToImage(wxImage *image) const;
	148	};
	149
	150
	151	#endif // wxUSE_STREAM && wxUSE_GIF
	152	#endif // _WX_GIFDECOD_H
	153