typedef struct TkCimeth TkCimeth;typedef struct TkCitem TkCitem;typedef struct TkCanvas TkCanvas;typedef struct TkCline TkCline;typedef struct TkCtag TkCtag;typedef struct TkCpoints TkCpoints;typedef struct TkCwind TkCwind; struct TkCline{	int		arrow;	int		shape[3];	int		width;	Image*		stipple;	Image*		pen;	int		arrowf;	int		arrowl;	int		capstyle;	int		smooth;	int		steps;}; struct TkCwind{	Tk*		sub;		/* Subwindow of canvas */	Tk*		focus;		/* Current Mouse focus */	int		width;		/* Requested width */	int		height;		/* Requested height */	int		flags;		/* possible: Tkanchor|Tksetwidth|Tksetheight */}; struct TkCpoints{	int		npoint;		/* Number of points */	Point*		parampt;	/* Parameters in fixed point */	Point*		drawpt;		/* Draw coord in pixels */	Rectangle	bb;		/* Bounding box in pixels */}; struct TkCitem{	int		id;		/* Unique id */	int		type;		/* Object type */	TkCpoints	p;		/* Points plus bounding box */	TkEnv*		env;		/* Colors & fonts */	TkCitem*	next;		/* Z order */	TkName*		tags;		/* Temporary tag spot */	TkCtag*		stag;		/* Real tag structure *///	char		obj[TKSTRUCTALIGN];}; struct TkCtag{	TkCitem*	item;		/* Link to item */	TkName*		name;		/* Text name or id */	TkCtag*		taglist;	/* link items with this tag */	TkCtag*		itemlist;	/* link tags for this item */}; enum{	/* Item types */	TkCVline,	TkCVtext,	TkCVrect,	TkCVoval,	TkCVbitmap,	TkCVpoly,	TkCVwindow,	TkCVimage,	TkCVarc, 	TkCselto	= 0,	TkCselfrom,	TkCseladjust, 	TkCbufauto	= 0,	TkCbufnone,	TkCbufvisible,	TkCbufall, 	TkCadd		= 0,	TkCfind,		TkChash		= 32, 	TkCarrowf	= (1<<0),	TkCarrowl	= (1<<1),	Tknarrow	= 6		/* Number of points in arrow */}; struct TkCanvas{	int		close;	int		confine;	int		cleanup;	int		scrollr[4];	Rectangle	region;	Rectangle	update;		/* Area to paint next draw */	Point		view;	TkCitem*	selection;	int		width;	int		height;	int		sborderwidth;	int		xscrolli;	/* Scroll increment */	int		yscrolli;	char*		xscroll;	/* Scroll commands */	char*		yscroll;	int		id;		/* Unique id */	TkCitem*	head;		/* Items in Z order */	TkCitem*	tail;		/* Head is lowest, tail is highest */	TkCitem*	focus;		/* Keyboard focus */	TkCitem*	mouse;		/* Mouse focus */	TkCitem* grab;	TkName*		current;	/* Fake for current tag */	TkCtag		curtag;	Image*		image;		/* Drawing space */	int			ialloc;		/* image was allocated by us? */	Image*		mask;		/* mask space (for stippling) */	TkName*		thash[TkChash];	/* Tag hash */	int		actions;	int		actlim;	int		buffer;}; struct TkCimeth{	char*	name;	char*	(*create)(Tk*, char *arg, char **val);	void	(*draw)(Image*, TkCitem*, TkEnv*);	void	(*free)(TkCitem*);	char*	(*coord)(TkCitem*, char*, int, int);	char*	(*cget)(TkCitem*, char*, char**);	char*	(*conf)(Tk*, TkCitem*, char*);	int		(*hit)(TkCitem*, Point);}; extern	TkCimeth	tkcimethod[];extern	int	cvslshape[];extern	Rectangle	bbnil;extern	Rectangle	huger; /* General */extern	char*		tkcaddtag(Tk*, TkCitem*, int);extern	TkCtag*		tkcfirsttag(TkCitem*, TkCtag*);extern	TkCtag*		tkclasttag(TkCitem*, TkCtag*);extern	void		tkcvsappend(TkCanvas*, TkCitem*);extern	TkCitem*	 tkcnewitem(Tk*, int, int);extern	void		tkcvsfreeitem(TkCitem*);extern	Point		tkcvsrelpos(Tk*);extern	Tk*		tkcvsinwindow(Tk*, Point*);extern	char*		tkcvstextdchar(Tk*, TkCitem*, char*);extern	char*		tkcvstextindex(Tk*, TkCitem*, char*, char **val);extern	char*		tkcvstextinsert(Tk*, TkCitem*, char*);extern	char*		tkcvstexticursor(Tk*, TkCitem*, char*);extern	void		tkmkpen(Image**, TkEnv*, Image*);extern	void		tkcvstextfocus(Tk*, TkCitem*, int);extern	char*		tkcvstextselect(Tk*, TkCitem*, char*, int);extern	void		tkcvstextclr(Tk*);extern	Tk*		tkcvsevent(Tk*, int, void*);extern	Point		tkcvsanchor(Point, int, int, int);extern	void		tkcvsdirty(Tk*);extern	void		tkfreectag(TkCtag*);extern	char*		tkparsepts(TkTop*, TkCpoints*, char**, int);extern	void		tkfreepoint(TkCpoints*);extern	void		tkxlatepts(Point*, int, int, int);extern	void		tkpolybound(Point*, int, Rectangle*);extern	TkName*		tkctaglook(Tk*, TkName*, char*);extern	void		tkbbmax(Rectangle*, Rectangle*);extern	void		tkcvssetdirty(Tk*); /* Canvas Item methods - required to populate tkcimethod in canvs.c */extern	char*	tkcvslinecreat(Tk*, char *arg, char **val);extern	void	tkcvslinedraw(Image*, TkCitem*, TkEnv*);extern	void	tkcvslinefree(TkCitem*);extern	char*	tkcvslinecoord(TkCitem*, char*, int, int);extern	char*	tkcvslinecget(TkCitem*, char*, char**);extern	char*	tkcvslineconf(Tk*, TkCitem*, char*);extern	int		tkcvslinehit(TkCitem*, Point); extern	char*	tkcvstextcreat(Tk*, char *arg, char **val);extern	void	tkcvstextdraw(Image*, TkCitem*, TkEnv*);extern	void	tkcvstextfree(TkCitem*);extern	char*	tkcvstextcoord(TkCitem*, char*, int, int);extern	char*	tkcvstextcget(TkCitem*, char*, char**);extern	char*	tkcvstextconf(Tk*, TkCitem*, char*); extern	char*	tkcvsrectcreat(Tk*, char *arg, char **val);extern	void	tkcvsrectdraw(Image*, TkCitem*, TkEnv*);extern	void	tkcvsrectfree(TkCitem*);extern	char*	tkcvsrectcoord(TkCitem*, char*, int, int);extern	char*	tkcvsrectcget(TkCitem*, char*, char**);extern	char*	tkcvsrectconf(Tk*, TkCitem*, char*); extern	char*	tkcvsovalcreat(Tk*, char *arg, char **val);extern	void	tkcvsovaldraw(Image*, TkCitem*, TkEnv*);extern	void	tkcvsovalfree(TkCitem*);extern	char*	tkcvsovalcoord(TkCitem*, char*, int, int);extern	char*	tkcvsovalcget(TkCitem*, char*, char**);extern	char*	tkcvsovalconf(Tk*, TkCitem*, char*);extern	int		tkcvsovalhit(TkCitem*, Point); extern	char*	tkcvsarccreat(Tk*, char *arg, char **val);extern	void	tkcvsarcdraw(Image*, TkCitem*, TkEnv*);extern	void	tkcvsarcfree(TkCitem*);extern	char*	tkcvsarccoord(TkCitem*, char*, int, int);extern	char*	tkcvsarccget(TkCitem*, char*, char**);extern	char*	tkcvsarcconf(Tk*, TkCitem*, char*); extern	char*	tkcvsbitcreat(Tk*, char *arg, char **val);extern	void	tkcvsbitdraw(Image*, TkCitem*, TkEnv*);extern	void	tkcvsbitfree(TkCitem*);extern	char*	tkcvsbitcoord(TkCitem*, char*, int, int);extern	char*	tkcvsbitcget(TkCitem*, char*, char**);extern	char*	tkcvsbitconf(Tk*, TkCitem*, char*); extern	char*	tkcvswindcreat(Tk*, char *arg, char **val);extern	void	tkcvswinddraw(Image*, TkCitem*, TkEnv*);extern	void	tkcvswindfree(TkCitem*);extern	char*	tkcvswindcoord(TkCitem*, char*, int, int);extern	char*	tkcvswindcget(TkCitem*, char*, char**);extern	char*	tkcvswindconf(Tk*, TkCitem*, char*); extern	char*	tkcvspolycreat(Tk*, char *arg, char **val);extern	void	tkcvspolydraw(Image*, TkCitem*, TkEnv*);extern	void	tkcvspolyfree(TkCitem*);extern	char*	tkcvspolycoord(TkCitem*, char*, int, int);extern	char*	tkcvspolycget(TkCitem*, char*, char**);extern	char*	tkcvspolyconf(Tk*, TkCitem*, char*);extern	int		tkcvspolyhit(TkCitem*, Point); extern	char*	tkcvsimgcreat(Tk*, char *arg, char **val);extern	void	tkcvsimgdraw(Image*, TkCitem*, TkEnv*);extern	void	tkcvsimgfree(TkCitem*);extern	char*	tkcvsimgcoord(TkCitem*, char*, int, int);extern	char*	tkcvsimgcget(TkCitem*, char*, char**);extern	char*	tkcvsimgconf(Tk*, TkCitem*, char*);