#pragma src "/sys/src/alef/lib/libg"
#pragma lib "/$M/lib/alef/libg.a"

/*
 * Types
 */

aggr	Point
{
	int	x;
	int	y;
};

aggr Rectangle
{
	Point min;
	Point max;
};

aggr	Bitmap
{
	Rectangle r;		/* rectangle in data area, local coords */
	Rectangle clipr;	/* clipping region */
	int	ldepth;
	int	id;
	Bitmap	*cache;		/* zero; distinguishes bitmap from layer */
};

aggr	Mouse
{
	int  	buttons;
	Point	xy;
	uint	msec;
};

aggr	Cursor
{
	Point	offset;
	byte	clr[2*16];
	byte	set[2*16];
};

aggr Linedesc
{
	int	x0;
	int	y0;
	byte	xmajor;
	byte	slopeneg;
	int	dminor;
	int	dmajor;
};

adt Menu
{
extern	byte	**item;
extern	byte	*(*gen)(int);
		int	lasthit;

		(int, Mouse)	hit(*Menu, int, chan(Mouse), Mouse);
};


/*
 * Subfonts
 *
 * given char c, Subfont *f, Fontchar *i, and Point p, one says
 *	i = f->info+c;
 *	bitblt(b, Pt(p.x+i->left,p.y+i->top),
 *		bitmap, Rect(i->x,i->top,(i+1)->x,i->bottom),
 *		fc);
 *	p.x += i->width;
 * where bitmap b is the repository of the images.
 *
 */

aggr	Fontchar
{
	usint	x;		/* left edge of bits */
	byte	top;		/* first non-zero scan-line */
	byte	bottom;		/* last non-zero scan-line + 1 */
	byte	left;		/* offset of baseline */
	byte	width;		/* width of baseline */
};

aggr	Subfont
{
	sint	n;		/* number of chars in font */
	byte	height;		/* height of bitmap */
	byte	ascent;		/* top of bitmap to baseline */
	Fontchar *info;		/* n+1 character descriptors */
	int	id;		/* of font */
};

enum
{
	/* starting values */
	LOG2NFCACHE =	6,
	NFCACHE =	(1<<LOG2NFCACHE),	/* #chars cached */
	NFLOOK =	5,			/* #chars to scan in cache */
	NFSUBF =	2,			/* #subfonts to cache */
	/* max value */
	MAXFCACHE =	2048+NFLOOK,		/* generous upper limit */
	MAXSUBF =	50,			/* generous upper limit */
	/* deltas */
	DSUBF = 	4,
	/* expiry ages */
	SUBFAGE	=	10000,
	CACHEAGE =	10000,
};

aggr Cachefont
{
	Rune	min;	/* lowest rune value to be taken from subfont */
	Rune	max;	/* highest rune value+1 to be taken from subfont */
	int	offset;	/* position in subfont of character at min */
	int	abs;	/* name has been made absolute */
	byte	*name;
};

aggr Cacheinfo
{
	Rune		value;	/* value of character at this slot in cache */
	usint		age;
	uint		xright;	/* right edge of bits */
	Fontchar;
};

aggr Cachesubf
{
	uint		age;	/* for replacement */
	Cachefont	*cf;	/* loaded subfont */
	Subfont		*f;	/* subfont font; multiplexed between subfonts */
};

aggr Font
{
	byte		*name;
	byte		height;	/* max height of bitmap, interline spacing */
	byte		ascent;	/* top of bitmap to baseline */
	byte		width;	/* widest so far; used in caching only */	
	byte		ldepth;	/* of images */
	sint		id;	/* of font */
	sint		nsub;	/* number of subfonts */
	uint		age;	/* increasing counter; used for LRU */
	int		ncache;	/* size of cache */
	int		nsubf;	/* size of subfont list */
	Cacheinfo	*cache;
	Cachesubf	*subf;
	Cachefont	**sub;	/* as read from file */
};

aggr RGB
{
	uint	red;
	uint	green;
	uint	blue;
};

/*
 * Codes for bitblt etc.
 *
 *	       D
 *	     0   1
 *         ---------
 *	 0 | 1 | 2 |
 *     S   |---|---|
 * 	 1 | 4 | 8 |
 *         ---------
 *
 *	Usually used as D|S; DorS is so tracebacks are readable.
 */
enum Fcode
{
	Zero		= 0x0,
	DnorS		= 0x1,
	DandnotS	= 0x2,
	notS		= 0x3,
	notDandS	= 0x4,
	notD		= 0x5,
	DxorS		= 0x6,
	DnandS		= 0x7,
	DandS		= 0x8,
	DxnorS		= 0x9,
	D		= 0xA,
	DornotS		= 0xB,
	S		= 0xC,
	notDorS		= 0xD,
	DorS		= 0xE,
	F		= 0xF,
};

/*
 * Miscellany
 */

extern Point	 add(Point, Point);
extern Point	 sub(Point, Point);
extern Point	 mul(Point, int);
extern Point	 div(Point, int);
extern Rectangle rsubp(Rectangle, Point);
extern Rectangle raddp(Rectangle, Point);
extern Rectangle inset(Rectangle, int);
extern Rectangle rmul(Rectangle, int);
extern Rectangle rdiv(Rectangle, int);
extern Rectangle rshift(Rectangle, int);
extern Rectangle rcanon(Rectangle);
extern Bitmap*	 balloc(Rectangle, int);
extern void	 bfree(Bitmap*);
extern int	 rectclip(Rectangle*, Rectangle);
extern void	 binit(void(*)(byte*), byte*, byte*);
extern void	 bclose(void);
extern void	 berror(byte*);
extern void	 bitblt(Bitmap*, Point, Bitmap*, Rectangle, Fcode);
extern int	 bitbltclip(void*);
extern Font*	 rdfontfile(byte*, int);
extern void	 ffree(Font*);
extern Font*	 mkfont(Subfont*, Rune);
extern Subfont*	 subfalloc(int, int, int, Fontchar*, Bitmap*, uint, uint);
extern void	 subffree(Subfont*);
extern int	 cachechars(Font*, byte**, usint*, int, int*);
extern Point	 string(Bitmap*, Point, Font*, byte*, Fcode);
extern void	 segment(Bitmap*, Point, Point, int, Fcode);
extern void	 point(Bitmap*, Point, int, Fcode);
extern void	 arc(Bitmap*, Point, Point, Point, int, Fcode);
extern void	 circle(Bitmap*, Point, int, int, Fcode);
extern void	 disc(Bitmap*, Point, int, int, Fcode);
extern void	 ellipse(Bitmap*, Point, int, int, int, Fcode);
extern int	 strwidth(Font*, byte*);
extern void	 agefont(Font*);
extern int	 loadchar(Font*, Rune, Cacheinfo*, int, int);
extern Point	 strsize(Font*, byte*);
extern int	 charwidth(Font*, Rune);
extern void	 texture(Bitmap*, Rectangle, Bitmap*, Fcode);
extern void	 wrbitmap(Bitmap*, int, int, byte*);
extern void	 rdbitmap(Bitmap*, int, int, byte*);
extern void	 wrbitmapfile(int, Bitmap*);
extern Bitmap*	 rdbitmapfile(int);
extern void	 wrsubfontfile(int, Subfont*);
extern Subfont*	 rdsubfontfile(int, Bitmap*);
extern void	_unpackinfo(Fontchar*, byte*, int);
extern void	 rdcolmap(Bitmap*, RGB*);
extern void	 wrcolmap(Bitmap*, RGB*);
extern int	 ptinrect(Point, Rectangle);
extern int	 rectinrect(Rectangle, Rectangle);
extern int	 rectXrect(Rectangle, Rectangle);
extern int	 eqpt(Point, Point);
extern int	 eqrect(Rectangle, Rectangle);
extern void	 border(Bitmap*, Rectangle, int, Fcode);
extern void	 cursorswitch(Cursor*);
extern void	 cursorset(Point);
extern Rectangle bscreenrect(Rectangle*);
extern byte*	 bneed(int);
extern void	 bflush(void);
extern void	 bexit(void);
extern int	 bwrite(void);
extern int	 _clipline(Rectangle, Point*, Point*, Linedesc*);
extern int	 clipline(Rectangle, Point*, Point*);
extern int	 clipr(Bitmap*, Rectangle);

extern uint	 rgbpix(Bitmap*, RGB);
extern int	_gminor(int, Linedesc*);

#define	Pt(x, y)		((Point)(x, y))
#define	Rect(x1, y1, x2, y2)	((Rectangle)(Pt(x1, y1), Pt(x2, y2)))
#define	Rpt(p1, p2)		((Rectangle)(p1, p2))


#define	Dx(r)	((r).max.x-(r).min.x)
#define	Dy(r)	((r).max.y-(r).min.y)

extern	int	bitbltfd;
extern	Bitmap	screen;
extern	Font	*font;
extern	byte	_btmp[8192];

#define	BGSHORT(p)		(((p)[0]<<0) | ((p)[1]<<8))
#define	BGLONG(p)		((BGSHORT(p)<<0) | (BGSHORT(p+2)<<16))
#define	BPSHORT(p, v)		{(p)[0]=(v); (p)[1]=(v)>>8; }
#define	BPLONG(p, v)		{(p)[0]=(v); (p)[1]=(v)>>8; (p)[2]=(v)>>16; (p)[3]=(v)>>24; }