#include <u.h>#include <libc.h>#include <libg.h> 	int	bitbltfd;	Bitmap	screen;	Font	*font;static	uchar	bbuf[8000];	uchar	_btmp[8000];static	uchar	*bbufp = bbuf;static	void	(*onerr)(char*);static	char	oldlabel[128+1];static	char	*label; uchar*bneed(int n){	if(n < 0)		berror("negative count in bneed");	if(n==0 || bbufp-bbuf>sizeof bbuf-n){		if(!bwrite())			berror("write to /dev/bitblt");		if(n > sizeof bbuf)			berror("write to /dev/bitblt too big");	}	bbufp += n;	return bbufp-n;} voidbflush(void){	bneed(0);} intbwrite(void){	int r;	if(bbufp == bbuf)		return 1;	r = (write(bitbltfd, bbuf, bbufp-bbuf) == bbufp-bbuf);	bbufp = bbuf;	return r;} intRconv(void *oa, Fconv *f){	Rectangle *r;	char buf[128]; 	r = oa;	sprint(buf, "%P %P", r->min, r->max);	strconv(buf, f);	return sizeof(Rectangle);} intPconv(void *oa, Fconv *f){	Point *p;	char buf[64]; 	p = oa;	sprint(buf, "[%ld %ld]", p->x, p->y);	strconv(buf, f);	return sizeof(Point);} voidbinit(void (*f)(char *), char *s, char *nlabel){	uchar *buf, *p;	char fontname[128];	int fd, n, m, j;	Fontchar *info;	Subfont	*subfont; 	if(s == 0){		fd = open("/env/font", OREAD);		if(fd >= 0){			n = read(fd, fontname, sizeof(fontname));			if(n > 0){				fontname[n] = 0;				s = fontname;			}			close(fd);		}	}	onerr = f;	if(access("/dev/bitblt", 0) < 0)		bind("#b", "/dev", MAFTER);	bitbltfd = open("/dev/bitblt", ORDWR);	if(bitbltfd < 0)		berror("open /dev/bitblt");	if(write(bitbltfd, "i", 1) != 1)		berror("binit write /dev/bitblt"); 	n = 18+16;	m = 18+16;	if(s == 0){		m += 3*12;		n += 3*12+1300*6;	/* 1300 charinfos: big enough? */	}	buf = malloc(n);	if(buf == 0){		free(buf);		berror("binit alloc");	}	j = read(bitbltfd, buf, n);	if(j<m || buf[0]!='I'){		free(buf);		berror("binit read");	}	screen.ldepth = buf[1];	screen.r.min.x = BGLONG(buf+2);	screen.r.min.y = BGLONG(buf+6);	screen.r.max.x = BGLONG(buf+10);	screen.r.max.y = BGLONG(buf+14);	screen.clipr.min.x = BGLONG(buf+18);	screen.clipr.min.y = BGLONG(buf+22);	screen.clipr.max.x = BGLONG(buf+26);	screen.clipr.max.y = BGLONG(buf+30);	screen.cache = 0;	fmtinstall('P', Pconv);	fmtinstall('R', Rconv); 	if(s){		/*		 * Load specified font		 */		font = rdfontfile(s, screen.ldepth);		if(font == 0)			berror("binit font load");	}else{		/*		 * Cobble fake font using existing subfont		 */		n = atoi((char*)buf+18+16);		info = malloc(sizeof(Fontchar)*(n+1));		if(info == 0){			free(buf);			berror("binit info alloc");		}		p = buf+18+16+3*12;		_unpackinfo(info, p, n);		subfont = malloc(sizeof(Subfont));		if(subfont == 0){	Err:			free(buf);			free(info);			berror("binit font alloc");		}		subfont->n = n;		subfont->height = atoi((char*)buf+18+16+12);		subfont->ascent = atoi((char*)buf+18+16+24);		subfont->info = info;		subfont->id = 0;		font = mkfont(subfont, 0);		if(font == 0)			goto Err;	}	free(buf);		label = nlabel;	if(label){		fd = open("/dev/label", OREAD);		if(fd >= 0){			read(fd, oldlabel, sizeof oldlabel-1);			close(fd);			fd = create("/dev/label", OWRITE, 0666);			if(fd >= 0){				n = strlen(label);				if(n > sizeof(oldlabel)-1)					n = sizeof(oldlabel)-1;				write(fd, label, n);				close(fd);			}		}	}	atexit(bexit);} voidbclose(void){	close(bitbltfd);	atexitdont(bexit);} voidbexit(void){	int fd; 	bflush();	if(label){		fd = open("/dev/label", OWRITE);		if(fd >= 0){			write(fd, oldlabel, strlen(oldlabel));			close(fd);		}	}} voidberror(char *s){	char err[ERRLEN]; 	if(onerr)		(*onerr)(s);	else{		errstr(err);		fprint(2, "bitblt: %s: %s\n", s, err);		exits(s);	}}