scat.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

#include <u.h>
#include <libc.h>
#include <bio.h>
#include <draw.h>
#include <event.h>
#include "sky.h"
#include "strings.c"

enum
{
	NNGC=7840,	/* number of NGC numbers [1..NNGC] */
	NIC = 5386,	/* number of IC numbers */
	NNGCrec=NNGC+NIC,	/* number of records in the NGC catalog (including IC's, starting at NNGC */
	NMrec=122,	/* number of M records */
	NM=110,		/* number of M numbers */
	NAbell=2712,	/* number of records in the Abell catalog */
	NName=1000,	/* number of prose names; estimated maximum (read from editable text file) */
	NBayer=1517,	/* number of bayer entries */
	NSAO=258998,	/* number of SAO stars */
	MAXcon=1932,	/* maximum number of patches in a constellation */
	Ncon=88,	/* number of constellations */
	Npatch=92053,	/* highest patch number */
};

char		ngctype[NNGCrec];
Mindexrec	mindex[NMrec];
Namerec		name[NName];
Bayerec		bayer[NBayer];
long		con[MAXcon];
ushort		conindex[Ncon+1];
long		patchaddr[Npatch+1];

Record	*rec;
Record	*orec;
Record	*cur;

char	*dir=DIR;
int	saodb;
int	ngcdb;
int	abelldb;
int	ngctypedb;
int	mindexdb;
int	namedb;
int	bayerdb;
int	condb;
int	conindexdb;
int	patchdb;
char	parsed[3];
long	nrec;
long	nreca;
long	norec;
long	noreca;

Biobuf	bin;
Biobuf	bout;

main(int argc, char *argv[])
{
	char *line;

	Binit(&bin, 0, OREAD);
	Binit(&bout, 1, OWRITE);
	if(argc != 1)
		dir = argv[1];
	astro("", 1);
	while(line = Brdline(&bin, '\n')){
		line[Blinelen(&bin)-1] = 0;
		lookup(line, 1);
		Bflush(&bout);
	}
	if(display != nil){
		closedisplay(display);
		/* automatic refresh of rio window is triggered by mouse */
		close(open("/dev/mouse", OREAD));
	}
	return 0;
}

void
reset(void)
{
	nrec = 0;
	cur = rec;
}

void
grow(void)
{
	nrec++;
	if(nreca < nrec){
		nreca = nrec+50;
		rec = realloc(rec, nreca*sizeof(Record));
		if(rec == 0){
			fprint(2, "scat: realloc fails\n");
			exits("realloc");
		}
	}
	cur = rec+nrec-1;
}

void
copy(void)
{
	if(noreca < nreca){
		noreca = nreca;
		orec = realloc(orec, nreca*sizeof(Record));
		if(orec == 0){
			fprint(2, "scat: realloc fails\n");
			exits("realloc");
		}
	}
	memmove(orec, rec, nrec*sizeof(Record));
	norec = nrec;
}

int
eopen(char *s)
{
	char buf[128];
	int f;

	sprint(buf, "%s/%s.scat", dir, s);
	f = open(buf, 0);
	if(f<0){
		fprint(2, "scat: can't open %s\n", buf);
		exits("open");
	}
	return f;
}


void
Eread(int f, char *name, void *addr, long n)
{
	if(read(f, addr, n) != n){	/* BUG! */
		fprint(2, "scat: read error on %s\n", name);
		exits("read");
	}
}

char*
skipbl(char *s)
{
	while(*s!=0 && (*s==' ' || *s=='\t'))
		s++;
	return s;
}

char*
skipstr(char *s, char *t)
{
	while(*s && *s==*t)
		s++, t++;
	return skipbl(s);
}

/* produce little-endian long at address l */
long
Long(long *l)
{
	uchar *p;

	p = (uchar*)l;
	return (long)p[0]|((long)p[1]<<8)|((long)p[2]<<16)|((long)p[3]<<24);
}

/* produce little-endian long at address l */
int
Short(short *s)
{
	uchar *p;

	p = (uchar*)s;
	return p[0]|(p[1]<<8);
}

void
nameopen(void)
{
	Biobuf b;
	int i;
	char *l, *p;

	if(namedb == 0){
		namedb = eopen("name");
		Binit(&b, namedb, OREAD);
		for(i=0; i<NName; i++){
			l = Brdline(&b, '\n');
			if(l == 0)
				break;
			p = strchr(l, '\t');
			if(p == 0){
		Badformat:
				Bprint(&bout, "warning: name.scat bad format; line %d\n", i+1);
				break;
			}
			*p++ = 0;
			strcpy(name[i].name, l);
			if(strncmp(p, "ngc", 3) == 0)
				name[i].ngc = atoi(p+3);
			else if(strncmp(p, "ic", 2) == 0)
				name[i].ngc = atoi(p+2)+NNGC;
			else if(strncmp(p, "sao", 3) == 0)
				name[i].sao = atoi(p+3);
			else if(strncmp(p, "abell", 5) == 0)
				name[i].abell = atoi(p+5);
			else
				goto Badformat;
		}
		if(i == NName)
			Bprint(&bout, "warning: too many names in name.scat (max %d); extra ignored\n", NName);
		close(namedb);

		bayerdb = eopen("bayer");
		Eread(bayerdb, "bayer", bayer, sizeof bayer);
		close(bayerdb);
		for(i=0; i<NBayer; i++)
			bayer[i].sao = Long(&bayer[i].sao);
	}
}

void
saoopen(void)
{
	if(saodb == 0){
		nameopen();
		saodb = eopen("sao");
	}
}

void
ngcopen(void)
{
	if(ngcdb == 0){
		nameopen();
		ngcdb = eopen("ngc2000");
		ngctypedb = eopen("ngc2000type");
		Eread(ngctypedb, "ngctype", ngctype, sizeof ngctype);
		close(ngctypedb);
	}
}

void
abellopen(void)
{
	/* nothing extra to do with abell: it's directly indexed by number */
	if(abelldb == 0)
		abelldb = eopen("abell");
}

void
patchopen(void)
{
	Biobuf *b;
	long l, m;
	char buf[100];

	if(patchdb == 0){
		patchdb = eopen("patch");
		sprint(buf, "%s/patchindex.scat", dir);
		b = Bopen(buf, OREAD);
		if(b == 0){
			fprint(2, "can't open %s\n", buf);
			exits("open");
		}
		for(m=0,l=0; l<=Npatch; l++)
			patchaddr[l] = m += Bgetc(b)*4;
		Bterm(b);
	}
}

void
mopen(void)
{
	int i;

	if(mindexdb == 0){
		mindexdb = eopen("mindex");
		Eread(mindexdb, "mindex", mindex, sizeof mindex);
		close(mindexdb);
		for(i=0; i<NMrec; i++)
			mindex[i].ngc = Short(&mindex[i].ngc);
	}
}

void
constelopen(void)
{
	int i;

	if(condb == 0){
		condb = eopen("con");
		conindexdb = eopen("conindex");
		Eread(conindexdb, "conindex", conindex, sizeof conindex);
		close(conindexdb);
		for(i=0; i<Ncon+1; i++)
			conindex[i] = Short((short*)&conindex[i]);
	}
}

void
lowercase(char *s)
{
	for(; *s; s++)
		if('A'<=*s && *s<='Z')
			*s += 'a'-'A';
}

int
loadngc(long index)
{
	static int failed;
	long j;

	ngcopen();
	j = (index-1)*sizeof(NGCrec);
	grow();
	cur->type = NGC;
	cur->index = index;
	seek(ngcdb, j, 0);
	/* special case: NGC data may not be available */
	if(read(ngcdb, &cur->ngc, sizeof(NGCrec)) != sizeof(NGCrec)){
		if(!failed){
			fprint(2, "scat: NGC database not available\n");
			failed++;
		}
		cur->type = NONGC;
		cur->ngc.ngc = 0;
		cur->ngc.ra = 0;
		cur->ngc.dec = 0;
		cur->ngc.diam = 0;
		cur->ngc.mag = 0;
		return 0;
	}
	cur->ngc.ngc = Short(&cur->ngc.ngc);
	cur->ngc.ra = Long(&cur->ngc.ra);
	cur->ngc.dec = Long(&cur->ngc.dec);
	cur->ngc.diam = Long(&cur->ngc.diam);
	cur->ngc.mag = Short(&cur->ngc.mag);
	return 1;
}

int
loadabell(long index)
{
	long j;

	abellopen();
	j = index-1;
	grow();
	cur->type = Abell;
	cur->index = index;
	seek(abelldb, j*sizeof(Abellrec), 0);
	Eread(abelldb, "abell", &cur->abell, sizeof(Abellrec));
	cur->abell.abell = Short(&cur->abell.abell);
	if(cur->abell.abell != index){
		fprint(2, "bad format in abell catalog\n");
		exits("abell");
	}
	cur->abell.ra = Long(&cur->abell.ra);
	cur->abell.dec = Long(&cur->abell.dec);
	cur->abell.glat = Long(&cur->abell.glat);
	cur->abell.glong = Long(&cur->abell.glong);
	cur->abell.rad = Long(&cur->abell.rad);
	cur->abell.mag10 = Short(&cur->abell.mag10);
	cur->abell.pop = Short(&cur->abell.pop);
	cur->abell.dist = Short(&cur->abell.dist);
	return 1;
}

int
loadsao(int index)
{
	if(index<=0 || index>NSAO)
		return 0;
	saoopen();
	grow();
	cur->type = SAO;
	cur->index = index;
	seek(saodb, (index-1)*sizeof(SAOrec), 0);
	Eread(saodb, "sao", &cur->sao, sizeof(SAOrec));
	cur->sao.ra = Long(&cur->sao.ra);
	cur->sao.dec = Long(&cur->sao.dec);
	cur->sao.dra = Long(&cur->sao.dra);
	cur->sao.ddec = Long(&cur->sao.ddec);
	cur->sao.mag = Short(&cur->sao.mag);
	cur->sao.mpg = Short(&cur->sao.mpg);
	cur->sao.hd = Long(&cur->sao.hd);
	return 1;
}

int
loadplanet(int index, Record *r)
{
	if(index<0 || index>NPlanet || planet[index].name[0]=='\0')
		return 0;
	grow();
	cur->type = Planet;
	cur->index = index;
	/* check whether to take new or existing record */
	if(r == nil)
		memmove(&cur->planet, &planet[index], sizeof(Planetrec));
	else
		memmove(&cur->planet, &r->planet, sizeof(Planetrec));
	return 1;
}

int
loadpatch(long index)
{
	int i;

	patchopen();
	if(index<=0 || index>Npatch)
		return 0;
	grow();
	cur->type = Patch;
	cur->index = index;
	seek(patchdb, patchaddr[index-1], 0);
	cur->patch.nkey = (patchaddr[index]-patchaddr[index-1])/4;
	Eread(patchdb, "patch", cur->patch.key, cur->patch.nkey*4);
	for(i=0; i<cur->patch.nkey; i++)
		cur->patch.key[i] = Long(&cur->patch.key[i]);
	return 1;
}

int
loadtype(int t)
{
	int i;

	ngcopen();
	for(i=0; i<NNGCrec; i++)
		if(t == (ngctype[i])){
			grow();
			cur->type = NGCN;
			cur->index = i+1;
		}
	return 1;
}

void
flatten(void)
{
	int i, j, notflat;
	Record *or;
	long key;

    loop:
	copy();
	reset();
	notflat = 0;
	for(i=0,or=orec; i<norec; i++,or++){
		switch(or->type){
		default:
			fprint(2, "bad type %d in flatten\n", or->type);
			break;

		case NONGC:
			break;

		case Planet:
		case Abell:
		case NGC:
		case SAO:
			grow();
			memmove(cur, or, sizeof(Record));
			break;

		case NGCN:
			if(loadngc(or->index))
				notflat = 1;
			break;

		case NamedSAO:
			loadsao(or->index);
			notflat = 1;
			break;

		case NamedNGC:
			if(loadngc(or->index))
				notflat = 1;
			break;

		case NamedAbell:
			loadabell(or->index);
			notflat = 1;
			break;

		case PatchC:
			loadpatch(or->index);
			notflat = 1;
			break;

		case Patch:
			for(j=1; j<or->patch.nkey; j++){
				key = or->patch.key[j];
				if((key&0x3F) == SAO)
					loadsao((key>>8)&0xFFFFFF);
				else if((key&0x3F) == Abell)
					loadabell((key>>8)&0xFFFFFF);
				else
					loadngc((key>>16)&0xFFFF);
			}
			break;
		}
	}
	if(notflat)
		goto loop;
}

int
ism(int index)
{
	int i;

	for(i=0; i<NMrec; i++)
		if(mindex[i].ngc == index)
			return 1;
	return 0;
}

char*
alpha(char *s, char *t)
{
	int n;

	n = strlen(t);
	if(strncmp(s, t, n)==0 && (s[n]<'a' || 'z'<s[n]))
		return skipbl(s+n);
	return 0;
	
}

char*
text(char *s, char *t)
{
	int n;

	n = strlen(t);
	if(strncmp(s, t, n)==0 && (s[n]==0 || s[n]==' ' || s[n]=='\t'))
		return skipbl(s+n);
	return 0;
	
}

int
cull(char *s, int keep, int dobbox)
{
	int i, j, nobj, keepthis;
	Record *or;
	char *t;
	int dogrtr, doless, dom, dosao, dongc, doabell;
	int mgrtr, mless;
	char obj[100];

	memset(obj, 0, sizeof(obj));
	nobj = 0;
	dogrtr = 0;
	doless = 0;
	dom = 0;
	dongc = 0;
	dosao = 0;
	doabell = 0;
	mgrtr = mless= 0;
	if(dobbox)
		goto Cull;
	for(;;){
		if(s[0] == '>'){
			dogrtr = 1;
			mgrtr = 10 * strtod(s+1, &t);
			if(mgrtr==0  && t==s+1){
				fprint(2, "bad magnitude\n");
				return 0;
			}
			s = skipbl(t);
			continue;
		}
		if(s[0] == '<'){
			doless = 1;
			mless = 10 * strtod(s+1, &t);
			if(mless==0  && t==s+1){
				fprint(2, "bad magnitude\n");
				return 0;
			}
			s = skipbl(t);
			continue;
		}
		if(t = text(s, "m")){
 			dom = 1;
			s = t;
			continue;
		}
		if(t = text(s, "sao")){
			dosao = 1;
			s = t;
			continue;
		}
		if(t = text(s, "ngc")){
			dongc = 1;
			s = t;
			continue;
		}
		if(t = text(s, "abell")){
			doabell = 1;
			s = t;
			continue;
		}
		for(i=0; names[i].name; i++)
			if(t = alpha(s, names[i].name)){
				if(nobj > 100){
					fprint(2, "too many object types\n");
					return 0;
				}
				obj[nobj++] = names[i].type;
				s = t;
				goto Continue;
			}
		break;
	    Continue:;
	}
	if(*s){
		fprint(2, "syntax error in object list\n");
		return 0;
	}

    Cull:
	flatten();
	copy();
	reset();
	if(dom)
		mopen();
	if(dosao)
		saoopen();
	if(dongc || nobj)
		ngcopen();
	if(doabell)
		abellopen();
	for(i=0,or=orec; i<norec; i++,or++){
		keepthis = !keep;
		if(dobbox && inbbox(or->ngc.ra, or->ngc.dec))
			keepthis = keep;
		if(doless && or->ngc.mag <= mless)
			keepthis = keep;
		if(dogrtr && or->ngc.mag >= mgrtr)
			keepthis = keep;
		if(dom && (or->type==NGC && ism(or->ngc.ngc)))
			keepthis = keep;
		if(dongc && or->type==NGC)
			keepthis = keep;
		if(doabell && or->type==Abell)
			keepthis = keep;
		if(dosao && or->type==SAO)
			keepthis = keep;
		for(j=0; j<nobj; j++)
			if(or->type==NGC && or->ngc.type==obj[j])
				keepthis = keep;
		if(keepthis){
			grow();
			memmove(cur, or, sizeof(Record));
		}
	}
	return 1;
}

int
compar(void *va, void *vb)
{
	Record *a=va, *b=vb;

	if(a->type == b->type)
		return a->index - b->index;
	return a->type - b->type;
}

void
sort(void)
{
	int i;
	Record *r, *s;

	if(nrec == 0)
		return;
	qsort(rec, nrec, sizeof(Record), compar);
	r = rec+1;
	s = rec;
	for(i=1; i<nrec; i++,r++){
		/* may have multiple instances of a planet in the scene */
		if(r->type==s->type && r->index==s->index && r->type!=Planet)
			continue;
		memmove(++s, r, sizeof(Record));
	}
	nrec = (s+1)-rec;
}

char	greekbuf[128];

char*
togreek(char *s)
{
	char *t;
	int i, n;
	Rune r;

	t = greekbuf;
	while(*s){
		for(i=1; i<=24; i++){
			n = strlen(greek[i]);
			if(strncmp(s, greek[i], n)==0 && (s[n]==' ' || s[n]=='\t')){
				s += n;
				t += runetochar(t, &greeklet[i]);
				goto Cont;
			}
		}
		n = chartorune(&r, s);
		for(i=0; i<n; i++)
			*t++ = *s++;
    Cont:;
	}
	*t = 0;
	return greekbuf;
}

char*
fromgreek(char *s)
{
	char *t;
	int i, n;
	Rune r;

	t = greekbuf;
	while(*s){
		n = chartorune(&r, s);
		for(i=1; i<=24; i++){
			if(r == greeklet[i]){
				strcpy(t, greek[i]);
				t += strlen(greek[i]);
				s += n;
				goto Cont;
			}
		}
		for(i=0; i<n; i++)
			*t++ = *s++;
    Cont:;
	}
	*t = 0;
	return greekbuf;
}

#ifdef OLD
/*
 * Old version
 */
int
coords(int deg)
{
	int i;
	int x, y;
	Record *or;
	long dec, ra, ndec, nra;
	int rdeg;

	flatten();
	copy();
	reset();
	deg *= 2;
	for(i=0,or=orec; i<norec; i++,or++){
		if(or->type == Planet)	/* must keep it here */
			loadplanet(or->index, or);
		dec = or->ngc.dec/MILLIARCSEC;
		ra = or->ngc.ra/MILLIARCSEC;
		rdeg = deg/cos((dec*PI)/180);
		for(y=-deg; y<=+deg; y++){
			ndec = dec*2+y;
			if(ndec/2>=90 || ndec/2<=-90)
				continue;
			/* fp errors hurt here, so we round 1' to the pole */
			if(ndec >= 0)
				ndec = ndec*500*60*60 + 60000;
			else
				ndec = ndec*500*60*60 - 60000;
			for(x=-rdeg; x<=+rdeg; x++){
				nra = ra*2+x;
				if(nra/2 < 0)
					nra += 360*2;
				if(nra/2 >= 360)
					nra -= 360*2;
				/* fp errors hurt here, so we round up 1' */
				nra = nra/2*MILLIARCSEC + 60000;
				loadpatch(patcha(angle(nra), angle(ndec)));
			}
		}
	}
	sort();
	return 1;
}
#endif

/*
 * New version attempts to match the boundaries of the plot better.
 */
int
coords(int deg)
{
	int i;
	int x, y, xx;
	Record *or;
	long min, circle;
	double factor;

	flatten();
	circle = 360*MILLIARCSEC;
	deg *= MILLIARCSEC;

	/* find center */
	folded = 0;
	bbox(0, 0, 0);
	/* now expand */
	factor = cos(angle((decmax+decmin)/2));
	if(factor < .2)
		factor = .2;
	factor = floor(1/factor);
	folded = 0;
	bbox(factor*deg, deg, 1);
	Bprint(&bout, "%s to ", hms(angle(ramin)));
	Bprint(&bout, "%s\n", hms(angle(ramax)));
	Bprint(&bout, "%s to ", dms(angle(decmin)));
	Bprint(&bout, "%s\n", dms(angle(decmax)));
	copy();
	reset();
	for(i=0,or=orec; i<norec; i++,or++)
		if(or->type == Planet)	/* must keep it here */
			loadplanet(or->index, or);
	min = ramin;