#include <u.h>#include <libc.h>#include <libg.h> int	npix;int	nbit;char	msg[128];RGB	map[256]; void extmapcolor(void), mapcolor(void), mapgrey(int), mapfile(char *), dumpmap(void); voidmain(int argc, char **argv){	int f, cons;	char c;	Bitmap *b; 	binit(0,0,"showimage");	nbit = (1 << screen.ldepth);	npix = 1 << nbit; 	ARGBEGIN{	case 'c':	mapcolor();		break;	case 'e':	extmapcolor();		break;	case 'g':	mapgrey(0);		break;	case 'r':	mapgrey(1);		break;	case 'm':	mapfile(ARGF());	break;	case 'd':	dumpmap();		break;	default:		fprint(2, "Usage: %s [-cgrd] [-m mapfile] [file ...]\n");		exits("usage");	}ARGEND 	cons = open("/dev/cons", OREAD);	if(cons < 0)		cons = 0;	for( ;argc > 0; argc--, argv++) {		f = open(argv[0], OREAD);		if(f < 0) {			sprint(msg, "opening file %s", argv[1]);			perror(msg);			continue;		}		b = rdbitmapfile(f);		close(f);		if(!b) {			perror("reading bitmap");			continue;		}		bitblt(&screen, screen.r.min, b, b->r, S);		bfree(b);		bflush();		read(cons, &c, 1);		if(c == 'q')			break;	}	exits(0);} /* replicate (from top) value in v (n bits) until it fills a ulong */ulongrep(ulong v, int n){	int o;	ulong rv; 	rv = 0;	for(o = 32 - n; o >= 0; o -= n)		rv |= (v << o);	if(o != -n)		rv |= v >> (-o);	return rv;} /* * Standard Plan 9 Grey Scale map: *  linear from 0 (white) to 1 (black) *  or inverse, if rev is 1 */voidmapgrey(int rev){	ulong rv;	int i; 	if(npix > 256)		return;	for(i = 0; i < npix; i++){		rv = rep(i, nbit);		if(!rev)			rv = ~rv;		map[i].red = rv;		map[i].green = rv;		map[i].blue = rv;	}	wrcolmap(&screen, map);} /* * Standard Plan 9 Color map (8 bits): *   top 3 bits: ~red, next 3 bits: ~green, next 2 bits: ~red *   exceptions: pixels 85 and 170 are set to the values they *   		have in the grey scale map */voidmapcolor(void){	int i; 	if(npix == 256){		for(i = 0; i < npix; i++){			map[i].red = ~rep((i>>5) & 7, 3);			map[i].green = ~rep((i>>2) & 7, 3);			map[i].blue = ~rep(i & 3, 2);		}		map[85].red = map[85].green = map[85].blue = 0xB5B5B5B5;	/* was 0xAAAAAAAA */		map[170].red = map[170].green = map[170].blue = 0x80808080;	/* was 0x55555555 */		wrcolmap(&screen, map);	} else if(npix == 16){		for(i = 0; i < npix; i++){			map[i].red = ~rep((i>>2) & 3, 2);			map[i].green = ~rep(i & 1, 1);			map[i].blue = ~rep(i & 3, 2);		}		map[5].red = map[5].green = map[5].blue = 0xB5B5B5B5;	/* was 0xAAAAAAAA */		map[10].red = map[10].green = map[10].blue = 0x80808080;	/* was 0x55555555 */		wrcolmap(&screen, map);	}} /* * Read Color map */voidextmapcolor(void){	int i;	uchar buf[3]; 	for(i = 0; i < npix; i++){		read(0, buf, 3);		map[i].red = ~rep(buf[0], 8);		map[i].green = ~rep(buf[1], 8);		map[i].blue = ~rep(buf[2], 8);	}	wrcolmap(&screen, map);} voidmapfile(char *file){	int i, f, n;	uchar *p, amap[256*12]; 	if(npix > 256)		return;	f = open(file, OREAD);	if(f < 0){		sprint(msg, "can't open map file %s\n", file);		perror(msg);		return;	}	n = read(f, amap, npix*12);	if(n < 0){		sprint(msg, "can't read map file %s\n", file);		perror(msg);		return;	} else if(n != npix*12){		fprint(2, "wrong size for map file %s: %d\n", file, n);		return;	}	p = amap;	for(i = 0; i < npix; i++){		map[i].red = BGLONG(p);		map[i].green = BGLONG(p+4);		map[i].blue = BGLONG(p+8);		p += 12;	}	close(f);	wrcolmap(&screen, map);} voiddumpmap(void){	int i;	uchar *p, amap[256*12]; 	rdcolmap(&screen, map);	p = amap;	for(i = 0; i < npix; i++){		BPLONG(p, map[i].red);		BPLONG(p+4, map[i].green);		BPLONG(p+8, map[i].blue);		p += 12;	}	write(1, amap, 12*npix);}