shithub: pico

--- a/README

+++ b/README

@@ -1,14 +1,70 @@

-This is a hacked-up version of rsc's version of pico.

+pico: a reimplementation of rsc's implementation of pico

+========================================================

-Changes:

-- remove p9p shit and some bitrot

-- use mk to build binary instead of hardcoding CC/LD

-- arbitrary image sizes; set when loading or displaying an image; default

-  248x248

-- work on ABGR32 images; channels are accessed via a third 'z' coordinate

-- add &&, || operators

-- name nameless images as $1, $2,...

-- images are always written once to /tmp prior to any processing

-- fix numerous memory leaks

-- accept integers in octal and hexadecimal, as well as doubles

-- accept digits and utf in names

+A language for composing digital images

+---------------------------------------

+This does not really reimplement the pico[1] language, but builds on the same

+idea.

+rsc initially implemented a version in C and YACC[2], which parsed a simplified

+language based on pico.

+It essentially parses a simple syntax to output a C file which performed the

+specified image manipulations in an expression embedded in a simple nested loop.

+It was an elegant hack, and possibly worked on plan9port as well as on plan9,

+but suffered from a number of bugs and limitations preventing its use in

+practice.

+This repository contains in its initial commit an improved version, which

+fixed some of the bugs and added a number of features:

+- removal of plan9port code and fixes on some bitrot

+- numerous memory leaks fixed

+- use of mk(1) instead of hardcoding CC and LD

+- arbitrary image sizes, set from loaded images, or 248x248 by default as

+  before

+- ABGR32 images instead of GREY8 images, with channels accessible via a third

+  'z' coordinate

+- some parser changes: addition of &&, || operators, integers in octal and

+  hexadecimal notation, floating point numbers; accept digits and utf8 runes

+  in image names

+- always name all images to allow referencing them

+- some simple optimizations in the execution, such as not writing images

+  multiple times to disk, etc.

+However, several problems remained unfixed.

+In particular, due to the way it was specified, the parser allocated

+an exponential number of strings while processing input.

+This, and the need of a few other features, prompted a reimplementation,

+this time without YACC, also in the repository, and which was also

+unsatisfactory for a number of reasons.

+Several reimplementations later, the current pico "implementation" is merely

+an awk script, in less than half the size of the initial code.

+It does everything the previous versions do, and some more:

+- no more memory issues

+- excepting image coordinate specifications, the syntax is straight C and

+  almost any valid expression (and operator) is allowed; using libc functions

+  and definitions such as sqrt(2) or PI is also allowed

+- image coordinate specifications needn't always specify all channels

+- images are displayed via plumb(1) and subsequently page(1) instead of a

+  makeshift viewer

+- image names may be any string not containing C operators, whitespace and

+  not beginning with a digit

+- add a command for specifying default image size when no other images are

+  referenced

+- comments via #

+Some other features are planned as well.

+Manpage pending.

+References:

+-----------

+[1] http://doc.cat-v.org/unix/v10/10thEdMan/pico.pdf

+[2] Found in plan9 contrib at /n/sources/contrib/rsc/pico/

--- a/dat.h

+++ /dev/null

@@ -1,20 +1,0 @@

-typedef struct Sym Sym;

-extern char wdir[], pref[];

-extern char **tok;

-extern int ntok;

-struct Sym{

-	int ref;

-	char *iname;

-	char *cname;

-	char *name;

-	char *path;

-};

-extern Sym *sym;

-extern int nsym;

-extern int Δx, Δy;

-extern char *prolog, *prepstr, *tailstr;

-extern int quiet;

--- a/defs.c

+++ /dev/null

@@ -1,110 +1,0 @@

-#include <u.h>

-#include <libc.h>

-#include "dat.h"

-#include "fns.h"

-char* prolog =

-"#include <u.h>\n"

-"#include <libc.h>\n"

-"#include <draw.h>\n"

-"#include <memdraw.h>\n"

-"\n"

-"Memimage*\n"

-"READ(char *file)\n"

-"{\n"

-"	int fd;\n"

-"	Memimage *m, *m1;\n"

-"	if((fd = open(file, OREAD)) < 0)\n"

-"		sysfatal(\"open: %r\");\n"

-"	if((m = readmemimage(fd)) == nil)\n"

-"		sysfatal(\"readmemimage: %r\");\n"

-"	close(fd);\n"

-"	if(m->chan != ABGR32){\n"

-"		m1 = allocmemimage(m->r, ABGR32);\n"

-"		memfillcolor(m1, DBlack);\n"

-"		memimagedraw(m1, m1->r, m, m->r.min, memopaque, ZP, S);\n"

-"		freememimage(m);\n"

-"		m = m1;\n"

-"	}\n"

-"	return m;\n"

-"}\n\n"

-"void\n"

-"WRITE(Memimage *m, char *file)\n"

-"{\n"

-"	int fd;\n"

-"	if((fd = create(file, OWRITE, 0666)) < 0)\n"

-"		sysfatal(\"create: %r\");\n"

-"	if(writememimage(fd, m) < 0)\n"

-"		sysfatal(\"writememimage: %r\");\n"

-"	close(fd);\n"

-"}\n\n"

-"int\n"

-"POW(int a, int b)\n"

-"{\n"

-"	int t;\n"

-"	if(b <= 0) return 1;\n"

-"	if(b == 1) return a;\n"

-"	t = POW(a, b/2);\n"

-"	t *= t;\n"

-"	if(b%2) t *= a;\n"

-"	return t;\n"

-"}\n"

-"\n"

-"int\n"

-"DIV(int a, int b)\n"

-"{\n"

-"	if(b == 0) return 0;\n"

-"	return a/b;\n"

-"}\n"

-"\n"

-"int\n"

-"MOD(int a, int b)\n"

-"{\n"

-"	if(b == 0) return 0;\n"

-"	return a%b;\n"

-"}\n"

-"\n"

-"#define Z 255\n"

-"\n"

-"uchar\n"

-"RIMAGE(Memimage *m, int x, int y, int z)\n"

-"{\n"

-"	if(x < 0 || y < 0 || z < 0 || x >= Dx(m->r) || y >= Dy(m->r) || z > 3) return 0;\n"

-"	return byteaddr(m, addpt(m->r.min, Pt(x,y)))[z];\n"

-"}\n"

-"\n"

-"uchar*\n"

-"WIMAGE(Memimage *m, int x, int y, int z)\n"

-"{\n"

-"	static uchar devnull;\n"

-"	if(x < 0 || y < 0 || z < 0 || x >= Dx(m->r) || y >= Dy(m->r) || z > 3) return &devnull;\n"

-"	return byteaddr(m, addpt(m->r.min, Pt(x,y))) + z;\n"

-"}\n"

-"\n"

-"#define CLIP(x) ((x) < 0 ? 0 : (x) > 255 ? 255 : (x))\n"

-"\n"

-"void main(void) {\n"

-"	int x, y, z, X, Y, T;\n"

-"	Memimage *﹩new;\n"

-"	if(memimageinit() < 0) sysfatal(\"initmemimage: %r\");\n"

-;

-char *prepstr =

-"	for(﹩i=﹩im; ﹩i<﹩im+nelem(﹩im); ﹩i++){\n"

-"		if(*﹩i == nil) continue;\n"

-"		if(X < Dx((*﹩i)->r)) X = Dx((*﹩i)->r);\n"

-"		if(Y < Dy((*﹩i)->r)) Y = Dy((*﹩i)->r);\n"

-"	}\n"

-"	if((﹩new = allocmemimage(Rect(0,0,X,Y), ABGR32)) == nil)\n"

-"		sysfatal(\"allocmemimage: %r\");\n"

-"	for(z=0; z<4; z++) for(y=0; y<Y; y++) for(x=0; x<X; x++){\n"

-;

-char *tailstr =

-";\n"

-"		*WIMAGE(﹩new, x,y,z) = CLIP(T);\n"

-"	}\n"

-"	WRITE(﹩new, out);\n"

-"	exits(nil);\n"

-"}\n"

-;

--- a/examples

+++ b/examples

@@ -1,12 +1,12 @@

 ; hget http://9front.org/img/9bind.png | png -t9 > /tmp/bind

 ; hget http://9front.org/img/ninefront.bit > /tmp/nine

-; pixo <<EOF

+; pico

 # read in images

-r nine /tmp/nine

-r bind /tmp/bind

+!r /tmp/nine nine

+!r /tmp/bind bind

 # combine two images at an offset

-bind + (y > 100 ? nine[x,y-100,z] : 0)

+bind + (y > 100 ? nine[x,y-100] : 0)

 # extract red and alpha channels

 z == 3 ? bind : z == 0 ? bind : 0

 # halve color intensity

@@ -15,15 +15,14 @@

 bind[x,y,0] + bind[x,y,1] + bind[x,y,2] == 0 && z == 3 ? 0 : bind

 # set black pixels to cyan

 bind[x,y,0] + bind[x,y,1] + bind[x,y,2] == 0 ? z == 0 ? 0 : z == 1 ? Z : z == 2 ? Z : bind : bind

-EOF

 # doug demo

-; pixo -q <<EOF

-r bind /tmp/bind

+; pico

+!r /tmp/bind bind

+# set default size to that of bind

+!s 598 879

 lerp = z != 3 ? (x < X/3 ? 0 : x > 2*X/3 ? 255 : (x-X/3)*Z/(X/3)) : Z

-rbind = bind[X-x,y,z]

+rbind = bind[X-x]	# same as bind[X-x,y,z]

 z != 3 ? (bind*lerp+rbind*(Z-lerp))/Z : Z

 z != 3 ? (rbind*lerp+bind*(Z-lerp))/Z : Z

-d

-EOF

--- a/exec.c

+++ /dev/null

@@ -1,119 +1,0 @@

-#include <u.h>

-#include <libc.h>

-#include <plumb.h>

-#include "dat.h"

-#include "fns.h"

-char wdir[1024], pref[64];

-char **tok;

-int ntok;

-static int plumbfd, mkfd;

-void

-show(char *path)

-{

-	if(plumbfd < 0)

-		return;

-	if(plumbsendtext(plumbfd, "pixo", nil, wdir, path) < 0)

-		fprint(2, "plumbsendtext: %r\n");

-}

-static int

-system(char *cmd)

-{

-	int r, argc, pid;

-	char name[64], *argv[32];

-	Waitmsg *w;

-	argc = tokenize(cmd, argv, nelem(argv)-1);

-	argv[argc] = nil;

-	snprint(name, sizeof name, "/bin/%s", argv[0]);

-	switch(pid = fork()){

-	case -1:

-		fprint(2, "fork: %r\n");

-		return -1;

-	case 0:

-		USED(pid);

-		exec(name, argv);

-		sysfatal("execl: %r");

-	}

-	if((w = wait()) == nil){

-		fprint(2, "system: lost children\n");

-		return -1;

-	}

-	r = 0;

-	if(w->msg != nil && w->msg[0] != 0){

-		fprint(2, "system: failure: %s\n", w->msg);

-		r = -1;

-	}

-	free(w);

-	return r;

-}

-char *

-execute(void)

-{

-	int fd;

-	char **p, cmd[128];

-	Sym *s;

-	static char path[128];

-	snprint(path, sizeof path, "%s.c", pref);

-	if((fd = create(path, OWRITE, 0666)) < 0){

-		fprint(2, "create: %r");

-		return nil;

-	}

-	write(fd, prolog, strlen(prolog));

-	snprint(path, sizeof path, "%s.%d.bit", pref, nsym + 1);

-	fprint(fd,

-		"	Memimage **﹩i, *﹩im[%d];\n"

-		"	char *out = \"%s\";\n",

-		nsym > 0 ? nsym : 1, path);

-	for(s=sym; s<sym+nsym; s++)

-		if(s->ref)

-			fprint(fd, "	﹩im[%zd] = READ(\"%s\");\n",

-				s-sym, s->path);

-	fprint(fd,

-		"	X = %d;\n"

-		"	Y = %d;\n",

-		Δx, Δy);

-	write(fd, prepstr, strlen(prepstr));

-	fprint(fd, "		T = ");

-	for(p=tok; p<tok+ntok; p++)

-		write(fd, *p, strlen(*p));

-	write(fd, tailstr, strlen(tailstr));

-	close(fd);

-	snprint(cmd, sizeof cmd, "mk -f %s.mk %s", pref, pref);

-	if(system(cmd) < 0)

-		return nil;

-	return path;

-}

-static void

-mkfile(void)

-{

-	char path[64];

-	snprint(path, sizeof path, "%s.mk", pref);

-	if((mkfd = create(path, OWRITE|ORCLOSE, 0666)) < 0)

-		sysfatal("mkfile: %r");

-	fprint(mkfd,

-		"</$objtype/mkfile\n"

-		"%s:Q: %s.c\n"

-		"	$CC $CFLAGS -o %s.$O $prereq\n"

-		"	$LD -o $target %s.$O\n"

-		"	$target\n"

-		"	rm -f $target $prereq %s.$O\n",

-		pref, pref, pref, pref, pref);

-}

-void

-initfiles(void)

-{

-	getwd(wdir, sizeof wdir);

-	snprint(pref, sizeof pref, "/tmp/pixo.%d", getpid());

-	mkfile();

-	if((plumbfd = plumbopen("send", OWRITE)) < 0)

-		fprint(2, "plumbopen: %r\n");

-}

--- a/fns.h

+++ /dev/null

@@ -1,4 +1,0 @@

-void	show(char*);

-char*	execute(void);

-void	initfiles(void);

-void	parse(char*);

--- a/mkfile

+++ /dev/null

@@ -1,11 +1,0 @@

-</$objtype/mkfile

-BIN=$home/bin/$objtype

-TARG=pixo

-OFILES=\

-	defs.$O\

-	exec.$O\

-	parse.$O\

-	pixo.$O\

-HFILES=dat.h fns.h

-</sys/src/cmd/mkone

--- a/parse.c

+++ /dev/null

@@ -1,432 +1,0 @@

-#include <u.h>

-#include <libc.h>

-#include <ctype.h>

-#include "dat.h"

-#include "fns.h"

-Sym *sym;

-int nsym;

-int Δx, Δy;

-static char*

-esmprint(char *fmt, ...)

-{

-	char *p;

-	va_list arg;

-	va_start(arg, fmt);

-	p = vsmprint(fmt, arg);

-	va_end(arg);

-	if(p == nil)

-		sysfatal("smprint: %r");

-	return p;

-}

-static char *

-estrdup(char *s)

-{

-	if((s = strdup(s)) == nil)

-		sysfatal("estrdup: %r");

-	setmalloctag(s, getcallerpc(&s));

-	return s;

-}

-static void *

-erealloc(void *p, ulong n)

-{

-	if((p = realloc(p, n)) == nil)

-		sysfatal("realloc: %r");

-	setrealloctag(p, getcallerpc(&p));

-	return p;

-}

-static void *

-emalloc(ulong n)

-{

-	void *p;

-	if((p = mallocz(n, 1)) == nil)

-		sysfatal("emalloc: %r");

-	setmalloctag(p, getcallerpc(&n));

-	return p;

-}

-static void

-nuketok(void)

-{

-	char **p;

-	for(p=tok; p<tok+ntok; p++)

-		free(*p);

-	free(tok);

-	tok = nil;

-	ntok = 0;

-}

-static char **

-newtok(char *s)

-{

-	char **p;

-	tok = erealloc(tok, ++ntok * sizeof *tok);

-	p = tok + ntok - 1;

-	*p = s;

-	return p;

-}

-static char *

-addtok(char *s, int n)

-{

-	char **p;

-	p = newtok(s);

-	*p = emalloc(n + 1);

-	memcpy(*p, s, n);

-	return *p;

-}

-static Sym *

-newsym(char *name)

-{

-	Sym *s;

-	sym = erealloc(sym, ++nsym * sizeof *sym);

-	s = sym + nsym - 1;

-	s->iname = esmprint("$%zd", s - sym + 1);

-	s->cname = esmprint("﹩im[%zd]", s - sym);

-	s->name = name == nil ? esmprint("﹩%zd", s - sym + 1) : estrdup(name);

-	return s;

-}

-static Sym *

-getsym(char *name, int n)

-{

-	Sym *s;

-	if(n == 0)

-		n = strlen(name);

-	for(s=sym; s<sym+nsym; s++)

-		if(strncmp(s->name, name, n) == 0 && strlen(s->name) == n

-		|| strncmp(s->iname, name, n) == 0 && strlen(s->iname) == n)

-			return s;

-	return nil;

-}

-static Sym *

-addsym(char *name)

-{

-	Sym *s;

-	if((s = getsym(name, 0)) == nil)

-		s = newsym(name);

-	return s;

-}

-static void

-cleanup(void)

-{

-	Sym *s;

-	nuketok();

-	for(s=sym; s<sym+nsym; s++)

-		s->ref = 0;

-}

-static void

-fnwrite(int argc, char **argv)

-{

-	int n, fd, dfd;

-	uchar buf[65536];

-	Sym *s;

-	if(argc != 3){

-		fprint(2, "usage: w name path\n");

-		return;

-	}

-	if((s = getsym(argv[1], 0)) == nil){

-		fprint(2, "fnwrite: no such image %s\n", argv[1]);

-		return;

-	}

-	if(strcmp(argv[2], s->path) == 0){

-		fprint(2, "not overwriting image with itself\n");

-		return;

-	}

-	if((fd = open(s->path, OREAD)) < 0){

-		fprint(2, "open: %r\n");

-		return;

-	}

-	if((dfd = create(argv[2], OWRITE, 0666)) < 0){

-		fprint(2, "create: %r\n");

-		return;

-	}

-	while((n = read(fd, buf, sizeof buf)) > 0)

-		if(write(dfd, buf, n) != n){

-			n = -1;

-			break;

-		}

-	close(fd);

-	close(dfd);

-	if(n < 0)

-		fprint(2, "fnwrite: %r\n");

-}

-static void

-fnadd(int argc, char **argv)

-{

-	char *path;

-	Sym *s;

-	if(argc < 2 || argc > 3){

-		fprint(2, "usage: r name [path]\n");

-		return;

-	}

-	s = addsym(argv[1]);

-	path = argc < 3 ? argv[1] : argv[2];

-	if(access(path, OREAD) < 0){

-		fprint(2, "access %s: %r\n", path);

-		return;

-	}

-	s->path = esmprint("%s%s%s",

-		path[0] == '/' ? "" : wdir,

-		path[0] == '/' ? "" : "/",

-		path);

-}

-static void

-fndisplay(int argc, char **argv)

-{

-	int i;

-	Sym *s;

-	if(argc == 1){

-		if(nsym > 0)

-			show(sym[nsym-1].path);

-		return;

-	}

-	for(i=1; i<argc; i++){

-		if((s = getsym(argv[i], 0)) != nil)

-			show(s->path);

-		else

-			fprint(2, "fndisplay: no such image %s\n", argv[i]);

-	}

-}

-static void

-fnsize(int argc, char **argv)

-{

-	char *p;

-	if(argc != 3){

-		fprint(2, "usage: s width height\n");

-		return;

-	}

-	Δx = strtol(argv[1], &p, 0);

-	if(p == argv[1]){

-		fprint(2, "fnsize: invalid width\n");

-		return;

-	}

-	Δy = strtol(argv[2], &p, 0);

-	if(p == argv[1])

-		fprint(2, "fnsize: invalid height\n");

-}

-static void

-fnfiles(int, char **)

-{

-	Sym *s;

-	for(s=sym; s<sym+nsym; s++)

-		print("%s %s %s\n", s->iname, s->name, s->path);

-}

-static int

-command(char *p)

-{

-	struct{

-		char *name;

-		void (*fn)(int, char**);

-	} *cp, cmd[] = {

-		"f", fnfiles,

-		"s", fnsize,

-		"r", fnadd,

-		"w", fnwrite,

-		"d", fndisplay

-	};

-	int n;

-	char *f[16];

-	for(cp=cmd; cp<cmd+nelem(cmd); cp++){

-		n = strlen(cp->name);

-		if(strncmp(p, cp->name, n) == 0

-		&& (p[n] == 0 || isspace(p[n]))){

-			n = tokenize(p, f, nelem(f));

-			cp->fn(n, f);

-			return 1;

-		}

-	}

-	return 0;

-}

-static int

-isbuiltin(char *p, int n)

-{

-	char **fp, *fn[] = {

-		"X", "Y", "Z",

-		"x", "y", "z"

-	};

-	for(fp=fn; fp<fn+nelem(fn); fp++)

-		if(strncmp(p, *fp, n) == 0 && strlen(*fp) == n)

-			return 1;

-	return 0;

-}

-static int

-mkcoords(char *s, char *e)

-{

-	char *p, **cp, *c[2] = {nil};

-	while(isspace(*s))

-		s++;

-	for(p=s+1, cp=c; p<e; p++){

-		if(*p == ']'){

-			*p = 0;

-			break;

-		}else if(*p == ','){

-			if(cp >= c + nelem(c)){

-				fprint(2, "invalid index spec\n");

-				return -1;

-			}

-			*p = 0;

-			*cp++ = p + 1;

-		}

-	}

-	p = esmprint(", %s,%s,%s)", s+1,

-		c[0] != nil ? c[0] : "y",

-		c[1] != nil ? c[1] : "z");

-	newtok(p);

-	return 0;

-}

-static int

-getcoords(char *s)

-{

-	char *p;

-	for(p=s; *p!=']' && *p!=0; p++)

-		;

-	return *p == 0 ? -1 : p + 2 - s;

-}

-static int

-peekrune(char *p, Rune ro)

-{

-	Rune r;

-	while(isspace(*p))

-		p++;

-	chartorune(&r, p);

-	return r == ro;

-}

-static int

-notaword(Rune r)

-{

-	char *o, *op = "+-*/%?:^,&|<>=![], ()";

-	if(isdigitrune(r))

-		return 1;

-	for(o=op; o<op+strlen(op); o++)

-		if(r == *o)

-			return 1;

-	return 0;

-}

-static int

-getname(char *s)

-{

-	char *p, *q;

-	Rune r;

-	q = p = s + chartorune(&r, s);

-	while(r != 0 && !notaword(r) && !isspace(r)){

-		q = p;

-		p += chartorune(&r, p);

-	}

-	return q - s;

-}

-void

-parse(char *s)

-{

-	int n, m, nchar;

-	char *p, *new;

-	Rune r;

-	Sym *sp;

-	for(p=s, nchar=0, new=nil; *p != 0; p++){

-		if(isspace(*p))

-			continue;

-		if(nchar == 0 && command(p))

-			return;

-		if(*p == '#')

-			break;

-		nchar++;

-		n = chartorune(&r, p);

-		if(notaword(r))

-			goto next;

-		n = getname(p);

-		if(peekrune(p + n, '('))

-			goto next;

-		if(isbuiltin(p, n))

-			goto next;

-		if((sp = getsym(p, n)) == nil){

-			if(nchar > 1 || !peekrune(p + n, '=')){

-				s = emalloc(n + 1);

-				memcpy(s, p, n);

-				fprint(2, "unknown symbol %s\n", s);

-				free(s);

-				goto end;

-			}

-			new = emalloc(n + 1);

-			memcpy(new, p, n);

-			while(isspace(p[n]))

-				n++;

-			n++;

-			s = p + n;

-			goto next;

-		}

-		addtok(s, p - s);

-		sp->ref = 1;

-		newtok(estrdup("RIMAGE("));

-		newtok(estrdup(sp->cname));

-		s = p + n;

-		if(!peekrune(s, '[')){

-			newtok(estrdup(",x,y,z)"));

-			goto next;

-		}

-		if((m = getcoords(s)) < 0){

-			fprint(2, "syntax error: no matching ]\n");

-			goto end;

-		}

-		if(mkcoords(s, s + m - 1) < 0)

-			goto end;

-		s += m;

-		p += m - 1;

-	next:

-		p += n - 1;

-	}

-	if(nchar == 0)

-		return;

-	if(p > s)

-		addtok(s, p - s);

-	if((p = execute()) != nil){

-		sp = newsym(new);

-		sp->path = estrdup(p);

-		if(!quiet)

-			show(p);

-	}

-end:

-	free(new);

-	cleanup();

-}

--- /dev/null

+++ b/pico

@@ -1,0 +1,258 @@

+#!/bin/rc

+fn clean{

+	rm -f /tmp/pico.^$pid^*

+}

+fn sigexit{

+	clean

+}

+fn sigint{

+	clean

+}

+awk '

+function show(s){

+	system("plumb -d image " path[s])

+}

+function newname(file, name){

+	if(name == "")

+		name = "$" length(ref)+1

+	if(!(name in ref)){

+		ref[name] = ""

+		idx[name] = length(ref)

+	}

+	path[name] = file

+	new = name

+}

+function command(){

+	if($1 == "!d"){

+		if(NF > 1){

+			if($2 in path)

+				show($2)

+			else

+				print "unknown name " $2

+		}else if(new != "")

+			show(new)

+		else

+			print "nothing to show"

+	}else if($1 == "!r"){

+		if(NF < 2 || NF > 3)

+			print "usage: !r path [name]"

+		else

+			newname($2, NF < 3 ? "" : $3)

+	}else if($1 == "!w"){

+		if(NF < 3)

+			print "usage: !w name path"

+		else if($2 in path)

+			system("cp " path[$2] " " $3)

+		else

+			print "unknown name " $2

+	}else if($1 == "!f"){

+		for(i in ref)

+			print idx[i] "\t" i "\t" path[i]

+	}else if($1 == "!s"){

+		if(NF < 3)

+			print "usage: !s x y"

+		else{

+			X = $2

+			Y = $3

+		}

+	}else

+		print "unknown command"

+}

+BEGIN{

+	X = 0

+	Y = 0

+	opx = "!-\\/:-@\\[-\\^`\\{-~"

+	namex = "[^0-9" opx "][^" opx "]*"

+	pref="/tmp/pico.'^$pid^'"

+	mkfile = pref ".mk"

+	libfile = pref ".lib.c"

+	cfile = pref ".c"

+	print \

+"</$objtype/mkfile\n" \

+"%.$O:Q:	%.c\n" \

+"	$CC $CFLAGS -o $target $stem.c\n" \

+pref ":Q:	" pref ".lib.$O " pref ".$O\n" \

+"	$LD -o $target $prereq\n" \

+"	$target\n" \

+"	rm -f $target " pref ".$O\n" \

+	>mkfile

+	print \

+"#include <u.h>\n" \

+"#include <libc.h>\n" \

+"#include <draw.h>\n" \

+"#include <memdraw.h>\n" \

+"\n" \

+"Memimage*\n" \

+"﹩read(char *file)\n" \

+"{\n" \

+"	int fd;\n" \

+"	Memimage *m, *m1;\n" \

+"	if((fd = open(file, OREAD)) < 0)\n" \

+"		sysfatal(\"open: %r\");\n" \

+"	if((m = readmemimage(fd)) == nil)\n" \

+"		sysfatal(\"readmemimage: %r\");\n" \

+"	close(fd);\n" \

+"	if(m->chan != ABGR32){\n" \

+"		m1 = allocmemimage(m->r, ABGR32);\n" \

+"		memfillcolor(m1, DBlack);\n" \

+"		memimagedraw(m1, m1->r, m, m->r.min, memopaque, ZP, S);\n" \

+"		freememimage(m);\n" \

+"		m = m1;\n" \

+"	}\n" \

+"	return m;\n" \

+"}\n\n" \

+"void\n" \

+"﹩write(Memimage *m, char *file)\n" \

+"{\n" \

+"	int fd;\n" \

+"	if((fd = create(file, OWRITE, 0666)) < 0)\n" \

+"		sysfatal(\"create: %r\");\n" \

+"	if(writememimage(fd, m) < 0)\n" \

+"		sysfatal(\"writememimage: %r\");\n" \

+"	close(fd);\n" \

+"}\n\n" \

+"uchar*\n" \

+"﹩byte(Memimage *m, int x, int y, int z)\n" \

+"{\n" \

+"	static uchar devnull;\n" \

+"	if(x < 0 || y < 0 || z < 0 || x >= Dx(m->r) || y >= Dy(m->r) || z > 3) return &devnull;\n" \

+"	return byteaddr(m, addpt(m->r.min, Pt(x,y))) + z;\n" \

+"}" \

+	>libfile

+	prog = \

+"#include <u.h>\n" \

+"#include <libc.h>\n" \

+"#include <draw.h>\n" \

+"#include <memdraw.h>\n" \

+"Memimage*	﹩read(char*);\n" \

+"void	﹩write(Memimage*, char*);\n" \

+"uchar*	﹩byte(Memimage*, int, int, int);\n" \

+"#define Z 255\n" \

+"#define ﹩clip(x) ((x) < 0 ? 0 : (x) > 255 ? 255 : (x))\n" \

+"void\n" \

+"main(void)\n" \

+"{\n" \

+"	int x, y, z, X, Y, T;\n" \

+"	Memimage *﹩new;\n" \

+"	if(memimageinit() < 0)\n" \

+"		sysfatal(\"initmemimage: %r\");"

+	prep = \

+"	for(﹩i=﹩im; ﹩i<﹩im+nelem(﹩im); ﹩i++){\n" \

+"		if(*﹩i == nil) continue;\n" \

+"		if(X < Dx((*﹩i)->r)) X = Dx((*﹩i)->r);\n" \

+"		if(Y < Dy((*﹩i)->r)) Y = Dy((*﹩i)->r);\n" \

+"	}\n" \

+"	if((﹩new = allocmemimage(Rect(0,0,X,Y), ABGR32)) == nil)\n" \

+"		sysfatal(\"allocmemimage: %r\");\n" \

+"	for(z=0; z<4; z++) for(y=0; y<Y; y++) for(x=0; x<X; x++){"

+	footer = \

+"		*﹩byte(﹩new, x,y,z) = ﹩clip(T);\n" \

+"	}\n" \

+"	﹩write(﹩new, out);\n" \

+"	exits(nil);\n" \

+"}"

+}

+{

+	if($1 ~ /^!.$/){

+		command()

+		next

+	}

+	gsub("[ 	]", "", $0)

+	gsub("(" namex "|=)", " & ", $0)

+	while((i = match($0, "[" opx "] +=")) != 0)

+		$0 = substr($0, 1, i) substr($0, i+RLENGTH-1)

+	gsub("[\\(\\[\\],#]", " & ", $0)

+	ntok = split($0, tok)

+	expr = ""

+	new = ""

+	gotsym = 0

+	ncomma = 0

+	for(i in ref)

+		ref[i] = ""

+	for(i=1; i<=ntok; i++){

+		if(tok[i] ~ namex && tok[i] !~ "^[XxYyZz]$"){

+			if(gotsym){

+				print "invalid syntax"

+				next

+			}else if(i < ntok && tok[i+1] == "(")

+				expr = expr " " tok[i]

+			else if(tok[i] in ref){

+				ref[tok[i]] = 1

+				expr = expr " *﹩byte(﹩im[" idx[tok[i]] "], "

+				if(i < ntok && tok[i+1] == "["){

+					i++

+					gotsym = 1

+				}else

+					expr = expr "x,y,z)"

+			}else{

+				if(i == 1 && ntok >= 3 && tok[2] == "=")

+					new = tok[i]

+				else

+					expr = expr " " tok[i]

+			}

+		}else if(tok[i] == "="){

+			if(i != 2){

+				print "invalid assignment"

+				next

+			}

+		}else if(tok[i] == "["){

+			print "invalid index"

+			next

+		}else if(tok[i] == "#")

+			break

+		else if(gotsym){

+			if(tok[i] == "]"){

+				if(ncomma == 0)

+					tok[i] = ",y,z)"

+				else if(ncomma == 1)

+					tok[i] = ",z)"

+				else

+					tok[i] = ")"

+				ncomma = 0

+				gotsym = 0

+			}else if(tok[i] == ","){

+				if(ncomma > 1){

+					print "invalid index"

+					next

+				}

+				ncomma++

+			}

+			expr = expr " " tok[i]

+		}else

+			expr = expr " " tok[i]

+	}

+	if(expr == "")

+		next

+	if(gotsym){

+		print "invalid index"

+		next

+	}

+	out = pref "." length(ref)+1 ".bit"

+	print prog >cfile

+	print \

+"\tMemimage **﹩i, *﹩im[" length(ref)+1 "];\n" \

+"\tchar *out = \"" out "\";\n" \

+"\tX = " X ";\n" \

+"\tY = " Y ";" >>cfile

+	for(i in ref)

+		if(ref[i])

+			print "\t﹩im[" idx[i] "] = ﹩read(\"" path[i] "\");\n" >>cfile

+	print prep >>cfile

+	print "\t\tT = " expr ";" >>cfile

+	print footer >>cfile

+	close(cfile)

+	if(system("mk -f " mkfile " " pref) != "0")

+		next

+	newname(out, new)

+	show(new)

+}

+'

--- a/pixo.c

+++ /dev/null

@@ -1,30 +1,0 @@

-#include <u.h>

-#include <libc.h>

-#include <ctype.h>

-#include <bio.h>

-#include "dat.h"

-#include "fns.h"

-int quiet;

-void

-main(int argc, char **argv)

-{

-	char *s;

-	Biobuf *bf;

-	ARGBEGIN{

-	case 'q': quiet = 1; break;

-	}ARGEND

-	initfiles();

-	if((bf = Bfdopen(0, OREAD)) == nil)

-		sysfatal("Bfdopen: %r");

-	for(;;){

-		if(!quiet)

-			print("→ ");

-		if((s = Brdstr(bf, '\n', 1)) == nil)

-			break;

-		parse(s);

-		free(s);

-	}

-}

--

⑨