1 /*
2  * ps.c
3  * 
4  * provide postscript file reading support for page
5  */
6 
7 #include <u.h>
8 #include <libc.h>
9 #include <draw.h>
10 #include <cursor.h>
11 #include <event.h>
12 #include <bio.h>
13 #include <ctype.h>
14 #include "page.h"
15 
16 typedef struct PSInfo	PSInfo;
17 typedef struct Page	Page;
18 	
19 struct Page {
20 	char *name;
21 	int offset;			/* offset of page beginning within file */
22 };
23 
24 struct PSInfo {
25 	GSInfo gs;
26 	Rectangle bbox;	/* default bounding box */
27 	Page *page;
28 	int npage;
29 	int clueless;	/* don't know where page boundaries are */
30 	long psoff;	/* location of %! in file */
31 	char ctm[256];
32 };
33 
34 static int	pswritepage(Document *d, int fd, int page);
35 static Image*	psdrawpage(Document *d, int page);
36 static char*	pspagename(Document*, int);
37 
38 #define R(r) (r).min.x, (r).min.y, (r).max.x, (r).max.y
39 Rectangle
40 rdbbox(char *p)
41 {
42 	Rectangle r;
43 	int a;
44 	char *f[4];
45 	while(*p == ':' || *p == ' ' || *p == '\t')
46 		p++;
47 	if(tokenize(p, f, 4) != 4)
48 		return Rect(0,0,0,0);
49 	r = Rect(atoi(f[0]), atoi(f[1]), atoi(f[2]), atoi(f[3]));
50 	r = canonrect(r);
51 	if(Dx(r) <= 0 || Dy(r) <= 0)
52 		return Rect(0,0,0,0);
53 
54 	if(truetoboundingbox)
55 		return r;
56 
57 	/* initdraw not called yet, can't use %R */
58 	if(chatty) fprint(2, "[%d %d %d %d] -> ", R(r));
59 	/*
60 	 * attempt to sniff out A4, 8½×11, others
61 	 * A4 is 596×842
62 	 * 8½×11 is 612×792
63 	 */
64 
65 	a = Dx(r)*Dy(r);
66 	if(a < 300*300){	/* really small, probably supposed to be */
67 		/* empty */
68 	} else if(Dx(r) <= 596 && r.max.x <= 596 && Dy(r) > 792 && Dy(r) <= 842 && r.max.y <= 842)	/* A4 */
69 		r = Rect(0, 0, 596, 842);
70 	else {	/* cast up to 8½×11 */
71 		if(Dx(r) <= 612 && r.max.x <= 612){
72 			r.min.x = 0;
73 			r.max.x = 612;
74 		}
75 		if(Dy(r) <= 792 && r.max.y <= 792){
76 			r.min.y = 0;
77 			r.max.y = 792;
78 		}
79 	}
80 	if(chatty) fprint(2, "[%d %d %d %d]\n", R(r));
81 	return r;
82 }
83 
84 #define RECT(X) X.min.x, X.min.y, X.max.x, X.max.y
85 
86 int
87 prefix(char *x, char *y)
88 {
89 	return strncmp(x, y, strlen(y)) == 0;
90 }
91 
92 /*
93  * document ps is really being printed as n-up pages.
94  * we need to treat every n pages as 1.
95  */
96 void
97 repaginate(PSInfo *ps, int n)
98 {
99 	int i, np, onp;
100 	Page *page;
101 
102 	page = ps->page;
103 	onp = ps->npage;
104 	np = (ps->npage+n-1)/n;
105 
106 	if(chatty) {
107 		for(i=0; i<=onp+1; i++)
108 			print("page %d: %d\n", i, page[i].offset);
109 	}
110 
111 	for(i=0; i<np; i++)
112 		page[i] = page[n*i];
113 
114 	/* trailer */
115 	page[np] = page[onp];
116 
117 	/* EOF */
118 	page[np+1] = page[onp+1];
119 
120 	ps->npage = np;
121 
122 	if(chatty) {
123 		for(i=0; i<=np+1; i++)
124 			print("page %d: %d\n", i, page[i].offset);
125 	}
126 
127 }
128 
129 Document*
130 initps(Biobuf *b, int argc, char **argv, uchar *buf, int nbuf)
131 {
132 	Document *d;
133 	PSInfo *ps;
134 	char *p;
135 	char *q, *r;
136 	char eol;
137 	char *nargv[1];
138 	char fdbuf[20];
139 	char tmp[32];
140 	int fd;
141 	int i;
142 	int incomments;
143 	int cantranslate;
144 	int trailer=0;
145 	int nesting=0;
146 	int dumb=0;
147 	int landscape=0;
148 	long psoff;
149 	long npage, mpage;
150 	Page *page;
151 	Rectangle bbox = Rect(0,0,0,0);
152 
153 	if(argc > 1) {
154 		fprint(2, "can only view one ps file at a time\n");
155 		return nil;
156 	}
157 
158 	fprint(2, "reading through postscript...\n");
159 	if(b == nil){	/* standard input; spool to disk (ouch) */
160 		fd = spooltodisk(buf, nbuf, nil);
161 		sprint(fdbuf, "/fd/%d", fd);
162 		b = Bopen(fdbuf, OREAD);
163 		if(b == nil){
164 			fprint(2, "cannot open disk spool file\n");
165 			wexits("Bopen temp");
166 		}
167 		nargv[0] = fdbuf;
168 		argv = nargv;
169 	}
170 
171 	/* find %!, perhaps after PCL nonsense */
172 	Bseek(b, 0, 0);
173 	psoff = 0;
174 	eol = 0;
175 	for(i=0; i<16; i++){
176 		psoff = Boffset(b);
177 		if(!(p = Brdline(b, eol='\n')) && !(p = Brdline(b, eol='\r'))) {
178 			fprint(2, "cannot find end of first line\n");
179 			wexits("initps");
180 		}
181 		if(p[0]=='\x1B')
182 			p++, psoff++;
183 		if(p[0] == '%' && p[1] == '!')
184 			break;
185 	}
186 	if(i == 16){
187 		werrstr("not ps");
188 		return nil;
189 	}
190 
191 	/* page counting */
192 	npage = 0;
193 	mpage = 16;
194 	page = emalloc(mpage*sizeof(*page));
195 	memset(page, 0, mpage*sizeof(*page));
196 
197 	cantranslate = goodps;
198 	incomments = 1;
199 Keepreading:
200 	while(p = Brdline(b, eol)) {
201 		if(p[0] == '%')
202 			if(chatty) fprint(2, "ps %.*s\n", utfnlen(p, Blinelen(b)-1), p);
203 		if(npage == mpage) {
204 			mpage *= 2;
205 			page = erealloc(page, mpage*sizeof(*page));
206 			memset(&page[npage], 0, npage*sizeof(*page));
207 		}
208 
209 		if(p[0] != '%' || p[1] != '%')
210 			continue;
211 
212 		if(prefix(p, "%%BeginDocument")) {
213 			nesting++;
214 			continue;
215 		}
216 		if(nesting > 0 && prefix(p, "%%EndDocument")) {
217 			nesting--;
218 			continue;
219 		}
220 		if(nesting)
221 			continue;
222 
223 		if(prefix(p, "%%EndComment")) {
224 			incomments = 0;
225 			continue;
226 		}
227 		if(reverse == -1 && prefix(p, "%%PageOrder")) {
228 			/* glean whether we should reverse the viewing order */
229 			p[Blinelen(b)-1] = 0;
230 			if(strstr(p, "Ascend"))
231 				reverse = 0;
232 			else if(strstr(p, "Descend"))
233 				reverse = 1;
234 			else if(strstr(p, "Special"))
235 				dumb = 1;
236 			p[Blinelen(b)-1] = '\n';
237 			continue;
238 		} else if(prefix(p, "%%Trailer")) {
239 			incomments = 1;
240 			page[npage].offset = Boffset(b)-Blinelen(b);
241 			trailer = 1;
242 			continue;
243 		} else if(incomments && prefix(p, "%%Orientation")) {
244 			if(strstr(p, "Landscape"))
245 				landscape = 1;
246 		} else if(incomments && Dx(bbox)==0 && prefix(p, q="%%BoundingBox")) {
247 			bbox = rdbbox(p+strlen(q)+1);
248 			if(chatty)
249 				/* can't use %R because haven't initdraw() */
250 				fprint(2, "document bbox [%d %d %d %d]\n",
251 					RECT(bbox));
252 			continue;
253 		}
254 
255 		/*
256 		 * If they use the initgraphics command, we can't play our translation tricks.
257 		 */
258 		p[Blinelen(b)-1] = 0;
259 		if((q=strstr(p, "initgraphics")) && ((r=strchr(p, '%'))==nil || r > q))
260 			cantranslate = 0;
261 		p[Blinelen(b)-1] = eol;
262 
263 		if(!prefix(p, "%%Page:"))
264 			continue;
265 
266 		/* 
267 		 * figure out of the %%Page: line contains a page number
268 		 * or some other page description to use in the menu bar.
269 		 * 
270 		 * lines look like %%Page: x y or %%Page: x
271 		 * we prefer just x, and will generate our
272 		 * own if necessary.
273 		 */
274 		p[Blinelen(b)-1] = 0;
275 		if(chatty) fprint(2, "page %s\n", p);
276 		r = p+7;
277 		while(*r == ' ' || *r == '\t')
278 			r++;
279 		q = r;
280 		while(*q && *q != ' ' && *q != '\t')
281 			q++;
282 		free(page[npage].name);
283 		if(*r) {
284 			if(*r == '"' && *q == '"')
285 				r++, q--;
286 			if(*q)
287 				*q = 0;
288 			page[npage].name = estrdup(r);
289 			*q = 'x';
290 		} else {
291 			snprint(tmp, sizeof tmp, "p %ld", npage+1);
292 			page[npage].name = estrdup(tmp);
293 		}
294 
295 		/*
296 		 * store the offset info for later viewing
297 		 */
298 		trailer = 0;
299 		p[Blinelen(b)-1] = eol;
300 		page[npage++].offset = Boffset(b)-Blinelen(b);
301 	}
302 	if(Blinelen(b) > 0){
303 		fprint(2, "page: linelen %d\n", Blinelen(b));
304 		Bseek(b, Blinelen(b), 1);
305 		goto Keepreading;
306 	}
307 
308 	if(Dx(bbox) == 0 || Dy(bbox) == 0)
309 		bbox = Rect(0,0,612,792);	/* 8½×11 */
310 	/*
311 	 * if we didn't find any pages, assume the document
312 	 * is one big page
313 	 */
314 	if(npage == 0) {
315 		dumb = 1;
316 		if(chatty) fprint(2, "don't know where pages are\n");
317 		reverse = 0;
318 		goodps = 0;
319 		trailer = 0;
320 		page[npage].name = "p 1";
321 		page[npage++].offset = 0;
322 	}
323 
324 	if(npage+2 > mpage) {
325 		mpage += 2;
326 		page = erealloc(page, mpage*sizeof(*page));
327 		memset(&page[mpage-2], 0, 2*sizeof(*page));
328 	}
329 
330 	if(!trailer)
331 		page[npage].offset = Boffset(b);
332 
333 	Bseek(b, 0, 2); /* EOF */
334 	page[npage+1].offset = Boffset(b);
335 
336 	d = emalloc(sizeof(*d));
337 	ps = emalloc(sizeof(*ps));
338 	ps->page = page;
339 	ps->npage = npage;
340 	ps->bbox = bbox;
341 	ps->psoff = psoff;
342 
343 	d->extra = ps;
344 	d->npage = ps->npage;
345 	d->b = b;
346 	d->drawpage = psdrawpage;
347 	d->pagename = pspagename;
348 
349 	d->fwdonly = ps->clueless = dumb;
350 	d->docname = argv[0];
351 
352 	if(spawngs(&ps->gs, "-dSAFER") < 0)
353 		return nil;
354 
355 	if(!cantranslate)
356 		bbox.min = ZP;
357 	setdim(&ps->gs, bbox, ppi, landscape);
358 
359 	if(goodps){
360 		/*
361 		 * We want to only send the page (i.e. not header and trailer) information
362 	 	 * for each page, so initialize the device by sending the header now.
363 		 */
364 		pswritepage(d, ps->gs.gsfd, -1);
365 		waitgs(&ps->gs);
366 	}
367 
368 	if(dumb) {
369 		fprint(ps->gs.gsfd, "(%s) run\n", argv[0]);
370 		fprint(ps->gs.gsfd, "(/fd/3) (w) file dup (THIS IS NOT A PLAN9 BITMAP 01234567890123456789012345678901234567890123456789\\n) writestring flushfile\n");
371 	}
372 
373 	ps->bbox = bbox;
374 
375 	return d;
376 }
377 
378 static int
379 pswritepage(Document *d, int fd, int page)
380 {
381 	Biobuf *b = d->b;
382 	PSInfo *ps = d->extra;
383 	int t, n, i;
384 	long begin, end;
385 	char buf[8192];
386 
387 	if(page == -1)
388 		begin = ps->psoff;
389 	else
390 		begin = ps->page[page].offset;
391 
392 	end = ps->page[page+1].offset;
393 
394 	if(chatty) {
395 		fprint(2, "writepage(%d)... from #%ld to #%ld...\n",
396 			page, begin, end);
397 	}
398 	Bseek(b, begin, 0);
399 
400 	t = end-begin;
401 	n = sizeof(buf);
402 	if(n > t) n = t;
403 	while(t > 0 && (i=Bread(b, buf, n)) > 0) {
404 		if(write(fd, buf, i) != i)
405 			return -1;
406 		t -= i;
407 		if(n > t)
408 			n = t;
409 	}
410 	return end-begin;
411 }
412 
413 static Image*
414 psdrawpage(Document *d, int page)
415 {
416 	PSInfo *ps = d->extra;
417 	Image *im;
418 
419 	if(ps->clueless)
420 		return readimage(display, ps->gs.gsdfd, 0);
421 
422 	waitgs(&ps->gs);
423 
424 	if(goodps)
425 		pswritepage(d, ps->gs.gsfd, page);
426 	else {
427 		pswritepage(d, ps->gs.gsfd, -1);
428 		pswritepage(d, ps->gs.gsfd, page);
429 		pswritepage(d, ps->gs.gsfd, d->npage);
430 	}
431 	/*
432 	 * If last line terminator is \r, gs will read ahead to check for \n
433 	 * so send one to avoid deadlock.
434 	 */
435 	write(ps->gs.gsfd, "\n", 1);
436 	im = readimage(display, ps->gs.gsdfd, 0);
437 	if(im == nil) {
438 		fprint(2, "fatal: readimage error %r\n");
439 		wexits("readimage");
440 	}
441 	waitgs(&ps->gs);
442 
443 	return im;
444 }
445 
446 static char*
447 pspagename(Document *d, int page)
448 {
449 	PSInfo *ps = (PSInfo *) d->extra;
450 	return ps->page[page].name;
451 }