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