xref: /plan9/sys/src/cmd/gs/src/gdevplan9.c (revision 6a9fc400c33447ef5e1cda7185cb4de2c8e8010e)
1 /*
2  *		Copyright (c) 1998 by Lucent Technologies.
3  * Permission to use, copy, modify, and distribute this software for any
4  * purpose without fee is hereby granted, provided that this entire notice
5  * is included in all copies of any software which is or includes a copy
6  * or modification of this software.
7  *
8  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
9  * WARRANTY.  IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE ANY
10  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
11  * OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
12  */
13 
14 /*
15  * gdevplan9.c: gs device to generate plan9 bitmaps
16  * Russ Cox <rsc@plan9.bell-labs.com>, 3/25/98 (gdevifno)
17  * Updated to fit in the standard GS distribution, 5/14/98
18  * Added support for true-color bitmaps, 6/7/02
19  */
20 
21 #include "gdevprn.h"
22 #include "gsparam.h"
23 #include "gxlum.h"
24 #include <stdlib.h>
25 #undef printf
26 
27 #define nil ((void*)0)
28 enum {
29 	ERROR = -2
30 };
31 
32 typedef struct WImage WImage;
33 typedef struct Rectangle Rectangle;
34 typedef struct Point Point;
35 
36 struct Point {
37 	int x;
38 	int y;
39 };
40 
41 struct Rectangle {
42 	Point min;
43 	Point max;
44 };
45 private Point ZP = { 0, 0 };
46 
47 private WImage* initwriteimage(FILE *f, Rectangle r, char*, int depth);
48 private int writeimageblock(WImage *w, uchar *data, int ndata);
49 private int bytesperline(Rectangle, int);
50 private int rgb2cmap(int, int, int);
51 private long cmap2rgb(int);
52 
53 #define X_DPI	100
54 #define Y_DPI	100
55 
56 private dev_proc_map_rgb_color(plan9_rgb2cmap);
57 private dev_proc_map_color_rgb(plan9_cmap2rgb);
58 private dev_proc_open_device(plan9_open);
59 private dev_proc_close_device(plan9_close);
60 private dev_proc_print_page(plan9_print_page);
61 private dev_proc_put_params(plan9_put_params);
62 private dev_proc_get_params(plan9_get_params);
63 
64 typedef struct plan9_device_s {
65 	gx_device_common;
66 	gx_prn_device_common;
67 	int dither;
68 
69 	int ldepth;
70 	int lastldepth;
71 	int cmapcall;
72 } plan9_device;
73 
74 enum {
75 	Nbits = 8,
76 	Bitmask = (1<<Nbits)-1,
77 };
78 
79 private const gx_device_procs plan9_procs =
80 	prn_color_params_procs(plan9_open, gdev_prn_output_page, gdev_prn_close,
81 		plan9_rgb2cmap, plan9_cmap2rgb,
82 		gdev_prn_get_params, gdev_prn_put_params);
83 /*
84 		plan9_get_params, plan9_put_params);
85 */
86 
87 
88 plan9_device far_data gs_plan9_device =
89 { prn_device_body(plan9_device, plan9_procs, "plan9",
90 	DEFAULT_WIDTH_10THS, DEFAULT_HEIGHT_10THS,
91 	X_DPI, Y_DPI,
92 	0,0,0,0,	/* margins */
93 	3,		/* 3 = RGB, 1 = gray, 4 = CMYK */
94 	Nbits*3,		/* # of bits per pixel */
95 	(1<<Nbits)-1,		/* # of distinct gray levels. */
96 	(1<<Nbits)-1,		/* # of distinct color levels. */
97 	1<<Nbits,		/* dither gray ramp size.  used in alpha? */
98 	1<<Nbits,    	/* dither color ramp size.  used in alpha? */
99 	plan9_print_page),
100 	1,
101 };
102 
103 /*
104  * ghostscript asks us how to convert between
105  * rgb and color map entries
106  */
107 private gx_color_index
108 plan9_rgb2cmap(P4(gx_device *dev, gx_color_value r,
109   gx_color_value g, gx_color_value b)) {
110 	int shift;
111 	plan9_device *idev;
112 	ulong red, green, blue;
113 
114 	idev = (plan9_device*) dev;
115 
116 	shift = gx_color_value_bits - Nbits;
117 	red = r >> shift;
118 	green = g >> shift;
119 	blue = b >> shift;
120 
121 	/*
122 	 * we keep track of what ldepth bitmap this is by watching
123 	 * what colors gs asks for.
124 	 *
125 	 * one catch: sometimes print_page gets called more than one
126 	 * per page (for multiple copies) without cmap calls inbetween.
127 	 * if idev->cmapcall is 0 when print_page gets called, it uses
128 	 * the ldepth of the last page.
129 	 */
130 	if(red == green && green == blue) {
131 		if(red == 0 || red == Bitmask)
132 			;
133 		else if(red == Bitmask/3 || red == 2*Bitmask/3) {
134 			if(idev->ldepth < 1)
135 				idev->ldepth = 1;
136 		} else {
137 			if(idev->ldepth < 2)
138 				idev->ldepth = 2;
139 		}
140 	} else
141 		idev->ldepth = 3;
142 
143 	idev->cmapcall = 1;
144 	return (blue << (2*Nbits)) | (green << Nbits) | red;
145 }
146 
147 private int
148 plan9_cmap2rgb(P3(gx_device *dev, gx_color_index color,
149   gx_color_value rgb[3])) {
150 	int shift, i;
151 	plan9_device *idev;
152 
153 	if((ulong)color > 0xFFFFFF)
154 		return_error(gs_error_rangecheck);
155 
156 	idev = (plan9_device*) dev;
157 	shift = gx_color_value_bits - Nbits;
158 
159 	rgb[2] = ((color >> (2*Nbits)) & Bitmask) << shift;
160 	rgb[1] = ((color >> Nbits) & Bitmask) << shift;
161 	rgb[0] = (color & Bitmask) << shift;
162 
163 	return 0;
164 }
165 
166 private int
167 plan9_put_param_int(gs_param_list *plist, gs_param_name pname, int *pv,
168 	int minval, int maxval, int ecode)
169 {
170 	int code, value;
171 	switch(code = param_read_int(plist, pname, &value)) {
172 	default:
173 		return code;
174 
175 	case 1:
176 		return ecode;
177 
178 	case 0:
179 		if(value < minval || value > maxval)
180 			param_signal_error(plist, pname, gs_error_rangecheck);
181 		*pv = value;
182 		return (ecode < 0 ? ecode : 1);
183 	}
184 }
185 
186 private int
187 plan9_get_params(gx_device *pdev, gs_param_list *plist)
188 {
189 	int code;
190 	plan9_device *idev;
191 
192 	idev = (plan9_device*) pdev;
193 //	printf("plan9_get_params dither %d\n", idev->dither);
194 
195 	if((code = gdev_prn_get_params(pdev, plist)) < 0
196 	 || (code = param_write_int(plist, "Dither", &idev->dither)) < 0)
197 		return code;
198 	printf("getparams: dither=%d\n", idev->dither);
199 	return code;
200 }
201 
202 private int
203 plan9_put_params(gx_device * pdev, gs_param_list * plist)
204 {
205 	int code;
206 	int dither;
207 	plan9_device *idev;
208 
209 	printf("plan9_put_params\n");
210 
211 	idev = (plan9_device*)pdev;
212 	dither = idev->dither;
213 
214 	code = plan9_put_param_int(plist, "Dither", &dither, 0, 1, 0);
215 	if(code < 0)
216 		return code;
217 
218 	idev->dither = dither;
219 	return 0;
220 }
221 /*
222  * plan9_open() is supposed to initialize the device.
223  * there's not much to do.
224  */
225 private int
226 plan9_open(P1(gx_device *dev))
227 {
228 	int code;
229 	plan9_device *idev;
230 
231 	idev = (plan9_device*) dev;
232 	idev->cmapcall = 0;
233 	idev->ldepth = 0;
234 
235 //	printf("plan9_open gs_plan9_device.dither = %d idev->dither = %d\n",
236 //		gs_plan9_device.dither, idev->dither);
237 	setbuf(stderr, 0);
238 	init_p9color();
239 
240 	return gdev_prn_open(dev);
241 }
242 
243 /*
244  * plan9_print_page() is called once for each page
245  * (actually once for each copy of each page, but we won't
246  * worry about that).
247  */
248 private int
249 plan9_print_page(P2(gx_device_printer *pdev, FILE *f))
250 {
251 	char *chanstr;
252 	uchar *buf;	/* [8192*3*8/Nbits] BUG: malloc this */
253 	uchar *p;
254 	WImage *w;
255 	int bpl, y;
256 	int x, xmod;
257 	int ldepth;
258 	int ppb[] = {8, 4, 2, 1};	/* pixels per byte */
259 	int bpp[] = {1, 2, 4, 8};	/* bits per pixel */
260 	int gsbpl;
261 	int dither;
262 	int depth;
263 	ulong u;
264 	ushort us;
265 	Rectangle rect;
266 	plan9_device *idev;
267 	uchar *r;
268 
269 	setbuf(stderr, 0);
270 	gsbpl = gdev_prn_raster(pdev);
271 	buf = gs_malloc(gsbpl, 1, "plan9_print_page");
272 
273 	if(buf == nil) {
274 		fprintf(stderr, "out of memory\n");
275 		return_error(gs_error_Fatal);
276 	}
277 
278 	idev = (plan9_device *) pdev;
279 	if(idev->cmapcall) {
280 		idev->lastldepth = idev->ldepth;
281 		idev->ldepth = 0;
282 		idev->cmapcall = 0;
283 	}
284 	ldepth = idev->lastldepth;
285 	dither = idev->dither;
286 
287 	if(pdev->color_info.anti_alias.graphics_bits || pdev->color_info.anti_alias.text_bits)
288 		if(ldepth < 2)
289 			ldepth = 2;
290 
291 	chanstr = nil;
292 	depth = 0;
293 	switch(ldepth){
294 	case 0:
295 		chanstr = "k1";
296 		depth = 1;
297 		break;
298 	case 1:
299 		return_error(gs_error_Fatal);
300 	case 2:
301 		chanstr = "k4";
302 		depth = 4;
303 		break;
304 	case 3:
305 		chanstr = "r8g8b8";
306 		depth = 24;
307 		break;
308 	}
309 
310 //	printf("plan9_print_page dither %d ldepth %d idither %d\n", dither, ldepth, gs_plan9_device.dither);
311 	rect.min = ZP;
312 	rect.max.x = pdev->width;
313 	rect.max.y = pdev->height;
314 	bpl = bytesperline(rect, depth);
315 	w = initwriteimage(f, rect, chanstr, depth);
316 	if(w == nil) {
317 		fprintf(stderr, "initwriteimage failed\n");
318 		return_error(gs_error_Fatal);
319 	}
320 
321 	/*
322 	 * i wonder if it is faster to put the switch around the for loops
323 	 * to save all the ldepth lookups.
324 	 */
325 	for(y=0; y<pdev->height; y++) {
326 		gdev_prn_get_bits(pdev, y, buf, &p);
327 		r = p+2;
328 		switch(depth){
329 		default:
330 			return_error(gs_error_Fatal);
331 		case 1:
332 			for(x=0; x<pdev->width; x++){
333 				if((x%8) == 0)
334 					p[x/8] = (*r>>4)&1;
335 				else
336 					p[x/8] = (p[x/8]<<1) | (*r>>4)&1;
337 				r += 3;
338 			}
339 			break;
340 		case 4:
341 			for(x=0; x<pdev->width; x++){
342 				if((x%2) == 0)
343 					p[x/2] = (*r>>4) & 0xF;
344 				else
345 					p[x/2] = (p[x/2]<<4) | ((*r>>4)&0xF);
346 				r += 3;
347 			}
348 			break;
349 		case 24:
350 			break;
351 		}
352 
353 		/* pad last byte over if we didn't fill it */
354 		xmod = pdev->width % ppb[ldepth];
355 		if(xmod && ldepth<3)
356 			p[(x-1)/ppb[ldepth]] <<= ((ppb[ldepth]-xmod)*bpp[ldepth]);
357 
358 		if(writeimageblock(w, p, bpl) == ERROR) {
359 			gs_free(buf, gsbpl, 1, "plan9_print_page");
360 			return_error(gs_error_Fatal);
361 		}
362 	}
363 	if(writeimageblock(w, nil, 0) == ERROR) {
364 		gs_free(buf, gsbpl, 1, "plan9_print_page");
365 		return_error(gs_error_Fatal);
366 	}
367 
368 	gs_free(buf, gsbpl, 1, "plan9_print_page");
369 	return 0;
370 }
371 
372 /*
373  * this is a modified version of the image compressor
374  * from fb/bit2enc.  it is modified only in that it
375  * now compiles as part of gs.
376  */
377 
378 /*
379  * Compressed image file parameters
380  */
381 #define	NMATCH	3		/* shortest match possible */
382 #define	NRUN	(NMATCH+31)	/* longest match possible */
383 #define	NMEM	1024		/* window size */
384 #define	NDUMP	128		/* maximum length of dump */
385 #define	NCBLOCK	6000		/* size of compressed blocks */
386 
387 #define	HSHIFT	3	/* HSHIFT==5 runs slightly faster, but hash table is 64x bigger */
388 #define	NHASH	(1<<(HSHIFT*NMATCH))
389 #define	HMASK	(NHASH-1)
390 #define	hupdate(h, c)	((((h)<<HSHIFT)^(c))&HMASK)
391 
392 typedef struct Dump	Dump;
393 typedef struct Hlist Hlist;
394 
395 struct Hlist{
396 	ulong p;
397 	Hlist *next, *prev;
398 };
399 
400 struct Dump {
401 	int ndump;
402 	uchar *dumpbuf;
403 	uchar buf[1+NDUMP];
404 };
405 
406 struct WImage {
407 	FILE *f;
408 
409 	/* image attributes */
410 	Rectangle origr, r;
411 	int bpl;
412 
413 	/* output buffer */
414 	uchar outbuf[NCBLOCK], *outp, *eout, *loutp;
415 
416 	/* sliding input window */
417 	/*
418 	 * ibase is the pointer to where the beginning of
419 	 * the input "is" in memory.  whenever we "slide" the
420 	 * buffer N bytes, what we are actually doing is
421 	 * decrementing ibase by N.
422 	 * the ulongs in the Hlist structures are just
423 	 * pointers relative to ibase.
424 	 */
425 	uchar *inbuf;	/* inbuf should be at least NMEM+NRUN+NMATCH long */
426 	uchar *ibase;
427 	int minbuf;	/* size of inbuf (malloc'ed bytes) */
428 	int ninbuf;	/* size of inbuf (filled bytes) */
429 	ulong line;	/* the beginning of the line we are currently encoding,
430 			 * relative to inbuf (NOT relative to ibase) */
431 
432 	/* raw dump buffer */
433 	Dump dump;
434 
435 	/* hash tables */
436 	Hlist hash[NHASH];
437 	Hlist chain[NMEM], *cp;
438 	int h;
439 	int needhash;
440 };
441 
442 private void
443 zerohash(WImage *w)
444 {
445 	memset(w->hash, 0, sizeof(w->hash));
446 	memset(w->chain, 0, sizeof(w->chain));
447 	w->cp=w->chain;
448 	w->needhash = 1;
449 }
450 
451 private int
452 addbuf(WImage *w, uchar *buf, int nbuf)
453 {
454 	int n;
455 	if(buf == nil || w->outp+nbuf > w->eout) {
456 		if(w->loutp==w->outbuf){	/* can't really happen -- we checked line length above */
457 			fprintf(stderr, "buffer too small for line\n");
458 			return ERROR;
459 		}
460 		n=w->loutp-w->outbuf;
461 		fprintf(w->f, "%11d %11d ", w->r.max.y, n);
462 		fwrite(w->outbuf, 1, n, w->f);
463 		w->r.min.y=w->r.max.y;
464 		w->outp=w->outbuf;
465 		w->loutp=w->outbuf;
466 		zerohash(w);
467 		return -1;
468 	}
469 
470 	memmove(w->outp, buf, nbuf);
471 	w->outp += nbuf;
472 	return nbuf;
473 }
474 
475 /* return 0 on success, -1 if buffer is full */
476 private int
477 flushdump(WImage *w)
478 {
479 	int n = w->dump.ndump;
480 
481 	if(n == 0)
482 		return 0;
483 
484 	w->dump.buf[0] = 0x80|(n-1);
485 	if((n=addbuf(w, w->dump.buf, n+1)) == ERROR)
486 		return ERROR;
487 	if(n < 0)
488 		return -1;
489 	w->dump.ndump = 0;
490 	return 0;
491 }
492 
493 private void
494 updatehash(WImage *w, uchar *p, uchar *ep)
495 {
496 	uchar *q;
497 	Hlist *cp;
498 	Hlist *hash;
499 	int h;
500 
501 	hash = w->hash;
502 	cp = w->cp;
503 	h = w->h;
504 	for(q=p; q<ep; q++) {
505 		if(cp->prev)
506 			cp->prev->next = cp->next;
507 		cp->next = hash[h].next;
508 		cp->prev = &hash[h];
509 		cp->prev->next = cp;
510 		if(cp->next)
511 			cp->next->prev = cp;
512 		cp->p = q - w->ibase;
513 		if(++cp == w->chain+NMEM)
514 			cp = w->chain;
515 		if(&q[NMATCH] < &w->inbuf[w->ninbuf])
516 			h = hupdate(h, q[NMATCH]);
517 	}
518 	w->cp = cp;
519 	w->h = h;
520 }
521 
522 /*
523  * attempt to process a line of input,
524  * returning the number of bytes actually processed.
525  *
526  * if the output buffer needs to be flushed, we flush
527  * the buffer and return 0.
528  * otherwise we return bpl
529  */
530 private int
531 gobbleline(WImage *w)
532 {
533 	int runlen, n, offs;
534 	uchar *eline, *es, *best, *p, *s, *t;
535 	Hlist *hp;
536 	uchar buf[2];
537 	int rv;
538 
539 	if(w->needhash) {
540 		w->h = 0;
541 		for(n=0; n!=NMATCH; n++)
542 			w->h = hupdate(w->h, w->inbuf[w->line+n]);
543 		w->needhash = 0;
544 	}
545 	w->dump.ndump=0;
546 	eline=w->inbuf+w->line+w->bpl;
547 	for(p=w->inbuf+w->line;p!=eline;){
548 		es = (eline < p+NRUN) ? eline : p+NRUN;
549 
550 		best=nil;
551 		runlen=0;
552 		/* hash table lookup */
553 		for(hp=w->hash[w->h].next;hp;hp=hp->next){
554 			/*
555 			 * the next block is an optimization of
556 			 * for(s=p, t=w->ibase+hp->p; s<es && *s == *t; s++, t++)
557 			 * 	;
558 			 */
559 
560 			{	uchar *ss, *tt;
561 				s = p+runlen;
562 				t = w->ibase+hp->p+runlen;
563 				for(ss=s, tt=t; ss>=p && *ss == *tt; ss--, tt--)
564 					;
565 				if(ss < p)
566 					while(s<es && *s == *t)
567 						s++, t++;
568 			}
569 
570 			n = s-p;
571 
572 			if(n > runlen) {
573 				runlen = n;
574 				best = w->ibase+hp->p;
575 				if(p+runlen == es)
576 					break;
577 			}
578 		}
579 
580 		/*
581 		 * if we didn't find a long enough run, append to
582 		 * the raw dump buffer
583 		 */
584 		if(runlen<NMATCH){
585 			if(w->dump.ndump==NDUMP) {
586 				if((rv = flushdump(w)) == ERROR)
587 					return ERROR;
588 				if(rv < 0)
589 					return 0;
590 			}
591 			w->dump.dumpbuf[w->dump.ndump++]=*p;
592 			runlen=1;
593 		}else{
594 		/*
595 		 * otherwise, assuming the dump buffer is empty,
596 		 * add the compressed rep.
597 		 */
598 			if((rv = flushdump(w)) == ERROR)
599 				return ERROR;
600 			if(rv < 0)
601 				return 0;
602 			offs=p-best-1;
603 			buf[0] = ((runlen-NMATCH)<<2)|(offs>>8);
604 			buf[1] = offs&0xff;
605 			if(addbuf(w, buf, 2) < 0)
606 				return 0;
607 		}
608 
609 		/*
610 		 * add to hash tables what we just encoded
611 		 */
612 		updatehash(w, p, p+runlen);
613 		p += runlen;
614 	}
615 
616 	if((rv = flushdump(w)) == ERROR)
617 		return ERROR;
618 	if(rv < 0)
619 		return 0;
620 	w->line += w->bpl;
621 	w->loutp=w->outp;
622 	w->r.max.y++;
623 	return w->bpl;
624 }
625 
626 private uchar*
627 shiftwindow(WImage *w, uchar *data, uchar *edata)
628 {
629 	int n, m;
630 
631 	/* shift window over */
632 	if(w->line > NMEM) {
633 		n = w->line-NMEM;
634 		memmove(w->inbuf, w->inbuf+n, w->ninbuf-n);
635 		w->line -= n;
636 		w->ibase -= n;
637 		w->ninbuf -= n;
638 	}
639 
640 	/* fill right with data if available */
641 	if(w->minbuf > w->ninbuf && edata > data) {
642 		m = w->minbuf - w->ninbuf;
643 		if(edata-data < m)
644 			m = edata-data;
645 		memmove(w->inbuf+w->ninbuf, data, m);
646 		data += m;
647 		w->ninbuf += m;
648 	}
649 
650 	return data;
651 }
652 
653 private WImage*
654 initwriteimage(FILE *f, Rectangle r, char *chanstr, int depth)
655 {
656 	WImage *w;
657 	int n, bpl;
658 
659 	bpl = bytesperline(r, depth);
660 	if(r.max.y <= r.min.y || r.max.x <= r.min.x || bpl <= 0) {
661 		fprintf(stderr, "bad rectangle, ldepth");
662 		return nil;
663 	}
664 
665 	n = NMEM+NMATCH+NRUN+bpl*2;
666 	w = malloc(n+sizeof(*w));
667 	if(w == nil)
668 		return nil;
669 	w->inbuf = (uchar*) &w[1];
670 	w->ibase = w->inbuf;
671 	w->line = 0;
672 	w->minbuf = n;
673 	w->ninbuf = 0;
674 	w->origr = r;
675 	w->r = r;
676 	w->r.max.y = w->r.min.y;
677 	w->eout = w->outbuf+sizeof(w->outbuf);
678 	w->outp = w->loutp = w->outbuf;
679 	w->bpl = bpl;
680 	w->f = f;
681 	w->dump.dumpbuf = w->dump.buf+1;
682 	w->dump.ndump = 0;
683 	zerohash(w);
684 
685 	fprintf(f, "compressed\n%11s %11d %11d %11d %11d ",
686 		chanstr, r.min.x, r.min.y, r.max.x, r.max.y);
687 	return w;
688 }
689 
690 private int
691 writeimageblock(WImage *w, uchar *data, int ndata)
692 {
693 	uchar *edata;
694 
695 	if(data == nil) {	/* end of data, flush everything */
696 		while(w->line < w->ninbuf)
697 			if(gobbleline(w) == ERROR)
698 				return ERROR;
699 		addbuf(w, nil, 0);
700 		if(w->r.min.y != w->origr.max.y) {
701 			fprintf(stderr, "not enough data supplied to writeimage\n");
702 		}
703 		free(w);
704 		return 0;
705 	}
706 
707 	edata = data+ndata;
708 	data = shiftwindow(w, data, edata);
709 	while(w->ninbuf >= w->line+w->bpl+NMATCH) {
710 		if(gobbleline(w) == ERROR)
711 			return ERROR;
712 		data = shiftwindow(w, data, edata);
713 	}
714 	if(data != edata) {
715 		fprintf(w->f, "data != edata.  uh oh\n");
716 		return ERROR; /* can't happen */
717 	}
718 	return 0;
719 }
720 
721 /*
722  * functions from the Plan9/Brazil drawing libraries
723  */
724 static
725 int
726 unitsperline(Rectangle r, int d, int bitsperunit)
727 {
728 	ulong l, t;
729 
730 	if(d <= 0 || d > 32)	/* being called wrong.  d is image depth. */
731 		abort();
732 
733 	if(r.min.x >= 0){
734 		l = (r.max.x*d+bitsperunit-1)/bitsperunit;
735 		l -= (r.min.x*d)/bitsperunit;
736 	}else{			/* make positive before divide */
737 		t = (-r.min.x*d+bitsperunit-1)/bitsperunit;
738 		l = t+(r.max.x*d+bitsperunit-1)/bitsperunit;
739 	}
740 	return l;
741 }
742 
743 int
744 wordsperline(Rectangle r, int d)
745 {
746 	return unitsperline(r, d, 8*sizeof(ulong));
747 }
748 
749 int
750 bytesperline(Rectangle r, int d)
751 {
752 	return unitsperline(r, d, 8);
753 }
754