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Date:: Thu Jan 13 04:49:19 2005 UTC
Message:: Many small edits.
Actions:: History | Blame | Raw File
1 /*
2  * Some of the stuff in this file is not X-dependent and should be elsewhere.
3  */
4 #include <u.h>
5 #include "x11-inc.h"
6 #include <libc.h>
7 #include <draw.h>
8 #include <memdraw.h>
9 #include <keyboard.h>
10 #include <mouse.h>
11 #include <cursor.h>
12 #include "x11-memdraw.h"
13 
14 char *winsize;
15 static int parsewinsize(char*, Rectangle*, int*);
16 
17 static Memimage	*xattach(char*);
18 static void	plan9cmap(void);
19 static int	setupcmap(XWindow);
20 static int	xreplacescreenimage(void);
21 static XGC	xgc(XDrawable, int, int);
22 static Image	*getimage0(Display*, Image*);
23 
24 Xprivate _x;
25 
26 Display*
27 _initdisplay(void (*error)(Display*, char*), char *label)
28 {
29 	Display *d;
30 	Memimage *m;
31 
32 	/*
33 	 * This rfork(RFNOTEG) isn't exactly right,
34 	 * but we need some way to signal window 
35 	 * closes.  Right now we post a hangup
36 	 * note to the note group, which kills a whole
37 	 * lot more than just the current program
38 	 * if we don't do this.
39 	 */
40 	/*
41 	 * Actually, I don't know what I changed but
42 	 * this appears not to be necessary anymore.
43 	 * I'll regret this probably.
44 	rfork(RFNOTEG);
45 	*/
46 	memimageinit();
47 
48 	d = mallocz(sizeof(Display), 1);
49 	if(d == nil)
50 		return nil;
51 
52 	d->buf = malloc(16000+5);
53 	d->obuf = malloc(16000);
54 	if(d->buf == nil || d->obuf == nil){
55 		free(d->buf);
56 		free(d->obuf);
57 		free(d);
58 		return nil;
59 	}
60 	d->bufsize = 16000;
61 	d->obufsize = 16000;
62 	d->bufp = d->buf;
63 	d->obufp = d->obuf;
64 
65 	m = xattach(label);
66 	if(m == nil){
67 		free(d);
68 		return nil;
69 	}
70 
71 	d->error = error;
72 	_initdisplaymemimage(d, m);
73 	d->screenimage = getimage0(d, 0);
74 	return d;
75 }
76 
77 static Image*
78 getimage0(Display *d, Image *image)
79 {
80 	char info[12*12+1];
81 	uchar *a;
82 	int n;
83 	extern int _freeimage1(Image*);
84 
85 	/*
86 	 * If there's an old screen, it has id 0.  The 'J' request below
87 	 * will try to install the new screen as id 0, so the old one 
88 	 * must be freed first.
89 	 */
90 	if(image){
91 		_freeimage1(image);
92 		memset(image, 0, sizeof(Image));
93 	}
94 
95 	a = bufimage(d, 2);
96 	a[0] = 'J';
97 	a[1] = 'I';
98 	if(flushimage(d, 0) < 0){
99 		fprint(2, "cannot read screen info: %r\n");
100 		abort();
101 	}
102 
103 	n = _drawmsgread(d, info, sizeof info);
104 	if(n != 12*12){
105 		fprint(2, "short screen info\n");
106 		abort();
107 	}
108 
109 	if(image == nil){
110 		image = mallocz(sizeof(Image), 1);
111 		if(image == nil){
112 			fprint(2, "cannot allocate image: %r\n");
113 			abort();
114 		}
115 	}
116 
117 	image->display = d;
118 	image->id = 0;
119 	image->chan = strtochan(info+2*12);
120 	image->depth = chantodepth(image->chan);
121 	image->repl = atoi(info+3*12);
122 	image->r.min.x = atoi(info+4*12);
123 	image->r.min.y = atoi(info+5*12);
124 	image->r.max.x = atoi(info+6*12);
125 	image->r.max.y = atoi(info+7*12);
126 	image->clipr.min.x = atoi(info+8*12);
127 	image->clipr.min.y = atoi(info+9*12);
128 	image->clipr.max.x = atoi(info+10*12);
129 	image->clipr.max.y = atoi(info+11*12);
130 	return image;
131 }
132 
133 int
134 getwindow(Display *d, int ref)
135 {
136 	Image *i;
137 	Image *oi;
138 
139 	if(_x.destroyed)
140 		postnote(PNGROUP, getpgrp(), "hangup");
141 	if(xreplacescreenimage() == 0)
142 		return 0;
143 
144 	/*
145 	 * Libdraw promises not to change the value of "screen",
146 	 * so we have to reuse the image structure
147 	 * memory we already have.
148 	 */
149 	oi = d->screenimage;
150 	i = getimage0(d, oi);
151 	screen = d->screenimage = d->image = i;
152 	// fprint(2, "getwindow %p -> %p\n", oi, i);
153 	return 0;
154 }
155 
156 static int
157 xerror(XDisplay *d, XErrorEvent *e)
158 {
159 	char buf[200];
160 
161 	if(e->request_code == 42) /* XSetInputFocus */
162 		return 0;
163 	if(e->request_code == 18) /* XChangeProperty */
164 		return 0;
165 
166 	print("X error: error_code=%d, request_code=%d, minor=%d disp=%p\n",
167 		e->error_code, e->request_code, e->minor_code, d);
168 	XGetErrorText(d, e->error_code, buf, sizeof buf);
169 	print("%s\n", buf);
170 	return 0;
171 }
172 
173 static int
174 xioerror(XDisplay *d)
175 {
176 	//print("X I/O error\n");
177 	sysfatal("X I/O error\n");
178 	abort();
179 	return -1;
180 }
181 
182 
183 static Memimage*
184 xattach(char *label)
185 {
186 	char *argv[2], *disp;
187 	int i, havemin, height, mask, n, width, x, xrootid, y;
188 	Rectangle r;
189 	XClassHint classhint;
190 	XDrawable pmid;
191 	XPixmapFormatValues *pfmt;
192 	XScreen *xscreen;
193 	XSetWindowAttributes attr;
194 	XSizeHints normalhint;
195 	XTextProperty name;
196 	XVisualInfo xvi;
197 	XWindow xrootwin;
198 	XWindowAttributes wattr;
199 	XWMHints hint;
200 	Atom atoms[2];
201 
202 	/*
203 	if(XInitThreads() == 0){
204 		fprint(2, "XInitThreads failed\n");
205 		abort();
206 	}
207 	*/
208 
209 	/*
210 	 * Connect to X server.
211 	 */
212 	_x.display = XOpenDisplay(NULL);
213 	if(_x.display == nil){
214 		disp = getenv("DISPLAY");
215 		werrstr("XOpenDisplay %s: %r", disp ? disp : ":0");
216 		free(disp);
217 		return nil;
218 	}
219 	XSetErrorHandler(xerror);
220 	XSetIOErrorHandler(xioerror);
221 	xrootid = DefaultScreen(_x.display);
222 	xrootwin = DefaultRootWindow(_x.display);
223 
224 	/* 
225 	 * Figure out underlying screen format.
226 	 */
227 	if(XMatchVisualInfo(_x.display, xrootid, 16, TrueColor, &xvi)
228 	|| XMatchVisualInfo(_x.display, xrootid, 16, DirectColor, &xvi)){
229 		_x.vis = xvi.visual;
230 		_x.depth = 16;
231 	}
232 	else
233 	if(XMatchVisualInfo(_x.display, xrootid, 15, TrueColor, &xvi)
234 	|| XMatchVisualInfo(_x.display, xrootid, 15, DirectColor, &xvi)){
235 		_x.vis = xvi.visual;
236 		_x.depth = 15;
237 	}
238 	else
239 	if(XMatchVisualInfo(_x.display, xrootid, 24, TrueColor, &xvi)
240 	|| XMatchVisualInfo(_x.display, xrootid, 24, DirectColor, &xvi)){
241 		_x.vis = xvi.visual;
242 		_x.depth = 24;
243 	}
244 	else
245 	if(XMatchVisualInfo(_x.display, xrootid, 8, PseudoColor, &xvi)
246 	|| XMatchVisualInfo(_x.display, xrootid, 8, StaticColor, &xvi)){
247 		if(_x.depth > 8){
248 			werrstr("can't deal with colormapped depth %d screens",
249 				_x.depth);
250 			goto err0;
251 		}
252 		_x.vis = xvi.visual;
253 		_x.depth = 8;
254 	}
255 	else{
256 		_x.depth = DefaultDepth(_x.display, xrootid);
257 		if(_x.depth != 8){
258 			werrstr("can't understand depth %d screen", _x.depth);
259 			goto err0;
260 		}
261 		_x.vis = DefaultVisual(_x.display, xrootid);
262 	}
263 
264 	if(DefaultDepth(_x.display, xrootid) == _x.depth)
265 		_x.usetable = 1;
266 
267 	/*
268 	 * _x.depth is only the number of significant pixel bits,
269 	 * not the total number of pixel bits.  We need to walk the
270 	 * display list to find how many actual bits are used
271 	 * per pixel.
272 	 */
273 	_x.chan = 0;
274 	pfmt = XListPixmapFormats(_x.display, &n);
275 	for(i=0; i<n; i++){
276 		if(pfmt[i].depth == _x.depth){
277 			switch(pfmt[i].bits_per_pixel){
278 			case 1:	/* untested */
279 				_x.chan = GREY1;
280 				break;
281 			case 2:	/* untested */
282 				_x.chan = GREY2;
283 				break;
284 			case 4:	/* untested */
285 				_x.chan = GREY4;
286 				break;
287 			case 8:
288 				_x.chan = CMAP8;
289 				break;
290 			case 15:
291 				_x.chan = RGB15;
292 				break;
293 			case 16: /* how to tell RGB15? */
294 				_x.chan = RGB16;
295 				break;
296 			case 24: /* untested (impossible?) */
297 				_x.chan = RGB24;
298 				break;
299 			case 32:
300 				_x.chan = XRGB32;
301 				break;
302 			}
303 		}
304 	}
305 	if(_x.chan == 0){
306 		werrstr("could not determine screen pixel format");
307 		goto err0;
308 	}
309 
310 	/*
311 	 * Set up color map if necessary.
312 	 */
313 	xscreen = DefaultScreenOfDisplay(_x.display);
314 	_x.cmap = DefaultColormapOfScreen(xscreen);
315 	if(_x.vis->class != StaticColor){
316 		plan9cmap();
317 		setupcmap(xrootwin);
318 	}
319 
320 	/*
321 	 * We get to choose the initial rectangle size.
322 	 * This is arbitrary.  In theory we should read the
323 	 * command line and allow the traditional X options.
324 	 */
325 	mask = 0;
326 	x = 0;
327 	y = 0;
328 	if(winsize){
329 		if(parsewinsize(winsize, &r, &havemin) < 0)
330 			sysfatal("%r");
331 	}else{
332 		/*
333 		 * Parse the various X resources.  Thanks to Peter Canning.
334 		 */
335 		char *screen_resources, *display_resources, *geom, 
336 			*geomrestype, *home, *file;
337 		XrmDatabase database;
338 		XrmValue geomres;
339 
340 		database = XrmGetDatabase(_x.display);
341 		screen_resources = XScreenResourceString(xscreen);
342 		if(screen_resources != nil){
343 			XrmCombineDatabase(XrmGetStringDatabase(screen_resources), &database, False);
344 			XFree(screen_resources);
345 		}
346 
347 		display_resources = XResourceManagerString(_x.display);
348 		if(display_resources == nil){
349 			home = getenv("HOME");
350 			if(home!=nil && (file=smprint("%s/.Xdefaults", home)) != nil){
351 				XrmCombineFileDatabase(file, &database, False);
352 				free(file);
353 			}
354 			free(home);
355 		}else
356 			XrmCombineDatabase(XrmGetStringDatabase(display_resources), &database, False);
357 
358 		geom = smprint("%s.geometry", label);
359 		if(geom && XrmGetResource(database, geom, nil, &geomrestype, &geomres))
360 			mask = XParseGeometry(geomres.addr, &x, &y, (uint*)&width, (uint*)&height);
361 		free(geom);
362 
363 		if((mask & WidthValue) && (mask & HeightValue)){
364 			r = Rect(0, 0, width, height);
365 		}else{
366 			r = Rect(0, 0, WidthOfScreen(xscreen)*3/4,
367 					HeightOfScreen(xscreen)*3/4);
368 			if(Dx(r) > Dy(r)*3/2)
369 				r.max.x = r.min.x + Dy(r)*3/2;
370 			if(Dy(r) > Dx(r)*3/2)
371 				r.max.y = r.min.y + Dx(r)*3/2;
372 		}
373 		if(mask & XNegative){
374 			x += WidthOfScreen(xscreen);
375 		}
376 		if(mask & YNegative){
377 			y += HeightOfScreen(xscreen);
378 		}
379 		havemin = 0;
380 	}
381 
382 	memset(&attr, 0, sizeof attr);
383 	attr.colormap = _x.cmap;
384 	attr.background_pixel = ~0;
385 	attr.border_pixel = 0;
386 	_x.drawable = XCreateWindow(
387 		_x.display,	/* display */
388 		xrootwin,	/* parent */
389 		x,		/* x */
390 		y,		/* y */
391 		Dx(r),		/* width */
392 	 	Dy(r),		/* height */
393 		0,		/* border width */
394 		_x.depth,	/* depth */
395 		InputOutput,	/* class */
396 		_x.vis,		/* visual */
397 				/* valuemask */
398 		CWBackPixel|CWBorderPixel|CWColormap,
399 		&attr		/* attributes (the above aren't?!) */
400 	);
401 
402 	/*
403 	 * Label and other properties required by ICCCCM.
404 	 */
405 	memset(&name, 0, sizeof name);
406 	if(label == nil)
407 		label = "pjw-face-here";
408 	name.value = (uchar*)label;
409 	name.encoding = XA_STRING;
410 	name.format = 8;
411 	name.nitems = strlen((char*)name.value);
412 
413 	memset(&normalhint, 0, sizeof normalhint);
414 	normalhint.flags = PSize|PMaxSize;
415 	if(winsize){
416 		normalhint.flags &= ~PSize;
417 		normalhint.flags |= USSize;
418 		normalhint.width = Dx(r);
419 		normalhint.height = Dy(r);
420 	}else{
421 		if((mask & WidthValue) && (mask & HeightValue)){
422 			normalhint.flags &= ~PSize;
423 			normalhint.flags |= USSize;
424 			normalhint.width = width;
425 			normalhint.height = height;
426 		}
427 		if((mask & WidthValue) && (mask & HeightValue)){
428 			normalhint.flags |= USPosition;
429 			normalhint.x = x;
430 			normalhint.y = y;
431 		}
432 	}
433 
434 	normalhint.max_width = WidthOfScreen(xscreen);
435 	normalhint.max_height = HeightOfScreen(xscreen);
436 
437 	memset(&hint, 0, sizeof hint);
438 	hint.flags = InputHint|StateHint;
439 	hint.input = 1;
440 	hint.initial_state = NormalState;
441 
442 	memset(&classhint, 0, sizeof classhint);
443 	classhint.res_name = label;
444 	classhint.res_class = label;
445 
446 	argv[0] = label;
447 	argv[1] = nil;
448 
449 	XSetWMProperties(
450 		_x.display,	/* display */
451 		_x.drawable,	/* window */
452 		&name,		/* XA_WM_NAME property */
453 		&name,		/* XA_WM_ICON_NAME property */
454 		argv,		/* XA_WM_COMMAND */
455 		1,		/* argc */
456 		&normalhint,	/* XA_WM_NORMAL_HINTS */
457 		&hint,		/* XA_WM_HINTS */
458 		&classhint	/* XA_WM_CLASSHINTS */
459 	);
460 	XFlush(_x.display);
461 
462 	if(havemin){
463 		XWindowChanges ch;
464 
465 		memset(&ch, 0, sizeof ch);
466 		ch.x = r.min.x;
467 		ch.y = r.min.y;
468 		XConfigureWindow(_x.display, _x.drawable, CWX|CWY, &ch);
469 	}
470 	/*
471 	 * Look up clipboard atom.
472 	 */
473 	_x.clipboard = XInternAtom(_x.display, "CLIPBOARD", False);
474 	_x.utf8string = XInternAtom(_x.display, "UTF8_STRING", False);
475 	_x.targets = XInternAtom(_x.display, "TARGETS", False);
476 	_x.text = XInternAtom(_x.display, "TEXT", False);
477 	_x.compoundtext = XInternAtom(_x.display, "COMPOUND_TEXT", False);
478 	_x.takefocus = XInternAtom(_x.display, "WM_TAKE_FOCUS", False);
479 	_x.losefocus = XInternAtom(_x.display, "_9WM_LOSE_FOCUS", False);
480 	_x.wmprotos = XInternAtom(_x.display, "WM_PROTOCOLS", False);
481 
482 	atoms[0] = _x.takefocus;
483 	atoms[1] = _x.losefocus;
484 	XChangeProperty(_x.display, _x.drawable, _x.wmprotos, XA_ATOM, 32,
485 		PropModeReplace, (uchar*)atoms, 2);
486 
487 	/*
488 	 * Put the window on the screen, check to see what size we actually got.
489 	 */
490 	XMapWindow(_x.display, _x.drawable);
491 	XSync(_x.display, False);
492 
493 	if(!XGetWindowAttributes(_x.display, _x.drawable, &wattr))
494 		fprint(2, "XGetWindowAttributes failed\n");
495 	else if(wattr.width && wattr.height){
496 		if(wattr.width != Dx(r) || wattr.height != Dy(r)){
497 			r.max.x = wattr.width;
498 			r.max.y = wattr.height;
499 		}
500 	}else
501 		fprint(2, "XGetWindowAttributes: bad attrs\n");
502 
503 	/*
504 	 * Allocate our local backing store.
505 	 */
506 	_x.screenr = r;
507 	_x.screenpm = XCreatePixmap(_x.display, _x.drawable, Dx(r), Dy(r), _x.depth);
508 	_x.nextscreenpm = _x.screenpm;
509 	_x.screenimage = _xallocmemimage(r, _x.chan, _x.screenpm);
510 
511 	/*
512 	 * Allocate some useful graphics contexts for the future.
513 	 */
514 	_x.gcfill	= xgc(_x.screenpm, FillSolid, -1);
515 	_x.gccopy	= xgc(_x.screenpm, -1, -1);
516 	_x.gcsimplesrc 	= xgc(_x.screenpm, FillStippled, -1);
517 	_x.gczero	= xgc(_x.screenpm, -1, -1);
518 	_x.gcreplsrc	= xgc(_x.screenpm, FillTiled, -1);
519 
520 	pmid = XCreatePixmap(_x.display, _x.drawable, 1, 1, 1);
521 	_x.gcfill0	= xgc(pmid, FillSolid, 0);
522 	_x.gccopy0	= xgc(pmid, -1, -1);
523 	_x.gcsimplesrc0	= xgc(pmid, FillStippled, -1);
524 	_x.gczero0	= xgc(pmid, -1, -1);
525 	_x.gcreplsrc0	= xgc(pmid, FillTiled, -1);
526 	XFreePixmap(_x.display, pmid);
527 
528 	/*
529 	 * Lots of display connections for various procs.
530 	 */
531 	_x.kbdcon	= XOpenDisplay(NULL);
532 	_x.mousecon	= XOpenDisplay(NULL);
533 	_x.snarfcon	= XOpenDisplay(NULL);
534 
535 	if(0) fprint(2, "x: display=%p kbd=%p mouse=%p snarf=%p\n",
536 		_x.display, _x.kbdcon, _x.mousecon, _x.snarfcon);
537 
538 	_x.black	= xscreen->black_pixel;
539 	_x.white	= xscreen->white_pixel;
540 
541 	return _x.screenimage;
542 
543 err0:
544 fprint(2, "%r\n");
545 	/*
546 	 * Should do a better job of cleaning up here.
547 	 */
548 	XCloseDisplay(_x.display);
549 	return nil;
550 }
551 
552 int
553 drawsetlabel(char *label)
554 {
555 	XTextProperty name;
556 
557 	/*
558 	 * Label and other properties required by ICCCCM.
559 	 */
560 	memset(&name, 0, sizeof name);
561 	if(label == nil)
562 		label = "pjw-face-here";
563 	name.value = (uchar*)label;
564 	name.encoding = XA_STRING;
565 	name.format = 8;
566 	name.nitems = strlen((char*)name.value);
567 
568 	XSetWMProperties(
569 		_x.display,	/* display */
570 		_x.drawable,	/* window */
571 		&name,		/* XA_WM_NAME property */
572 		&name,		/* XA_WM_ICON_NAME property */
573 		nil,		/* XA_WM_COMMAND */
574 		0,		/* argc */
575 		nil,		/* XA_WM_NORMAL_HINTS */
576 		nil,		/* XA_WM_HINTS */
577 		nil	/* XA_WM_CLASSHINTS */
578 	);
579 	XFlush(_x.display);
580 	return 0;
581 }
582 
583 /*
584  * Create a GC with a particular fill style and XXX.
585  * Disable generation of GraphicsExpose/NoExpose events in the GC.
586  */
587 static XGC
588 xgc(XDrawable d, int fillstyle, int foreground)
589 {
590 	XGC gc;
591 	XGCValues v;
592 
593 	memset(&v, 0, sizeof v);
594 	v.function = GXcopy;
595 	v.graphics_exposures = False;
596 	gc = XCreateGC(_x.display, d, GCFunction|GCGraphicsExposures, &v);
597 	if(fillstyle != -1)
598 		XSetFillStyle(_x.display, gc, fillstyle);
599 	if(foreground != -1)
600 		XSetForeground(_x.display, gc, 0);
601 	return gc;
602 }
603 
604 
605 /*
606  * Initialize map with the Plan 9 rgbv color map.
607  */
608 static void
609 plan9cmap(void)
610 {
611 	int r, g, b, cr, cg, cb, v, num, den, idx, v7, idx7;
612 	static int once;
613 
614 	if(once)
615 		return;
616 	once = 1;
617 
618 	for(r=0; r!=4; r++)
619 	for(g = 0; g != 4; g++)
620 	for(b = 0; b!=4; b++)
621 	for(v = 0; v!=4; v++){
622 		den=r;
623 		if(g > den)
624 			den=g;
625 		if(b > den)
626 			den=b;
627 		/* divide check -- pick grey shades */
628 		if(den==0)
629 			cr=cg=cb=v*17;
630 		else {
631 			num=17*(4*den+v);
632 			cr=r*num/den;
633 			cg=g*num/den;
634 			cb=b*num/den;
635 		}
636 		idx = r*64 + v*16 + ((g*4 + b + v - r) & 15);
637 		_x.map[idx].red = cr*0x0101;
638 		_x.map[idx].green = cg*0x0101;
639 		_x.map[idx].blue = cb*0x0101;
640 		_x.map[idx].pixel = idx;
641 		_x.map[idx].flags = DoRed|DoGreen|DoBlue;
642 
643 		v7 = v >> 1;
644 		idx7 = r*32 + v7*16 + g*4 + b;
645 		if((v & 1) == v7){
646 			_x.map7to8[idx7][0] = idx;
647 			if(den == 0) { 		/* divide check -- pick grey shades */
648 				cr = ((255.0/7.0)*v7)+0.5;
649 				cg = cr;
650 				cb = cr;
651 			}
652 			else {
653 				num=17*15*(4*den+v7*2)/14;
654 				cr=r*num/den;
655 				cg=g*num/den;
656 				cb=b*num/den;
657 			}
658 			_x.map7[idx7].red = cr*0x0101;
659 			_x.map7[idx7].green = cg*0x0101;
660 			_x.map7[idx7].blue = cb*0x0101;
661 			_x.map7[idx7].pixel = idx7;
662 			_x.map7[idx7].flags = DoRed|DoGreen|DoBlue;
663 		}
664 		else
665 			_x.map7to8[idx7][1] = idx;
666 	}
667 }
668 
669 /*
670  * Initialize and install the rgbv color map as a private color map
671  * for this application.  It gets the best colors when it has the
672  * cursor focus.
673  *
674  * We always choose the best depth possible, but that might not
675  * be the default depth.  On such "suboptimal" systems, we have to allocate an
676  * empty color map anyway, according to Axel Belinfante.
677  */
678 static int 
679 setupcmap(XWindow w)
680 {
681 	char buf[30];
682 	int i;
683 	u32int p, pp;
684 	XColor c;
685 
686 	if(_x.depth <= 1)
687 		return 0;
688 
689 	if(_x.depth >= 24) {
690 		if(_x.usetable == 0)
691 			_x.cmap = XCreateColormap(_x.display, w, _x.vis, AllocNone); 
692 
693 		/*
694 		 * The pixel value returned from XGetPixel needs to
695 		 * be converted to RGB so we can call rgb2cmap()
696 		 * to translate between 24 bit X and our color. Unfortunately,
697 		 * the return value appears to be display server endian 
698 		 * dependant. Therefore, we run some heuristics to later
699 		 * determine how to mask the int value correctly.
700 		 * Yeah, I know we can look at _x.vis->byte_order but 
701 		 * some displays say MSB even though they run on LSB.
702 		 * Besides, this is more anal.
703 		 */
704 		c = _x.map[19];	/* known to have different R, G, B values */
705 		if(!XAllocColor(_x.display, _x.cmap, &c)){
706 			werrstr("XAllocColor: %r");
707 			return -1;
708 		}
709 		p  = c.pixel;
710 		pp = rgb2cmap((p>>16)&0xff,(p>>8)&0xff,p&0xff);
711 		if(pp != _x.map[19].pixel) {
712 			/* check if endian is other way */
713 			pp = rgb2cmap(p&0xff,(p>>8)&0xff,(p>>16)&0xff);
714 			if(pp != _x.map[19].pixel){
715 				werrstr("cannot detect X server byte order");
716 				return -1;
717 			}
718 
719 			switch(_x.chan){
720 			case RGB24:
721 				_x.chan = BGR24;
722 				break;
723 			case XRGB32:
724 				_x.chan = XBGR32;
725 				break;
726 			default:
727 				werrstr("cannot byteswap channel %s",
728 					chantostr(buf, _x.chan));
729 				break;
730 			}
731 		}
732 	}else if(_x.vis->class == TrueColor || _x.vis->class == DirectColor){
733 		/*
734 		 * Do nothing.  We have no way to express a
735 		 * mixed-endian 16-bit screen, so pretend they don't exist.
736 		 */
737 		if(_x.usetable == 0)
738 			_x.cmap = XCreateColormap(_x.display, w, _x.vis, AllocNone);
739 	}else if(_x.vis->class == PseudoColor){
740 		if(_x.usetable == 0){
741 			_x.cmap = XCreateColormap(_x.display, w, _x.vis, AllocAll); 
742 			XStoreColors(_x.display, _x.cmap, _x.map, 256);
743 			for(i = 0; i < 256; i++){
744 				_x.tox11[i] = i;
745 				_x.toplan9[i] = i;
746 			}
747 		}else{
748 			for(i = 0; i < 128; i++){
749 				c = _x.map7[i];
750 				if(!XAllocColor(_x.display, _x.cmap, &c)){
751 					werrstr("can't allocate colors in 7-bit map");
752 					return -1;
753 				}
754 				_x.tox11[_x.map7to8[i][0]] = c.pixel;
755 				_x.tox11[_x.map7to8[i][1]] = c.pixel;
756 				_x.toplan9[c.pixel] = _x.map7to8[i][0];
757 			}
758 		}
759 	}else{
760 		werrstr("unsupported visual class %d", _x.vis->class);
761 		return -1;
762 	}
763 	return 0;
764 }
765 
766 void
767 _flushmemscreen(Rectangle r)
768 {
769 	if(_x.nextscreenpm != _x.screenpm){
770 		qlock(&_x.screenlock);
771 		XSync(_x.display, False);
772 		XFreePixmap(_x.display, _x.screenpm);
773 		_x.screenpm = _x.nextscreenpm;
774 		qunlock(&_x.screenlock);
775 	}
776 
777 	if(r.min.x >= r.max.x || r.min.y >= r.max.y)
778 		return;
779 	XCopyArea(_x.display, _x.screenpm, _x.drawable, _x.gccopy, r.min.x, r.min.y,
780 		Dx(r), Dy(r), r.min.x, r.min.y);
781 	XFlush(_x.display);
782 }
783 
784 void
785 _xexpose(XEvent *e, XDisplay *xd)
786 {
787 	XExposeEvent *xe;
788 	Rectangle r;
789 
790 	qlock(&_x.screenlock);
791 	if(_x.screenpm != _x.nextscreenpm){
792 		qunlock(&_x.screenlock);
793 		return;
794 	}
795 	xe = (XExposeEvent*)e;
796 	r.min.x = xe->x;
797 	r.min.y = xe->y;
798 	r.max.x = xe->x+xe->width;
799 	r.max.y = xe->y+xe->height;
800 	XCopyArea(xd, _x.screenpm, _x.drawable, _x.gccopy, r.min.x, r.min.y,
801 		Dx(r), Dy(r), r.min.x, r.min.y);
802 	XSync(xd, False);
803 	qunlock(&_x.screenlock);
804 }
805 
806 int
807 _xdestroy(XEvent *e, XDisplay *xd)
808 {
809 	XDestroyWindowEvent *xe;
810 
811 	xe = (XDestroyWindowEvent*)e;
812 	if(xe->window == _x.drawable){
813 		_x.destroyed = 1;
814 		return 1;
815 	}
816 	return 0;
817 }
818 
819 int
820 _xconfigure(XEvent *e, XDisplay *xd)
821 {
822 	Rectangle r;
823 	XConfigureEvent *xe = (XConfigureEvent*)e;
824 
825 	if(xe->width == Dx(_x.screenr) && xe->height == Dy(_x.screenr))
826 		return 0;
827 	if(xe->width==0 || xe->height==0)
828 		fprint(2, "ignoring resize to %dx%d\n", xe->width, xe->height);
829 	r = Rect(0, 0, xe->width, xe->height);
830 	qlock(&_x.screenlock);
831 	if(_x.screenpm != _x.nextscreenpm){
832 		XCopyArea(xd, _x.screenpm, _x.drawable, _x.gccopy, r.min.x, r.min.y,
833 			Dx(r), Dy(r), r.min.x, r.min.y);
834 		XSync(xd, False);
835 	}
836 	qunlock(&_x.screenlock);
837 	_x.newscreenr = r;
838 	return 1;
839 }
840 
841 static int
842 xreplacescreenimage(void)
843 {
844 	Memimage *m;
845 	XDrawable pixmap;
846 	Rectangle r;
847 
848 	r = _x.newscreenr;
849 	if(eqrect(_x.screenr, r))
850 		return 0;
851 
852 	pixmap = XCreatePixmap(_x.display, _x.drawable, Dx(r), Dy(r), _x.depth);
853 	m = _xallocmemimage(r, _x.chan, pixmap);
854 	if(_x.nextscreenpm != _x.screenpm)
855 		XFreePixmap(_x.display, _x.nextscreenpm);
856 	_x.nextscreenpm = pixmap;
857 	_x.screenr = r;
858 	_drawreplacescreenimage(m);
859 	return 1;
860 }
861 
862 static int
863 parsewinsize(char *s, Rectangle *r, int *havemin)
864 {
865 	char c, *os;
866 	int i, j, k, l;
867 
868 	os = s;
869 	*havemin = 0;
870 	*r = Rect(0,0,0,0);
871 	if(!isdigit(*s))
872 		goto oops;
873 	i = strtol(s, &s, 0);
874 	if(*s == 'x'){
875 		s++;
876 		if(!isdigit(*s))
877 			goto oops;
878 		j = strtol(s, &s, 0);
879 		r->max.x = i;
880 		r->max.y = j;
881 		if(*s == 0)
882 			return 0;
883 		if(*s != '@')
884 			goto oops;
885 
886 		s++;
887 		if(!isdigit(*s))
888 			goto oops;
889 		i = strtol(s, &s, 0);
890 		if(*s != ',' && *s != ' ')
891 			goto oops;
892 		s++;
893 		if(!isdigit(*s))
894 			goto oops;
895 		j = strtol(s, &s, 0);
896 		if(*s != 0)
897 			goto oops;
898 		*r = rectaddpt(*r, Pt(i,j));
899 		*havemin = 1;
900 		return 0;
901 	}
902 
903 	c = *s;
904 	if(c != ' ' && c != ',')
905 		goto oops;
906 	s++;
907 	if(!isdigit(*s))
908 		goto oops;
909 	j = strtol(s, &s, 0);
910 	if(*s != c)
911 		goto oops;
912 	s++;
913 	if(!isdigit(*s))
914 		goto oops;
915 	k = strtol(s, &s, 0);
916 	if(*s != c)
917 		goto oops;
918 	s++;
919 	if(!isdigit(*s))
920 		goto oops;
921 	l = strtol(s, &s, 0);
922 	if(*s != 0)
923 		goto oops;
924 	*r = Rect(i,j,k,l);
925 	*havemin = 1;
926 	return 0;
927 
928 oops:
929 	werrstr("bad syntax in window size '%s'", os);
930 	return -1;
931 }