new draw server

1 files changed, 788 insertions, 0 deletions

diff --git a/src/cmd/devdraw/x11-init.c b/src/cmd/devdraw/x11-init.c
new file mode 100644
index 00000000..9820ea24
--- /dev/null
+++ b/src/cmd/devdraw/x11-init.c
@@ -0,0 +1,788 @@
+/*
+ * Some of the stuff in this file is not X-dependent and should be elsewhere.
+ */
+#include <u.h>
+#include "x11-inc.h"
+#include <libc.h>
+#include <draw.h>
+#include <memdraw.h>
+#include <keyboard.h>
+#include <mouse.h>
+#include <cursor.h>
+#include "x11-memdraw.h"
+
+static int parsewinsize(char*, Rectangle*, int*);
+
+static void	plan9cmap(void);
+static int	setupcmap(XWindow);
+static XGC	xgc(XDrawable, int, int);
+
+Xprivate _x;
+
+static int
+xerror(XDisplay *d, XErrorEvent *e)
+{
+	char buf[200];
+
+	if(e->request_code == 42) /* XSetInputFocus */
+		return 0;
+	if(e->request_code == 18) /* XChangeProperty */
+		return 0;
+
+	print("X error: error_code=%d, request_code=%d, minor=%d disp=%p\n",
+		e->error_code, e->request_code, e->minor_code, d);
+	XGetErrorText(d, e->error_code, buf, sizeof buf);
+	print("%s\n", buf);
+	return 0;
+}
+
+static int
+xioerror(XDisplay *d)
+{
+	/*print("X I/O error\n"); */
+	sysfatal("X I/O error\n");
+	abort();
+	return -1;
+}
+
+
+Memimage*
+_xattach(char *label, char *winsize)
+{
+	char *argv[2], *disp;
+	int i, havemin, height, mask, n, width, x, xrootid, y;
+	Rectangle r;
+	XClassHint classhint;
+	XDrawable pmid;
+	XPixmapFormatValues *pfmt;
+	XScreen *xscreen;
+	XSetWindowAttributes attr;
+	XSizeHints normalhint;
+	XTextProperty name;
+	XVisualInfo xvi;
+	XWindow xrootwin;
+	XWindowAttributes wattr;
+	XWMHints hint;
+	Atom atoms[2];
+
+	/*
+	if(XInitThreads() == 0){
+		fprint(2, "XInitThreads failed\n");
+		abort();
+	}
+	*/
+
+	/*
+	 * Connect to X server.
+	 */
+	_x.display = XOpenDisplay(NULL);
+	if(_x.display == nil){
+		disp = getenv("DISPLAY");
+		werrstr("XOpenDisplay %s: %r", disp ? disp : ":0");
+		free(disp);
+		return nil;
+	}
+	_x.fd = ConnectionNumber(_x.display);
+	XSetErrorHandler(xerror);
+	XSetIOErrorHandler(xioerror);
+	xrootid = DefaultScreen(_x.display);
+	xrootwin = DefaultRootWindow(_x.display);
+
+	/* 
+	 * Figure out underlying screen format.
+	 */
+	if(XMatchVisualInfo(_x.display, xrootid, 16, TrueColor, &xvi)
+	|| XMatchVisualInfo(_x.display, xrootid, 16, DirectColor, &xvi)){
+		_x.vis = xvi.visual;
+		_x.depth = 16;
+	}
+	else
+	if(XMatchVisualInfo(_x.display, xrootid, 15, TrueColor, &xvi)
+	|| XMatchVisualInfo(_x.display, xrootid, 15, DirectColor, &xvi)){
+		_x.vis = xvi.visual;
+		_x.depth = 15;
+	}
+	else
+	if(XMatchVisualInfo(_x.display, xrootid, 24, TrueColor, &xvi)
+	|| XMatchVisualInfo(_x.display, xrootid, 24, DirectColor, &xvi)){
+		_x.vis = xvi.visual;
+		_x.depth = 24;
+	}
+	else
+	if(XMatchVisualInfo(_x.display, xrootid, 8, PseudoColor, &xvi)
+	|| XMatchVisualInfo(_x.display, xrootid, 8, StaticColor, &xvi)){
+		if(_x.depth > 8){
+			werrstr("can't deal with colormapped depth %d screens",
+				_x.depth);
+			goto err0;
+		}
+		_x.vis = xvi.visual;
+		_x.depth = 8;
+	}
+	else{
+		_x.depth = DefaultDepth(_x.display, xrootid);
+		if(_x.depth != 8){
+			werrstr("can't understand depth %d screen", _x.depth);
+			goto err0;
+		}
+		_x.vis = DefaultVisual(_x.display, xrootid);
+	}
+
+	if(DefaultDepth(_x.display, xrootid) == _x.depth)
+		_x.usetable = 1;
+
+	/*
+	 * _x.depth is only the number of significant pixel bits,
+	 * not the total number of pixel bits.  We need to walk the
+	 * display list to find how many actual bits are used
+	 * per pixel.
+	 */
+	_x.chan = 0;
+	pfmt = XListPixmapFormats(_x.display, &n);
+	for(i=0; i<n; i++){
+		if(pfmt[i].depth == _x.depth){
+			switch(pfmt[i].bits_per_pixel){
+			case 1:	/* untested */
+				_x.chan = GREY1;
+				break;
+			case 2:	/* untested */
+				_x.chan = GREY2;
+				break;
+			case 4:	/* untested */
+				_x.chan = GREY4;
+				break;
+			case 8:
+				_x.chan = CMAP8;
+				break;
+			case 15:
+				_x.chan = RGB15;
+				break;
+			case 16: /* how to tell RGB15? */
+				_x.chan = RGB16;
+				break;
+			case 24: /* untested (impossible?) */
+				_x.chan = RGB24;
+				break;
+			case 32:
+				_x.chan = XRGB32;
+				break;
+			}
+		}
+	}
+	if(_x.chan == 0){
+		werrstr("could not determine screen pixel format");
+		goto err0;
+	}
+
+	/*
+	 * Set up color map if necessary.
+	 */
+	xscreen = DefaultScreenOfDisplay(_x.display);
+	_x.cmap = DefaultColormapOfScreen(xscreen);
+	if(_x.vis->class != StaticColor){
+		plan9cmap();
+		setupcmap(xrootwin);
+	}
+
+	/*
+	 * We get to choose the initial rectangle size.
+	 * This is arbitrary.  In theory we should read the
+	 * command line and allow the traditional X options.
+	 */
+	mask = 0;
+	x = 0;
+	y = 0;
+	if(winsize && winsize[0]){
+		if(parsewinsize(winsize, &r, &havemin) < 0)
+			sysfatal("%r");
+	}else{
+		/*
+		 * Parse the various X resources.  Thanks to Peter Canning.
+		 */
+		char *screen_resources, *display_resources, *geom, 
+			*geomrestype, *home, *file;
+		XrmDatabase database;
+		XrmValue geomres;
+
+		database = XrmGetDatabase(_x.display);
+		screen_resources = XScreenResourceString(xscreen);
+		if(screen_resources != nil){
+			XrmCombineDatabase(XrmGetStringDatabase(screen_resources), &database, False);
+			XFree(screen_resources);
+		}
+
+		display_resources = XResourceManagerString(_x.display);
+		if(display_resources == nil){
+			home = getenv("HOME");
+			if(home!=nil && (file=smprint("%s/.Xdefaults", home)) != nil){
+				XrmCombineFileDatabase(file, &database, False);
+				free(file);
+			}
+			free(home);
+		}else
+			XrmCombineDatabase(XrmGetStringDatabase(display_resources), &database, False);
+
+		geom = smprint("%s.geometry", label);
+		if(geom && XrmGetResource(database, geom, nil, &geomrestype, &geomres))
+			mask = XParseGeometry(geomres.addr, &x, &y, (uint*)&width, (uint*)&height);
+		free(geom);
+
+		if((mask & WidthValue) && (mask & HeightValue)){
+			r = Rect(0, 0, width, height);
+		}else{
+			r = Rect(0, 0, WidthOfScreen(xscreen)*3/4,
+					HeightOfScreen(xscreen)*3/4);
+			if(Dx(r) > Dy(r)*3/2)
+				r.max.x = r.min.x + Dy(r)*3/2;
+			if(Dy(r) > Dx(r)*3/2)
+				r.max.y = r.min.y + Dx(r)*3/2;
+		}
+		if(mask & XNegative){
+			x += WidthOfScreen(xscreen);
+		}
+		if(mask & YNegative){
+			y += HeightOfScreen(xscreen);
+		}
+		havemin = 0;
+	}
+
+	memset(&attr, 0, sizeof attr);
+	attr.colormap = _x.cmap;
+	attr.background_pixel = ~0;
+	attr.border_pixel = 0;
+	_x.drawable = XCreateWindow(
+		_x.display,	/* display */
+		xrootwin,	/* parent */
+		x,		/* x */
+		y,		/* y */
+		Dx(r),		/* width */
+	 	Dy(r),		/* height */
+		0,		/* border width */
+		_x.depth,	/* depth */
+		InputOutput,	/* class */
+		_x.vis,		/* visual */
+				/* valuemask */
+		CWBackPixel|CWBorderPixel|CWColormap,
+		&attr		/* attributes (the above aren't?!) */
+	);
+
+	/*
+	 * Label and other properties required by ICCCCM.
+	 */
+	memset(&name, 0, sizeof name);
+	if(label == nil)
+		label = "pjw-face-here";
+	name.value = (uchar*)label;
+	name.encoding = XA_STRING;
+	name.format = 8;
+	name.nitems = strlen((char*)name.value);
+
+	memset(&normalhint, 0, sizeof normalhint);
+	normalhint.flags = PSize|PMaxSize;
+	if(winsize && winsize[0]){
+		normalhint.flags &= ~PSize;
+		normalhint.flags |= USSize;
+		normalhint.width = Dx(r);
+		normalhint.height = Dy(r);
+	}else{
+		if((mask & WidthValue) && (mask & HeightValue)){
+			normalhint.flags &= ~PSize;
+			normalhint.flags |= USSize;
+			normalhint.width = width;
+			normalhint.height = height;
+		}
+		if((mask & WidthValue) && (mask & HeightValue)){
+			normalhint.flags |= USPosition;
+			normalhint.x = x;
+			normalhint.y = y;
+		}
+	}
+
+	normalhint.max_width = WidthOfScreen(xscreen);
+	normalhint.max_height = HeightOfScreen(xscreen);
+
+	memset(&hint, 0, sizeof hint);
+	hint.flags = InputHint|StateHint;
+	hint.input = 1;
+	hint.initial_state = NormalState;
+
+	memset(&classhint, 0, sizeof classhint);
+	classhint.res_name = label;
+	classhint.res_class = label;
+
+	argv[0] = label;
+	argv[1] = nil;
+
+	XSetWMProperties(
+		_x.display,	/* display */
+		_x.drawable,	/* window */
+		&name,		/* XA_WM_NAME property */
+		&name,		/* XA_WM_ICON_NAME property */
+		argv,		/* XA_WM_COMMAND */
+		1,		/* argc */
+		&normalhint,	/* XA_WM_NORMAL_HINTS */
+		&hint,		/* XA_WM_HINTS */
+		&classhint	/* XA_WM_CLASSHINTS */
+	);
+	XFlush(_x.display);
+
+	if(havemin){
+		XWindowChanges ch;
+
+		memset(&ch, 0, sizeof ch);
+		ch.x = r.min.x;
+		ch.y = r.min.y;
+		XConfigureWindow(_x.display, _x.drawable, CWX|CWY, &ch);
+		/*
+		 * Must pretend origin is 0,0 for X.
+		 */
+		r = Rect(0,0,Dx(r),Dy(r));
+	}
+	/*
+	 * Look up clipboard atom.
+	 */
+	_x.clipboard = XInternAtom(_x.display, "CLIPBOARD", False);
+	_x.utf8string = XInternAtom(_x.display, "UTF8_STRING", False);
+	_x.targets = XInternAtom(_x.display, "TARGETS", False);
+	_x.text = XInternAtom(_x.display, "TEXT", False);
+	_x.compoundtext = XInternAtom(_x.display, "COMPOUND_TEXT", False);
+	_x.takefocus = XInternAtom(_x.display, "WM_TAKE_FOCUS", False);
+	_x.losefocus = XInternAtom(_x.display, "_9WM_LOSE_FOCUS", False);
+	_x.wmprotos = XInternAtom(_x.display, "WM_PROTOCOLS", False);
+
+	atoms[0] = _x.takefocus;
+	atoms[1] = _x.losefocus;
+	XChangeProperty(_x.display, _x.drawable, _x.wmprotos, XA_ATOM, 32,
+		PropModeReplace, (uchar*)atoms, 2);
+
+	/*
+	 * Put the window on the screen, check to see what size we actually got.
+	 */
+	XMapWindow(_x.display, _x.drawable);
+	XSync(_x.display, False);
+
+	if(!XGetWindowAttributes(_x.display, _x.drawable, &wattr))
+		fprint(2, "XGetWindowAttributes failed\n");
+	else if(wattr.width && wattr.height){
+		if(wattr.width != Dx(r) || wattr.height != Dy(r)){
+			r.max.x = wattr.width;
+			r.max.y = wattr.height;
+		}
+	}else
+		fprint(2, "XGetWindowAttributes: bad attrs\n");
+
+	/*
+	 * Allocate our local backing store.
+	 */
+	_x.screenr = r;
+	_x.screenpm = XCreatePixmap(_x.display, _x.drawable, Dx(r), Dy(r), _x.depth);
+	_x.nextscreenpm = _x.screenpm;
+	_x.screenimage = _xallocmemimage(r, _x.chan, _x.screenpm);
+
+	/*
+	 * Allocate some useful graphics contexts for the future.
+	 */
+	_x.gcfill	= xgc(_x.screenpm, FillSolid, -1);
+	_x.gccopy	= xgc(_x.screenpm, -1, -1);
+	_x.gcsimplesrc 	= xgc(_x.screenpm, FillStippled, -1);
+	_x.gczero	= xgc(_x.screenpm, -1, -1);
+	_x.gcreplsrc	= xgc(_x.screenpm, FillTiled, -1);
+
+	pmid = XCreatePixmap(_x.display, _x.drawable, 1, 1, 1);
+	_x.gcfill0	= xgc(pmid, FillSolid, 0);
+	_x.gccopy0	= xgc(pmid, -1, -1);
+	_x.gcsimplesrc0	= xgc(pmid, FillStippled, -1);
+	_x.gczero0	= xgc(pmid, -1, -1);
+	_x.gcreplsrc0	= xgc(pmid, FillTiled, -1);
+	XFreePixmap(_x.display, pmid);
+
+	return _x.screenimage;
+
+err0:
+	/*
+	 * Should do a better job of cleaning up here.
+	 */
+	XCloseDisplay(_x.display);
+	return nil;
+}
+
+int
+_xsetlabel(char *label)
+{
+	XTextProperty name;
+
+	/*
+	 * Label and other properties required by ICCCCM.
+	 */
+	memset(&name, 0, sizeof name);
+	if(label == nil)
+		label = "pjw-face-here";
+	name.value = (uchar*)label;
+	name.encoding = XA_STRING;
+	name.format = 8;
+	name.nitems = strlen((char*)name.value);
+
+	XSetWMProperties(
+		_x.display,	/* display */
+		_x.drawable,	/* window */
+		&name,		/* XA_WM_NAME property */
+		&name,		/* XA_WM_ICON_NAME property */
+		nil,		/* XA_WM_COMMAND */
+		0,		/* argc */
+		nil,		/* XA_WM_NORMAL_HINTS */
+		nil,		/* XA_WM_HINTS */
+		nil	/* XA_WM_CLASSHINTS */
+	);
+	XFlush(_x.display);
+	return 0;
+}
+
+/*
+ * Create a GC with a particular fill style and XXX.
+ * Disable generation of GraphicsExpose/NoExpose events in the GC.
+ */
+static XGC
+xgc(XDrawable d, int fillstyle, int foreground)
+{
+	XGC gc;
+	XGCValues v;
+
+	memset(&v, 0, sizeof v);
+	v.function = GXcopy;
+	v.graphics_exposures = False;
+	gc = XCreateGC(_x.display, d, GCFunction|GCGraphicsExposures, &v);
+	if(fillstyle != -1)
+		XSetFillStyle(_x.display, gc, fillstyle);
+	if(foreground != -1)
+		XSetForeground(_x.display, gc, 0);
+	return gc;
+}
+
+
+/*
+ * Initialize map with the Plan 9 rgbv color map.
+ */
+static void
+plan9cmap(void)
+{
+	int r, g, b, cr, cg, cb, v, num, den, idx, v7, idx7;
+	static int once;
+
+	if(once)
+		return;
+	once = 1;
+
+	for(r=0; r!=4; r++)
+	for(g = 0; g != 4; g++)
+	for(b = 0; b!=4; b++)
+	for(v = 0; v!=4; v++){
+		den=r;
+		if(g > den)
+			den=g;
+		if(b > den)
+			den=b;
+		/* divide check -- pick grey shades */
+		if(den==0)
+			cr=cg=cb=v*17;
+		else {
+			num=17*(4*den+v);
+			cr=r*num/den;
+			cg=g*num/den;
+			cb=b*num/den;
+		}
+		idx = r*64 + v*16 + ((g*4 + b + v - r) & 15);
+		_x.map[idx].red = cr*0x0101;
+		_x.map[idx].green = cg*0x0101;
+		_x.map[idx].blue = cb*0x0101;
+		_x.map[idx].pixel = idx;
+		_x.map[idx].flags = DoRed|DoGreen|DoBlue;
+
+		v7 = v >> 1;
+		idx7 = r*32 + v7*16 + g*4 + b;
+		if((v & 1) == v7){
+			_x.map7to8[idx7][0] = idx;
+			if(den == 0) { 		/* divide check -- pick grey shades */
+				cr = ((255.0/7.0)*v7)+0.5;
+				cg = cr;
+				cb = cr;
+			}
+			else {
+				num=17*15*(4*den+v7*2)/14;
+				cr=r*num/den;
+				cg=g*num/den;
+				cb=b*num/den;
+			}
+			_x.map7[idx7].red = cr*0x0101;
+			_x.map7[idx7].green = cg*0x0101;
+			_x.map7[idx7].blue = cb*0x0101;
+			_x.map7[idx7].pixel = idx7;
+			_x.map7[idx7].flags = DoRed|DoGreen|DoBlue;
+		}
+		else
+			_x.map7to8[idx7][1] = idx;
+	}
+}
+
+/*
+ * Initialize and install the rgbv color map as a private color map
+ * for this application.  It gets the best colors when it has the
+ * cursor focus.
+ *
+ * We always choose the best depth possible, but that might not
+ * be the default depth.  On such "suboptimal" systems, we have to allocate an
+ * empty color map anyway, according to Axel Belinfante.
+ */
+static int 
+setupcmap(XWindow w)
+{
+	char buf[30];
+	int i;
+	u32int p, pp;
+	XColor c;
+
+	if(_x.depth <= 1)
+		return 0;
+
+	if(_x.depth >= 24) {
+		if(_x.usetable == 0)
+			_x.cmap = XCreateColormap(_x.display, w, _x.vis, AllocNone); 
+
+		/*
+		 * The pixel value returned from XGetPixel needs to
+		 * be converted to RGB so we can call rgb2cmap()
+		 * to translate between 24 bit X and our color. Unfortunately,
+		 * the return value appears to be display server endian 
+		 * dependant. Therefore, we run some heuristics to later
+		 * determine how to mask the int value correctly.
+		 * Yeah, I know we can look at _x.vis->byte_order but 
+		 * some displays say MSB even though they run on LSB.
+		 * Besides, this is more anal.
+		 */
+		c = _x.map[19];	/* known to have different R, G, B values */
+		if(!XAllocColor(_x.display, _x.cmap, &c)){
+			werrstr("XAllocColor: %r");
+			return -1;
+		}
+		p  = c.pixel;
+		pp = rgb2cmap((p>>16)&0xff,(p>>8)&0xff,p&0xff);
+		if(pp != _x.map[19].pixel) {
+			/* check if endian is other way */
+			pp = rgb2cmap(p&0xff,(p>>8)&0xff,(p>>16)&0xff);
+			if(pp != _x.map[19].pixel){
+				werrstr("cannot detect X server byte order");
+				return -1;
+			}
+
+			switch(_x.chan){
+			case RGB24:
+				_x.chan = BGR24;
+				break;
+			case XRGB32:
+				_x.chan = XBGR32;
+				break;
+			default:
+				werrstr("cannot byteswap channel %s",
+					chantostr(buf, _x.chan));
+				break;
+			}
+		}
+	}else if(_x.vis->class == TrueColor || _x.vis->class == DirectColor){
+		/*
+		 * Do nothing.  We have no way to express a
+		 * mixed-endian 16-bit screen, so pretend they don't exist.
+		 */
+		if(_x.usetable == 0)
+			_x.cmap = XCreateColormap(_x.display, w, _x.vis, AllocNone);
+	}else if(_x.vis->class == PseudoColor){
+		if(_x.usetable == 0){
+			_x.cmap = XCreateColormap(_x.display, w, _x.vis, AllocAll); 
+			XStoreColors(_x.display, _x.cmap, _x.map, 256);
+			for(i = 0; i < 256; i++){
+				_x.tox11[i] = i;
+				_x.toplan9[i] = i;
+			}
+		}else{
+			for(i = 0; i < 128; i++){
+				c = _x.map7[i];
+				if(!XAllocColor(_x.display, _x.cmap, &c)){
+					werrstr("can't allocate colors in 7-bit map");
+					return -1;
+				}
+				_x.tox11[_x.map7to8[i][0]] = c.pixel;
+				_x.tox11[_x.map7to8[i][1]] = c.pixel;
+				_x.toplan9[c.pixel] = _x.map7to8[i][0];
+			}
+		}
+	}else{
+		werrstr("unsupported visual class %d", _x.vis->class);
+		return -1;
+	}
+	return 0;
+}
+
+void
+_flushmemscreen(Rectangle r)
+{
+	if(_x.nextscreenpm != _x.screenpm){
+		qlock(&_x.screenlock);
+		XSync(_x.display, False);
+		XFreePixmap(_x.display, _x.screenpm);
+		_x.screenpm = _x.nextscreenpm;
+		qunlock(&_x.screenlock);
+	}
+
+	if(r.min.x >= r.max.x || r.min.y >= r.max.y)
+		return;
+	XCopyArea(_x.display, _x.screenpm, _x.drawable, _x.gccopy, r.min.x, r.min.y,
+		Dx(r), Dy(r), r.min.x, r.min.y);
+	XFlush(_x.display);
+}
+
+void
+_xexpose(XEvent *e)
+{
+	XExposeEvent *xe;
+	Rectangle r;
+
+	qlock(&_x.screenlock);
+	if(_x.screenpm != _x.nextscreenpm){
+		qunlock(&_x.screenlock);
+		return;
+	}
+	xe = (XExposeEvent*)e;
+	r.min.x = xe->x;
+	r.min.y = xe->y;
+	r.max.x = xe->x+xe->width;
+	r.max.y = xe->y+xe->height;
+	XCopyArea(_x.display, _x.screenpm, _x.drawable, _x.gccopy, r.min.x, r.min.y,
+		Dx(r), Dy(r), r.min.x, r.min.y);
+	XSync(_x.display, False);
+	qunlock(&_x.screenlock);
+}
+
+int
+_xdestroy(XEvent *e)
+{
+	XDestroyWindowEvent *xe;
+
+	xe = (XDestroyWindowEvent*)e;
+	if(xe->window == _x.drawable){
+		_x.destroyed = 1;
+		return 1;
+	}
+	return 0;
+}
+
+int
+_xconfigure(XEvent *e)
+{
+	Rectangle r;
+	XConfigureEvent *xe = (XConfigureEvent*)e;
+
+	if(xe->width == Dx(_x.screenr) && xe->height == Dy(_x.screenr))
+		return 0;
+	if(xe->width==0 || xe->height==0)
+		fprint(2, "ignoring resize to %dx%d\n", xe->width, xe->height);
+	r = Rect(0, 0, xe->width, xe->height);
+	qlock(&_x.screenlock);
+	if(_x.screenpm != _x.nextscreenpm){
+		XCopyArea(_x.display, _x.screenpm, _x.drawable, _x.gccopy, r.min.x, r.min.y,
+			Dx(r), Dy(r), r.min.x, r.min.y);
+		XSync(_x.display, False);
+	}
+	qunlock(&_x.screenlock);
+	_x.newscreenr = r;
+	return 1;
+}
+
+int
+_xreplacescreenimage(void)
+{
+	Memimage *m;
+	XDrawable pixmap;
+	Rectangle r;
+
+	r = _x.newscreenr;
+	if(eqrect(_x.screenr, r))
+		return 0;
+
+	pixmap = XCreatePixmap(_x.display, _x.drawable, Dx(r), Dy(r), _x.depth);
+	m = _xallocmemimage(r, _x.chan, pixmap);
+	if(_x.nextscreenpm != _x.screenpm)
+		XFreePixmap(_x.display, _x.nextscreenpm);
+	_x.nextscreenpm = pixmap;
+	_x.screenr = r;
+	_drawreplacescreenimage(m);
+	return 1;
+}
+
+static int
+parsewinsize(char *s, Rectangle *r, int *havemin)
+{
+	char c, *os;
+	int i, j, k, l;
+
+	os = s;
+	*havemin = 0;
+	*r = Rect(0,0,0,0);
+	if(!isdigit((uchar)*s))
+		goto oops;
+	i = strtol(s, &s, 0);
+	if(*s == 'x'){
+		s++;
+		if(!isdigit((uchar)*s))
+			goto oops;
+		j = strtol(s, &s, 0);
+		r->max.x = i;
+		r->max.y = j;
+		if(*s == 0)
+			return 0;
+		if(*s != '@')
+			goto oops;
+
+		s++;
+		if(!isdigit((uchar)*s))
+			goto oops;
+		i = strtol(s, &s, 0);
+		if(*s != ',' && *s != ' ')
+			goto oops;
+		s++;
+		if(!isdigit((uchar)*s))
+			goto oops;
+		j = strtol(s, &s, 0);
+		if(*s != 0)
+			goto oops;
+		*r = rectaddpt(*r, Pt(i,j));
+		*havemin = 1;
+		return 0;
+	}
+
+	c = *s;
+	if(c != ' ' && c != ',')
+		goto oops;
+	s++;
+	if(!isdigit((uchar)*s))
+		goto oops;
+	j = strtol(s, &s, 0);
+	if(*s != c)
+		goto oops;
+	s++;
+	if(!isdigit((uchar)*s))
+		goto oops;
+	k = strtol(s, &s, 0);
+	if(*s != c)
+		goto oops;
+	s++;
+	if(!isdigit((uchar)*s))
+		goto oops;
+	l = strtol(s, &s, 0);
+	if(*s != 0)
+		goto oops;
+	*r = Rect(i,j,k,l);
+	*havemin = 1;
+	return 0;
+
+oops:
+	werrstr("bad syntax in window size '%s'", os);
+	return -1;
+}