#include <u.h>#include <libc.h>#include <libg.h>#include <layer.h> 	/*	 * string	 *	 *	'u'		1	 *	id		2	 *	pt		8	 *	font id		2	 *	code		2	 *	n		2	 * 	cache indexes	2*n (not null terminated)	 */ void_lcstring(int id, uchar *s, int nindex){	uchar *p;	int n; 	n = 17+2*nindex;	p = bneed(n);	memcpy(p, s, n);	BPSHORT(p+1, id);} /* * db is known to be a layer; deal with bitmap clipping in the * /dev/bitblt message to draw the string */voidlcstring(Bitmap *db, int height, int nwidth, uchar *width, uchar *s, int nindex){	Layer *dl, *cover;	Rectangle r, rc;	int wid;	int i, j, fits;	Point pt; 	dl = (Layer*)db;	if(dl->cache == 0){    Easy:		_lcstring(db->id, s, nindex);		return;	}	wid = 0;	for(i=0; i<nindex; i++){		j = BGSHORT(s+17+2*i);		if(j<0 || j>=nwidth)			continue;		wid += width[j];	}	pt.x = BGLONG(s+3);	pt.y = BGLONG(s+7);	r.min = pt;	r.max.x = r.min.x+wid;	r.max.y = r.min.y+height;	fits = rectinrect(r, dl->clipr);	if(fits && dl->vis==Visible)		/*		 * Look for a Bitmap we can write on instead of a Layer.		 * r is known to fit within dl->clipr.  As long as we have		 * only Visible covering layers, we know that r will		 * therefore fit within their cliprs and no more clipping		 * is required.		 */		for(cover=dl->cover->layer; ; cover=cover->cover->layer){			if(cover->cache == 0){				db = cover;				goto Easy;			}			if(cover->vis != Visible)				break;		}	/*	 * Either dl or one of the covering layers is not Visible.	 * Do the operation in the cache and restore as necessary.	 * If dl is Visible, r is contained within cover->clipr and	 * the cache must be restored from the cover; otherwise the	 * cache is up to date but the restoration of the screen may	 * require clipping.	 */	if(!fits && !rectclip(&r, dl->clipr))		return;	/* r is now bbox of the portion of dl that will be modified */	cover = dl->cover->layer;	if(dl->vis == Visible)		bitblt(dl->cache, r.min, cover, r, S);	if(!fits){		rc = dl->cache->clipr;		clipr(dl->cache, r);	}	_lcstring(dl->cache->id, s, nindex);	if(!fits)		clipr(dl->cache, rc);	if(dl->vis == Visible)		bitblt(cover, r.min, dl->cache, r, S);	else if(dl->vis==Obscured)		layerop(lupdate, r, dl, (void *)0);}