devdraw.c

在x86平台上运行不可信任代码的sandbox。

			scrnid = BGSHORT(a+5);
			refresh = a[9];
			chan = BGLONG(a+10);
			repl = a[14];
			drawrectangle(&r, a+15);
			drawrectangle(&clipr, a+31);
			value = BGLONG(a+47);
			if(drawlookup(client, dstid, 0))
				error(Eimageexists);
			if(scrnid){
				dscrn = drawlookupscreen(client, scrnid, &cs);
				scrn = dscrn->screen;
				if(repl || chan!=scrn->image->chan)
					error("image parameters incompatible with screen");
				reffn = nil;
				switch(refresh){
				case Refbackup:
					break;
				case Refnone:
					reffn = memlnorefresh;
					break;
				case Refmesg:
					reffn = drawrefresh;
					break;
				default:
					error("unknown refresh method");
				}
				l = memlalloc(scrn, r, reffn, 0, value);
				if(l == 0)
					error(Edrawmem);
				addflush(l->layer->screenr);
				l->clipr = clipr;
				rectclip(&l->clipr, r);
				if(drawinstall(client, dstid, l, dscrn) == 0){
					memldelete(l);
					error(Edrawmem);
				}
				dscrn->ref++;
				if(reffn){
					refx = nil;
					if(reffn == drawrefresh){
						refx = malloc(sizeof(Refx));
						if(refx == 0){
							drawuninstall(client, dstid);
							error(Edrawmem);
						}
						refx->client = client;
						refx->dimage = drawlookup(client, dstid, 1);
					}
					memlsetrefresh(l, reffn, refx);
				}
				continue;
			}
			i = allocmemimage(r, chan);
			if(i == 0)
				error(Edrawmem);
			if(repl)
				i->flags |= Frepl;
			i->clipr = clipr;
			if(!repl)
				rectclip(&i->clipr, r);
			if(drawinstall(client, dstid, i, 0) == 0){
				freememimage(i);
				error(Edrawmem);
			}
			memfillcolor(i, value);
			continue;

		/* allocate screen: 'A' id[4] imageid[4] fillid[4] public[1] */
		case 'A':
			printmesg(fmt="LLLb", a, 1);
			m = 1+4+4+4+1;
			if(n < m)
				error(Eshortdraw);
			dstid = BGLONG(a+1);
			if(dstid == 0)
				error(Ebadarg);
			if(drawlookupdscreen(dstid))
				error(Escreenexists);
			ddst = drawlookup(client, BGLONG(a+5), 1);
			dsrc = drawlookup(client, BGLONG(a+9), 1);
			if(ddst==0 || dsrc==0)
				error(Enodrawimage);
			if(drawinstallscreen(client, 0, dstid, ddst, dsrc, a[13]) == 0)
				error(Edrawmem);
			continue;

		/* set repl and clip: 'c' dstid[4] repl[1] clipR[4*4] */
		case 'c':
			printmesg(fmt="LbR", a, 0);
			m = 1+4+1+4*4;
			if(n < m)
				error(Eshortdraw);
			ddst = drawlookup(client, BGLONG(a+1), 1);
			if(ddst == nil)
				error(Enodrawimage);
			if(ddst->name)
				error("cannot change repl/clipr of shared image");
			dst = ddst->image;
			if(a[5])
				dst->flags |= Frepl;
			drawrectangle(&dst->clipr, a+6);
			continue;

		/* draw: 'd' dstid[4] srcid[4] maskid[4] R[4*4] P[2*4] P[2*4] */
		case 'd':
			printmesg(fmt="LLLRPP", a, 0);
			m = 1+4+4+4+4*4+2*4+2*4;
			if(n < m)
				error(Eshortdraw);
			dst = drawimage(client, a+1);
			dstid = BGLONG(a+1);
			src = drawimage(client, a+5);
			mask = drawimage(client, a+9);
			drawrectangle(&r, a+13);
			drawpoint(&p, a+29);
			drawpoint(&q, a+37);
			op = drawclientop(client);
			memdraw(dst, r, src, p, mask, q, op);
			dstflush(dstid, dst, r);
			continue;

		/* toggle debugging: 'D' val[1] */
		case 'D':
			printmesg(fmt="b", a, 0);
			m = 1+1;
			if(n < m)
				error(Eshortdraw);
			drawdebug = a[1];
			continue;

		/* ellipse: 'e' dstid[4] srcid[4] center[2*4] a[4] b[4] thick[4] sp[2*4] alpha[4] phi[4]*/
		case 'e':
		case 'E':
			printmesg(fmt="LLPlllPll", a, 0);
			m = 1+4+4+2*4+4+4+4+2*4+2*4;
			if(n < m)
				error(Eshortdraw);
			dst = drawimage(client, a+1);
			dstid = BGLONG(a+1);
			src = drawimage(client, a+5);
			drawpoint(&p, a+9);
			e0 = BGLONG(a+17);
			e1 = BGLONG(a+21);
			if(e0<0 || e1<0)
				error("invalid ellipse semidiameter");
			j = BGLONG(a+25);
			if(j < 0)
				error("negative ellipse thickness");
			drawpoint(&sp, a+29);
			c = j;
			if(*a == 'E')
				c = -1;
			ox = BGLONG(a+37);
			oy = BGLONG(a+41);
			op = drawclientop(client);
			/* high bit indicates arc angles are present */
			if(ox & (1<<31)){
				if((ox & (1<<30)) == 0)
					ox &= ~(1<<31);
				memarc(dst, p, e0, e1, c, src, sp, ox, oy, op);
			}else
				memellipse(dst, p, e0, e1, c, src, sp, op);
			dstflush(dstid, dst, Rect(p.x-e0-j, p.y-e1-j, p.x+e0+j+1, p.y+e1+j+1));
			continue;

		/* free: 'f' id[4] */
		case 'f':
			printmesg(fmt="L", a, 1);
			m = 1+4;
			if(n < m)
				error(Eshortdraw);
			ll = drawlookup(client, BGLONG(a+1), 0);
			if(ll && ll->dscreen && ll->dscreen->owner != client)
				ll->dscreen->owner->refreshme = 1;
			drawuninstall(client, BGLONG(a+1));
			continue;

		/* free screen: 'F' id[4] */
		case 'F':
			printmesg(fmt="L", a, 1);
			m = 1+4;
			if(n < m)
				error(Eshortdraw);
			drawlookupscreen(client, BGLONG(a+1), &cs);
			drawuninstallscreen(client, cs);
			continue;

		/* initialize font: 'i' fontid[4] nchars[4] ascent[1] */
		case 'i':
			printmesg(fmt="Llb", a, 1);
			m = 1+4+4+1;
			if(n < m)
				error(Eshortdraw);
			dstid = BGLONG(a+1);
			if(dstid == 0)
				error("cannot use display as font");
			font = drawlookup(client, dstid, 1);
			if(font == 0)
				error(Enodrawimage);
			if(font->image->layer)
				error("cannot use window as font");
			ni = BGLONG(a+5);
			if(ni<=0 || ni>4096)
				error("bad font size (4096 chars max)");
			free(font->fchar);	/* should we complain if non-zero? */
			font->fchar = malloc(ni*sizeof(FChar));
			if(font->fchar == 0)
				error("no memory for font");
			memset(font->fchar, 0, ni*sizeof(FChar));
			font->nfchar = ni;
			font->ascent = a[9];
			continue;

		/* load character: 'l' fontid[4] srcid[4] index[2] R[4*4] P[2*4] left[1] width[1] */
		case 'l':
			printmesg(fmt="LLSRPbb", a, 0);
			m = 1+4+4+2+4*4+2*4+1+1;
			if(n < m)
				error(Eshortdraw);
			font = drawlookup(client, BGLONG(a+1), 1);
			if(font == 0)
				error(Enodrawimage);
			if(font->nfchar == 0)
				error(Enotfont);
			src = drawimage(client, a+5);
			ci = BGSHORT(a+9);
			if(ci >= font->nfchar)
				error(Eindex);
			drawrectangle(&r, a+11);
			drawpoint(&p, a+27);
			memdraw(font->image, r, src, p, memopaque, p, S);
			fc = &font->fchar[ci];
			fc->minx = r.min.x;
			fc->maxx = r.max.x;
			fc->miny = r.min.y;
			fc->maxy = r.max.y;
			fc->left = a[35];
			fc->width = a[36];
			continue;

		/* draw line: 'L' dstid[4] p0[2*4] p1[2*4] end0[4] end1[4] radius[4] srcid[4] sp[2*4] */
		case 'L':
			printmesg(fmt="LPPlllLP", a, 0);
			m = 1+4+2*4+2*4+4+4+4+4+2*4;
			if(n < m)
				error(Eshortdraw);
			dst = drawimage(client, a+1);
			dstid = BGLONG(a+1);
			drawpoint(&p, a+5);
			drawpoint(&q, a+13);
			e0 = BGLONG(a+21);
			e1 = BGLONG(a+25);
			j = BGLONG(a+29);
			if(j < 0)
				error("negative line width");
			src = drawimage(client, a+33);
			drawpoint(&sp, a+37);
			op = drawclientop(client);
			memline(dst, p, q, e0, e1, j, src, sp, op);
			/* avoid memlinebbox if possible */
			if(dstid==0 || dst->layer!=nil){
				/* BUG: this is terribly inefficient: update maximal containing rect*/
				r = memlinebbox(p, q, e0, e1, j);
				dstflush(dstid, dst, insetrect(r, -(1+1+j)));
			}
			continue;

		/* create image mask: 'm' newid[4] id[4] */
/*
 *
		case 'm':
			printmesg("LL", a, 0);
			m = 4+4;
			if(n < m)
				error(Eshortdraw);
			break;
 *
 */

		/* attach to a named image: 'n' dstid[4] j[1] name[j] */
		case 'n':
			printmesg(fmt="Lz", a, 0);
			m = 1+4+1;
			if(n < m)
				error(Eshortdraw);
			j = a[5];
			if(j == 0)	/* give me a non-empty name please */
				error(Eshortdraw);
			m += j;
			if(n < m)
				error(Eshortdraw);
			dstid = BGLONG(a+1);
			if(drawlookup(client, dstid, 0))
				error(Eimageexists);
			dn = drawlookupname(j, (char*)a+6);
			if(dn == nil)
				error(Enoname);
			if(drawinstall(client, dstid, dn->dimage->image, 0) == 0)
				error(Edrawmem);
			di = drawlookup(client, dstid, 0);
			if(di == 0)
				error("draw: cannot happen");
			di->vers = dn->vers;
			di->name = smalloc(j+1);
			di->fromname = dn->dimage;
			di->fromname->ref++;
			memmove(di->name, a+6, j);
			di->name[j] = 0;
			client->infoid = dstid;
			continue;

		/* name an image: 'N' dstid[4] in[1] j[1] name[j] */
		case 'N':
			printmesg(fmt="Lbz", a, 0);
			m = 1+4+1+1;
			if(n < m)
				error(Eshortdraw);
			c = a[5];
			j = a[6];
			if(j == 0)	/* give me a non-empty name please */
				error(Eshortdraw);
			m += j;
			if(n < m)
				error(Eshortdraw);
			di = drawlookup(client, BGLONG(a+1), 0);
			if(di == 0)
				error(Enodrawimage);
			if(di->name)
				error(Enamed);
			if(c)
				drawaddname(client, di, j, (char*)a+7);
			else{
				dn = drawlookupname(j, (char*)a+7);
				if(dn == nil)
					error(Enoname);
				if(dn->dimage != di)
					error(Ewrongname);
				drawdelname(dn);
			}
			continue;

		/* position window: 'o' id[4] r.min [2*4] screenr.min [2*4] */
		case 'o':
			printmesg(fmt="LPP", a, 0);
			m = 1+4+2*4+2*4;
			if(n < m)
				error(Eshortdraw);
			dst = drawimage(client, a+1);
			if(dst->layer){
				drawpoint(&p, a+5);
				drawpoint(&q, a+13);
				r = dst->layer->screenr;
				ni = memlorigin(dst, p, q);
				if(ni < 0)
					error("image origin failed");
				if(ni > 0){
					addflush(r);
					addflush(dst->layer->screenr);
					ll = drawlookup(client, BGLONG(a+1), 1);
					drawrefreshscreen(ll, client);
				}
			}
			continue;

		/* set compositing operator for next draw operation: 'O' op */
		case 'O':
			printmesg(fmt="b", a, 0);
			m = 1+1;
			if(n < m)
				error(Eshortdraw);
			client->op = a[1];
			continue;

		/* filled polygon: 'P' dstid[4] n[2] wind[4] ignore[2*4] srcid[4] sp[2*4] p0[2*4] dp[2*2*n] */
		/* polygon: 'p' dstid[4] n[2] end0[4] end1[4] radius[4] srcid[4] sp[2*4] p0[2*4] dp[2*2*n] */
		case 'p':
		case 'P':
			printmesg(fmt="LslllLPP", a, 0);
			m = 1+4+2+4+4+4+4+2*4;
			if(n < m)
				error(Eshortdraw);
			dstid = BGLONG(a+1);
			dst = drawimage(client, a+1);
			ni = BGSHORT(a+5);
			if(ni < 0)
				error("negative count in polygon");
			e0 = BGLONG(a+7);
			e1 = BGLONG(a+11);
			j = 0;
			if(*a == 'p'){
				j = BGLONG(a+15);
				if(j < 0)
					error("negative polygon line width");
			}
			src = drawimage(client, a+19);
			drawpoint(&sp, a+23);
			drawpoint(&p, a+31);
			ni++;
			pp = malloc(ni*sizeof(Point));
			if(pp == nil)
				error(Enomem);
			doflush = 0;
			if(dstid==0 || (dst->layer && dst->layer->screen->image->data == screenimage->data))
				doflush = 1;	/* simplify test in loop */
			ox = oy = 0;
			esize = 0;
			u = a+m;
			for(y=0; y<ni; y++){
				q = p;
				oesize = esize;
				u = drawcoord(u, a+n, ox, &p.x);
				u = drawcoord(u, a+n, oy, &p.y);
				ox = p.x;
				oy = p.y;
				if(doflush){
					esize = j;
					if(*a == 'p'){
						if(y == 0){
							c = memlineendsize(e0);
							if(c > esize)
								esize = c;
						}
						if(y == ni-1){
							c = memlineendsize(e1);
							if(c > esize)
								esize = c;
						}
					}
					if(*a=='P' && e0!=1 && e0 !=~0)
						r = dst->clipr;
					else if(y > 0){
						r = Rect(q.x-oesize, q.y-oesize, q.x+oesize+1, q.y+oesize+1);
						combinerect(&r, Rect(p.x-esize, p.y-esize, p.x+esize+1, p.y+esize+1));
					}
					if(rectclip(&r, dst->clipr))		/* should perhaps be an arg to dstflush */
						dstflush(dstid, dst, r);
				}
				pp[y] = p;
			}
			if(y == 1)
				dstflush(dstid, dst, Rect(p.x-esize, p.y-esize, p.x+esize+1, p.y+esize+1));
			op = drawclientop(client);
			if(*a == 'p')
				mempoly(dst, pp, ni, e0, e1, j, src, sp, op);
			else
				memfillpoly(dst, pp, ni, e0, src, sp, op);
			free(pp);
			m = u-a;
			continue;

		/* read: 'r' id[4] R[4*4] */
		case 'r':
			printmesg(fmt="LR", a, 0);
			m = 1+4+4*4;
			if(n < m)
				error(Eshortdraw);
			i = drawimage(client, a+1);
			drawrectangle(&r, a+5);
			if(!rectinrect(r, i->r))
				error(Ereadoutside);
			c = bytesperline(r, i->depth);
			c *= Dy(r);
			free(client->readdata);
			client->readdata = mallocz(c, 0);
			if(client->readdata == nil)
				error("readimage malloc failed");
			client->nreaddata = memunload(i, r, client->readdata, c);
			if(client->nreaddata < 0){
				free(client->readdata);
				client->readdata = nil;
				error("bad readimage call");
			}
			continue;

		/* string: 's' dstid[4] srcid[4] fontid[4] P[2*4] clipr[4*4] sp[2*4] ni[2] ni*(index[2]) */
		/* stringbg: 'x' dstid[4] srcid[4] fontid[4] P[2*4] clipr[4*4] sp[2*4] ni[2] bgid[4] bgpt[2*4] ni*(index[2]) */
		case 's':
		case 'x':
			printmesg(fmt="LLLPRPs", a, 0);
			m = 1+4+4+4+2*4+4*4+2*4+2;
			if(*a == 'x')
				m += 4+2*4;
			if(n < m)
				error(Eshortdraw);

			dst = drawimage(client, a+1);
			dstid = BGLONG(a+1);
			src = drawimage(client, a+5);
			font = drawlookup(client, BGLONG(a+9), 1);
			if(font == 0)
				error(Enodrawimage);
			if(font->nfchar == 0)
				error(Enotfont);
			drawpoint(&p, a+13);
			drawrectangle(&r, a+21);
			drawpoint(&sp, a+37);
			ni = BGSHORT(a+45);
			u = a+m;
			m += ni*2;
			if(n < m)
				error(Eshortdraw);
			clipr = dst->clipr;
			dst->clipr = r;
			op = drawclientop(client);
			bg = dst;
			if(*a == 'x'){
				/* paint background */
				bg = drawimage(client, a+47);
				drawpoint(&q, a+51);
				r.min.x = p.x;
				r.min.y = p.y-font->ascent;
				r.max.x = p.x;
				r.max.y = r.min.y+Dy(font->image->r);
				j = ni;
				while(--j >= 0){
					ci = BGSHORT(u);
					if(ci<0 || ci>=font->nfchar){
						dst->clipr = clipr;
						error(Eindex);
					}
					r.max.x += font->fchar[ci].width;
					u += 2;
				}
				memdraw(dst, r, bg, q, memopaque, ZP, op);
				u -= 2*ni;
			}
			q = p;
			while(--ni >= 0){
				ci = BGSHORT(u);
				if(ci<0 || ci>=font->nfchar){
					dst->clipr = clipr;
					error(Eindex);
				}
				q = drawchar(dst, bg, q, src, &sp, font, ci, op);
				u += 2;
			}
			dst->clipr = clipr;
			p.y -= font->ascent;
			dstflush(dstid, dst, Rect(p.x, p.y, q.x, p.y+Dy(font->image->r)));
			continue;

		/* use public screen: 'S' id[4] chan[4] */
		case 'S':
			printmesg(fmt="Ll", a, 0);
			m = 1+4+4;
			if(n < m)
				error(Eshortdraw);
			dstid = BGLONG(a+1);
			if(dstid == 0)
				error(Ebadarg);
			dscrn = drawlookupdscreen(dstid);
			if(dscrn==0 || (dscrn->public==0 && dscrn->owner!=client))
				error(Enodrawscreen);
			if(dscrn->screen->image->chan != BGLONG(a+5))
				error("inconsistent chan");
			if(drawinstallscreen(client, dscrn, 0, 0, 0, 0) == 0)
				error(Edrawmem);
			continue;

		/* top or bottom windows: 't' top[1] nw[2] n*id[4] */
		case 't':
			printmesg(fmt="bsL", a, 0);
			m = 1+1+2;
			if(n < m)
				error(Eshortdraw);
			nw = BGSHORT(a+2);
			if(nw < 0)
				error(Ebadarg);
			if(nw == 0)
				continue;
			m += nw*4;
			if(n < m)
				error(Eshortdraw);
			lp = malloc(nw*sizeof(Memimage*));
			if(lp == 0)
				error(Enomem);
			if(waserror()){
				free(lp);
				nexterror();
			}
			for(j=0; j<nw; j++)
				lp[j] = drawimage(client, a+1+1+2+j*4);
			if(lp[0]->layer == 0)
				error("images are not windows");
			for(j=1; j<nw; j++)
				if(lp[j]->layer->screen != lp[0]->layer->screen)
					error("images not on same screen");
			if(a[1])
				memltofrontn(lp, nw);
			else
				memltorearn(lp, nw);
			if(lp[0]->layer->screen->image->data == screenimage->data)
				for(j=0; j<nw; j++)
					addflush(lp[j]->layer->screenr);
			ll = drawlookup(client, BGLONG(a+1+1+2), 1);
			drawrefreshscreen(ll, client);
			poperror();
			free(lp);
			continue;

		/* visible: 'v' */
		case 'v':
			printmesg(fmt="", a, 0);
			m = 1;
			drawflush();
			continue;

		/* write: 'y' id[4] R[4*4] data[x*1] */
		/* write from compressed data: 'Y' id[4] R[4*4] data[x*1] */
		case 'y':
		case 'Y':
			printmesg(fmt="LR", a, 0);
		//	iprint("load %c\n", *a);
			m = 1+4+4*4;
			if(n < m)
				error(Eshortdraw);
			dstid = BGLONG(a+1);
			dst = drawimage(client, a+1);
			drawrectangle(&r, a+5);
			if(!rectinrect(r, dst->r))
				error(Ewriteoutside);
			y = memload(dst, r, a+m, n-m, *a=='Y');
			if(y < 0)
				error("bad writeimage call");
			dstflush(dstid, dst, r);
			m += y;
			continue;
		}
	}
	poperror();
}

Dev drawdevtab = {
	'i',
	"draw",

	devreset,
	devinit,
	devshutdown,
	drawattach,
	drawwalk,
	drawstat,
	drawopen,
	devcreate,
	drawclose,
	drawread,
	devbread,
	drawwrite,
	devbwrite,
	devremove,
	devwstat,
};

/*
 * On 8 bit displays, load the default color map
 */
void
drawcmap(void)
{
	int r, g, b, cr, cg, cb, v;
	int num, den;
	int i, j;

	drawactive(1);	/* to restore map from backup */
	for(r=0,i=0; r!=4; r++)
	    for(v=0; v!=4; v++,i+=16){
		for(g=0,j=v-r; g!=4; g++)
		    for(b=0;b!=4;b++,j++){
			den = r;
			if(g > den)
				den = g;
			if(b > den)
				den = b;
			if(den == 0)	/* divide check -- pick grey shades */
				cr = cg = cb = v*17;
			else{
				num = 17*(4*den+v);
				cr = r*num/den;
				cg = g*num/den;
				cb = b*num/den;
			}
			setcolor(i+(j&15),
				cr*0x01010101, cg*0x01010101, cb*0x01010101);
		    }
	}
}

void
drawblankscreen(int blank)
{
	int i, nc;
	ulong *p;

	if(blank == sdraw.blanked)
		return;
	if(!drawcanqlock())
		return;
	if(!initscreenimage()){
		drawqunlock();
		return;
	}
	p = sdraw.savemap;
	nc = screenimage->depth > 8 ? 256 : 1<<screenimage->depth;

	/*
	 * blankscreen uses the hardware to blank the screen
	 * when possible.  to help in cases when it is not possible,
	 * we set the color map to be all black.
	 */
	if(blank == 0){	/* turn screen on */
		for(i=0; i<nc; i++, p+=3)
			setcolor(i, p[0], p[1], p[2]);
		blankscreen(0);
	}else{	/* turn screen off */
		blankscreen(1);
		for(i=0; i<nc; i++, p+=3){
			getcolor(i, &p[0], &p[1], &p[2]);
			setcolor(i, 0, 0, 0);
		}
	}
	sdraw.blanked = blank;
	drawqunlock();
}

/*
 * record activity on screen, changing blanking as appropriate
 */
void
drawactive(int active)
{
	if(active){
		drawblankscreen(0);
		sdraw.blanktime = msec();
	}else{
		if(blanktime && sdraw.blanktime && (msec() - sdraw.blanktime)/1000/60 >= blanktime)
			drawblankscreen(1);
	}
}

int
drawidletime(void)
{
	return (msec() - sdraw.blanktime)/1000/60;
}

/* why is this here? why can't caller use drawqlock himself? */
void
drawflushr(Rectangle r)
{
	drawqlock();
	flushmemscreen(r);
	drawqunlock();
}