--- ray/src/common/instance.c	1989/10/13 19:45:50	1.5
+++ ray/src/common/instance.c	2003/07/10 03:30:11	2.9
@@ -1,55 +1,65 @@
-/* Copyright (c) 1988 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char RCSid[] = "$Id: instance.c,v 2.9 2003/07/10 03:30:11 greg Exp $";
 #endif
-
 /*
  *  instance.c - routines for octree objects.
- *
- *	11/10/88
  */
 
+#include "copyright.h"
+
 #include  "standard.h"
 
+#include  "octree.h"
+
 #include  "object.h"
 
 #include  "instance.h"
 
+#define  IO_ILLEGAL	(IO_FILES|IO_INFO)
+
 static SCENE  *slist = NULL;		/* list of loaded octrees */
 
 
 SCENE *
-getscene(sname, flags)			/* load octree sname */
+getscene(sname, flags)			/* get new octree reference */
 char  *sname;
 int  flags;
 {
-	extern char  *libpath;
 	char  *pathname;
 	register SCENE  *sc;
 
-	flags &= ~(IO_FILES|IO_INFO);		/* not allowed */
+	flags &= ~IO_ILLEGAL;		/* not allowed */
 	for (sc = slist; sc != NULL; sc = sc->next)
-		if (!strcmp(sname, sc->name)) {
-			if ((sc->ldflags & flags) == flags)
-				return(sc);		/* loaded */
-			break;			/* load the rest */
-		}
+		if (!strcmp(sname, sc->name))
+			break;
 	if (sc == NULL) {
 		sc = (SCENE *)malloc(sizeof(SCENE));
 		if (sc == NULL)
 			error(SYSTEM, "out of memory in getscene");
 		sc->name = savestr(sname);
+		sc->nref = 0;
 		sc->ldflags = 0;
+		sc->scube.cutree = EMPTY;
+		sc->scube.cuorg[0] = sc->scube.cuorg[1] =
+				sc->scube.cuorg[2] = 0.;
+		sc->scube.cusize = 0.;
+		sc->firstobj = sc->nobjs = 0;
 		sc->next = slist;
 		slist = sc;
 	}
-	if ((pathname = getpath(sname, libpath, R_OK)) == NULL) {
+	if ((pathname = getpath(sname, getrlibpath(), R_OK)) == NULL) {
 		sprintf(errmsg, "cannot find octree file \"%s\"", sname);
 		error(USER, errmsg);
 	}
-	readoct(pathname, flags & ~sc->ldflags, &sc->scube, NULL);
+	flags &= ~sc->ldflags;		/* skip what's already loaded */
+	if (flags & IO_SCENE)
+		sc->firstobj = nobjects;
+	if (flags)
+		readoct(pathname, flags, &sc->scube, NULL);
+	if (flags & IO_SCENE)
+		sc->nobjs = nobjects - sc->firstobj;
 	sc->ldflags |= flags;
+	sc->nref++;			/* increase reference count */
 	return(sc);
 }
 
@@ -59,25 +69,78 @@ getinstance(o, flags)			/* get instance structure */
 register OBJREC  *o;
 int  flags;
 {
-	register INSTANCE  *in;
+	register INSTANCE  *ins;
 
-	if ((in = (INSTANCE *)o->os) == NULL) {
-		if ((in = (INSTANCE *)malloc(sizeof(INSTANCE))) == NULL)
+	flags &= ~IO_ILLEGAL;		/* not allowed */
+	if ((ins = (INSTANCE *)o->os) == NULL) {
+		if ((ins = (INSTANCE *)malloc(sizeof(INSTANCE))) == NULL)
 			error(SYSTEM, "out of memory in getinstance");
 		if (o->oargs.nsargs < 1)
 			objerror(o, USER, "bad # of arguments");
-		if (xf(in->f.xfm, &in->f.sca, o->oargs.nsargs-1,
+		if (fullxf(&ins->x, o->oargs.nsargs-1,
 				o->oargs.sarg+1) != o->oargs.nsargs-1)
 			objerror(o, USER, "bad transform");
-		if (in->f.sca < 0.0)
-			in->f.sca = -in->f.sca;
-		invxf(in->b.xfm, &in->b.sca,o->oargs.nsargs-1,o->oargs.sarg+1);
-		if (in->b.sca < 0.0)
-			in->b.sca = -in->b.sca;
-		in->obj = NULL;
-		o->os = (char *)in;
+		if (ins->x.f.sca < 0.0) {
+			ins->x.f.sca = -ins->x.f.sca;
+			ins->x.b.sca = -ins->x.b.sca;
+		}
+		ins->obj = NULL;
+		o->os = (char *)ins;
 	}
-	if (in->obj == NULL || (in->obj->ldflags & flags) != flags)
-		in->obj = getscene(o->oargs.sarg[0], flags);
-	return(in);
+	if (ins->obj == NULL)
+		ins->obj = getscene(o->oargs.sarg[0], flags);
+	else if ((flags &= ~ins->obj->ldflags)) {
+		if (flags & IO_SCENE)
+			ins->obj->firstobj = nobjects;
+		if (flags)
+			readoct(getpath(o->oargs.sarg[0], getrlibpath(), R_OK),
+					flags, &ins->obj->scube, NULL);
+		if (flags & IO_SCENE)
+			ins->obj->nobjs = nobjects - ins->obj->firstobj;
+		ins->obj->ldflags |= flags;
+	}
+	return(ins);
+}
+
+
+void
+freescene(sc)		/* release a scene reference */
+SCENE *sc;
+{
+	SCENE  shead;
+	register SCENE  *scp;
+
+	if (sc == NULL)
+		return;
+	if (sc->nref <= 0)
+		error(CONSISTENCY, "unreferenced scene in freescene");
+	sc->nref--;
+	if (sc->nref)			/* still in use? */
+		return;
+	shead.next = slist;		/* else remove from our list */
+	for (scp = &shead; scp->next != NULL; scp = scp->next)
+		if (scp->next == sc) {
+			scp->next = sc->next;
+			sc->next = NULL;
+			break;
+		}
+	if (sc->next != NULL)		/* can't be in list anymore */
+		error(CONSISTENCY, "unlisted scene in freescene");
+	slist = shead.next;
+	freestr(sc->name);		/* free memory */
+	octfree(sc->scube.cutree);
+	freeobjects(sc->firstobj, sc->nobjs);
+	free((void *)sc);
+}
+
+
+void
+freeinstance(o)		/* free memory associated with instance */
+OBJREC  *o;
+{
+	if (o->os == NULL)
+		return;
+	freescene((*(INSTANCE *)o->os).obj);
+	free((void *)o->os);
+	o->os = NULL;
 }