--- ray/src/cv/mgflib/xf.c	1994/07/11 14:47:12	1.6
+++ ray/src/cv/mgflib/xf.c	1995/11/29 19:55:45	1.12
@@ -1,4 +1,4 @@
-/* Copyright (c) 1994 Regents of the University of California */
+/* Copyright (c) 1995 Regents of the University of California */
 
 #ifndef lint
 static char SCCSid[] = "$SunId$ LBL";
@@ -21,17 +21,11 @@ MAT4  m4ident = MAT4IDENT;
 
 static MAT4  m4tmp;		/* for efficiency */
 
-int	xf_argc;			/* total # transform args. */
-char	**xf_argv;			/* transform arguments */
-XF_SPEC	*xf_context;			/* current context */
+XF_SPEC	*xf_context;		/* current context */
+char	**xf_argend;		/* end of transform argument list */
+static char	**xf_argbeg;	/* beginning of transform argument list */
 
-static int	xf_maxarg;		/* # allocated arguments */
 
-static XF_SPEC	*new_xf();
-static long	comp_xfid();
-static int	put_oname();
-
-
 int
 xf_handler(ac, av)		/* handle xf entity */
 int	ac;
@@ -40,16 +34,15 @@ char	**av;
 	register XF_SPEC	*spec;
 	register int	n;
 	int	rv;
-	XF	thisxf;
 
 	if (ac == 1) {			/* something with existing transform */
 		if ((spec = xf_context) == NULL)
-			return(MG_OK);		/* should be error? */
+			return(MG_ECNTXT);
 		n = -1;
 		if (spec->xarr != NULL) {	/* check for iteration */
 			register struct xf_array	*ap = spec->xarr;
 
-			(void)put_oname((struct xf_array *)NULL);
+			(void)xf_aname((struct xf_array *)NULL);
 			n = ap->ndim;
 			while (n--) {
 				if (++ap->aarg[n].i < ap->aarg[n].n)
@@ -61,37 +54,42 @@ char	**av;
 				if ((rv = mg_fgoto(&ap->spos)) != MG_OK)
 					return(rv);
 				sprintf(ap->aarg[n].arg, "%d", ap->aarg[n].i);
-				(void)put_oname(ap);
-			} else
-				free((MEM_PTR)ap);
+				(void)xf_aname(ap);
+			}
 		}
 		if (n < 0) {			/* pop transform */
-			xf_argv[xf_argc=spec->xav0] = NULL;
 			xf_context = spec->prev;
-			free((MEM_PTR)spec);
+			free_xf(spec);
 			return(MG_OK);
 		}
 	} else {			/* else allocate transform */
 		if ((spec = new_xf(ac-1, av+1)) == NULL)
 			return(MG_EMEM);
+		if (spec->xarr != NULL)
+			(void)xf_aname(spec->xarr);
 		spec->prev = xf_context;	/* push onto stack */
 		xf_context = spec;
 	}
 					/* translate new specification */
-	if (xf(&thisxf, spec->xac, &xf_argv[spec->xav0]) != spec->xac)
+	n = xf_ac(spec);
+	n -= xf_ac(spec->prev);		/* incremental comp. is more eff. */
+	if (xf(&spec->xf, n, xf_av(spec)) != n)
 		return(MG_ETYPE);
+					/* check for vertex reversal */
+	if ((spec->rev = (spec->xf.sca < 0.)))
+		spec->xf.sca = -spec->xf.sca;
 					/* compute total transformation */
 	if (spec->prev != NULL) {
-		multmat4(spec->xf.xfm, thisxf.xfm, spec->prev->xf.xfm);
-		spec->xf.sca = thisxf.sca * spec->prev->xf.sca;
-	} else
-		spec->xf = thisxf;
+		multmat4(spec->xf.xfm, spec->xf.xfm, spec->prev->xf.xfm);
+		spec->xf.sca *= spec->prev->xf.sca;
+		spec->rev ^= spec->prev->rev;
+	}
 	spec->xid = comp_xfid(spec->xf.xfm);	/* compute unique ID */
 	return(MG_OK);
 }
 
 
-static XF_SPEC *
+XF_SPEC *
 new_xf(ac, av)			/* allocate new transform structure */
 int	ac;
 char	**av;
@@ -122,41 +120,49 @@ char	**av;
 		spec->xarr->ndim = 0;		/* incremented below */
 	} else
 		spec->xarr = NULL;
-	spec->xav0 = xf_argc;
-	spec->xac = ac;
+	spec->xac = ac + xf_argc;
 					/* and store new xf arguments */
-	if (xf_argc+ac+1 > xf_maxarg) {
-		if (!xf_maxarg)
-			xf_argv = (char **)malloc(
-					(xf_maxarg=ac+1)*sizeof(char *));
-		else
-			xf_argv = (char **)realloc((MEM_PTR)xf_argv,
-				(xf_maxarg=xf_argc+ac+1)*sizeof(char *));
-		if (xf_argv == NULL)
+	if (xf_argbeg == NULL || xf_av(spec) < xf_argbeg) {
+		register char	**newav =
+				(char **)malloc((spec->xac+1)*sizeof(char *));
+		if (newav == NULL)
 			return(NULL);
+		for (i = xf_argc; i-- > 0; )
+			newav[ac+i] = xf_argend[i-xf_context->xac];
+		*(xf_argend = newav + spec->xac) = NULL;
+		if (xf_argbeg != NULL)
+			free((MEM_PTR)xf_argbeg);
+		xf_argbeg = newav;
 	}
 	cp = (char *)(spec + 1);	/* use memory allocated above */
 	for (i = 0; i < ac; i++)
 		if (!strcmp(av[i], "-a")) {
-			xf_argv[xf_argc++] = "-i";
-			xf_argv[xf_argc++] = strcpy(
+			xf_av(spec)[i++] = "-i";
+			xf_av(spec)[i] = strcpy(
 					spec->xarr->aarg[spec->xarr->ndim].arg,
 					"0");
 			spec->xarr->aarg[spec->xarr->ndim].i = 0;
-			spec->xarr->aarg[spec->xarr->ndim++].n = atoi(av[++i]);
+			spec->xarr->aarg[spec->xarr->ndim++].n = atoi(av[i]);
 		} else {
-			xf_argv[xf_argc++] = strcpy(cp, av[i]);
+			xf_av(spec)[i] = strcpy(cp, av[i]);
 			cp += strlen(av[i]) + 1;
 		}
-	xf_argv[xf_argc] = NULL;
-	if (spec->xarr != NULL)
-		(void)put_oname(spec->xarr);
 	return(spec);
 }
 
 
-static int
-put_oname(ap)			/* put out name for this instance */
+void
+free_xf(spec)			/* free a transform */
+register XF_SPEC	*spec;
+{
+	if (spec->xarr != NULL)
+		free((MEM_PTR)spec->xarr);
+	free((MEM_PTR)spec);
+}
+
+
+int
+xf_aname(ap)			/* put out name for this instance */
 register struct xf_array	*ap;
 {
 	static char	oname[10*XF_MAXDIM];
@@ -178,7 +184,7 @@ register struct xf_array	*ap;
 }
 
 
-static long
+long
 comp_xfid(xfm)			/* compute unique ID from matrix */
 register MAT4	xfm;
 {
@@ -204,17 +210,13 @@ xf_clear()			/* clear transform stack */
 {
 	register XF_SPEC	*spec;
 
-	if (xf_maxarg) {
-		free((MEM_PTR)xf_argv);
-		xf_argv = NULL;
-		xf_maxarg = 0;
+	if (xf_argbeg != NULL) {
+		free((MEM_PTR)xf_argbeg);
+		xf_argbeg = xf_argend = NULL;
 	}
-	xf_argc = 0;
 	while ((spec = xf_context) != NULL) {
 		xf_context = spec->prev;
-		if (spec->xarr != NULL)
-			free((MEM_PTR)spec->xarr);
-		free((MEM_PTR)spec);
+		free_xf(spec);
 	}
 }
 
@@ -224,9 +226,7 @@ xf_xfmpoint(v1, v2)		/* transform a point by the curre
 FVECT	v1, v2;
 {
 	if (xf_context == NULL) {
-		v1[0] = v2[0];
-		v1[1] = v2[1];
-		v1[2] = v2[2];
+		VCOPY(v1, v2);
 		return;
 	}
 	multp3(v1, v2, xf_context->xf.xfm);
@@ -238,9 +238,7 @@ xf_xfmvect(v1, v2)		/* transform a vector using curren
 FVECT	v1, v2;
 {
 	if (xf_context == NULL) {
-		v1[0] = v2[0];
-		v1[1] = v2[1];
-		v1[2] = v2[2];
+		VCOPY(v1, v2);
 		return;
 	}
 	multv3(v1, v2, xf_context->xf.xfm);