--- ray/src/cv/mgflib/xf.c	1994/06/21 14:45:48	1.1
+++ ray/src/cv/mgflib/xf.c	1997/12/15 09:41:37	1.13
@@ -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";
@@ -10,6 +10,7 @@ static char SCCSid[] = "$SunId$ LBL";
 
 #include <stdio.h>
 #include <math.h>
+#include <stdlib.h>
 #include <string.h>
 #include "parser.h"
 
@@ -21,79 +22,212 @@ 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 */
 
-
 int
 xf_handler(ac, av)		/* handle xf entity */
 int	ac;
 char	**av;
 {
-	register int	i;
 	register XF_SPEC	*spec;
-	XF	thisxf;
+	register int	n;
+	int	rv;
 
-	if (ac == 1) {			/* pop top transform */
+	if (ac == 1) {			/* something with existing transform */
 		if ((spec = xf_context) == NULL)
-			return(MG_OK);		/* should be error? */
-		while (xf_argc > spec->xav0)
-			free((MEM_PTR)xf_argv[--xf_argc]);
-		xf_argv[xf_argc] = NULL;
-		xf_context = spec->prev;
-		free((MEM_PTR)spec);
-		return(MG_OK);
+			return(MG_ECNTXT);
+		n = -1;
+		if (spec->xarr != NULL) {	/* check for iteration */
+			register struct xf_array	*ap = spec->xarr;
+
+			(void)xf_aname((struct xf_array *)NULL);
+			n = ap->ndim;
+			while (n--) {
+				if (++ap->aarg[n].i < ap->aarg[n].n)
+					break;
+				(void)strcpy(ap->aarg[n].arg, "0");
+				ap->aarg[n].i = 0;
+			}
+			if (n >= 0) {
+				if ((rv = mg_fgoto(&ap->spos)) != MG_OK)
+					return(rv);
+				sprintf(ap->aarg[n].arg, "%d", ap->aarg[n].i);
+				(void)xf_aname(ap);
+			}
+		}
+		if (n < 0) {			/* pop transform */
+			xf_context = spec->prev;
+			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, ac-1, av+1) != ac-1)
+	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);
-					/* allocate space for new transform */
-	spec = (XF_SPEC *)malloc(sizeof(XF_SPEC));
+					/* 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, 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);
+}
+
+
+XF_SPEC *
+new_xf(ac, av)			/* allocate new transform structure */
+int	ac;
+char	**av;
+{
+	register XF_SPEC	*spec;
+	register int	i;
+	char	*cp;
+	int	n, ndim;
+
+	ndim = 0;
+	n = 0;				/* compute space req'd by arguments */
+	for (i = 0; i < ac; i++)
+		if (!strcmp(av[i], "-a")) {
+			ndim++;
+			i++;
+		} else
+			n += strlen(av[i]) + 1;
+	if (ndim > XF_MAXDIM)
+		return(NULL);
+	spec = (XF_SPEC *)malloc(sizeof(XF_SPEC) + n);
 	if (spec == NULL)
-		return(MG_EMEM);
-	spec->xav0 = xf_argc;
-	spec->xac = ac-1;
+		return(NULL);
+	if (ndim) {
+		spec->xarr = (struct xf_array *)malloc(sizeof(struct xf_array));
+		if (spec->xarr == NULL)
+			return(NULL);
+		mg_fgetpos(&spec->xarr->spos);
+		spec->xarr->ndim = 0;		/* incremented below */
+	} else
+		spec->xarr = NULL;
+	spec->xac = ac + xf_argc;
 					/* and store new xf arguments */
-	if (xf_argc+ac > xf_maxarg) {
-		if (!xf_maxarg)
-			xf_argv = (char **)malloc(
-					(xf_maxarg=ac)*sizeof(char *));
-		else
-			xf_argv = (char **)realloc((MEM_PTR)xf_argv,
-					(xf_maxarg+=ac)*sizeof(char *));
-		if (xf_argv == NULL)
-			return(MG_EMEM);
+	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;
 	}
-	for (i = 0; i < ac-1; i++) {
-		xf_argv[xf_argc] = (char *)malloc(strlen(av[i+1])+1);
-		if (xf_argv[xf_argc] == NULL)
-			return(MG_EMEM);
-		strcpy(xf_argv[xf_argc++], av[i+1]);
+	cp = (char *)(spec + 1);	/* use memory allocated above */
+	for (i = 0; i < ac; i++)
+		if (!strcmp(av[i], "-a")) {
+			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]);
+		} else {
+			xf_av(spec)[i] = strcpy(cp, av[i]);
+			cp += strlen(av[i]) + 1;
+		}
+	return(spec);
+}
+
+
+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];
+	static char	*oav[3] = {mg_ename[MG_E_OBJECT], oname};
+	register int	i;
+	register char	*cp1, *cp2;
+
+	if (ap == NULL)
+		return(mg_handle(MG_E_OBJECT, 1, oav));
+	cp1 = oname;
+	*cp1 = 'a';
+	for (i = 0; i < ap->ndim; i++) {
+		for (cp2 = ap->aarg[i].arg; *cp2; )
+			*++cp1 = *cp2++;
+		*++cp1 = '.';
 	}
-	xf_argv[xf_argc] = NULL;
-					/* compute total transformation */
-	if (xf_context != NULL) {
-		multmat4(spec->xf.xfm, xf_context->xf.xfm, thisxf.xfm);
-		spec->xf.sca = xf_context->xf.sca * thisxf.sca;
-	} else
-		spec->xf = thisxf;
-	spec->prev = xf_context;	/* push new transform onto stack */
-	xf_context = spec;
-	return(MG_OK);
+	*cp1 = '\0';
+	return(mg_handle(MG_E_OBJECT, 2, oav));
 }
 
 
+long
+comp_xfid(xfm)			/* compute unique ID from matrix */
+register MAT4	xfm;
+{
+	static char	shifttab[64] = { 15, 5, 11, 5, 6, 3,
+				9, 15, 13, 2, 13, 5, 2, 12, 14, 11,
+				11, 12, 12, 3, 2, 11, 8, 12, 1, 12,
+				5, 4, 15, 9, 14, 5, 13, 14, 2, 10,
+				10, 14, 12, 3, 5, 5, 14, 6, 12, 11,
+				13, 9, 12, 8, 1, 6, 5, 12, 7, 13,
+				15, 8, 9, 2, 6, 11, 9, 11 };
+	register int	i;
+	register long	xid;
+
+	xid = 0;			/* compute unique transform id */
+	for (i = 0; i < sizeof(MAT4)/sizeof(unsigned short); i++)
+		xid ^= (long)(((unsigned short *)xfm)[i]) << shifttab[i&63];
+	return(xid);
+}
+
+
 void
+xf_clear()			/* clear transform stack */
+{
+	register XF_SPEC	*spec;
+
+	if (xf_argbeg != NULL) {
+		free((MEM_PTR)xf_argbeg);
+		xf_argbeg = xf_argend = NULL;
+	}
+	while ((spec = xf_context) != NULL) {
+		xf_context = spec->prev;
+		free_xf(spec);
+	}
+}
+
+
+void
 xf_xfmpoint(v1, v2)		/* transform a point by the current matrix */
 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);
@@ -105,9 +239,7 @@ 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);
@@ -188,7 +320,7 @@ int
 xf(ret, ac, av)			/* get transform specification */
 register XF  *ret;
 int  ac;
-char  *av[];
+char  **av;
 {
 	MAT4  xfmat, m4;
 	double  xfsca, dtmp;