--- ray/src/common/calprnt.c	2003/02/22 02:07:21	2.2
+++ ray/src/common/calprnt.c	2021/07/30 00:22:32	2.7
@@ -1,81 +1,50 @@
 #ifndef lint
-static const char	RCSid[] = "$Id: calprnt.c,v 2.2 2003/02/22 02:07:21 greg Exp $";
+static const char	RCSid[] = "$Id: calprnt.c,v 2.7 2021/07/30 00:22:32 greg Exp $";
 #endif
 /*
  *  calprint.c - routines for printing calcomp expressions.
  */
 
-/* ====================================================================
- * The Radiance Software License, Version 1.0
- *
- * Copyright (c) 1990 - 2002 The Regents of the University of California,
- * through Lawrence Berkeley National Laboratory.   All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- *
- * 1. Redistributions of source code must retain the above copyright
- *         notice, this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright
- *       notice, this list of conditions and the following disclaimer in
- *       the documentation and/or other materials provided with the
- *       distribution.
- *
- * 3. The end-user documentation included with the redistribution,
- *           if any, must include the following acknowledgment:
- *             "This product includes Radiance software
- *                 (http://radsite.lbl.gov/)
- *                 developed by the Lawrence Berkeley National Laboratory
- *               (http://www.lbl.gov/)."
- *       Alternately, this acknowledgment may appear in the software itself,
- *       if and wherever such third-party acknowledgments normally appear.
- *
- * 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
- *       and "The Regents of the University of California" must
- *       not be used to endorse or promote products derived from this
- *       software without prior written permission. For written
- *       permission, please contact radiance@radsite.lbl.gov.
- *
- * 5. Products derived from this software may not be called "Radiance",
- *       nor may "Radiance" appear in their name, without prior written
- *       permission of Lawrence Berkeley National Laboratory.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
- * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED.   IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
- * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
- * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
- * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
- * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- * ====================================================================
- *
- * This software consists of voluntary contributions made by many
- * individuals on behalf of Lawrence Berkeley National Laboratory.   For more
- * information on Lawrence Berkeley National Laboratory, please see
- * <http://www.lbl.gov/>.
- */
+#include "copyright.h"
 
 #include  <stdio.h>
+#include  <string.h>
 
+#include  "rterror.h"
 #include  "calcomp.h"
 
 
+/* is child binary operation lower precedence than parent? */
+static int
+lower_precedent_binop(int typ, EPNODE *ekid)
+{
+    if (ekid == NULL)
+	return(0);
+    switch (typ) {
+	case '+':
+		return(0);
+	case '-':
+		return(ekid->type == '+');
+	case '*':
+		return(strchr("+-", ekid->type) != NULL);
+	case '/':
+		return(strchr("+-*", ekid->type) != NULL);
+	case '^':
+		return(strchr("+-*/^", ekid->type) != NULL);
+	}
+    return(0);			/* child not binary op */
+}
+
 void
-eprint(ep, fp)			/* print a parse tree */
-register EPNODE  *ep;
-FILE  *fp;
+eprint(				/* print a parse tree */
+	EPNODE  *ep,
+	FILE  *fp
+)
 {
     static EPNODE  *curdef = NULL;
-    register EPNODE  *ep1;
+    EPNODE  *ep1 = NULL;
 
-    switch (ep->type) {
+    switch (ep==NULL ? -1 : ep->type) {
 
 	case VAR:
 	    fputs(ep->v.ln->name, fp);
@@ -110,11 +79,6 @@ FILE  *fp;
 	    fprintf(fp, "%.9g", ep->v.num);
 	    break;
 
-	case UMINUS:
-	    fputc('-', fp);
-	    eprint(ep->v.kid, fp);
-	    break;
-
 	case CHAN:
 	    fprintf(fp, "$%d", ep->v.chan);
 	    break;
@@ -130,19 +94,40 @@ FILE  *fp;
 	    eprint(ep->v.kid->sibling, fp);
 	    curdef = ep1;
 	    break;
-	    
+
+	case UMINUS:
+	    fputc('-', fp);
+	    if (ep->v.kid != NULL && strchr("+-*/^", ep->v.kid->type)) {
+		fputc('(', fp);
+		eprint(ep->v.kid, fp);
+		fputc(')', fp);
+	    } else
+		eprint(ep->v.kid, fp);
+	    break;
+
 	case '+':
 	case '-':
 	case '*':
 	case '/':
 	case '^':
-	    fputc('(', fp);
-	    eprint(ep->v.kid, fp);
-	    fputc(' ', fp);
-	    fputc(ep->type, fp);
-	    fputc(' ', fp);
-	    eprint(ep->v.kid->sibling, fp);
-	    fputc(')', fp);
+	    if (lower_precedent_binop(ep->type, ep->v.kid)) {
+		fputc('(', fp);
+		eprint(ep->v.kid, fp);
+		fputc(')', fp);
+	    } else
+		eprint(ep->v.kid, fp);
+	    if (ep->type != '^') {
+		fputc(' ', fp);
+		fputc(ep->type, fp);
+		fputc(' ', fp);
+	    } else
+		fputc(ep->type, fp);
+	    if (lower_precedent_binop(ep->type, ep->v.kid->sibling)) {
+		fputc('(', fp);
+		eprint(ep->v.kid->sibling, fp);
+		fputc(')', fp);
+	    } else
+		eprint(ep->v.kid->sibling, fp);
 	    break;
 
 	default:
@@ -150,16 +135,16 @@ FILE  *fp;
 	    quit(1);
 
     }
-
 }
 
 
 void
-dprint(name, fp)		/* print a definition (all if no name) */
-char  *name;
-FILE  *fp;
+dprint(			/* print a definition (all if no name) */
+	char  *name,
+	FILE  *fp
+)
 {
-    register EPNODE  *ep;
+    EPNODE  *ep;
     
     if (name == NULL)
 	for (ep = dfirst(); ep != NULL; ep = dnext()) {