--- ray/src/common/cone.c	1989/02/02 10:34:30	1.1
+++ ray/src/common/cone.c	2003/07/27 22:12:01	2.9
@@ -1,15 +1,12 @@
-/* Copyright (c) 1986 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: cone.c,v 2.9 2003/07/27 22:12:01 schorsch Exp $";
 #endif
-
 /*
  *  cone.c - routines for making cones
- *
- *     2/12/86
  */
 
+#include "copyright.h"
+
 #include  "standard.h"
 
 #include  "object.h"
@@ -48,7 +45,7 @@ getcone(o, getxf)			/* get cone structure */
 register OBJREC  *o;
 int  getxf;
 {
-	double  fabs(), sqrt();
+	int  sgn0, sgn1;
 	register CONE  *co;
 
 	if ((co = (CONE *)o->os) == NULL) {
@@ -59,36 +56,68 @@ int  getxf;
 
 		co->ca = o->oargs.farg;
 						/* get radii */
-		if (o->otype == OBJ_CYLINDER || o->otype == OBJ_TUBE) {
+		if ((o->otype == OBJ_CYLINDER) | (o->otype == OBJ_TUBE)) {
 			if (o->oargs.nfargs != 7)
 				goto argcerr;
-			if (co->ca[6] <= FTINY)
+			if (co->ca[6] < -FTINY) {
+				objerror(o, WARNING, "negative radius");
+				o->otype = o->otype == OBJ_CYLINDER ?
+						OBJ_TUBE : OBJ_CYLINDER;
+				co->ca[6] = -co->ca[6];
+			} else if (co->ca[6] <= FTINY)
 				goto raderr;
+			co->p0 = 0; co->p1 = 3;
 			co->r0 = co->r1 = 6;
 		} else {
 			if (o->oargs.nfargs != 8)
 				goto argcerr;
-			if (co->ca[6] < 0.0 || co->ca[7] < 0.0)
+			if (co->ca[6] < -FTINY) sgn0 = -1;
+			else if (co->ca[6] > FTINY) sgn0 = 1;
+			else sgn0 = 0;
+			if (co->ca[7] < -FTINY) sgn1 = -1;
+			else if (co->ca[7] > FTINY) sgn1 = 1;
+			else sgn1 = 0;
+			if (sgn0+sgn1 == 0)
 				goto raderr;
-			if (fabs(co->ca[7] - co->ca[6]) <= FTINY)
-				goto raderr;
-			co->r0 = 6;
-			co->r1 = 7;
+			if ((sgn0 < 0) | (sgn1 < 0)) {
+				objerror(o, o->otype==OBJ_RING?USER:WARNING,
+					"negative radii");
+				o->otype = o->otype == OBJ_CONE ?
+						OBJ_CUP : OBJ_CONE;
+			}
+			co->ca[6] = co->ca[6]*sgn0;
+			co->ca[7] = co->ca[7]*sgn1;
+			if (co->ca[7] - co->ca[6] > FTINY) {
+				if (o->otype == OBJ_RING)
+					co->p0 = co->p1 = 0;
+				else {
+					co->p0 = 0; co->p1 = 3;
+				}
+				co->r0 = 6; co->r1 = 7;
+			} else if (co->ca[6] - co->ca[7] > FTINY) {
+				if (o->otype == OBJ_RING)
+					co->p0 = co->p1 = 0;
+				else {
+					co->p0 = 3; co->p1 = 0;
+				}
+				co->r0 = 7; co->r1 = 6;
+			} else {
+				if (o->otype == OBJ_RING)
+					goto raderr;
+				o->otype = o->otype == OBJ_CONE ?
+						OBJ_CYLINDER : OBJ_TUBE;
+				o->oargs.nfargs = 7;
+				co->p0 = 0; co->p1 = 3;
+				co->r0 = co->r1 = 6;
+			}
 		}
 						/* get axis orientation */
-		co->p0 = 0;
-		if (o->otype == OBJ_RING) {
-			if (co->ca[6] > co->ca[7]) {	/* make r0 smaller */
-				co->r0 = 7;
-				co->r1 = 6;
-			}
-			co->p1 = 0;
+		if (o->otype == OBJ_RING)
 			VCOPY(co->ad, o->oargs.farg+3);
-		} else {
-			co->p1 = 3;
-			co->ad[0] = co->ca[3] - co->ca[0];
-			co->ad[1] = co->ca[4] - co->ca[1];
-			co->ad[2] = co->ca[5] - co->ca[2];
+		else {
+			co->ad[0] = CO_P1(co)[0] - CO_P0(co)[0];
+			co->ad[1] = CO_P1(co)[1] - CO_P0(co)[1];
+			co->ad[2] = CO_P1(co)[2] - CO_P0(co)[2];
 		}
 		co->al = normalize(co->ad);
 		if (co->al == 0.0)
@@ -96,15 +125,15 @@ int  getxf;
 					/* compute axis and side lengths */
 		if (o->otype == OBJ_RING) {
 			co->al = 0.0;
-			co->sl = co->ca[co->r1] - co->ca[co->r0];
-		} else if (o->otype == OBJ_CONE || o->otype == OBJ_CUP) {
+			co->sl = CO_R1(co) - CO_R0(co);
+		} else if ((o->otype == OBJ_CONE) | (o->otype == OBJ_CUP)) {
 			co->sl = co->ca[7] - co->ca[6];
 			co->sl = sqrt(co->sl*co->sl + co->al*co->al);
-		} else { /* OBJ_CYLINDER || OBJ_TUBE */
+		} else { /* OBJ_CYLINDER or OBJ_TUBE */
 			co->sl = co->al;
 		}
 		co->tm = NULL;
-		(CONE *)o->os = co;
+		o->os = (char *)co;
 	}
 	if (getxf && co->tm == NULL)
 		conexform(co);
@@ -114,30 +143,34 @@ argcerr:
 	objerror(o, USER, "bad # arguments");
 raderr:
 	objerror(o, USER, "illegal radii");
+	return NULL; /* pro forma return */
 }
 
 
+void
 freecone(o)			/* free memory associated with cone */
 OBJREC  *o;
 {
 	register CONE  *co = (CONE *)o->os;
 
+	if (co == NULL)
+		return;
 	if (co->tm != NULL)
-		free((char *)co->tm);
-	free(o->os);
+		free((void *)co->tm);
+	free((void *)co);
 	o->os = NULL;
 }
 
 
+void
 conexform(co)			/* get cone transformation matrix */
 register CONE  *co;
 {
-	double  sqrt(), fabs();
-	double  m4[4][4];
+	MAT4  m4;
 	register double  d;
 	register int  i;
 
-	co->tm = (double (*)[4])malloc(sizeof(m4));
+	co->tm = (RREAL (*)[4])malloc(sizeof(MAT4));
 	if (co->tm == NULL)
 		error(SYSTEM, "out of memory in conexform");
 
@@ -146,10 +179,10 @@ register CONE  *co;
 	if (co->r0 == co->r1)
 		d = 0.0;
 	else
-		d = co->ca[co->r0] / (co->ca[co->r1] - co->ca[co->r0]);
+		d = CO_R0(co) / (CO_R1(co) - CO_R0(co));
 	for (i = 0; i < 3; i++)
-		co->tm[3][i] = d*(co->ca[co->p1+i] - co->ca[co->p0+i])
-				- co->ca[co->p0+i];
+		co->tm[3][i] = d*(CO_P1(co)[i] - CO_P0(co)[i])
+				- CO_P0(co)[i];
 	
 				/* rotate to positive z-axis */
 	setident4(m4);
@@ -173,10 +206,9 @@ register CONE  *co;
 	multmat4(co->tm, co->tm, m4);
 
 				/* scale z-axis */
-	setident4(m4);
-	if (co->p0 != co->p1 && co->r0 != co->r1) {
-		d = fabs(co->ca[co->r1] - co->ca[co->r0]);
-		m4[2][2] = d/co->al;
+	if ((co->p0 != co->p1) & (co->r0 != co->r1)) {
+		setident4(m4);
+		m4[2][2] = (CO_R1(co) - CO_R0(co)) / co->al;
+		multmat4(co->tm, co->tm, m4);
 	}
-	multmat4(co->tm, co->tm, m4);
 }