--- ray/src/rt/ambcomp.c	1998/06/24 09:35:00	2.7
+++ ray/src/rt/ambcomp.c	2003/07/27 22:12:03	2.12
@@ -1,33 +1,21 @@
-/* Copyright (c) 1991 Regents of the University of California */
-
 #ifndef lint
-static char SCCSid[] = "$SunId$ LBL";
+static const char	RCSid[] = "$Id: ambcomp.c,v 2.12 2003/07/27 22:12:03 schorsch Exp $";
 #endif
-
 /*
  * Routines to compute "ambient" values using Monte Carlo
+ *
+ *  Declarations of external symbols in ambient.h
  */
 
+#include "copyright.h"
+
 #include  "ray.h"
 
 #include  "ambient.h"
 
 #include  "random.h"
 
-typedef struct {
-	short  t, p;		/* theta, phi indices */
-	COLOR  v;		/* value sum */
-	float  r;		/* 1/distance sum */
-	float  k;		/* variance for this division */
-	int  n;			/* number of subsamples */
-}  AMBSAMP;		/* ambient sample division */
 
-typedef struct {
-	FVECT  ux, uy, uz;	/* x, y and z axis directions */
-	short  nt, np;		/* number of theta and phi directions */
-}  AMBHEMI;		/* ambient sample hemisphere */
-
-
 static int
 ambcmp(d1, d2)				/* decreasing order */
 AMBSAMP  *d1, *d2;
@@ -46,12 +34,13 @@ AMBSAMP  *d1, *d2;
 {
 	register int  c;
 
-	if (c = d1->t - d2->t)
+	if ( (c = d1->t - d2->t) )
 		return(c);
 	return(d1->p - d2->p);
 }
 
 
+int
 divsample(dp, h, r)			/* sample a division */
 register AMBSAMP  *dp;
 AMBHEMI  *h;
@@ -73,8 +62,8 @@ RAY  *r;
 	multisamp(spt, 2, urand(ilhash(hlist,3)+dp->n));
 	zd = sqrt((dp->t + spt[0])/h->nt);
 	phi = 2.0*PI * (dp->p + spt[1])/h->np;
-	xd = cos(phi) * zd;
-	yd = sin(phi) * zd;
+	xd = tcos(phi) * zd;
+	yd = tsin(phi) * zd;
 	zd = sqrt(1.0 - zd*zd);
 	for (i = 0; i < 3; i++)
 		ar.rdir[i] =	xd*h->ux[i] +
@@ -84,9 +73,9 @@ RAY  *r;
 	rayvalue(&ar);
 	ndims--;
 	addcolor(dp->v, ar.rcol);
-					/* be conservative and use rot */
-	if (ar.rot > FTINY && ar.rot < FHUGE)
-		dp->r += 1.0/ar.rot;
+					/* use rt to improve gradient calc */
+	if (ar.rt > FTINY && ar.rt < FHUGE)
+		dp->r += 1.0/ar.rt;
 					/* (re)initialize error */
 	if (dp->n++) {
 		b2 = bright(dp->v)/dp->n - bright(ar.rcol);
@@ -153,17 +142,17 @@ FVECT  pg, dg;
 		qsort(div, ndivs, sizeof(AMBSAMP), ambcmp);	/* sort divs */
 						/* super-sample */
 		for (i = ns; i > 0; i--) {
-			copystruct(&dnew, div);
+			dnew = *div;
 			if (divsample(&dnew, &hemi, r) < 0)
 				goto oopsy;
 							/* reinsert */
 			dp = div;
 			j = ndivs < i ? ndivs : i;
 			while (--j > 0 && dnew.k < dp[1].k) {
-				copystruct(dp, dp+1);
+				*dp = *(dp+1);
 				dp++;
 			}
-			copystruct(dp, &dnew);
+			*dp = dnew;
 		}
 		if (pg != NULL || dg != NULL)	/* restore order */
 			qsort(div, ndivs, sizeof(AMBSAMP), ambnorm);
@@ -202,7 +191,7 @@ FVECT  pg, dg;
 				for (i = 0; i < 3; i++)
 					dg[i] = 0.0;
 		}
-		free((char *)div);
+		free((void *)div);
 	}
 	b = 1.0/ndivs;
 	scalecolor(acol, b);
@@ -228,11 +217,12 @@ FVECT  pg, dg;
 	return(arad);
 oopsy:
 	if (div != NULL)
-		free((char *)div);
+		free((void *)div);
 	return(0.0);
 }
 
 
+void
 inithemi(hp, r, wt)		/* initialize sampling hemisphere */
 register AMBHEMI  *hp;
 RAY  *r;
@@ -261,6 +251,7 @@ double  wt;
 }
 
 
+void
 comperrs(da, hp)		/* compute initial error estimates */
 AMBSAMP  *da;		/* assumes standard ordering */
 register AMBHEMI  *hp;
@@ -311,6 +302,7 @@ register AMBHEMI  *hp;
 }
 
 
+void
 posgradient(gv, da, hp)				/* compute position gradient */
 FVECT  gv;
 AMBSAMP  *da;			/* assumes standard ordering */
@@ -358,7 +350,7 @@ register AMBHEMI  *hp;
 		}
 		mag0 *= 2.0*PI / hp->np;
 		phi = 2.0*PI * (double)j/hp->np;
-		cosp = cos(phi); sinp = sin(phi);
+		cosp = tcos(phi); sinp = tsin(phi);
 		xd += mag0*cosp - mag1*sinp;
 		yd += mag0*sinp + mag1*cosp;
 	}
@@ -367,6 +359,7 @@ register AMBHEMI  *hp;
 }
 
 
+void
 dirgradient(gv, da, hp)				/* compute direction gradient */
 FVECT  gv;
 AMBSAMP  *da;			/* assumes standard ordering */
@@ -392,8 +385,8 @@ register AMBHEMI  *hp;
 			dp += hp->np;
 		}
 		phi = 2.0*PI * (j+.5)/hp->np + PI/2.0;
-		xd += mag * cos(phi);
-		yd += mag * sin(phi);
+		xd += mag * tcos(phi);
+		yd += mag * tsin(phi);
 	}
 	for (i = 0; i < 3; i++)
 		gv[i] = (xd*hp->ux[i] + yd*hp->uy[i])/(hp->nt*hp->np);