--- ray/src/rt/rpict.c	2008/03/11 02:21:47	2.78
+++ ray/src/rt/rpict.c	2010/09/03 21:16:50	2.83
@@ -1,5 +1,5 @@
 #ifndef lint
-static const char RCSid[] = "$Id: rpict.c,v 2.78 2008/03/11 02:21:47 greg Exp $";
+static const char RCSid[] = "$Id: rpict.c,v 2.83 2010/09/03 21:16:50 greg Exp $";
 #endif
 /*
  *  rpict.c - routines and variables for picture generation.
@@ -9,20 +9,24 @@ static const char RCSid[] = "$Id: rpict.c,v 2.78 2008/
 
 #include  <sys/types.h>
 
-#ifndef NON_POSIX
-#ifdef BSD
-#include  <sys/time.h>
-#include  <sys/resource.h>
+#include  "platform.h"
+#ifdef NON_POSIX
+ #ifdef MINGW
+  #include  <sys/time.h>
+ #endif
 #else
-#include  <sys/times.h>
-#include  <unistd.h>
+ #ifdef BSD
+  #include  <sys/time.h>
+  #include  <sys/resource.h>
+ #else
+  #include  <sys/times.h>
+  #include  <unistd.h>
+ #endif
 #endif
-#endif
 
 #include  <time.h>
 #include  <signal.h>
 
-#include  "platform.h"
 #include  "ray.h"
 #include  "paths.h"
 #include  "ambient.h"
@@ -47,7 +51,6 @@ int  dimlist[MAXDIM];			/* sampling dimensions */
 int  ndims = 0;				/* number of sampling dimensions */
 int  samplendx;				/* sample index number */
 
-//extern void  ambnotify();
 void  (*addobjnotify[])() = {ambnotify, NULL};
 
 VIEW  ourview = STDVIEW;		/* view parameters */
@@ -115,10 +118,6 @@ int  hres, vres;			/* resolution for this frame */
 
 static VIEW	lastview;		/* the previous view input */
 
-//extern char  *mktemp();  /* XXX should be in stdlib.h or unistd.h */
-
-//double	pixvalue();
-
 static void report(int);
 static int nextview(FILE *fp);
 static void render(char *zfile, char *oldfile);
@@ -696,9 +695,11 @@ pixvalue(		/* compute pixel value */
 						/* optional depth-of-field */
 	if (dblur > FTINY && vdist > FTINY) {
 		double  vc, dfh, dfv;
-						/* PI/4. square/circle conv. */
-		dfh = PI/4.*dblur*(.5 - frandom());
-		dfv = PI/4.*dblur*(.5 - frandom());
+						/* square/circle conv. */
+		dfh = vc = 1. - 2.*frandom();
+		dfv = 1. - 2.*frandom();
+		dfh *= .5*dblur*sqrt(1. - .5*dfv*dfv);
+		dfv *= .5*dblur*sqrt(1. - .5*vc*vc);
 		if (ourview.type == VT_PER || ourview.type == VT_PAR) {
 			dfh /= sqrt(ourview.hn2);
 			dfv /= sqrt(ourview.vn2);