#!/bin/perl
# RCSid: $Id: compamb.csh,v 3.7 2008/08/25 04:50:32 greg Exp $
#
# Compute best ambient value for a scene and append to rad input file
# This is a re-write of Greg's CSH script compamb.csh
# (c) Axel Jacobs, Nov 2011

use strict;
use warnings;
use File::Temp qw/ tempdir /;

my $doexpos = 0;
my $docolor = 0;
my $radfile;
my $oct;

sub usage() {
	print "Usage: $0 [-e] [-c] rad_input_file.rad\n";
	exit 1;
}

while ($#ARGV > 0) {
	$_ = shift @ARGV;
	if (m/-e/) {
		$doexpos = 1;
	} elsif (m/-c/) {
		$docolor = 1;
	} else {
		&usage;
	}
}

if ($#ARGV == 0) {
	$radfile = $ARGV[0];
	if (! -f $radfile) {
		die ("Cannot open Radiance input file $ARGV[0]\n");
	}
} else {
	&usage;
}

my $td = tempdir( CLEANUP => 1 );
#set oct=`rad -w -s -e -v 0 $argv[1] QUA=High AMB=$tf.amb OPT=$tf.opt | sed -n 's/^OCTREE= //p'`
my $radout = `rad -w -s -e -v 0 $radfile QUA=High AMB=$td/compamb.amb OPT=$td/compamb.opt`;
exit 1;
#...my $oct = sed -n 's/^OCTREE= //p'`
my $rpictargs = '-av 0 0 0 -aw 16 -dv- -S 1 -x 16 -y 16 -ps 1';
system "rad -n -s -V $radfile | rpict @$td/compamb.opt $rpictargs $oct | ra_rgbe - '\!pvalue -h -H -d' > $td/compamb.dat";
#rad -n -s -V $argv[1] \
	#| rpict @$tf.opt -av 0 0 0 -aw 16 -dv- -S 1 -x 16 -y 16 -ps 1 $oct \
	#| ra_rgbe - '\!pvalue -h -H -d' > $tf.dat

#echo \# Rad input file modified by $0 `date` >> $argv[1]
my $now = localtime();
open (FHrad, ">>$radfile") or
		die("Unable to append to file $radfile\n");
print FHrad "# Rad input file modified by $0 $now";

if ($doexpos == 1) {
	my $expo = `total -u $td/compamb.dat | rcalc -e '$1=2/(.265*$1+.670*$2+.065*$3)'`;
	#chomp $expo;
	#(echo -n 'EXPOSURE= '; \
		#total -u $tf.dat | rcalc -e '$1=2/(.265*$1+.670*$2+.065*$3)') \
		#>> $argv[1]
	print FHrad "EXPOSURE= $expo\n";
}

#lookamb -h -d $tf.amb | rcalc -e '$1=$10;$2=$11;$3=$12' >> $tf.dat
system ("lookamb -h -d $td/compamb.amb | rcalc -e '$1=$10;$2=$11;$3=$12' >> $td/compamb.dat");

#set lavg=`rcalc -e '$1=lum;lum=.265*$1+.670*$2+.065*$3;cond=lum-1e-5' $tf.dat | total -m -p`
my $lavg = `rcalc -e '$1=lum;lum=.265*$1+.670*$2+.065*$3;cond=lum-1e-5' $td/compamb.dat | total -m -p`;

my $av = "$lavg $lavg $lavg";
if ($docolor == 1) {
	my $cavg = `total -m $td/compamb.dat`;
	my ($ravg, $gavg, $bavg) = split(/\t/, $cavg);
	my $sf = $lavg / (.265*$ravg + .670*$gavg + .065*$bavg);
	#my $av = `rcalc -n -e "r=$ravg;g=$gavg;b=$bavg;sf=$lavg/(.265*r+.670*g+.065*b)" -e '$1=sf*r;$2=sf*g;$3=sf*b'`)
	my $av = "$sf*$ravg $sf*$gavg $sf*$bavg";
}

print FHrad "render= -av $av";
close (FHrad);

#EOF