#!/usr/bin/perl 
# 
# perl interpolcmdinwf.pl in out cmd DISTFN commandwithDISTDEPVALUE
#
# Throws in a distance dependendent command after each jump
#
# in can be a file with like 'part1' or 'part1_snap'
#
#  e.g. perl interpolcmdinwf.pl part1_tripthruhipparcos_snap outfile 0.1+0.3\*\(DIST/860\)   g8 slum DISTDEPVALUE
#
# Note that you need to put backslashes before * and ( and ).
# The above eg should be interpreted as
#   define DISTDEPVALUE := 0.1+0.3*(DIST/860)
#   where DIST is the distance from the camera to the origin
#   and then the statement "g8 slum x", where x is the value of DISTDEPVALUE 
#   is inserted in the input file (in) after each jump statement 
#   to produce the resulting output file (out).

$in = $ARGV[0];
$out = $ARGV[1];
$distfn = $ARGV[2];       # defines the function of distance 

print "$distfn\n\n";

$distcmd = $ARGV[3];      # defines the command to place after each jump command

for ($i=4; $i<=$#ARGV; $i++)
{
  $distcmd = $distcmd." ".$ARGV[$i];
}


open (IN,"$in");
open (OUT,">$out");

while ($line = <IN>)
{
    chomp $line;
    @tmp = split /[\t\n ]+/, $line;
    print OUT $line, "\n";
    if ($line =~ /jump/)
    {
	$start = 0;
	while (length($tmp[$start]) == 0) {$start++;}
	$x = $tmp[$start+2];
	$y = $tmp[$start+3];
	$z = $tmp[$start+4];

	$dist = sqrt ($x*$x + $y*$y + $z*$z);
#	print "$x $y $z ... $dist  ";

	$somecmd = "\$val = $distfn;";
	$somecmd =~ s/DIST/$dist/;
	eval ($somecmd);

#	print $somecmd, "\n";;
#	print $val , "\n";
#	print "------\n";

	$somecmd = "\$cmd = \"echo $distcmd\"";
	$somecmd =~ s/DISTDEPVALUE/$val/;
	eval ($somecmd);

#	print $somecmd, "\n";;
#	print $cmd , "\n";
#	print "------\n";

	print OUT "$cmd\n";
    }
}

sub min
{
    my ($a, $b) = @_;
    if ($a < $b) {return $a;} else {return $b;}
}

sub max
{
    my ($a, $b) = @_;
    if ($a > $b) {return $a;} else {return $b;}
}

sub sigmoid   # creates function that increases from ya at a to yb at b, gives value at position x, which is between a and b.
{
    my ($x,$a,$b,$ya,$yb) = @_;    

    $x = log(0.001 + $x);
    $a = log(0.001 + $a);
    $b = log(0.001 + $b);

    # y = 1/(1+exp(-x)) goes from 0 to 1 as x goes from -5 to 5
    # y = ya + (yb-ya)/(1+exp(5-x)) goes from ya to yb as x goes from 0 to 10
    # y = ya + (yb-ya)/(1+exp(5-(10*x/(b-a)))) goes from ya to yb as x goes from 0 to b-a
    # y = ya + (yb-ya)/(1+exp(5-(10*(x-a)/(b-a)))) goes from ya to yb as x goes from a to b

    return $ya+($yb-$ya)/(1+exp(5-(10*($x-$a)/($b-$a))));
}

sub linear   # creates function that linearly increases from ya at a to yb at b, gives value at position x, which is between a and b.
{
    my ($x,$a,$b,$ya,$yb) = @_;    
    
    # y = 1/(1+exp(-x)) goes from 0 to 1 as x goes from -5 to 5
    # y = ya + (yb-ya)/(1+exp(5-x)) goes from ya to yb as x goes from 0 to 10
    # y = ya + (yb-ya)/(1+exp(5-(10*x/(b-a)))) goes from ya to yb as x goes from 0 to b-a
    # y = ya + (yb-ya)/(1+exp(5-(10*(x-a)/(b-a)))) goes from ya to yb as x goes from a to b

    $v = $ya+(($yb-$ya)*($x-$a)/($b-$a));
    $v = min($v,max($ya,$yb));
    $v = max($v,min($ya,$yb));
    return $v;
}