#! /bin/bash
# (C) J C Hill 2007

# script to construct, pixelize, and snap the approximate healpix polygons in mangle
# If no outfile is given, healpix polygon file is named automatically and put in masks/healpix/healpix_polys directory
# USAGE: healpixpolys.sh <Nside> <scheme> <p> <r> <polygon_outfile>
# EXAMPLE: healpixpolys.sh 16 s 0 3 
# EXAMPLE: healpixpolys.sh 16 s 0 3 nside16p3s.pol

if [ "$MANGLEBINDIR" = "" ] ; then
    MANGLEBINDIR="../../bin"
fi
if [ "$MANGLESCRIPTSDIR" = "" ] ; then
    MANGLESCRIPTSDIR="../../scripts"
fi
if [ "$MANGLEDATADIR" = "" ] ; then
    MANGLEDATADIR="../../masks"
fi

#check command line arguments
if [ $# -lt 4 ] ; then
    echo >&2 "ERROR: enter Nside value, pixelization scheme, maximum number of polygons per pixel <p>," 
    echo >&2 "resolution <r>, and (optionally) the name of the output file as command line arguments."
    echo >&2 "" 
    echo >&2 "USAGE: healpixpolys.sh <Nside> <scheme> <p> <r> <polygon_outfile>"
    echo >&2 "EXAMPLE: healpixpolys.sh 16 s 0 3" 
    echo >&2 "EXAMPLE: healpixpolys.sh 16 s 0 3 nside16p3s.pol"
    exit 1
fi

if [ "$1" != 0 ]; then
 for ((  I = 1 ;  I < 8192 ;  I = `expr 2 \* $I`  ))
 do
  if [ "$1" = "$I" ]; then
   FLAG=1
  fi
 done

 if [ "$FLAG" != 1 ]; then
     echo >&2 "ERROR: <Nside> must be a power of 2."
     echo >&2 "USAGE: healpixpolys.sh <Nside> <scheme> <p> <r> <polygon_outfile>"
     echo >&2 "EXAMPLE: healpixpolys.sh 16 s 0 3" 
     echo >&2 "EXAMPLE: healpixpolys.sh 16 s 0 3 nside16p3s.pol"
     exit 1
 fi
fi

if [ "$1" = 0 ]; then
 POLYS=1
else
 POLYS=`expr 12 \* $1 \* $1`
fi

#rm jhw
#echo healpix_weight $POLYS >> jhw
#for ((  I = 0 ;  I < POLYS;  I++  ))
#do
#  echo 0 >> jhw
#done

$MANGLEBINDIR/poly2poly -ob -iH$1 - jp || exit
#$MANGLEBINDIR/poly2poly -ob jhw jp || exit
#note that -vo switch is needed in order to keep the correct id numbers (the HEALPix NESTED pixel numbers)

$MANGLEBINDIR/pixelize -P$2$3,$4 -ib -ob -vo jp jpx || exit
rm jp

if [ "$5" = "" ]; then
    if [ ! -d "$MANGLEDATADIR/healpix/healpix_polys" ] ; then
	echo >&2 "ERROR: $MANGLEDATADIR/healpix/healpix_polys not found." 
#	echo >&2 "Check that the environment variable MANGLEDATADIR is pointing to" 
        echo >&2 "the appropriate directory (e.g., the mangle 'masks' directory)." 
        exit 1
    fi
    
    if [ "$3" = 0 ]; then 
        outfile="$MANGLEDATADIR/healpix/healpix_polys/nside${1}_p${4}${2}.pol"
    else
        outfile="$MANGLEDATADIR/healpix/healpix_polys/nside${1}_p-1${2}.pol"
    fi
else
    outfile=$5
fi

$MANGLEBINDIR/snap -ib -vo -os jpx $outfile || exit
rm jpx

echo "HEALPix pixels at Nside=$1 written to $outfile."