#!/bin/sh
# Given a directory and a 4 Lat/Lon coordinates for that image
# look for subdirectories named 1, 2, 3, 4 and traverse them,
# creating superoverlay images.
# To create the directory hierarchy, run subdivide2 first.
# We assume the subdirectories have this layout:
#  0 1
#  2 3 
# and that each subdirectory has a file called img.png.

# Edit dicekml to point to this script.  FIXME: there must be a better way.
dicekml=c:/cxh/src/fg/bmearth/dice3/dicekml

# Error checking
if [ ! -x $dicekml ]; then
    echo "$0: Can't find myself, edit $0 and set dicekml"
    exit 4
fi

if [ $# -ne 4 ]; then
    echo "$0: usage: $0 north south east west"
    echo "for example:"
    echo "$0 40.786612 40.740281 -119.199895 -119.271914"
    echo "$0 40.7868993953 40.7405683953 -119.199614647 -119.271633647"
    exit 2
fi
north=$1
south=$2
east=$3
west=$4

minLodPixels=460

# N/S and E/W Center points
northSouthCenter=`echo foo | awk '{printf("%3.20f\n",(north + south)/2.0)}' north=${north} south=${south}`
eastWestCenter=`echo foo | awk '{printf("%3.20f\n",(east + west)/2.0)}' east=${east} west=${west}`

echo "dicekml creating `pwd`/doc.kml"
#echo "`pwd`: $north $south $east $west"



if [ -d 1 ]; then
    # Go in to the subdirectories
# Create the doc.kml file for this level
cat > doc.kml <<EOF
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.1">
<Document>
  <Region>
    <LatLonAltBox>
      <north>$north</north><south>$south</south>
      <east>$east</east><west>$west</west>
    </LatLonAltBox>
    <Lod>
      <minLodPixels>0</minLodPixels><maxLodPixels>-1</maxLodPixels>
    </Lod>
  </Region>
  <NetworkLink>
    <name>1</name>
    <Region>
      <LatLonAltBox>
        <north>$north</north><south>$northSouthCenter</south>
        <east>$east</east><west>$eastWestCenter</west>
      </LatLonAltBox>
      <Lod>
        <minLodPixels>$minLodPixels</minLodPixels><maxLodPixels>-1</maxLodPixels>
      </Lod>
    </Region>
    <Link>
      <href>1/doc.kml</href>
      <viewRefreshMode>onRegion</viewRefreshMode>
    </Link>
  </NetworkLink>
  <NetworkLink>
    <name>0</name>
    <Region>
      <LatLonAltBox>
        <north>$north</north><south>$northSouthCenter</south>
        <east>$eastWestCenter</east><west>$west</west>
      </LatLonAltBox>
      <Lod>
        <minLodPixels>$minLodPixels</minLodPixels><maxLodPixels>-1</maxLodPixels>
      </Lod>
    </Region>
    <Link>
      <href>0/doc.kml</href>
      <viewRefreshMode>onRegion</viewRefreshMode>
    </Link>
  </NetworkLink>
  <NetworkLink>
    <name>3</name>
    <Region>
      <LatLonAltBox>
        <north>$northSouthCenter</north><south>$south</south>
        <east>$east</east><west>$eastWestCenter</west>
      </LatLonAltBox>
      <Lod>
        <minLodPixels>$minLodPixels</minLodPixels><maxLodPixels>-1</maxLodPixels>
      </Lod>
    </Region>
    <Link>
      <href>3/doc.kml</href>
      <viewRefreshMode>onRegion</viewRefreshMode>
    </Link>
  </NetworkLink>
  <NetworkLink>
    <name>2</name>
    <Region>
      <LatLonAltBox>
        <north>$northSouthCenter</north><south>$south</south>
        <east>$eastWestCenter</east><west>$west</west>
        <minAltitude>0.000000</minAltitude><maxAltitude>0.000000</maxAltitude>
      </LatLonAltBox>
      <Lod>
        <minLodPixels>$minLodPixels</minLodPixels><maxLodPixels>-1</maxLodPixels>
      </Lod>
    </Region>
    <Link>
      <href>2/doc.kml</href>
      <viewRefreshMode>onRegion</viewRefreshMode>
    </Link>
  </NetworkLink>
  <GroundOverlay>
    <drawOrder>21</drawOrder>
    <Icon>
      <href>img.png</href>
    </Icon>
    <LatLonBox>
      <north>$north</north><south>$south</south>
      <east>$east</east><west>$west</west>
    </LatLonBox>
  </GroundOverlay>
</Document>
</kml>
EOF
    (cd 0; $dicekml $north $northSouthCenter $eastWestCenter $west)
    (cd 1; $dicekml $north $northSouthCenter $east $eastWestCenter)
    (cd 2; $dicekml $northSouthCenter $south $eastWestCenter $west)
    (cd 3; $dicekml $northSouthCenter $south $east $eastWestCenter)

else
    # We just have one image in this directory, no subdirectories
cat > doc.kml <<EOF
<?xml version="1.0" encoding="UTF-8"?>
<kml xmlns="http://earth.google.com/kml/2.1">
<Document>
  <Region>
    <LatLonAltBox>
      <north>$north</north><south>$south</south>
      <east>$east</east><west>$west</west>
    </LatLonAltBox>
    <Lod>
      <minLodPixels>0</minLodPixels><maxLodPixels>-1</maxLodPixels>
    </Lod>
  </Region>
  <GroundOverlay>
    <drawOrder>21</drawOrder>
    <Icon>
      <href>img.png</href>
    </Icon>
    <LatLonBox>
      <north>$north</north><south>$south</south>
      <east>$east</east><west>$west</west>
    </LatLonBox>
  </GroundOverlay>
</Document>
</kml>
EOF

fi