#!/bin/bash

# ============================================
# Make a click map of all our locals.
# --------------------------------------------
# Alfred Klomp, May 2006
# ============================================

# Setup:

  MAP_WIDTH_IN_INCH=3      # Total map width, 1 inch = 300 pixels
  STAR_WIDTH_IN_INCH=0.05  # Size of the little stars
  LAT_MARGIN=2             # Top/bottom margin in degrees latitude
  LON_MARGIN=3             # Left/right margin in degrees longitude

# Input: the locations to plot are in a file called
# coordinates.txt in the following form:
# --------------------------------------------
# LOCALCODE:COUNTRY:NAME:LAT:LONG
# LOCALCODE:COUNTRY:NAME:LAT:LONG
# [ ... etc ... ]
# --------------------------------------------

# First, we have to find out the extents of our map. We parse the coordinate
# file to find the min/max lat/long pairs, and round off the values.
  MIN_LAT=$( cat coordinates.txt | awk 'BEGIN{FS=":"}{print $3}' | sort -n  | head -n1 | awk '{ print int($1 - '$LAT_MARGIN') }' )
  MAX_LAT=$( cat coordinates.txt | awk 'BEGIN{FS=":"}{print $3}' | sort -nr | head -n1 | awk '{ print int($1 + '$LAT_MARGIN') }' )
  MIN_LON=$( cat coordinates.txt | awk 'BEGIN{FS=":"}{print $4}' | sort -n  | head -n1 | awk '{ print int($1 - '$LON_MARGIN') }' )
  MAX_LON=$( cat coordinates.txt | awk 'BEGIN{FS=":"}{print $4}' | sort -nr | head -n1 | awk '{ print int($1 + '$LON_MARGIN') }')

# Create base map.
  pscoast -K -R$MIN_LON/$MAX_LON/$MIN_LAT/$MAX_LAT -JM${MAP_WIDTH_IN_INCH}i -P -G41/22/111 -S153/204/255 -Dh > clickmap.eps

# Export all coordinates from the master file to a temp file containing "LON LAT" pairs.
  awk 'BEGIN{FS=":"}{ print $4 " " $3 }' coordinates.txt > coordinates.tmp
# Plot LON LAT pairs on our base map as stars.
  psxy -R -J -O -K -Sa${STAR_WIDTH_IN_INCH}i -Gyellow  coordinates.tmp >> clickmap.eps

# Plot LON LAT pairs again, as points this time, to stdout for further filtering:
  psxy -R -J -O -Sp coordinates.tmp | \
# Of all the postscript on stdout, we're only interested in the point drawing commands:
  egrep "[0-9]* [0-9]* [0-9]* O" | \
# We filter out the x and y coordinates and write them to a file for later revisiting:
  awk '{ print $2, $3 }' > clickmap.coords

# Close EPS map file by writing a bogus coordinate:
  echo "9999 9999" | psxy -J -R -O >> clickmap.eps

# Render to PNG with Ghostscript:
  gs -sDEVICE=png16m -dGraphicsAlphaBits=2 -sOutputFile=clickmap.png -r300 -dSAFER -dBATCH -dNOPAUSE clickmap.eps

# Trim white border off image:
  convert -trim clickmap.png clickmap.out.png
  mv clickmap.out.png clickmap.png

# Now we have to convert our x y coordinate pairs to pixel coordinates.
# The postscript origin is bottom left, the pixel origin is top left.
# So we have to invert the y coordinates. ( y := HEIGHT - y )

# Get height of PNG image
  IMAGE_HEIGHT=$( file clickmap.png | egrep -o "x [0-9]*" | awk '{ print $2 }' )

# Invert Y coordinate in file:
  awk '{ print $1 ":" '${IMAGE_HEIGHT}' - $2 - 1 ":" }' clickmap.coords > clickmap.coords.tmp

# Note: the one-to-one correspondence of postscript coordinates to pixels
# only works when both the map and the raster image are rendered at 300 dpi,
# which is the native resolution for GMT.
# If you want a different size map, adjust the WIDTH_IN_INCH parameter at
# the beginning of this script, not the rasterization resolution!

# Get CLICK_RADIUS, it's half of STAR_WIDTH_IN_INCH * 300 pixels/inch:
  CLICK_RADIUS=$( echo "scale=0; ${STAR_WIDTH_IN_INCH} * 300 / 2" | bc )

# Rejoin pixel coordinates and original file of locals,
# delete tab character inserted in rejoining process:
  paste clickmap.coords.tmp coordinates.txt | tr -d '\t' | \
# Make HTML code from our pixel coordinate file:
  awk 'BEGIN { FS=":"; print "<map name=\"cmap\">" } \
       { print "    <area shape=\"circle\" coords=\"" $1 "," $2 "," '$CLICK_RADIUS' "\" href=\"http://www.karl.aegee.org/ab.nsf/BodiesByAbbreviationEdi/" $3 "\" alt=\"" $4 "\" title=\"" $4 "\">" } \
       END{ print "</map>" }' > clickmap.html

# Clean up
  rm clickmap.coords
  rm clickmap.coords.tmp
  rm coordinates.tmp
  rm clickmap.eps

# Optional: use pngquant to reduce the colour depth
  pngquant 16 clickmap.png
  mv clickmap-fs8.png clickmap.png

# Output: clickmap.png  = the clickmap image
#         clickmap.html = the HTML for the clickmap