#!/bin/sh
#
# Output an Encapsulated PostScript File with a 14:10 aspect grid on top
#

defs_file=@defs@

export PATH=@path@
export LD_LIBRARY_PATH=@ld_lib_path@

x_off=0
y_off=0
scaling=1
g_intvl=1.5
g_thick=0.05
g_color=0:0:0
p_size=a4

if [ -f $defs_file ]; then
    defs=$(cat $defs_file)
    oifs="$IFS"
    IFS="
"
    for line in $defs; do
	if [ "$IFS" != "$oifs" ]; then IFS="$oifs"; fi
	key="${line%%[ 	]*}"; val="${line##*[ 	]}"
	case "$key" in
	x_offset)       x_off=$val;;
	y_offset)       y_off=$val;;
	scaling)        scaling=$val;;
	grid_interval)  g_interval=$val;;
	grid_thickness) g_thick=$val;;
	grid_color)     g_color=$val;;
	paper_size)     p_size=$val;;
	esac
    done

fi

usage_defs="-x$x_off -y$y_off -s$scaling -i$g_intvl -t$g_thick -c$g_color -p$p_size"

usage ()
{
    echo "usage: grid [-x xoffset] [-y yoffset] [-s scaling] [-i gridinterval] [-t gridthickness] [-c gridcolor] [-r] [-p papersize] [-l] file

Default values: $usage_defs" >&2
    exit 1
}

while getopts ":x:y:s:i:t:c:rp:l" c
do
    case "$c" in
    x)    x_off=$OPTARG;;
    y)    y_off=$OPTARG;;
    s)    scaling=$OPTARG;;
    i)    g_intvl=$OPTARG;;
    t)    g_thick=$OPTARG;;
    c)    g_color=$OPTARG;;
    r)    r_flag=1;;
    p)    p_size=$OPTARG;;
    l)    l_flag=1;;
    :|'?')  usage;;
    esac
done
if [ $OPTIND -gt 1 ]; then shift $(($OPTIND - 1)); fi
if [ $# -lt 1 ]; then usage; fi

if [ ! -f "$1" ]; then
    echo "grid: Can't open file \`$1'" >&2
    exit 1
fi

ts="$(file "$1")"
t="${ts#*: }"
case "$t" in
PostScript\ document\ text*)
    eps=$1;;
JPEG\ image\ data*)
    pnmcmd=$(which djpeg) || \
	{ echo "grid: Can't find \`djpeg'" >&2; exit 1; };;
TIFF\ image\ data*)
    pnmcmd=$(which tifftopnm) || \
	{ echo "grid: Can't find \`tifftopnm'" >&2; exit 1; };;
GIF\ image\ data*)
    pnmcmd=$(which giftopnm) || pnmcmd=$(which giftoppm) || \
	{ echo "grid: Can't find \`giftopnm' or \`giftoppm'" >&2; exit 1; };;
*)
    echo "grid: Unknown file type" >&2
    exit 1;;
esac

case "$p_size" in
a4)     pw=210; ph=297;;
letter) pw=215.9; ph=279.4;;
*)      pw=${p_size%[X|x]*}; ph=${p_size#*[X|x]};;
esac

if [ -n "$pnmcmd" ]; then
    tmpfile=$(mktemp /usr/tmp/grid.XXXXXX) || exit 1
    eps=$tmpfile
    ps_in="$(echo "$pw $ph" | awk '{print ($1 / 25.4) " " ($2 / 25.4)}')"
    pw_in="${ps_in% *}"; ph_in="${ps_in#* }"
    $pnmcmd "$1" 2>/dev/null | pnmtops -width $pw_in -height $ph_in \
	-noturn >$eps 2>/dev/null || { rm -f $tmpfile; exit 1; }
fi

tmp=$(cat "$eps" | awk '/^%%BoundingBox:/ { print (- $2) " " (- $3) }')
llx_adj=${tmp% *}; lly_adj=${tmp#* }

g_hdiv=1.4; g_vdiv=1
if [ -n "$r_flag" ]; then
    g_hdiv=1; g_vdiv=1.4
fi

if [ -n "$l_flag" ]; then
    tmp=$pw; pw=$ph; ph=$tmp
fi

cat <<EOF
%!

/mm {72 mul 25.4 div} def

/pw $pw mm def
/ph $ph mm def

/x_off $x_off mm def
/y_off $y_off mm def
/scaling $scaling def
/llx_adj $llx_adj def
/lly_adj $lly_adj def

/g_intvl $g_intvl mm def
/g_thick $g_thick mm def
/g_dthick g_thick 2 mul def
/g_color [$(echo -n $g_color | sed 's/:/ /g')] def

/g_hdiv $g_hdiv def
/g_vdiv $g_vdiv def

1 dict dup /PageSize [pw ph] put setpagedevice

/BeginEPSF {
    /b4_Inc_state save def		% Save state for cleanup
    /dict_count countdictstack def	% Count objects on dict stack
    /op_count count 1 sub def		% Count objects on operand stack
    userdict begin			% Push userdict on dict stack
    /showpage { } def			% Redefine showpage to null proc
    0 setgray 0 setlinecap		% Prepare graphics state
    1 setlinewidth 0 setlinejoin
    10 setmiterlimit [ ] 0 setdash newpath
    /languagelevel where		% If languagelevel not equal to 1 then
    {pop languagelevel			% set strokeadjust and
    1 ne 				% overprint to their defaults
	{false setstrokeadjust false setoverprint
	} if
    } if
} bind def

/EndEPSF {
    count op_count sub {pop} repeat	% Clean up stacks
    countdictstack dict_count sub {end} repeat
    b4_Inc_state restore
} bind def

BeginEPSF
x_off y_off translate scaling dup scale llx_adj lly_adj translate
EOF
cat "$eps"
cat <<EOF
EndEPSF

g_thick setlinewidth
g_color aload pop setrgbcolor

% Horizontal grid lines
/nl 1 def
g_intvl g_hdiv div g_intvl g_hdiv div ph {
    nl 14 eq { g_dthick setlinewidth } if
    0 exch moveto pw 0 rlineto stroke
    nl 14 eq { g_thick setlinewidth /nl 0 def } if
    /nl nl 1 add def
} for

% Vertical grid lines
/nl 1 def
g_intvl g_vdiv div g_intvl g_vdiv div pw {
    nl 10 eq { g_dthick setlinewidth } if
    0 moveto 0 ph rlineto stroke
    nl 10 eq { g_thick setlinewidth /nl 0 def } if
    /nl nl 1 add def
} for

showpage
EOF

rm -f $tmpfile
.