#!/usr/bin/perl -w

if (1 != $#ARGV) {
    die "usage: eps2ppm PS/EPS_input [width]x[height]|dpi\n";
}

$gs = "/sw/bin/gs";
$me = "eps2ppm";
$fileIn = $ARGV[0];
$sizeInfo = $ARGV[1];

$blah = 0;
open(EPSFILE, $fileIn)
    or die "$0: Can't open $fileIn for reading.\n";
$hasShowpage = 0;
$foundBBox = 0;
while (<EPSFILE>) {
    chop;
    # print "$_, foundBBox = $foundBBox\n";
    if (not $foundBBox and /^%%BoundingBox:/) {
	($blah, $bndmX, $bndmY, $bndMX, $bndMY) = split;
	print STDERR "$me: bounding box: ($bndmX,$bndmY) ($bndMX,$bndMY).\n";
	$foundBBox = 1;
    }
    if (/showpage/) {
	$hasShowpage = 1;
    }
}
close(EPSFILE);
if (!($foundBBox)) {
    die "$me: Sorry, couldn't find valid BoundingBox command.\n";
}

if ($hasShowpage) {
    print STDERR "$me: Great: $fileIn seems to have its own showpage command.\n";
    print STDERR "$me: But if image is blank, you'll need to add a showpage command\n";
    print STDERR "$me: to the end of the eps file.\n";
    $showpage = "";
}
else {
    print STDERR "$me: $fileIn doesn't seem to have its own showpage command, adding one.\n";
    print STDERR "$me: If image file is twice as long as it should be, that is\n";
    print STDERR "$me: too bad until I add other options to this script.\n";
    $showpage = "showpage";
}


#
# determine output image dimensions and resolution
#
$pageX = $bndMX - $bndmX;
$pageY = $bndMY - $bndmY;
$aspect = $pageX/$pageY;
print STDERR "$me: page is $pageX by $pageY points, aspectratio = $aspect.\n";

if ($sizeInfo =~ "x") { 
    ($imageX, $imageY) = split(/x/, $sizeInfo);
    if (!($imageX)) {
	$imageX = int $imageY * $aspect;
    }
    if (!($imageY)) {
	$imageY = int $imageX / $aspect;
    }
}
else {
    $imageX = int $pageX*$sizeInfo/72;
    $imageY = int $pageY*$sizeInfo/72;
}
print STDERR "$me: Will generate $imageX by $imageY ppm.\n";

$resX = int 72*$imageX/$pageX;
$resY = int 72*$imageY/$pageY;

#
# set-up and run the actual gs command
#
#$epsCmd = "(echo \"%!\"; echo \"-$bndmX -$bndmY translate\"; /bin/cat $fileIn; echo $showpage) | $gs -dNOPAUSE -sDEVICE=ppmraw -sOutputFile=$fileOut -r".$resX."x".$resY." -g".$imageX."x".$imageY." -";
$epsCmd = "(echo \"%!\"; echo \"-$bndmX -$bndmY translate\"; /bin/cat $fileIn; echo $showpage) | $gs -dNOPAUSE -sDEVICE=ppmraw -sOutputFile=- -q -r".$resX."x".$resY." -g".$imageX."x".$imageY." -";
print STDERR "$me: running \"$epsCmd\" ... \n";
$rc = 0xffff & system($epsCmd);
print STDERR "$me: done. \n";

#
# do something with the return code
#
if ($rc == 0) {
    # no errors
}
elsif ($rc == 0xff00) {
    # not sure what good this does
    print STDERR "$me: gs failed";
    print STDERR " with error $!" if ($!);
    print STDERR ".\n";
}
elsif ($rc > 0x80) {
    $rc >>= 8;
    print STDERR "$me: gs ran with non-zero exit status $rc.\n";
}
else {
    print STDERR "$me: gs ran with ";
    if ($rc &   0x80) {
        $rc &= ~0x80;
        print STDERR "coredump from ";
    }
    print STDERR "signal $rc.\n";
}

# pass return code back to caller
exit($rc);