From 7354edee2b9e5af5d8e36a0ccc53c0963e8c1e31 Mon Sep 17 00:00:00 2001
From: Werner Almesberger <werner@almesberger.net>
Date: Thu, 15 Dec 2011 16:24:14 -0300
Subject: [PATCH] dxf2x/dxf2gp: simple DXF to Gnuplot converter

Mainly for the M1 case design:
http://projects.qi-hardware.com/index.php/p/m1/source/tree/master/cad/protocase_v7_laser.dxf
---
 dxf2x/dxf2gp | 99 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100755 dxf2x/dxf2gp

diff --git a/dxf2x/dxf2gp b/dxf2x/dxf2gp
new file mode 100755
index 0000000..6aeb0d9
--- /dev/null
+++ b/dxf2x/dxf2gp
@@ -0,0 +1,99 @@
+#!/usr/bin/perl
+#
+# dxf2gp - Convert simple DXF to Gnuplot
+#
+# Written 2011 by Werner Almesberger
+# Copyright 2011 Werner Almesberger
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+
+#
+# Currently, only the directives LINE, CIRCLE, and ARC are supported.
+# Adjacent line segments are not merged. Arcs and circles are translated
+# to (multi-segment) lines.
+#
+# The main purpose of this script is currently to convert the M1 case
+# design:
+# http://projects.qi-hardware.com/index.php/p/m1/source/tree/master/cad/protocase_v7_laser.dxf
+#
+
+$S_SCAN = 0;		# wait for LINE, CIRCLE, or ARC
+$S_ByLayer = 1;		# next is ByLayer
+$S_INDEX = 2;		# next is index
+$S_DATA = 3;		# next is indexed data
+$S_MARKER = 4;		# next is subclass marker
+
+
+sub line
+{
+	print "$_[10] $_[20]\n$_[11] $_[21]\n\n";
+}
+
+sub circle
+{
+	local ($x, $y, $r) = ($_[10], $_[20], $_[40]);
+
+	for (my $i = 0; $i != 100; $i++) {
+		local $v = 3.14159265*2/100*$i;
+		print $x+$r*sin($v), " ", $y+$r*cos($v), "\n";
+	}
+	print $x, " ", $y+$r, "\n\n";
+}
+
+sub arc
+{
+	local ($x, $y, $r) = ($_[10], $_[20], $_[40]);
+	local ($a0, $a1) = ($_[50], $_[51]);
+
+	$a1 += 360 if $a1 < $a0;
+	for (my $a = $a0; $a <= $a1; $a += 2) {
+		local $v = 3.14159265/180*$a;
+		print $x+$r*cos($v), " ", $y+$r*sin($v), "\n";
+	}
+	print "\n";
+}
+
+
+$s = $S_SCAN;
+while (<>) {
+	if ($s == $S_SCAN) {
+		if (/^LINE\b/) {
+			*fn = *line;
+		} elsif (/^CIRCLE/) {
+			*fn = *circle;
+		} elsif (/^ARC/) {
+			*fn = *arc;
+		} else {
+			next;
+		}
+		$s = $S_ByLayer;
+		next;
+	} elsif ($s == $S_ByLayer) {
+		if (/^ByLayer/) {
+			$s = $S_INDEX;
+		}
+		next;	
+	} elsif ($s == $S_INDEX) {
+		if ($_ == 0) {
+			&fn(@a);
+			@a = ();
+			$s = $S_SCAN;
+		} elsif ($_ == 100) {
+			$s = $S_MARKER;
+		} else {
+			$index = $_;
+			$s = $S_DATA;
+		}
+	} elsif ($s == $S_DATA) {
+		$a[$index] = $_+0;
+		$s = $S_INDEX;
+	} elsif ($s == $S_MARKER) {
+		$s = $S_INDEX;
+	} else {
+		die;
+	}
+}