From 230c2e260ddf89a920b070ee48832199b18e212a Mon Sep 17 00:00:00 2001
From: Ian Jackson <ijackson@chiark.greenend.org.uk>
Date: Sun, 7 Jan 2018 22:57:21 +0000
Subject: [PATCH] distort-stl: better, but still needs work

---
 distort-stl | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/distort-stl b/distort-stl
index f898992..9dab4ed 100755
--- a/distort-stl
+++ b/distort-stl
@@ -41,8 +41,13 @@ sub shift_arg () {
     scalar shift @ARGV;
 }
 
+#no warnings qw(recursion);
+
 sub subdivide_triangle ($$) {
     my ($t, $fn) = @_;
+
+    #print STDERR 'SUBDIV', Dumper($t, $fn);
+
     my @mids;
     foreach my $ix (0..2) {
 	my $jx = ($ix+1) % 3;
@@ -50,12 +55,14 @@ sub subdivide_triangle ($$) {
 	foreach my $ci (0..2) {
 	    push @midp, 0.5 * ($t->[$ix][$ci] + $t->[$jx][$ci]);
 	}
-	push @mids, @midp;
+	push @mids, \@midp;
     }
     foreach my $ix (0..2) {
+	#print STDERR 'SUBDIV IX ', $ix, "\n";
 	my $kx = ($ix+2) % 3;
-	$fn->([ $t->[$ix], $mids[$ix], $t->[$kx] ]);
+	$fn->([ $t->[$ix], $mids[$ix], $mids[$kx] ]);
     }
+    #print STDERR 'SUBDIV MID\n';
     $fn->(\@mids);
 }
 
@@ -67,6 +74,8 @@ our $project_cylinder_max_d_theta;
 sub project_cylinder_tri {
     my ($t) = @_;
 
+    #print STDERR 'PROJECT', Dumper($t);
+
     my $radius = $project_cylinder_radius;
 
     my @thetas = map { $_->[0] / $radius } @$t;
@@ -80,7 +89,7 @@ sub project_cylinder_tri {
     }
 
     my @ot;
-    foreach my $p ($t) {
+    foreach my $p (@$t) {
 	my ($x,$y,$z) = @$p;
 	my $r = $radius - $y;
 	my $theta = $x / $radius;
@@ -171,7 +180,9 @@ print "solid distort-stl\n";
 foreach my $t (@triangles) {
     print "  facet normal 0 0 0\n";
     print "    outer loop\n";
+    die unless @$t==3;
     foreach my $p (@$t) {
+	die unless @$p==3;
 	print "      vertex";
 	printf " %.18g", $_ foreach @$p;
 	print "\n";
-- 
2.30.2