distort-stl: debugging, make STDERR output conditional

Signed-off-by: Ian Jackson <ijackson@chiark.greenend.org.uk>

diff --git a/distort-stl b/distort-stl
index a470ae39c68a34965ea9fd5f5a3c0e66ddcf6a71..cc959dd7dbbd521054d5bbf2b54d7f1a9fdd34ca 100755 (executable)
--- a/distort-stl
+++ b/distort-stl
@@ -32,6 +32,8 @@ use Data::Dumper;
 
 sub TAU () { M_PI * 2; }
 
+our $debug = $ENV{DISTORT_DEBUG};
+
 my $ps = $ENV{DISTORT_PS};
 if ($ps) {
     open PS, "> $ps" or die $!;
@@ -53,6 +55,8 @@ sub shift_arg () {
 sub sprintf_triangle ($) {
     my ($t) = @_;
 
+    return '' unless $debug;
+
     if ($ps && $t->[3] =~ m/$ENV{DISTORT_PS_RE}/) {
        printf PS <<'END',
  %20.16g %20.16g %20.16g moveto
@@ -80,7 +84,7 @@ END
 sub maybe_subdivide_triangle ($$$$) {
     my ($t, $ok, $changed, $edge_need_subdivide_fn) = @_;
 
-    print STDERR sprintf_triangle $t;
+    print STDERR sprintf_triangle $t if $debug;
     
     foreach my $ix (0..2) {
        my $jx = ($ix+1) % 3;
@@ -88,7 +92,8 @@ sub maybe_subdivide_triangle ($$$$) {
        if ($edge_need_subdivide_fn->($t->[$ix], $t->[$jx])) {
            printf STDERR
                " S i=%d j=%d k=%d ",
-               $ix, $jx, $kx;
+               $ix, $jx, $kx
+               if $debug;
            my @midp;
            foreach my $ci (0..2) {
                push @midp, 0.5 * ($t->[$ix][$ci] + $t->[$jx][$ci]);
@@ -96,26 +101,28 @@ sub maybe_subdivide_triangle ($$$$) {
 
            printf STDERR
                " midp %11.6f,%11.6f,%11.6f\n",
-               @midp;
+               @midp
+               if $debug;
 
            # triangle i-j-k, splitting edge i-m
            # gives    i-m-k, k-m-j
            my $n = [ @$t ]; $n->[$ix] = \@midp;  $n->[3] = "$t->[3]a$ix$jx";
            unshift @$changed, $n;
 
-           printf STDERR "%s\n", sprintf_triangle $n;
+           printf STDERR "%s\n", sprintf_triangle $n if $debug;
 
            my $n = [ @$t ]; $n->[$jx] = \@midp;  $n->[3] = "$t->[3]b$ix$jx";
            unshift @$changed, $n;
 
-           printf STDERR "%s\n", sprintf_triangle $n;
+           printf STDERR "%s\n", sprintf_triangle $n if $debug;
 
            return;
        }
     }
     push @$ok, $t;
     printf STDERR "OK nok=%d nchanged=%d\n",
-       (scalar @$ok), (scalar @$changed);
+       (scalar @$ok), (scalar @$changed)
+       if $debug;
 }
 
 sub maybe_subdivide ($) {