distort-stl: introduce $gensplit (nfc)

[reprap-play.git] / distort-stl

diff --git a/distort-stl b/distort-stl
index 39e5a150512c339c38a7a635194194a95b886bce..9d8569062b193e10413a3c91e643feeed4f633b9 100755 (executable)
--- a/distort-stl
+++ b/distort-stl
@@ -32,6 +32,14 @@ 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 $!;
+    print PS "%!\n";
+}
+
 our $fa = 10;
 
 our $triangles;
@@ -44,27 +52,89 @@ sub shift_arg () {
 
 #no warnings qw(recursion);
 
-sub subdivide_triangle ($$) {
-    my ($t, $fn) = @_;
+sub sprintf_triangle ($) {
+    my ($t) = @_;
+
+    return '' unless $debug;
+
+    if ($ps && $t->[3] =~ m/$ENV{DISTORT_PS_RE}/) {
+       printf PS <<'END',
+ %20.16g %20.16g %20.16g moveto
+ %20.16g %20.16g %20.16g lineto
+ %20.16g %20.16g %20.16g lineto
+ closepath stroke
+END
+               $t->[0][0], $t->[0][1], $t->[0][2],
+               $t->[1][0], $t->[1][1], $t->[1][2],
+               $t->[2][0], $t->[2][1], $t->[2][2],
+               or die $!;
+       flush PS or die $!;
+    }
+
+    sprintf
+       "%11.6f,%11.6f,%11.6f / ".
+       "%11.6f,%11.6f,%11.6f / ".
+       "%11.6f,%11.6f,%11.6f  %-40s ",
+               $t->[0][0], $t->[0][1], $t->[0][2],
+               $t->[1][0], $t->[1][1], $t->[1][2],
+               $t->[2][0], $t->[2][1], $t->[2][2],
+               $t->[3];
+}
 
-    #print STDERR 'SUBDIV', Dumper($t, $fn);
+sub maybe_subdivide_triangle ($$$$) {
+    my ($t, $ok, $changed, $edge_need_subdivide_fn) = @_;
 
-    my @mids;
+    print STDERR sprintf_triangle $t if $debug;
+    
     foreach my $ix (0..2) {
        my $jx = ($ix+1) % 3;
-       my @midp;
-       foreach my $ci (0..2) {
-           push @midp, 0.5 * ($t->[$ix][$ci] + $t->[$jx][$ci]);
+       my $kx = ($ix+2) % 3;
+       if ($edge_need_subdivide_fn->($t->[$ix], $t->[$jx])) {
+           printf STDERR
+               " S i=%d j=%d k=%d ",
+               $ix, $jx, $kx
+               if $debug;
+           my @midp;
+           foreach my $ci (0..2) {
+               push @midp, 0.5 * ($t->[$ix][$ci] + $t->[$jx][$ci]);
+           }
+
+           printf STDERR
+               " midp %11.6f,%11.6f,%11.6f\n",
+               @midp
+               if $debug;
+
+           # triangle i-j-k, splitting edge i-m
+           # gives    i-m-k, k-m-j
+           my $gensplit = sub {
+               my ($ixjx, $xwhat) = @_;
+               my $n = [ @$t ];
+               $n->[$ixjx] = \@midp;
+               $n->[3] = "$t->[3]$xwhat";
+               printf STDERR "%s\n", sprintf_triangle $n if $debug;
+               unshift @$changed, $n;
+           };
+           $gensplit->($ix, "a$ix$jx");
+           $gensplit->($jx, "b$ix$jx");
+           return;
        }
-       push @mids, \@midp;
     }
-    foreach my $ix (0..2) {
-       #print STDERR 'SUBDIV IX ', $ix, "\n";
-       my $kx = ($ix+2) % 3;
-       $fn->([ $t->[$ix], $mids[$ix], $mids[$kx] ]);
+    push @$ok, $t;
+    printf STDERR "OK nok=%d nchanged=%d\n",
+       (scalar @$ok), (scalar @$changed)
+       if $debug;
+}
+
+sub maybe_subdivide ($) {
+    my ($edge_need_subdivide_fn) = @_;
+    
+    my @small_enough = ();
+    while (my $t = shift @$triangles) {
+       maybe_subdivide_triangle $t, \@small_enough, $triangles,
+           $edge_need_subdivide_fn;
     }
-    #print STDERR 'SUBDIV MID\n';
-    $fn->(\@mids);
+
+    $triangles = \@small_enough;
 }
 
 sub append_triangle ($) {
@@ -72,23 +142,20 @@ sub append_triangle ($) {
     push @$output, $t;
 }
 
+#---------- set-fa ----------
+
+sub op__set_fa () {
+    $fa = shift_arg;
+}
+
 #---------- project-cylinder ----------
 
 our $project_cylinder_radius;
 our $project_cylinder_max_d_theta;
 
-sub project_cylinder_need_subdivide () {
-    foreach my $t (@$triangles) {
-       my @thetas = map { $_->[0] / $project_cylinder_radius } @$t;
-
-       foreach my $ix (0..2) {
-           if (abs($thetas[$ix] - $thetas[($ix+1)%3])
-               > $project_cylinder_max_d_theta) {
-               return 1;
-           }
-       }
-    }
-    return 0;
+sub project_cylinder_edge_need_subdivide ($$) {
+    my @thetas = map { $_->[0] / $project_cylinder_radius } @_;
+    return abs($thetas[0] - $thetas[1]) > $project_cylinder_max_d_theta;
 }
 
 sub project_cylinder_tri {
@@ -114,14 +181,8 @@ sub op__project_cylinder () {
     $project_cylinder_radius = shift_arg;
     $project_cylinder_max_d_theta = $fa * TAU/360;
 
-    while (project_cylinder_need_subdivide()) {
-       $output = [];
-       foreach my $t (@$triangles) {
-           subdivide_triangle $t, \&append_triangle;
-       }
-       $triangles = $output;
-    }
-
+    maybe_subdivide \&project_cylinder_edge_need_subdivide;
+    
     $output = [];
     foreach my $t (@$triangles) {
        project_cylinder_tri $t;
@@ -175,6 +236,7 @@ while (<I>) {
        push @$triangle, \@xyz;
     } elsif (m/^endloop/) {
        die unless @$triangle == 3;
+       push @$triangle, $.;
        push @$triangles, $triangle;
        undef $triangle;
     } elsif (m/^(?:solid|facet\s+normal|endfacet|endsolid)\s/) {