sub TAU () { M_PI * 2; }
+our $debug = $ENV{DISTORT_DEBUG} // 0 ;
+
+my $ps = $ENV{DISTORT_PS};
+if ($ps) {
+ open PS, "> $ps" or die $!;
+ print PS "%!\n";
+}
+
our $fa = 10;
our $triangles;
#no warnings qw(recursion);
-sub subdivide_triangle ($$) {
- my ($t, $fn) = @_;
+sub sprintf_triangle ($) {
+ my ($t) = @_;
+
+ return '' unless $debug;
+
+ if ($ps && $t->[3] =~ m/$ENV{DISTORT_PS_RE}/) {
+ printf PS <<'END',
+ %20.16g %20.16g %20.16g moveto
+ %20.16g %20.16g %20.16g lineto
+ %20.16g %20.16g %20.16g lineto
+ closepath stroke
+END
+ $t->[0][0], $t->[0][1], $t->[0][2],
+ $t->[1][0], $t->[1][1], $t->[1][2],
+ $t->[2][0], $t->[2][1], $t->[2][2],
+ or die $!;
+ flush PS or die $!;
+ }
+
+ sprintf
+ "%11.6f,%11.6f,%11.6f / ".
+ "%11.6f,%11.6f,%11.6f / ".
+ "%11.6f,%11.6f,%11.6f %-40s ",
+ $t->[0][0], $t->[0][1], $t->[0][2],
+ $t->[1][0], $t->[1][1], $t->[1][2],
+ $t->[2][0], $t->[2][1], $t->[2][2],
+ $t->[3];
+}
+
+sub maybe_subdivide_triangle ($$$$) {
+ my ($t, $ok, $changed, $edge_need_subdivide_fn) = @_;
- #print STDERR 'SUBDIV', Dumper($t, $fn);
+ print STDERR sprintf_triangle $t if $debug;
+
+ my (@longest) = qw(-1);
- my @mids;
foreach my $ix (0..2) {
my $jx = ($ix+1) % 3;
- my @midp;
+ next unless $edge_need_subdivide_fn->($t->[$ix], $t->[$jx]);
+ my $l2 = 0;
foreach my $ci (0..2) {
- push @midp, 0.5 * ($t->[$ix][$ci] + $t->[$jx][$ci]);
+ my $d = $t->[$ix][$ci] - $t->[$jx][$ci];
+ $l2 += $d*$d;
}
- push @mids, \@midp;
+ next unless $l2 > $longest[0];
+ @longest = ($l2, $ix, $jx);
}
- foreach my $ix (0..2) {
- #print STDERR 'SUBDIV IX ', $ix, "\n";
- my $kx = ($ix+2) % 3;
- $fn->([ $t->[$ix], $mids[$ix], $mids[$kx] ]);
+ if ($longest[0] < 0) {
+ push @$ok, $t;
+ printf STDERR "OK nok=%d nchanged=%d\n",
+ (scalar @$ok), (scalar @$changed)
+ if $debug;
+ print STDERR Dumper(\@$ok) if $debug>=2;
+ return;
}
- #print STDERR 'SUBDIV MID\n';
- $fn->(\@mids);
+ my ($dummy,$ix,$jx) = @longest;
+ my $kx = ($ix+2) % 3;
+
+ 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;
+}
+
+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;
+ }
+
+ $triangles = \@small_enough;
}
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 {
my $radius = $project_cylinder_radius;
my @ot;
- foreach my $p (@$t) {
+ foreach my $p (@$t[0..2]) {
my ($x,$y,$z) = @$p;
my $r = $radius - $y;
my $theta = $x / $radius;
-$r * cos($theta),
$z ];
}
+ push @ot, $t->[3].'P';
append_triangle \@ot;
}
$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 $t;
push @$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/) {
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 @$t==4;
+ foreach my $p (@$t[0..2]) {
die unless @$p==3;
print " vertex";
printf " %.18g", $_ foreach @$p;