X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=reprap-play.git;a=blobdiff_plain;f=distort-stl;h=68290c410a6ae4738d680d6409abd8f3464c008e;hp=cc03ec5e7aea0776a516e12f900159adbdb2fb6f;hb=0dd084916e997047d879b074c71b5d40a311f747;hpb=6db9e531dbae0b0a6d381509788b1f386dcef0bc

diff --git a/distort-stl b/distort-stl
index cc03ec5..68290c4 100755
--- a/distort-stl
+++ b/distort-stl
@@ -32,6 +32,14 @@ use Data::Dumper;
 
 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;
@@ -44,27 +52,103 @@ sub shift_arg () {
 
 #no warnings qw(recursion);
 
-sub subdivide_triangle ($$) {
-    my ($t, $fn) = @_;
+sub sprintf_triangle ($) {
+    my ($t) = @_;
+
+    return '' unless $debug;
+
+    if ($ps && $t->[3] =~ m/$ENV{DISTORT_PS_RE}/) {
+	printf PS <<'END',
+ %20.16g %20.16g %20.16g moveto
+ %20.16g %20.16g %20.16g lineto
+ %20.16g %20.16g %20.16g lineto
+ closepath stroke
+END
+		$t->[0][0], $t->[0][1], $t->[0][2],
+		$t->[1][0], $t->[1][1], $t->[1][2],
+		$t->[2][0], $t->[2][1], $t->[2][2],
+		or die $!;
+	flush PS or die $!;
+    }
+
+    sprintf
+	"%11.6f,%11.6f,%11.6f / ".
+	"%11.6f,%11.6f,%11.6f / ".
+	"%11.6f,%11.6f,%11.6f  %-40s ",
+		$t->[0][0], $t->[0][1], $t->[0][2],
+		$t->[1][0], $t->[1][1], $t->[1][2],
+		$t->[2][0], $t->[2][1], $t->[2][2],
+		$t->[3];
+}
+
+sub maybe_subdivide_triangle ($$$$) {
+    my ($t, $ok, $changed, $edge_need_subdivide_fn) = @_;
+
+    print STDERR sprintf_triangle $t if $debug;
 
-    #print STDERR 'SUBDIV', Dumper($t, $fn);
+    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 $debug>=2;
+	return;
+    }
+    my ($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;
     }
-    #print STDERR 'SUBDIV MID\n';
-    $fn->(\@mids);
+
+    $triangles = \@small_enough;
 }
 
 sub append_triangle ($) {
@@ -72,30 +156,20 @@ sub append_triangle ($) {
     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_triangle_need_subdivide ($) {
-    my ($t) = @_;
-    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_need_subdivide () {
-    foreach my $t (@$triangles) {
-	next unless project_cylinder_triangle_need_subdivide $t;
-	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 {
@@ -106,7 +180,7 @@ 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 / $radius;
@@ -114,6 +188,7 @@ sub project_cylinder_tri {
 		    -$r * cos($theta),
 		    $z ];
     }
+    push @ot, $t->[3].'P';
     append_triangle \@ot;
 }
 
@@ -121,14 +196,8 @@ 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 $t;
@@ -182,6 +251,7 @@ while (<I>) {
 	push @$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/) {
@@ -206,8 +276,8 @@ 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 @$t==4;
+    foreach my $p (@$t[0..2]) {
 	die unless @$p==3;
 	print "      vertex";
 	printf " %.18g", $_ foreach @$p;