Slic3r/lib/Slic3r/GCode/MotionPlanner.pm

291 lines
11 KiB
Perl

package Slic3r::GCode::MotionPlanner;
use Moo;
has 'islands' => (is => 'ro', required => 1);
has 'no_internal' => (is => 'ro');
has 'last_crossings'=> (is => 'rw');
has '_inner' => (is => 'rw', default => sub { [] }); # arrayref of arrayrefs of expolygons
has '_outer' => (is => 'rw', default => sub { [] }); # arrayref of arrayrefs of polygons
has '_contours_ex' => (is => 'rw', default => sub { [] }); # arrayref of arrayrefs of expolygons
has '_pointmap' => (is => 'rw', default => sub { {} }); # { id => $point }
has '_edges' => (is => 'rw', default => sub { {} }); # node_idx => { node_idx => distance, ... }
has '_crossing_edges' => (is => 'rw', default => sub { {} }); # edge_idx => bool
has '_tolerance' => (is => 'lazy');
use List::Util qw(first);
use Slic3r::Geometry qw(A B scale epsilon);
use Slic3r::Geometry::Clipper qw(diff_ex offset);
# clearance (in mm) from the perimeters
has '_inner_margin' => (is => 'ro', default => sub { scale 0.5 });
has '_outer_margin' => (is => 'ro', default => sub { scale 2 });
# this factor weigths the crossing of a perimeter
# vs. the alternative path. a value of 5 means that
# a perimeter will be crossed if the alternative path
# is >= 5x the length of the straight line we could
# follow if we decided to cross the perimeter.
# a nearly-infinite value for this will only permit
# perimeter crossing when there's no alternative path.
use constant CROSSING_FACTOR => 20;
use constant INFINITY => 'inf';
sub _build__tolerance { scale epsilon }
# setup our configuration space
sub BUILD {
my $self = shift;
my $edges = $self->_edges;
my $crossing_edges = $self->_crossing_edges;
# simplify islands
@{$self->islands} = map $_->simplify($self->_inner_margin), @{$self->islands};
# process individual islands
for my $i (0 .. $#{$self->islands}) {
# offset the island inwards to make the boundaries for internal movements
# so that no motion along external perimeters happens
$self->_inner->[$i] = $self->no_internal
? []
: $self->islands->[$i]->offset_ex(-$self->_inner_margin);
# offset the island outwards to make the boundaries for external movements
$self->_outer->[$i] = offset([ $self->islands->[$i]->contour], $self->_outer_margin);
# if internal motion is enabled, build a set of utility expolygons representing
# the outer boundaries (as contours) and the inner boundaries (as holes). whenever
# we jump from a hole to a contour or viceversa, we know we're crossing a perimeter
if (!$self->no_internal) {
$self->_contours_ex->[$i] = diff_ex(
$self->_outer->[$i],
[ map $_->contour, @{$self->_inner->[$i]} ],
);
# lines enclosed in inner expolygons are visible
$self->_add_expolygon($_) for @{ $self->_inner->[$i] };
# lines enclosed in expolygons covering perimeters are visible
# (but discouraged)
$self->_add_expolygon($_, 1) for @{ $self->_contours_ex->[$i] };
}
}
{
my @outer = (map @$_, @{$self->_outer});
my @outer_ex = map [$_], @outer; # as ExPolygons
# lines of outer polygons connect visible points
for my $i (0 .. $#outer) {
foreach my $line ($outer[$i]->lines) {
my $dist = $line->length;
$edges->{$line->[A]}{$line->[B]} = $dist;
$edges->{$line->[B]}{$line->[A]} = $dist;
}
}
# lines connecting outer polygons are visible
for my $i (0 .. $#outer) {
for my $j (($i+1) .. $#outer) {
for my $m (0 .. $#{$outer[$i]}) {
for my $n (0 .. $#{$outer[$j]}) {
my $line = Slic3r::Line->new($outer[$i][$m], $outer[$j][$n]);
if (!@{Boost::Geometry::Utils::multi_polygon_multi_linestring_intersection(\@outer_ex, [$line])}) {
# this line does not cross any polygon
my $dist = $line->length;
$edges->{$outer[$i][$m]}{$outer[$j][$n]} = $dist;
$edges->{$outer[$j][$n]}{$outer[$i][$m]} = $dist;
}
}
}
}
}
}
# lines connecting inner polygons contours are visible but discouraged
if (!$self->no_internal) {
my @inner = (map $_->contour, map @$_, @{$self->_inner});
my @inner_ex = map [$_], @inner; # as ExPolygons
for my $i (0 .. $#inner) {
for my $j (($i+1) .. $#inner) {
for my $m (0 .. $#{$inner[$i]}) {
for my $n (0 .. $#{$inner[$j]}) {
my $line = Slic3r::Line->new($inner[$i][$m], $inner[$j][$n]);
if (!@{Boost::Geometry::Utils::multi_polygon_multi_linestring_intersection(\@inner_ex, [$line])}) {
# this line does not cross any polygon
my $dist = $line->length * CROSSING_FACTOR;
$edges->{$inner[$i][$m]}{$inner[$j][$n]} = $dist;
$edges->{$inner[$j][$n]}{$inner[$i][$m]} = $dist;
$crossing_edges->{$inner[$i][$m]}{$inner[$j][$n]} = 1;
$crossing_edges->{$inner[$j][$n]}{$inner[$i][$m]} = 1;
}
}
}
}
}
}
$self->_pointmap({
map +("$_" => $_),
(map @$_, map @$_, map @$_, @{$self->_inner}),
(map @$_, map @$_, @{$self->_outer}),
(map @$_, map @$_, map @$_, @{$self->_contours_ex}),
});
if (0) {
my @lines = ();
my %lines = ();
for my $i (keys %{$self->_edges}) {
for my $j (keys %{$self->_edges->{$i}}) {
next if $lines{join '_', sort $i, $j};
push @lines, [ map $self->_pointmap->{$_}, $i, $j ];
$lines{join '_', sort $i, $j} = 1;
}
}
require "Slic3r/SVG.pm";
Slic3r::SVG::output("space.svg",
lines => \@lines,
points => [ values %{$self->_pointmap} ],
no_arrows => 1,
expolygons => $self->islands,
#red_polygons => [ map @{$_->holes}, map @$_, @{$self->_inner} ],
#white_polygons => [ map @$_, @{$self->_outer} ],
);
printf "%d islands\n", scalar @{$self->islands};
eval "use Devel::Size";
print "MEMORY USAGE:\n";
printf " %-19s = %.1fMb\n", $_, Devel::Size::total_size($self->$_)/1024/1024
for qw(_inner _outer _contours_ex _pointmap _edges _crossing_edges islands last_crossings);
printf " %-19s = %.1fMb\n", 'self', Devel::Size::total_size($self)/1024/1024;
}
}
# given an expolygon, this subroutine connects all its visible points
sub _add_expolygon {
my $self = shift;
my ($expolygon, $crosses_perimeter) = @_;
my $edges = $self->_edges;
my $crossing_edges = $self->_crossing_edges;
my @points = map @$_, @$expolygon;
for my $i (0 .. $#points) {
for my $j (($i+1) .. $#points) {
my $line = Slic3r::Line->new($points[$i], $points[$j]);
if ($expolygon->encloses_line($line, $self->_tolerance)) {
my $dist = $line->length * ($crosses_perimeter ? CROSSING_FACTOR : 1);
$edges->{$points[$i]}{$points[$j]} = $dist;
$edges->{$points[$j]}{$points[$i]} = $dist;
$crossing_edges->{$points[$i]}{$points[$j]} = 1;
$crossing_edges->{$points[$j]}{$points[$i]} = 1;
}
}
}
}
sub find_node {
my $self = shift;
my ($point, $near_to) = @_;
# for optimal pathing, we should check visibility from $point to all $candidates, and then
# choose the one that is nearest to $near_to among the visible ones; however this is probably too slow
# if we're inside a hole, move to a point on hole;
{
my $polygon = first { $_->encloses_point($point) } (map @{$_->holes}, map @$_, @{$self->_inner});
return $point->nearest_point([ @$polygon ]) if $polygon;
}
# if we're inside an expolygon move to a point on contour or holes
{
my $expolygon = first { $_->encloses_point_quick($point) } (map @$_, @{$self->_inner});
return $point->nearest_point([ map @$_, @$expolygon ]) if $expolygon;
}
{
my $outer_polygon_idx;
if (!$self->no_internal) {
# look for an outer expolygon whose contour contains our point
$outer_polygon_idx = first { first { $_->contour->encloses_point($point) } @{$self->_contours_ex->[$_]} }
0 .. $#{ $self->_contours_ex };
} else {
# # look for an outer expolygon containing our point
$outer_polygon_idx = first { first { $_->encloses_point($point) } @{$self->_outer->[$_]} }
0 .. $#{ $self->_outer };
}
my $candidates = defined $outer_polygon_idx
? [ map @{$_->contour}, @{$self->_inner->[$outer_polygon_idx]} ]
: [ map @$_, map @$_, @{$self->_outer} ];
$candidates = [ map @$_, @{$self->_outer->[$outer_polygon_idx]} ]
if @$candidates == 0;
return $point->nearest_point($candidates);
}
}
sub shortest_path {
my $self = shift;
my ($from, $to) = @_;
return Slic3r::Polyline->new($from, $to) if !@{$self->islands};
# find nearest nodes
my $new_from = $self->find_node($from, $to);
my $new_to = $self->find_node($to, $from);
my $root = "$new_from";
my $target = "$new_to";
my $edges = $self->_edges;
my %dist = map { $_ => INFINITY } keys %$edges;
$dist{$root} = 0;
my %prev = map { $_ => undef } keys %$edges;
my @unsolved = keys %$edges;
my %crossings = (); # node_idx => bool
while (@unsolved) {
# sort unsolved by distance from root
# using a sorting option that accounts for infinity
@unsolved = sort {
$dist{$a} eq INFINITY ? +1 :
$dist{$b} eq INFINITY ? -1 :
$dist{$a} <=> $dist{$b};
} @unsolved;
# we'll solve the closest node
last if $dist{$unsolved[0]} eq INFINITY;
my $n = shift @unsolved;
# stop search
last if $n eq $target;
# now, look at all the nodes connected to n
foreach my $n2 (keys %{$edges->{$n}}) {
# .. and find out if any of their estimated distances
# can be improved if we go through n
if ( ($dist{$n2} eq INFINITY) || ($dist{$n2} > ($dist{$n} + $edges->{$n}{$n2})) ) {
$dist{$n2} = $dist{$n} + $edges->{$n}{$n2};
$prev{$n2} = $n;
$crossings{$n} = 1 if $self->_crossing_edges->{$n}{$n2};
}
}
}
my @points = ();
my $crossings = 0;
{
my $pointmap = $self->_pointmap;
my $u = $target;
while (defined $prev{$u}) {
unshift @points, $pointmap->{$u};
$crossings++ if $crossings{$u};
$u = $prev{$u};
}
}
$self->last_crossings($crossings);
return Slic3r::Polyline->new($from, $new_from, @points, $to); # @points already includes $new_to
}
1;