package Slic3r::GCode::ArcFitting; use Moo; use Slic3r::Geometry qw(X Y PI scale unscale deg2rad); extends 'Slic3r::GCode::Reader'; has 'config' => (is => 'ro', required => 1); has 'max_angle' => (is => 'rw', default => sub { deg2rad(15) }); has 'len_epsilon' => (is => 'rw', default => sub { scale 10 }); has 'parallel_degrees_limit' => (is => 'rw', default => sub { abs(deg2rad(3)) }); sub process { my $self = shift; my ($gcode) = @_; my $new_gcode = ""; my $buffer = ""; my @cur_path = (); my $cur_len = 0; my $cur_relative_angle = 0; $self->parse($gcode, sub { my ($reader, $cmd, $args, $info) = @_; if ($info->{extruding} && $info->{dist_XY} > 0) { my $point = Slic3r::Point->new_scale($args->{X}, $args->{Y}); if (@cur_path >= 2) { if ($cur_path[-1]->distance_to($point) > $self->len_epsilon) { # if the last distance is not compatible with the current arc, flush it $new_gcode .= $self->flush_path(\@cur_path, \$buffer); } elsif (@cur_path >= 3) { my $rel_angle = relative_angle(@cur_path[-2,-1], $point); if (($cur_relative_angle != 0 && abs($rel_angle - $cur_relative_angle) > $self->parallel_degrees_limit) # relative angle is too different from the previous one || abs($rel_angle) < $self->parallel_degrees_limit # relative angle is almost parallel || $rel_angle > $self->max_angle) { # relative angle is excessive (too sharp) # in these cases, $point does not really look like an additional point of the current arc $new_gcode .= $self->flush_path(\@cur_path, \$buffer); } } } if (@cur_path == 0) { # we're starting a path, so let's prepend the previous position push @cur_path, Slic3r::Point->new_scale($self->X, $self->Y), $point; $buffer .= $info->{raw} . "\n"; $cur_len = $cur_path[0]->distance_to($cur_path[1]); } else { push @cur_path, $point; $buffer .= $info->{raw} . "\n"; if (@cur_path == 3) { # we have two segments, time to compute a reference angle $cur_relative_angle = relative_angle(@cur_path[0,1,2]); } } } else { $new_gcode .= $self->flush_path(\@cur_path, \$buffer); $new_gcode .= $info->{raw} . "\n"; } }); $new_gcode .= $self->flush_path(\@cur_path, \$buffer); return $new_gcode; } sub flush_path { my ($self, $cur_path, $buffer) = @_; my $gcode = ""; if (@$cur_path >= 3) { # if we have enough points, then we have an arc $$buffer =~ s/^/;/mg; $gcode = "; these moves were replaced by an arc:\n" . $$buffer; my $orientation = $cur_path->[2]->ccw(@$cur_path[0,1]) ? 'ccw' : 'cw'; # to find the center, we intersect the perpendicular lines # passing by midpoints of $s1 and last segment # a better method would be to draw all the perpendicular lines # and find the centroid of the enclosed polygon, or to # intersect multiple lines and find the centroid of the convex hull # around the intersections my $arc_center; { my $s1_mid = Slic3r::Line->new(@$cur_path[0,1])->midpoint; my $last_mid = Slic3r::Line->new(@$cur_path[-2,-1])->midpoint; my $rotation_angle = PI/2 * ($orientation eq 'ccw' ? -1 : 1); my $ray1 = Slic3r::Line->new($s1_mid, $cur_path->[1]->clone->rotate($rotation_angle, $s1_mid)); my $last_ray = Slic3r::Line->new($last_mid, $cur_path->[-1]->clone->rotate($rotation_angle, $last_mid)); $arc_center = $ray1->intersection($last_ray, 0) or next POINT; } my $radius = $arc_center->distance_to($cur_path->[0]); my $total_angle = Slic3r::Geometry::angle3points($arc_center, @$cur_path[0,-1]); my $length = $orientation eq 'ccw' ? $radius * $total_angle : $radius * (2*PI - $total_angle); # compose G-code line $gcode .= $orientation eq 'cw' ? "G2" : "G3"; $gcode .= sprintf " X%.3f Y%.3f", map unscale($_), @{$cur_path->[-1]}; # destination point # XY distance of the center from the start position $gcode .= sprintf " I%.3f J%.3f", map { unscale($arc_center->[$_] - $cur_path->[0][$_]) } (X,Y); my $E = 0; # TODO: compute E using $length $gcode .= sprintf(" %s%.5f", $self->config->extrusion_axis, $E) if $E; my $F = 0; # TODO: extract F from original moves $gcode .= " F$F\n"; } else { $gcode = $$buffer; } $$buffer = ""; splice @$cur_path, 0, $#$cur_path; # keep last point as starting position for next path return $gcode; } sub relative_angle { my ($p1, $p2, $p3) = @_; my $s1 = Slic3r::Line->new($p1, $p2); my $s2 = Slic3r::Line->new($p2, $p3); my $s1_angle = $s1->atan; my $s2_angle = $s2->atan; $s1_angle += 2*PI if $s1_angle < 0; $s2_angle += 2*PI if $s2_angle < 0; return $s2_angle - $s1_angle; } 1;