72 lines
2.1 KiB
Raku
72 lines
2.1 KiB
Raku
class Pixel { has Int ($.R, $.G, $.B) }
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class Bitmap {
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has Int ($.width, $.height);
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has Pixel @.data;
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method pixel(
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$i where ^$!width,
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$j where ^$!height
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--> Pixel
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) is rw { @!data[$i + $j * $!width] }
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}
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role PPM {
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method P6 returns Blob {
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"P6\n{self.width} {self.height}\n255\n".encode('ascii')
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~ Blob.new: flat map { .R, .G, .B }, self.data
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}
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}
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sub load-ppm ( $ppm ) {
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my $fh = $ppm.IO.open( :enc('ISO-8859-1') );
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my $type = $fh.get;
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my ($width, $height) = $fh.get.split: ' ';
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my $depth = $fh.get;
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Bitmap.new( width => $width.Int, height => $height.Int,
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data => ( $fh.slurp.ords.rotor(3).map:
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{ Pixel.new(R => $_[0], G => $_[1], B => $_[2]) } )
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)
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}
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sub color-distance (Pixel $c1, Pixel $c2) {
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sqrt( ( ($c1.R - $c2.R)² + ($c1.G - $c2.G)² + ($c1.B - $c2.B)² ) / ( 255 * sqrt(3) ) );
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}
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sub flood ($img, $x, $y, $c1) {
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my $c2 = $img.pixel($x, $y);
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my $max-distance = 10;
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my @queue;
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my %checked;
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check($x, $y);
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for @queue -> [$x, $y] {
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$img.pixel($x, $y) = $c1.clone;
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}
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sub check ($x, $y) {
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my $c3 = $img.pixel($x, $y);
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if color-distance($c2, $c3) < $max-distance {
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@queue.push: [$x,$y];
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@queue.elems;
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%checked{"$x,$y"} = 1;
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check($x - 1, $y) if $x > 0 and %checked{"{$x - 1},$y"}:!exists;
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check($x + 1, $y) if $x < $img.width - 1 and %checked{"{$x + 1},$y"}:!exists;
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check($x, $y - 1) if $y > 0 and %checked{"$x,{$y - 1}"}:!exists;
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check($x, $y + 1) if $y < $img.height - 1 and %checked{"$x,{$y + 1}"}:!exists;
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}
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}
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}
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my $infile = './Unfilled-Circle.ppm';
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my Bitmap $b = load-ppm( $infile ) but PPM;
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flood($b, 5, 5, Pixel.new(:255R, :0G, :0B));
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flood($b, 5, 125, Pixel.new(:255R, :0G, :0B));
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flood($b, 125, 5, Pixel.new(:255R, :0G, :0B));
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flood($b, 125, 125, Pixel.new(:255R, :0G, :0B));
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flood($b, 50, 50, Pixel.new(:0R, :0G, :255B));
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my $outfile = open('./Bitmap-flood-perl6.ppm', :w, :bin);
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$outfile.write: $b.P6;
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