38 lines
967 B
Raku
38 lines
967 B
Raku
use Image::PNG::Portable;
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my ($w, $h) = 800, 600;
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my $out = Image::PNG::Portable.new: :width($w), :height($h);
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my $maxIter = 255;
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my $c = -0.7 + 0.27015i;
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julia($out);
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$out.write: 'Julia-set-perl6.png';
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sub julia ( $png ) {
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^$w .race.map: -> $x {
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for ^$h -> $y {
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my $z = Complex.new(($x - $w / 2) / $w * 3, ($y - $h / 2) / $h * 2);
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my $i = $maxIter;
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while (abs($z) < 2 and --$i) {
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$z = $z*$z + $c;
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}
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$png.set: $x, $y, |hsv2rgb($i / $maxIter, 1, ?$i).reverse;
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}
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}
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}
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sub hsv2rgb ( $h, $s, $v ){
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my $c = $v * $s;
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my $x = $c * (1 - abs( (($h*6) % 2) - 1 ) );
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my $m = $v - $c;
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[(do given $h {
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when 0..^1/6 { $c, $x, 0 }
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when 1/6..^1/3 { $x, $c, 0 }
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when 1/3..^1/2 { 0, $c, $x }
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when 1/2..^2/3 { 0, $x, $c }
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when 2/3..^5/6 { $x, 0, $c }
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when 5/6..1 { $c, 0, $x }
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} ).map: ((*+$m) * 255).Int]
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}
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