Draw a rotating cube

Raku has no native graphics libraries built in, but makes it fairly easy to bind to third party libraries. Here we'll use bindings to Libcaca, the Color ASCII Art library to generate a rotating cube in an ASCII terminal.

use Terminal::Caca;
given my $canvas = Terminal::Caca.new {
    .title('Rosetta Code - Rotating cube - Press any key to exit');

    sub scale-and-translate($x, $y, $z) {
        $x * 5 / ( 5 + $z ) * 15 + 40,
        $y * 5 / ( 5 + $z ) *  7 + 15,
        $z;
    }

    sub rotate3d-x( $x, $y, $z, $angle ) {
        my ($cosθ, $sinθ) = cis( $angle * π / 180.0 ).reals;
        $x,
        $y * $cosθ - $z * $sinθ,
        $y * $sinθ + $z * $cosθ;
    }

    sub rotate3d-y( $x, $y, $z, $angle ) {
        my ($cosθ, $sinθ) = cis( $angle * π / 180.0 ).reals;
        $x * $cosθ - $z * $sinθ,
        $y,
        $x * $sinθ + $z * $cosθ;
    }

    sub rotate3d-z( $x, $y, $z, $angle ) {
        my ($cosθ, $sinθ) = cis( $angle * π / 180.0 ).reals;
        $x * $cosθ - $y * $sinθ,
        $x * $cosθ + $y * $sinθ,
        $z;
    }

    # Unit cube from polygon mesh, aligned to axes
    my @mesh =
      [ [1, 1, -1], [-1, -1, -1], [-1,  1, -1] ], # far face
      [ [1, 1, -1], [-1, -1, -1], [ 1, -1, -1] ],
      [ [1, 1,  1], [-1, -1,  1], [-1,  1,  1] ], # near face
      [ [1, 1,  1], [-1, -1,  1], [ 1, -1,  1] ];
      @mesh.push: [$_».rotate( 1)».Array] for @mesh[^4]; # positive and
      @mesh.push: [$_».rotate(-1)».Array] for @mesh[^4]; # negative rotations

    # Rotate to correct orientation for task
    for ^@mesh X ^@mesh[0] -> ($i, $j) {
        @(@mesh[$i;$j]) = rotate3d-x |@mesh[$i;$j], 45;
        @(@mesh[$i;$j]) = rotate3d-z |@mesh[$i;$j], 40;
    }

    my @colors = red, blue, green, cyan, magenta, yellow;

    loop {
        for ^359 -> $angle {
            .color( white, white );
            .clear;

            # Flatten 3D into 2D and rotate for all faces
            my @faces-z;
            my $c-index = 0;
            for @mesh -> @triangle {
                my @points;
                my $sum-z = 0;
                for @triangle -> @node {
                    my ($px, $py, $z) = scale-and-translate |rotate3d-y |@node, $angle;
                    @points.append: $px.Int, $py.Int;
                    $sum-z += $z;
                }

                @faces-z.push: %(
                    color  => @colors[$c-index++ div 2],
                    points => @points,
                    avg-z  => $sum-z / +@points;
                );
            }

            # Draw all faces
            # Sort by z to draw farthest first
            for @faces-z.sort( -*.<avg-z> ) -> %face {
                # Draw filled triangle
                .color( %face<color>, %face<color> );
                .fill-triangle( |%face<points> );
                # And frame
                .color( black, black );
                .thin-triangle( |%face<points> );
            }

            .refresh;
            exit if .wait-for-event(key-press);
        }
    }

    # Cleanup on scope exit
    LEAVE {
        .cleanup;
    }
}