Schemaverse Galaxy Map Generation

schemaverse_galaxy_map_creation.sql

-- example image: http://imgur.com/9eGABd6
/*
-- map generation variable declarations
r numeric;
a numeric;
b numeric;
turns int := 1; -- values >= 1
arms int := 4;
loc point;
*/
-- map generation script
a := coalesce( get_numeric_variable( 'UNIVERSE_CREATOR' ), 6750000 )::numeric;
<<planet>>
while 1=1 loop
    r := random() * ( a - ( a / turns / arms ) );
    if r > a / 2 / pi() then -- point on spiral
        -- get angle from r and seperation ( reverse r = b * theta )
        b := r / ( 2 * a / turns / arms ) * pi();
        -- convert polar to cartesian
        loc := point( r * cos( b ), r * sin( b ) );
        -- get random angle for scattering along arm
        b := random() * 2 * pi();
        -- get random distance from arm
        -- cluster towards center of arm by squaring random value
        r := pow( random(), 2 ) * a / turns / arms / 2;
        -- apply transform
        loc := loc + point( r * cos( b ), r * sin( b ) );
        -- get angle of rotation for random arm
        b := 2 * pi() * ceil( random() * arms ) / arms;
        -- apply 2d rotation
        loc := point(
            loc[0] * cos( b ) - loc[1] * sin( b ),
            loc[1] * cos( b ) + loc[0] * sin( b )
        );
    else -- point on center disc
        b := random() * 2 * pi();
        loc := point( r * cos( b ), r * sin( b ) );
    end if;
    loc := point( round( loc[0] ), round( loc[1] ) );
    continue when exists (
        select 1 from planet
        where circle( location, 1 ) <@ circle( loc, 2 * get_numeric_variable( 'MAX_SHIP_RANGE' ) )
    );
    insert into planet ( id, fuel, mine_limit, difficulty, location, location_x, location_y )
    values (
        nextval( 'planet_id_seq' ),
        greatest( ( random() * 1000000000 )::int, 100000000 ),
        greatest( ( random() * 100 )::int, 30 ),
        greatest( ( random() * 10 )::int , 2 ),
        loc, loc[0], loc[1]
    );
    -- exit planet when ( select count(1) from planet ) >= ( select count(1) * 1.05 from player );
    exit planet when ( select count(1) from planet ) = 2100;
end loop;

-- give names to new planets in non-repeating series
update planet
set name = ( case row_number % 12
    when 0 then 'Aethra'
    when 1 then 'Mony'
    when 2 then 'Semper'
    when 3 then 'Voit'
    when 4 then 'Lester'
    when 5 then 'Rio'
    when 6 then 'Zergon'
    when 7 then 'Cannibalon'
    when 8 then 'Omicron Persei'
    when 9 then 'Urectum'
    when 10 then 'Wormulon'
    when 11 then 'Kepler'
end ) || '_' || ( ( row_number / 12 ) + 1 )::text        
from (
    select row_number() over ( order by random() ) - 1 row_number, id
    from planet
    where id <> 1
    and name is null
)a
where planet.id = a.id;