setup_planet: Concentrate the mass mostly in the middle of the system

This will increase the stability of the created planetar system. Most
of the central planets collapse into one large object, which will keep
most of the system more stable.

Signed-off-by: Timo Kokkonen <kaapeli@itanic.dy.fi>

diff --git a/planet.c b/planet.c
index 1cf5d1ef50251cf947edf7f58f5b19156a8291d5..c7b01a05995f91442d0c550df6e259a49c4e2dc4 100644 (file)
--- a/planet.c
+++ b/planet.c
@@ -51,7 +51,7 @@ static void setup_planet(struct planet *p, double mass, double total_mass,
        double velocity;
        double distance;
 
-       distance = radius * get_random_double();
+       distance = radius * pow(get_random_double(), 2);
        velocity = sqrt(total_mass / radius);
 
        velocity *= pow(distance / radius, 0.2);