gistfile1.txt

custom_math::vector_3 grav_acceleration(const custom_math::vector_3 &pos, const custom_math::vector_3 &vel, const double G)
{
	custom_math::vector_3 grav_dir = sun_pos - pos;

	float distance = grav_dir.length();

	grav_dir.normalize();

	float alpha = (vel.length()*vel.length()) / (speed_of_light * speed_of_light);
	alpha = pow(alpha, 0.01); // suit to taste

	float G_factor = G*(2.0f - sqrt(1 - alpha));

	custom_math::vector_3 accel = grav_dir * (G_factor*sun_mass / pow(distance, 2.0));

	return accel;
}