+// TODO: tweak values
+namespace SNOW {
+static const float SPIN_SPEED = 60.0f;
+static const float WIND_SPEED = 30.0f; // max speed of wind will be randf(WIND_SPEED) * randf(STATE_LENGTH)
+static const float STATE_LENGTH = 5.0f;
+static const float DECAY_RATIO = 0.2f; // ratio of attack speed to decay speed
+static const float EPSILON = 0.5f; //velocity changes by up to this much each tick
+static const float WOBBLE_DECAY = 0.99f; //wobble decays exponentially by this much each tick
+static const float WOBBLE_FACTOR = 4 * .005f; //wobble approaches drift_speed by this much each tick
+}
+
+SnowParticleSystem::SnowParticleSystem() :
+ state(RELEASING),
+ timer(),
+ gust_onset(0),
+ gust_current_velocity(0)