Terraria.Rain.Update C# (CSharp) Method

        public void Update()
        {
            this.position += this.velocity;
            if (!Collision.SolidCollision(this.position, 2, 2) && (double)this.position.Y <= (double)Main.screenPosition.Y + (double)Main.screenHeight + 100.0 && !Collision.WetCollision(this.position, 2, 2))
                return;
            this.active = false;
            if ((double)Main.rand.Next(100) >= (double)Main.gfxQuality * 100.0)
                return;
            int Type = 154;
            if ((int)this.type == 3 || (int)this.type == 4 || (int)this.type == 5)
                Type = 218;
            int index = Dust.NewDust(this.position - this.velocity, 2, 2, Type, 0.0f, 0.0f, 0, new Color(), 1f);
            Main.dust[index].position.X -= 2f;
            Main.dust[index].alpha = 38;
            Main.dust[index].velocity *= 0.1f;
            Main.dust[index].velocity += -this.velocity * 0.025f;
            Main.dust[index].scale = 0.75f;
        }