gistfile1.cs

using Microsoft.Xna.Framework;
using Monocle;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace TowerFall
{
    public class PlayerHair : Component
    {
        private const int SIZE = 3;

        public Entity Follow;
        public Vector2 Position;
        public float Alpha;

        private Vector2[] offsets;
        private Subtexture[] images;
        private Vector2 previousPosition;
        private Vector2 previousEntityPosition;
        private SineWave sine;
        private float scale;
        private Vector2 addSpeed;

        private int links;
        private float linkDist;
        private float timeSinceLastUpdate;
            
        public PlayerHair(Entity follow, Vector2 position, float scale)
            : base(true, true)
        {
            Follow = follow;
            previousPosition = Position = position;
            previousEntityPosition = follow.Position;
            this.scale = scale;
            Alpha = 1;

            if (scale > 1)
            {
                links = 4;
                linkDist = 5;
            }
            else
            {
                links = 5;
                linkDist = 3;
            }

            offsets = new Vector2[links];
            for (int i = 0; i < links; i++)
                offsets[i] = new Vector2(0, SIZE * i);

            images = new Subtexture[links];
            for (int i = 0; i < links - 1; i++)
                images[i] = TFGame.Atlas["player/hair"];
            images[links - 1] = TFGame.Atlas["player/hairEnd"];

            sine = new SineWave(30);
        }

        public void AddSpeed(Vector2 speed)
        {
            addSpeed = speed;
        }

        public override void Update()
        {
            sine.Update();

            timeSinceLastUpdate += Engine.DeltaTime;
            if (timeSinceLastUpdate < 1 / 60f)
                return;
            else
                timeSinceLastUpdate -= 1 / 60f;

            Vector2 speed = Follow.Position - previousEntityPosition;
            Vector2 difference = (Position - previousPosition) * .2f + speed + addSpeed;

            if (addSpeed != Vector2.Zero)
                addSpeed = Calc.Approach(addSpeed, Vector2.Zero, .1f);

            previousEntityPosition = Follow.Position;
            previousPosition = Position;

            if (difference == Vector2.Zero)
                difference = -Vector2.UnitY * .2f;

            float mag = difference.LengthSquared()/9;

            for (int i = 1; i < links; i++)
            {
                Vector2 prev = offsets[i - 1];

                Vector2 add = -difference * mag * .5f;
                add = Vector2.Lerp(add, offsets[i] - prev, (i / (float)offsets.Length) * .3f);
                add.Y += .06f + .04f * sine.Value * Math.Abs(speed.X);
                if (Math.Abs(speed.X) <= .2f)
                    add.X += .08f * sine.Value * Math.Abs(speed.Y);
                add.Normalize();
                add *= linkDist;

                offsets[i] = prev + add;
            }
        }

        public override void Render()
        {
            for (int i = 0; i < links; i++)
            {
                Vector2 at = Follow.Position + Position + offsets[i];
                float angle = (i == 0 ? 0 : Calc.Angle(offsets[i], offsets[i - 1]));

                Draw.TextureCentered(images[i], at, Color.White * Alpha * Alpha, scale, angle);
            }
        }

        public void RenderOutline()
        {
            for (int i = 0; i < links; i++)
            {
                Vector2 at = Follow.Position + Position + offsets[i];
                float angle = (i == 0 ? 0 : Calc.Angle(offsets[i], offsets[i - 1]));

                for (int j = -1; j < 2; j++)
                    for (int k = -1; k < 2; k++)
                        if (j != 0 || k != 0)
                            Draw.TextureCentered(images[i], at + new Vector2(j, k), Color.Black, scale, angle);
            }
        }
    }
}

all this for hair?