VCS/XnaLissajous - Sample is best!

開発環境	Microsoft Visual C# 2010 Express (SP1)
実行環境	Microsoft Windows XP Home Edition (SP3)
プロジェクトの種類	Windows Game (4.0)
プロジェクト名	XnaLissajous

Game1.cs

using System;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
 
namespace XnaLissajous
{
    class Game1 : Game
    {
        GraphicsDeviceManager graphics;
        BasicEffect effect;
        int deg = 0;
 
        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            graphics.PreferredBackBufferWidth = 1280;
            graphics.PreferredBackBufferHeight = 720;
            IsMouseVisible = true;
        }
 
        protected override void LoadContent()
        {
            effect = new BasicEffect(GraphicsDevice);
            effect.VertexColorEnabled = true;
            base.LoadContent();
        }
 
        protected override void Update(GameTime gameTime)
        {
            KeyboardState kState = Keyboard.GetState();
            if (kState.IsKeyDown(Keys.Escape)) Exit();
 
            deg = (deg + 1) % 360;
 
            base.Update(gameTime);
        }
 
        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);
            GraphicsDevice.BlendState = BlendState.AlphaBlend;
 
            VertexPositionColor[] vertices = new VertexPositionColor[240 + 1];
            for (int n = 0; n <= 240; n++)
            {
                float rad = MathHelper.ToRadians((deg + n));
                vertices[n] = new VertexPositionColor(
                    new Vector3((float)Math.Cos(rad * 3) * 0.9f, (float)Math.Sin(rad * 2) * 0.9f, 0),
                    Color.White * (n / 240.0f));
            }
 
            foreach (EffectPass pass in effect.CurrentTechnique.Passes)
            {
                pass.Apply();
                GraphicsDevice.DrawUserPrimitives<VertexPositionColor>(
                    PrimitiveType.LineStrip, vertices, 0, 240);
            }
 
            base.Draw(gameTime);
        }
    }
}