VCS/XnaSphere2 - 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	XnaSphere2

CustomVertex.cs

using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
 
namespace CustomVertex
{
    struct VertexPositionNormalColor : IVertexType
    {
        public Vector3 Position;
        public Vector3 Normal;
        public Color Color;
 
        public VertexPositionNormalColor(Vector3 position, Vector3 normal, Color color)
        {
            Position = position;
            Normal = normal;
            Color = color;
        }
 
        static readonly VertexDeclaration VertexDeclaration = new VertexDeclaration(
            new VertexElement(0,
                VertexElementFormat.Vector3, VertexElementUsage.Position, 0),
            new VertexElement(sizeof(float) * 3,
                VertexElementFormat.Vector3, VertexElementUsage.Normal, 0),
            new VertexElement(sizeof(float) * 6,
                VertexElementFormat.Color, VertexElementUsage.Color, 0));
 
        VertexDeclaration IVertexType.VertexDeclaration { get { return VertexDeclaration; } }
    }
}
 

Game1.cs

// XnaSphere2 - XNA 球体(法線)
using System;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using CustomVertex;
 
namespace XnaSphere
{
    class Game1 : Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch sprite;
        SpriteFont font;
        BasicEffect effect;
 
        VertexBuffer vertexBuffer;
        IndexBuffer indexBuffer;
 
        // fps
        int sec;
        int draw = 0;
        int fps = 0;
 
        // カメラ
        int camLat = 0;
        int camLong = 90;
        float camDist = 5;
 
        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            graphics.PreferredBackBufferWidth = 1280;
            graphics.PreferredBackBufferHeight = 720;
            Content.RootDirectory = "Content";
            IsMouseVisible = true;
        }
 
        protected override void LoadContent()
        {
            font = Content.Load<SpriteFont>("SpriteFont1");
            sprite = new SpriteBatch(GraphicsDevice);
            effect = new BasicEffect(GraphicsDevice);
            //effect.VertexColorEnabled = true;
            effect.EnableDefaultLighting();
            effect.Projection = Matrix.CreatePerspectiveFieldOfView(
                MathHelper.ToRadians(45), GraphicsDevice.Viewport.AspectRatio, 1, 100);
 
            // 頂点バッファ
            int stackNum = 16; // 輪切りの数
            VertexPositionNormalColor[] vertices =
                new VertexPositionNormalColor[stackNum * stackNum + 2];
            int i = 0;
            vertices[i++] = new VertexPositionNormalColor(
                new Vector3(0, 1, 0), new Vector3(0, 1, 0), Color.Yellow);
            for (int stack = 1; stack < stackNum; stack++)
            {
                float rad = ((stackNum - 2 * stack) / (float)stackNum) * MathHelper.PiOver2;
                float y = (float)Math.Sin(rad);
                float r = (float)Math.Cos(rad);
                int sliceNum = 4 * Math.Min(stack, stackNum - stack); // 放射頂点の数
                for (int slice = 0; slice < sliceNum; slice++)
                {
                    rad = (slice / (float)sliceNum) * MathHelper.TwoPi;
                    float x = (float)Math.Cos(rad) * r;
                    float z = (float)Math.Sin(rad) * r;
                    Vector3 normal = Vector3.Normalize(new Vector3(x, y, z));
                    vertices[i++] = new VertexPositionNormalColor(
                        normal, normal, (slice & 1) == 0 ? Color.Red : Color.Yellow);
                }
            }
            vertices[i++] = new VertexPositionNormalColor(
                new Vector3(0, -1, 0), new Vector3(0, -1, 0), Color.Yellow);
 
            vertexBuffer = new VertexBuffer(GraphicsDevice,
                typeof(VertexPositionNormalColor), vertices.Length, BufferUsage.WriteOnly);
            vertexBuffer.SetData(vertices);
 
            // 索引バッファ
            short[] indices = new short[stackNum * stackNum * 6];
            i = 0;
 
            int prevHead = 0; // 前の先頭頂点番号
            int prevVtx = 1; // 前の頂点数
            for (int stack = 0; stack < stackNum / 2; stack++)
            {
                int currHead = prevHead + prevVtx; // 現在の先頭頂点番号
                int currVtx = 4 * (stack + 1); // 現在の頂点数
                for (int quad = 0; quad < 4; quad++) // 4象限
                {
                    int prevQuad = quad * stack; // 前の象限オフセット
                    int currQuad = quad * (stack + 1); // 現在の象限オフセット
                    for (int n = 0; ; n++)
                    {
                        indices[i++] = (short)(prevHead + (prevQuad + n) % prevVtx);
                        indices[i++] = (short)(currHead + (currQuad + n));
                        indices[i++] = (short)(currHead + (currQuad + n + 1) % currVtx);
                        if (stack <= n) break;
                        indices[i++] = (short)(prevHead + (prevQuad + n));
                        indices[i++] = (short)(currHead + (currQuad + n + 1));
                        indices[i++] = (short)(prevHead + (prevQuad + n + 1) % prevVtx);
                    }
                }
                prevHead = currHead;
                prevVtx = currVtx;
            }
 
            for (int stack = stackNum / 2 - 1; 0 <= stack; stack--)
            {
                int currHead = prevHead + prevVtx;
                int currVtx = Math.Max(4 * stack, 1);
                for (int quad = 0; quad < 4; quad++) // 4象限
                {
                    int prevQuad = quad * (stack + 1);
                    int currQuad = quad * stack;
                    for (int n = 0; ; n++)
                    {
                        indices[i++] = (short)(currHead + (currQuad + n) % currVtx);
                        indices[i++] = (short)(prevHead + (prevQuad + n + 1) % prevVtx);
                        indices[i++] = (short)(prevHead + (prevQuad + n));
                        if (stack <= n) break;
                        indices[i++] = (short)(currHead + (currQuad + n));
                        indices[i++] = (short)(currHead + (currQuad + n + 1) % currVtx);
                        indices[i++] = (short)(prevHead + (prevQuad + n + 1));
                    }
                }
                prevHead = currHead;
                prevVtx = currVtx;
            }
 
            indexBuffer = new IndexBuffer(GraphicsDevice,
                typeof(short), indices.Length, BufferUsage.WriteOnly);
            indexBuffer.SetData(indices);
 
            base.LoadContent();
        }
 
        protected override void Update(GameTime gameTime)
        {
            KeyboardState kState = Keyboard.GetState();
            if (kState.IsKeyDown(Keys.Escape)) Exit();
            if (kState.IsKeyDown(Keys.Up)) camLat++;
            if (kState.IsKeyDown(Keys.Down)) camLat--;
            if (kState.IsKeyDown(Keys.Left)) camLong = (camLong + 1) % 360;
            if (kState.IsKeyDown(Keys.Right)) camLong = (camLong + 359) % 360;
            if (kState.IsKeyDown(Keys.PageUp)) camDist -= 0.1f;
            if (kState.IsKeyDown(Keys.PageDown)) camDist += 0.1f;
 
            base.Update(gameTime);
        }
 
        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);
            //GraphicsDevice.RasterizerState =
            //    new RasterizerState { FillMode = FillMode.WireFrame };
 
            // カメラ位置
            float rad = MathHelper.ToRadians(camLat);
            float y = (float)Math.Sin(rad) * camDist;
            float r = (float)Math.Cos(rad) * camDist;
            rad = MathHelper.ToRadians(camLong);
            float x = (float)Math.Cos(rad) * r;
            float z = (float)Math.Sin(rad) * r;
            effect.View = Matrix.CreateLookAt(new Vector3(x, y, z), Vector3.Zero, Vector3.Up);
 
            GraphicsDevice.SetVertexBuffer(vertexBuffer);
            GraphicsDevice.Indices = indexBuffer;
 
            foreach (EffectPass pass in effect.CurrentTechnique.Passes)
            {
                pass.Apply();
                GraphicsDevice.DrawIndexedPrimitives(PrimitiveType.TriangleList,
                    0, 0, vertexBuffer.VertexCount, 0, indexBuffer.IndexCount / 3);
            }
 
            // fps
            draw++;
            if (gameTime.TotalGameTime.Seconds != sec)
            {
                fps = draw;
                draw = 0;
                sec = gameTime.TotalGameTime.Seconds;
            }
 
            sprite.Begin();
            string text = String.Format(
                "fps={0} lat={1} long={2} dist={3:f1}", fps, camLat, camLong, camDist);
            sprite.DrawString(font, text, new Vector2(0, 0), Color.White);
            sprite.End();
 
            base.Draw(gameTime);
        }
    }
}