Concise Sample of Managed Direct3D for 2D Rendering (9.0c)

自批：读者注意，以下都是肤浅之谈，诚不足作为参考。

继续沿袭大片贴源码风格，发一个Managed Direct3D的典型2D渲染实例: ) 采用了Sprite+Texture方式，速度其实也不算慢，代码也还算简洁可靠(除了控制Device Lost异常比较烦琐以外)，尤其是在窗口模式下，要考虑的底层细节比DirectDraw要少得多，什么裁剪区域、页切换链等等，如果不想去碰它们，均可交给Direct3D自动管理，当然，如果需要的话也可以自行设置。

不爽的地方在于Direct3D对硬件要求起点比DirectDraw要高，实际2D绘制效率比起DirectDraw还是要慢不少；此外，Direct3D中以纹理绘制方式实现2D渲染决定了其局限性：纹理的形状必须是正方形的，则制作2D Sprite时也不得不将其制作成正方形的，这很不自然；更令人郁闷的是，纹理的象素尺寸必须是2的整数幂，否则在渲染时其尺寸将会被拉伸导致图像模糊、变形；上述两点要求对于传统的2D场景渲染而言都可以说是一些非常不合理的约束，不过我想至今还没有哪款2D Game是纯粹地用Direct3D来做的吧，呵呵，下面这个实例就当见识一下M$向我们所推荐的“未来”的2D渲染编程方式吧。

结论：对于2D的我还是喜欢用DirectDraw — Speed Rules!

//#define FULL_SCREEN

using System;
using System.Drawing;
using System.Collections;
using System.ComponentModel;
using System.Windows.Forms;
using System.Data;
using System.Threading;

using Microsoft.DirectX;
using Microsoft.DirectX.Direct3D;

namespace MDirect3D
{
    public class AppFrm : System.Windows.Forms.Form
    {
        private Device device;
        private Sprite sprite;
        private Texture[] texture=new Texture[2];

        private Rectangle[] textureSize=new Rectangle[2];
        private Vector3 centerPos = new Vector3(0, 0, 0);
        private Vector3 position = new Vector3(0,0,1);

        private int idx=0; //纹理索引
    
        private PresentParameters PreparePresentParameters()
        {
            PresentParameters presentParams = new PresentParameters();
            
            初始化设备参数#region 初始化设备参数
            #if FULL_SCREEN
                presentParams.Windowed = false;
                presentParams.BackBufferCount=1;
                presentParams.BackBufferWidth=1024;
                presentParams.BackBufferHeight=768;
                presentParams.BackBufferFormat=Format.X8R8G8B8;
                presentParams.SwapEffect = SwapEffect.Flip;
            #else
                presentParams.Windowed = true;
                presentParams.SwapEffect = SwapEffect.Discard;
            #endif
            #endregion
            
            return presentParams;
        }
        
        private void InitializeGraphics()
        {
            初始化设备#region 初始化设备
            device = new Device(0, DeviceType.Hardware, this,
                CreateFlags.SoftwareVertexProcessing, PreparePresentParameters());
            #endregion
            
            初始化纹理#region 初始化纹理
            //纹理资源创建类型: Pool.Managed - Device Lost之后无需再次创建
            texture[0] = TextureLoader.FromFile(device, @"..\..\01.tga");
            texture[1] = TextureLoader.FromFile(device, @"..\..\02.tga");

            for (int i=0;i<2;i++)
                using (Surface s = texture[i].GetSurfaceLevel(0))
                {
                    SurfaceDescription desc = s.Description;
                    //纹理的尺寸必须是2的整数次幂，否则会拉伸变形
                    textureSize[i] = new Rectangle(0, 0, desc.Width, desc.Height); 
                }
            #endregion

            sprite = new Sprite(device);
        }
        
        private void Restore()
        {
            恢复设备#region 恢复设备
            PresentParameters[] ps=new PresentParameters[1];
            ps[0]=PreparePresentParameters();
            device.Reset(ps);

            //由于纹理资源创建类型为Pool.Managed
            //所以恢复device的时候无需再次创建
            #endregion
        }

        public void Draw()
        {
            if (device==null || WindowState == FormWindowState.Minimized)
                return;

            int result=0;
            device.CheckCooperativeLevel(out result);
            
            try 
            {
                switch (result)
                {
                    case (int)ResultCode.Success:
                        2D绘制过程#region 2D绘制过程

                        device.BeginScene();
                        device.Clear(ClearFlags.Target, Color.White , 0.0f, 0);
                        sprite.Begin(SpriteFlags.None);
                        sprite.Draw(texture[idx], textureSize[idx], centerPos, position, Color.White);
                        sprite.End();
                        device.EndScene();
                        device.Present();
                        
                        idx^=1;
                        #endregion
                        break;
                    case (int)ResultCode.DeviceNotReset:
                        设备恢复过程#region 设备恢复过程
                        Restore();
                        #endregion
                        break;
                    case (int)ResultCode.DeviceLost:
                        break;
                }
            } 
            catch (Exception e)
            {
                return;
            }
        }
        
        乱七八糟#region 乱七八糟
        /**//// <summary>
        /// 必需的设计器变量。
        /// </summary>
        private System.ComponentModel.Container components = null;
    
        /**//// <summary>
        /// 清理所有正在使用的资源。
        /// </summary>
        protected override void Dispose( bool disposing )
        {
            if( disposing )
            {
                if (components != null) 
                {
                    components.Dispose();
                }
            }
            base.Dispose( disposing );
        }

        Windows 窗体设计器生成的代码#region Windows 窗体设计器生成的代码
        /**//// <summary>
        /// 设计器支持所需的方法 - 不要使用代码编辑器修改
        /// 此方法的内容。
        /// </summary>
        private void InitializeComponent()
        {
            // 
            // AppFrm
            // 
            this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
            this.ClientSize = new System.Drawing.Size(292, 266);
            this.Name = "AppFrm";
            this.Text = "Managed Direct 3D";
            this.KeyDown += new System.Windows.Forms.KeyEventHandler(this.AppFrm_KeyDown);

        }
        #endregion
        #endregion

        public AppFrm()
        {
            InitializeComponent();

            #if FULL_SCREEN
                FormBorderStyle = FormBorderStyle.None;
                WindowState = FormWindowState.Maximized;
            #endif

            InitializeGraphics();
        }
        
        private void AppFrm_KeyDown(object sender, System.Windows.Forms.KeyEventArgs e)
        {
            if (e.KeyCode==Keys.Escape) Close();
        }
                
        [STAThread]
        static void Main() 
        {
            AppFrm frm=new AppFrm();
            frm.Show();

            消息循环#region 消息循环
            while (frm.Created)
            {
                frm.Draw();
                Thread.Sleep(1000/60);
                try 
                {
                    Application.DoEvents();
                }
                catch (Exception e)
                {
                    continue;
                }
            } 
            #endregion
        }

    }
}