[3D]1.绘制三角形

　　作为一个.Net程序员学习3D开发好尴尬啊，因为不论是OpenGL还是Direct3D都是用C/C++开发的比较多。虽然有计划使用C++进行开发，但是平时还是C#使用的多。很少用C++做东西，如果仅仅是学习是很难有进步的，学习C++很长时间了至今仍感觉很肤浅，而且语言并不是编程的全部，真正的高手是不区分语言的，所以决定注重基本原理的学习，具体实现用C#也是可以的，这里选择Slimdx。

环境：

VS2010+C#

SlimDX SDK (January 2012).msi  

d3d9.dll, D3DX9_43.dll

using System;
using System.Drawing;
using System.Windows.Forms;
using SlimDX.Direct3D9;
using SlimDX;
using System.Runtime.InteropServices;

namespace D3Ddemo01
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        Device device = null;
        private void Form1_Load(object sender, EventArgs e)
        {
            this.ClientSize = new System.Drawing.Size(800, 600);
            this.Text = " 第1个D3D程序";

        }
        public bool InitializeDirect3D()
        {
            try
            {
                Direct3D direct3d = new Direct3D();
                //direct3d.GetAdapterDisplayMode(1);
                PresentParameters presentParams = new PresentParameters();
                presentParams.Windowed = true; //指定以Windows窗体形式显示 
                presentParams.SwapEffect = SwapEffect.Discard; //当前屏幕绘制后它将自动从内存中删除
                device = new Device(direct3d, 0, DeviceType.Hardware, this.Handle,
                CreateFlags.SoftwareVertexProcessing, presentParams); //实例化device对象 
                return true;
            }
            catch (Exception e)
            {
                MessageBox.Show(e.ToString(), "Error"); //处理异常 
                return false;
            }
        }
        public void Render()
        {
            if (device == null)   //如果device为空则不渲染 
            {
                return;
            }
            Vector3 eye = new Vector3(0,0, -30);
            Vector3 at = new Vector3(0, 0, 10);
            Vector3 up = new Vector3(0, 1, 0);
            Matrix viewMatrix = Matrix.LookAtLH(eye, at, up);

            Matrix projection = Matrix.PerspectiveFovLH((float)Math.PI / 4,
this.Width / this.Height, 1.0f, 50.0f);
            device.SetTransform(TransformState.Projection, projection);
            device.SetTransform(TransformState.View, viewMatrix);
            device.SetRenderState(RenderState.FillMode, FillMode.Solid);
            device.SetRenderState(RenderState.Lighting, false);
            //深度偏移
            //device.SetRenderState(RenderState.DepthBias, drawArgs.CurrentWorld.CurrentDepthBias - 0.00001f);//防止闪烁
            device.SetRenderState(RenderState.ZEnable, true);
            device.SetRenderState(RenderState.CullMode, Cull.None);

            //在此添加渲染图形代码 
            VertexBuffer Vertices = new VertexBuffer(device, 3 * 20, Usage.WriteOnly, VertexFormat.None, Pool.Managed);
            DataStream stream = Vertices.Lock(0, 0, LockFlags.None);
            Vertex[] vertexData = new Vertex[3];
            vertexData[0].PositionRhw = new Vector4(0.0f, 1.0f, 10.0f, 1.0f);
            vertexData[0].Color = Color.Red.ToArgb();
            vertexData[1].PositionRhw = new Vector4(1.0f, 0.0f, 10.0f, 1.0f);
            vertexData[1].Color = Color.Blue.ToArgb();
            vertexData[2].PositionRhw = new Vector4(2.0f, 2.0f, 10.0f, 1.0f);
            vertexData[2].Color = Color.Green.ToArgb();
            stream.WriteRange(vertexData);
            Vertices.Unlock();
            //PositionColored[] vertices = new PositionColored[3];//定义顶点 
            //vertices[0].Position = new Vector3(0f, 0f, 0f);
            //vertices[0].Color = Color.Red.ToArgb();
            //vertices[1].Position = new Vector3(5f, 10f, 0f);
            //vertices[1].Color = Color.Green.ToArgb();
            //vertices[2].Position = new Vector3(10f, 0f, 0f);
            //vertices[2].Color = Color.Yellow.ToArgb();
            //device.VertexFormat = VertexFormat.Position;
            //device.DrawUserPrimitives(PrimitiveType.TriangleList, 1, Vertices);
            //device.RenderState.CullMode = Cull.None; 
            // device.Clear(ClearFlags.Target, Color.DarkSlateBlue, 1.0f, 0);  //清除windows界面为深蓝色 
            device.Clear(ClearFlags.Target | ClearFlags.ZBuffer, Color.Black, 1.0f, 0);
            device.BeginScene();
            device.SetStreamSource(0, Vertices, 0, 20);
            device.VertexFormat = VertexFormat.Position | VertexFormat.Diffuse;
            device.DrawPrimitives(PrimitiveType.TriangleList, 0, 1);
            device.EndScene();
            device.Present();
        }
    }
    [StructLayout(LayoutKind.Sequential)]
    struct Vertex
    {
        public Vector4 PositionRhw;
        public int Color;
    }
}

调用代码：

 static class Program
    {
        /// <summary>
        /// 应用程序的主入口点。
        /// </summary>
        [STAThread]
        static void Main()
        {
            Form1 basicForm = new Form1(); //创建窗体对象 
            if (basicForm.InitializeDirect3D() == false) //检查Direct3D是否启动 
            {
                MessageBox.Show("无法启动Direct3D！", "错误！");
                return;
            }
            basicForm.Show(); //如果一切都初始化成功，则显示窗体 
            while (basicForm.Created) //设置一个循环用于实时更新渲染状态 
            {
                basicForm.Render(); //保持device渲染，直到程序结束 
                Application.DoEvents(); //处理键盘鼠标等输入事件 
            } 
        }
    }

结果：