菜鸟弱问，希望各位不吝赐教

zeus1031

问题是这样的：

我在顶点缓冲区里存了3个点(没有找到C#怎么能做索引，所有代码都是C++的)，画了一个三角形出来，现在我希望能在满足一个条件的情况下再画第二个出来，我需要怎么做？

if (!matrixForm.InitializeGraphics())
{
    MessageBox.Show("Could not initialize Direct3D. " +
         "This tutorial will exit.");
    return;
}
Application.Run(matrixForm);

InitializeGraphics()之后再做什么都不行了，改顶点坐标也不可以，再创建新对象也不可以，不知道怎么再画第二个了

希望赐教的各位可以给我改下代码，我C#刚入门而已，稍微复杂一些我就不明白了，谢谢

这个是完整代码，我想学习一下，做个PDA上的小游戏试试

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using Microsoft.WindowsMobile.DirectX;
using Microsoft.WindowsMobile.DirectX.Direct3D;

// The main class for this sample
public class Matrices : Form
{
    // Our global variables for this project
    // The rendering device
    Device device = null;
    VertexBuffer vertexBuffer = null;
    PresentParameters presentParams = new PresentParameters();

    public Matrices()
    {
        // Set the caption
        this.Text = "Direct3D Tutorial 3 - Matrices";
        // We want an Ok button
        this.MinimizeBox = false;
    }

    // Prepares the rendering device
    public bool InitializeGraphics()
    {
        try
        {
            // Now let's setup our D3D parameters
            presentParams.Windowed = true;
            presentParams.SwapEffect = SwapEffect.Discard;
            device = new Device(0, DeviceType.Default, this,
                CreateFlags.None, presentParams);
            device.DeviceReset += new System.EventHandler(
                this.OnResetDevice);
            this.OnCreateDevice(device, null);
            this.OnResetDevice(device, null);
            return true;
        }
        catch (DirectXException)
        {
            return false;
        }
    }

    // Called whenever the rendering device is created (or recreated)
    void OnCreateDevice(object sender, EventArgs e)
    {
        Pool vertexBufferPool;
        Caps caps;
        Device dev = (Device)sender;

        // Get the device capabilities

        caps = dev.DeviceCaps;

        if (caps.SurfaceCaps.SupportsVidVertexBuffer)
            vertexBufferPool = Pool.VideoMemory;
        else
            vertexBufferPool = Pool.SystemMemory;

        // Now Create the VB
        vertexBuffer = new VertexBuffer(
            typeof(CustomVertex.PositionColored), 8, dev, 0,
            CustomVertex.PositionColored.Format, vertexBufferPool);
        vertexBuffer.Created += new System.EventHandler(
            this.OnCreateVertexBuffer);
        this.OnCreateVertexBuffer(vertexBuffer, null);
    }

    // Called whenever the rendering device is reset
    void OnResetDevice(object sender, EventArgs e)
    {
        Device dev = (Device)sender;
        // Turn off culling, so we see the front and back of the triangle
        dev.RenderState.CullMode = Cull.None;
        // Turn off D3D lighting, since we are providing our own vertex
        // colors
        dev.RenderState.Lighting = false;
    }

    // Called whenever the vertex buffer is created (or recreated)
    void OnCreateVertexBuffer(object sender, EventArgs e)
    {
        VertexBuffer vb = (VertexBuffer)sender;
        CustomVertex.PositionColored[] verts = (CustomVertex.PositionColored[])vb.Lock(0, 0);
        verts[0].X=1.0f; verts[0].Y=1.0f; verts[0].Z=1.0f;
        verts[0].Color = System.Drawing.Color.White.ToArgb();

        verts[1].X=-1.0f; verts[1].Y=1.0f; verts[1].Z=1.0f;
        verts[1].Color = System.Drawing.Color.White.ToArgb();

        verts[2].X=1.0f; verts[2].Y=-1.0f; verts[2].Z=1.0f;
        verts[2].Color = System.Drawing.Color.White.ToArgb();

        verts[3].X=1.0f; verts[3].Y=1.0f; verts[3].Z=-1.0f;
        verts[3].Color = System.Drawing.Color.White.ToArgb();

        verts[4].X=-1.0f; verts[4].Y=-1.0f; verts[4].Z=1.0f;
        verts[4].Color = System.Drawing.Color.White.ToArgb();

        verts[5].X=-1.0f; verts[5].X=1.0f; verts[5].X=-1.0f;
        verts[5].Color = System.Drawing.Color.White.ToArgb();

        verts[6].X=1.0f; verts[6].X=-1.0f; verts[6].X=-1.0f;
        verts[6].Color = System.Drawing.Color.White.ToArgb();

        verts[7].X=-1.0f; verts[7].X=-1.0f; verts[7].X=-1.0f;
        verts[7].Color = System.Drawing.Color.White.ToArgb();

        vb.Unlock();
    }

    // All rendering for each frame occurs here
    private void Render()
    {
        if (device == null)
            return;

        //Clear the backbuffer to a blue color
        device.Clear(ClearFlags.Target, System.Drawing.Color.Blue,
            1.0f, 0);
        //Begin the scene
        device.BeginScene();
        // Setup the world, view, and projection matrices
        SetupMatrices();

        device.SetStreamSource(0, vertexBuffer, 0);
        device.DrawPrimitives(PrimitiveType.TriangleList, 0, 12);
        //End the scene
        device.EndScene();
        device.Present();
    }

    //Sets up the world, view, and projection matrices each frame
    private void SetupMatrices()
    {
        // For our world matrix, we will just rotate the object about
        // the y-axis. Set up the rotation matrix to generate 1 full
        // rotation (2*PI radians) every 1000 ms. To avoid the loss of
        // precision inherent in very high floating point numbers, the
        // system time is modulated by the rotation period before
        // conversion to a radian angle.
        int  iTime  = Environment.TickCount % 1000;
        float fAngle = iTime * (2.0f * (float)Math.PI) / 1000.0f;
        device.Transform.World = Matrix.RotationY( fAngle );

        // Set up our view matrix. A view matrix can be defined given
        // an eye point, a point to lookat, and a direction for which
        // way is up. Here, we set the eye five units back along the
        // z-axis and up three units, look at the origin, and define
        // "up" to be in the y-direction.
        device.Transform.View = Matrix.LookAtLH(
            new Vector3(0.0f, 3.0f, -5.0f),
            new Vector3(0.0f, 0.0f, 0.0f),
            new Vector3(0.0f, 1.0f, 0.0f));

        // For the projection matrix, we set up a perspective transform
        // (which transforms geometry from 3D view space to 2D viewport
        // space, with a perspective divide making objects smaller in
        // the distance). To build a perpsective transform, we need the
        // field of view (1/4 pi is common),
        // the aspect ratio, and the near and far clipping planes
        // (which define at what distances geometry should be no longer
        // be rendered).
        device.Transform.Projection =
            Matrix.PerspectiveFovLH( (float)Math.PI / 4,
            1.0f, 1.0f, 100.0f );
    }

    // Called when the window needs to be repainted
    protected override void OnPaint(
        System.Windows.Forms.PaintEventArgs e)
    {
         // Render on painting
        this.Render();

         // Render again
        this.Invalidate();
    }

    // Called when the window background needs to be repainted
    protected override void OnPaintBackground(
        System.Windows.Forms.PaintEventArgs e)
    {
        // Don't paint the background
    }

    // Handles any keyboard keys which have been pressed
    protected override void OnKeyPress(
        System.Windows.Forms.KeyPressEventArgs e)
    {
        if ((int)(byte)e.KeyChar ==
            (int)System.Windows.Forms.Keys.Escape)
            // Esc was pressed
            this.Close();
    }

    /// <summary>
    /// The main entry point for the application.
    /// </summary>
    static void Main()
    {
        Matrices matrixForm = new Matrices();

         // Initialize Direct3D
        if (!matrixForm.InitializeGraphics())
        {
            MessageBox.Show("Could not initialize Direct3D. " +
                "This tutorial will exit.");
            return;
        }

        Application.Run(matrixForm);
    }
}