DirextX编程

开发平台：
C#

PickObject.cs：源码内容
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// Copyright (c) 三峡大学水利与环境学院 肖泽云. All rights reserved.  //
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using System;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Windows.Forms;
using Microsoft.DirectX;
using Microsoft.DirectX.Direct3D;
namespace 拾取对象
{
    public partial class PickObject : Form
    {
        Device device = null;//定义绘图设备
        private float angleY=0.01f;//定义绕Y轴旋转变量
        private Vector3 CamPostion = new Vector3(0, 30, -30);//定义摄像机位置
        private Vector3 CamTarget = new Vector3(0, 0, 0);//定义摄像机目标位置
        private int mouseLastX,mouseLastY;//记录鼠标按下时的坐标位置
        private bool isRotateByMouse=false;//记录是否由鼠标控制旋转
        private bool isMoveByMouse = false;//记录是否由鼠标控制移动
        //private Mesh meshObj;//定义茶壶网格对象
        //private Material meshMaterials; //定义网格材质对象
        private Mesh[] meshObj;//定义茶壶网格对象
        private Material[] meshMaterials; //定义网格材质对象
        private Matrix[] meshPosition;//定义茶壶网格的位置
        public PickObject()
        {
            this.ClientSize = new Size(800, 600);//指定窗体尺寸
            this.Text = "拾取对象";//指定窗体标题
        }
        public bool InitializeDirect3D()
        {
            try
            {
                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
                presentParams.AutoDepthStencilFormat = DepthFormat.D16;
                presentParams.EnableAutoDepthStencil = true;
                presentParams.PresentationInterval = PresentInterval.Immediate;
                device = new Device(0, DeviceType.Hardware, this, CreateFlags.SoftwareVertexProcessing, presentParams); //实例化device对象
                
                /*
                meshObj = Mesh.Teapot(device);//定义茶壶对象
                //定义材质
                meshMaterials.Diffuse = Color.White;
                meshMaterials.Ambient = Color.White;
                meshMaterials.Specular = Color.LightGray;
                meshMaterials.SpecularSharpness = 15.0F;
                */
                //定义三个茶壶对象
                meshObj = new Mesh[3];
                meshObj[0] = Mesh.Teapot(device);//定义茶壶对象
                meshObj[1] = Mesh.Teapot(device);//定义茶壶对象
                meshObj[2] = Mesh.Teapot(device);//定义茶壶对象
                //定义茶壶位置
                meshPosition = new Matrix[3];
                meshPosition[0] = Matrix.Translation(-10f, 0f, 0f);
                meshPosition[1] = Matrix.Translation(0f, 0f, 0f);
                meshPosition[2] = Matrix.Translation(10f, 0f, 0f);
                //定义材质
                meshMaterials = new Material[3];
                meshMaterials[0].Diffuse = Color.White;
                meshMaterials[0].Ambient = Color.White;
                meshMaterials[0].Specular = Color.LightGray;
                meshMaterials[0].SpecularSharpness = 15.0F;
                meshMaterials[2] = meshMaterials[1] = meshMaterials[0];
                                
                return true;
            }
            catch (DirectXException 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;
            }
            SetUpCamera();
            device.Clear(ClearFlags.Target | ClearFlags.ZBuffer, Color.DarkSlateBlue, 1.0f, 0);  //清除windows界面为深蓝色
            device.BeginScene();
            //在此添加渲染图形代码
            //灯光设置            
            device.RenderState.Lighting = true;
            device.Lights[0].Type = LightType.Directional;
            device.Lights[0].Diffuse = System.Drawing.Color.Red;
            device.Lights[0].Direction = new Vector3(-1.0f, 1.0f, 1.0f);
            device.Lights[0].Enabled = true; //打开灯光
            device.Lights[1].Type = LightType.Directional;
            device.Lights[1].Diffuse = System.Drawing.Color.Green;
            device.Lights[1].Direction = new Vector3(1f, -1.0f, 1.0f);
            device.Lights[1].Enabled = true; //打开灯光            
            device.RenderState.Ambient = Color.SlateGray;
            
            device.RenderState.CullMode = Cull.None;
                       
            //以实体形式绘制茶壶模型
            device.RenderState.FillMode = FillMode.Solid;
            /*
            device.Material = meshMaterials;//设置当前材质
            meshObj.DrawSubset(0);
             */
            for (int i = 0; i < meshObj.Length; i++)
            {
                //设置当前世界矩阵
                device.Transform.World = meshPosition[i];
                //设置当前材质
                device.Material = meshMaterials[i];
                meshObj[i].DrawSubset(0);
            }
            /*
            device.Transform.World = meshPosition[0];
            device.Material = meshMaterials[0];//设置当前材质
            meshObj[0].DrawSubset(0);
            device.Transform.World = meshPosition[1];
            device.Material = meshMaterials[1];//设置当前材质
            meshObj[1].DrawSubset(0);
            device.Transform.World = meshPosition[2];
            device.Material = meshMaterials[2];//设置当前材质
            meshObj[2].DrawSubset(0);
            */
            device.EndScene();
            device.Present();
        }
        private void SetUpCamera()//摄像机
        {
            Matrix viewMatrix = Matrix.LookAtLH(CamPostion, CamTarget, new Vector3(0, 1, 0));
            device.Transform.Projection = Matrix.PerspectiveFovLH((float)Math.PI / 4, this.ClientSize.Width / this.ClientSize.Height, 0.3f, 500f);
            device.Transform.View = viewMatrix;
        }
        protected override void OnKeyDown(KeyEventArgs e)
        {
            Vector4 tempV4;
            Matrix currentView = device.Transform.View;//当前摄像机的视图矩阵
            switch (e.KeyCode)
            {
                case Keys.Left:
                    CamPostion.Subtract(CamTarget);
                    tempV4 = Vector3.Transform(CamPostion, Matrix.RotationQuaternion(
                            Quaternion.RotationAxis(new Vector3(currentView.M12, currentView.M22, currentView.M32), -angleY)));
                    CamPostion.X = tempV4.X + CamTarget.X;
                    CamPostion.Y = tempV4.Y + CamTarget.Y;
                    CamPostion.Z = tempV4.Z + CamTarget.Z;
                    break;
                case Keys.Right:
                    CamPostion.Subtract(CamTarget);
                    tempV4 = Vector3.Transform(CamPostion, Matrix.RotationQuaternion(
                            Quaternion.RotationAxis(new Vector3(currentView.M12, currentView.M22, currentView.M32), angleY)));
                    CamPostion.X = tempV4.X + CamTarget.X;
                    CamPostion.Y = tempV4.Y + CamTarget.Y;
                    CamPostion.Z = tempV4.Z + CamTarget.Z;
                    break;
                case Keys.Up:
                    CamPostion.Subtract(CamTarget);
                    tempV4 = Vector3.Transform(CamPostion, Matrix.RotationQuaternion(
                       Quaternion.RotationAxis(new Vector3(device.Transform.View.M11
                       , device.Transform.View.M21, device.Transform.View.M31), -angleY)));
                    CamPostion.X = tempV4.X + CamTarget.X;
                    CamPostion.Y = tempV4.Y + CamTarget.Y;
                    CamPostion.Z = tempV4.Z + CamTarget.Z;
                    break;
                case Keys.Down:
                    CamPostion.Subtract(CamTarget);
                    tempV4 = Vector3.Transform(CamPostion, Matrix.RotationQuaternion(
                       Quaternion.RotationAxis(new Vector3(device.Transform.View.M11
                       , device.Transform.View.M21, device.Transform.View.M31), angleY)));
                    CamPostion.X = tempV4.X + CamTarget.X;
                    CamPostion.Y = tempV4.Y + CamTarget.Y;
                    CamPostion.Z = tempV4.Z + CamTarget.Z;
                    break;
                case Keys.Add:
                    CamPostion.Subtract(CamTarget);
                    CamPostion.Scale(0.95f);
                    CamPostion.Add(CamTarget);
                    break;
                case Keys.Subtract:
                    CamPostion.Subtract(CamTarget);
                    CamPostion.Scale(1.05f);
                    CamPostion.Add(CamTarget);
                    break;
            }
            Matrix viewMatrix = Matrix.LookAtLH(CamPostion, CamTarget, new Vector3(0, 1, 0));
            device.Transform.View = viewMatrix;
        }
        protected override void OnMouseDown(MouseEventArgs e)
        {
            if (e.Button == MouseButtons.Left)
            {
                mouseLastX = e.X;
                mouseLastY = e.Y;
                isRotateByMouse = true;                
            }
            else if (e.Button == MouseButtons.Middle)
            {
                mouseLastX = e.X;
                mouseLastY = e.Y;
                isMoveByMouse=true;
            }
        }
        
        protected override void OnMouseUp(MouseEventArgs e)
        {
            isRotateByMouse = false;
            isMoveByMouse = false;
        }
        protected override void OnMouseMove(MouseEventArgs e)
        {
            //计算摄像机投影窗口上对应的点击位置坐标
            Vector3 SVector = new Vector3();
            SVector.X = 2 * (float)e.X / this.ClientSize.Width - 1;
            SVector.Y = -2 * (float)e.Y / this.ClientSize.Height + 1;
            SVector.Z = 1.0f / (float)Math.Tan(Math.PI / 8);
            //视图矩阵
            Matrix viewMatrix = device.Transform.View;
            viewMatrix.Invert();//计算视图矩阵的逆矩阵
            //射线位置
            Vector3 rayPos = Vector3.TransformCoordinate(SVector, viewMatrix);
            //射线方向
            Vector3 rayDir = Vector3.Subtract(rayPos, CamPostion);
            //碰撞检测            
            for (int i = 0; i < meshObj.Length; i++)
            {
                //将模型的世界矩阵进行逆变换
                Matrix inverseWorld = Matrix.Invert(meshPosition[i]);
                Vector3 localRayPos = Vector3.TransformCoordinate(rayPos, inverseWorld);
                Vector3 localRayDir = Vector3.TransformNormal(rayDir, inverseWorld);
                bool result = meshObj[i].Intersect(localRayPos, localRayDir);
                if (result)
                {
                    meshMaterials[i].Diffuse = Color.Red;//相交时漫反射为红色
                    meshMaterials[i].Ambient = Color.Red;//相交时环境色为红色
                }
                else
                {
                    meshMaterials[i].Diffuse = Color.White;//不相交时漫反射为白色
                    meshMaterials[i].Ambient = Color.White;//不相交时环境色为红色
                }
            }
            /*
            bool result = meshObj.Intersect(rayPos, rayDir);
            if (result)
            {
                meshMaterials.Diffuse = Color.Red;//相交时漫反射为红色
                meshMaterials.Ambient = Color.Red;//相交时环境色为红色
            }
            else
            {
                meshMaterials.Diffuse = Color.White;//不相交时漫反射为白色
                meshMaterials.Ambient = Color.White;//不相交时环境色为红色
            }
            */
            if (isRotateByMouse)
            {
                Matrix currentView = device.Transform.View;//当前摄像机的视图矩阵
                float tempAngleY = 2 * (float)(e.X - mouseLastX) / this.Width;
                CamPostion.Subtract(CamTarget);
                Vector4 tempV4 = Vector3.Transform(CamPostion, Matrix.RotationQuaternion(
                    Quaternion.RotationAxis(new Vector3(currentView.M12, currentView.M22, currentView.M32), tempAngleY)));
                CamPostion.X = tempV4.X;
                CamPostion.Y = tempV4.Y;
                CamPostion.Z = tempV4.Z;
                float tempAngleX = 4 * (float)(e.Y - mouseLastY) / this.Height;
                tempV4 = Vector3.Transform(CamPostion, Matrix.RotationQuaternion(
                    Quaternion.RotationAxis(new Vector3(currentView.M11, currentView.M21, currentView.M31), tempAngleX)));
                CamPostion.X = tempV4.X + CamTarget.X;
                CamPostion.Y = tempV4.Y + CamTarget.Y;
                CamPostion.Z = tempV4.Z + CamTarget.Z;
                viewMatrix = Matrix.LookAtLH(CamPostion, CamTarget, new Vector3(0, 1, 0));
                device.Transform.View = viewMatrix;
                mouseLastX = e.X;
                mouseLastY = e.Y;
            }
            else if (isMoveByMouse)
            {
                Matrix currentView = device.Transform.View;//当前摄像机的视图矩阵
                float moveFactor=0.01f;
                CamTarget.X += -moveFactor * ((e.X - mouseLastX) * currentView.M11 - (e.Y - mouseLastY) * currentView.M12);
                CamTarget.Y += -moveFactor * ((e.X - mouseLastX) * currentView.M21 - (e.Y - mouseLastY) * currentView.M22);
                CamTarget.Z += -moveFactor * ((e.X - mouseLastX) * currentView.M31 - (e.Y - mouseLastY) * currentView.M32);
                CamPostion.X +=- moveFactor * ((e.X - mouseLastX) * currentView.M11 - (e.Y - mouseLastY) * currentView.M12);
                CamPostion.Y += -moveFactor * ((e.X - mouseLastX) * currentView.M21 - (e.Y - mouseLastY) * currentView.M22);
                CamPostion.Z += -moveFactor * ((e.X - mouseLastX) * currentView.M31 - (e.Y - mouseLastY) * currentView.M32);
             
                viewMatrix = Matrix.LookAtLH(CamPostion, CamTarget, new Vector3(0, 1, 0));
                device.Transform.View = viewMatrix;
                mouseLastX = e.X;
                mouseLastY = e.Y;
            }
        }
        protected override void OnMouseWheel(MouseEventArgs e)
        {
            float scaleFactor = -(float)e.Delta / 2000 + 1f;
            CamPostion.Subtract(CamTarget);
            CamPostion.Scale(scaleFactor);
            CamPostion.Add(CamTarget);
            Matrix viewMatrix = Matrix.LookAtLH(CamPostion, CamTarget, new Vector3(0, 1, 0));
            device.Transform.View = viewMatrix;
        }
        static void Main()
        {
            PickObject pickObject = new PickObject(); //创建窗体对象
            if (pickObject.InitializeDirect3D() == false) //检查Direct3D是否启动
            {
                MessageBox.Show("无法启动Direct3D！", "错误！");
                return;
            }
            pickObject.Show(); //如果一切都初始化成功，则显示窗体
            while (pickObject.Created) //设置一个循环用于实时更新渲染状态
            {
                pickObject.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
            }
        }
    }
}

						