DirextX编程

开发平台：
C#

DrawCircleClass.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.  //
////////////////////////////////////////////////////////////////////////
using System;
using System.Collections.Generic;
using System.Text;
using System.Drawing;
using Microsoft.DirectX;
using Microsoft.DirectX.Direct3D;
namespace 绘制基本几何体
{
    class DrawCircleClass
    {
        /// <summary>
        /// <param name="device">device:设备对象</param>
        /// </summary>
        public Device device;//定义设备
        /// <summary>
        /// <param name="circleCenterVectors">circleCenterVectors:圆心坐标</param>
        /// </summary>
        public Vector3 circleCenterVectors;//定义圆心坐标
        ///<summary>
        ///<param name="radius">radius:圆半径</param>
        ///</summary>        
        public float radius;//定义圆半径
        /// <summary>
        /// <param name="circleNormalVectors">circleNormalVectors:圆的法线向量</param>
        /// </summary>
        public Vector3 circleNormalVectors;//定义圆的法线向量
        /// <summary>
        /// <param name="mNumber">mNumber:沿切向的分块数目</param>
        /// </summary>
        public int mNumber;//定义沿切向的分块数目
        /// <summary>
        /// <param name="nNumber">nNumber:沿径向的分块数目</param>
        /// </summary>
        public int nNumber;//定义沿径向的分块数目
        private CustomVertex.PositionColored[] vertices;//定义圆网格顶点
        private int[] indexData;//定义圆网格中三角形索引
        /// <summary>
        /// 定义一个绘制圆对象
        /// </summary>
        /// <param name="_device">设备对象</param>
        /// <param name="_circleCenterVectors">圆心坐标</param>
        /// <param name="_radius">圆半径</param>
        /// <param name="_circleNormalVectors">圆的法线向量</param>
        /// <param name="_mNumber">沿切向的分块数目</param>
        /// <param name="_nNumber">沿径向的分块数目</param>
        public DrawCircleClass(Device _device, Vector3 _circleCenterVectors, float _radius, Vector3 _circleNormalVectors, int _mNumber, int _nNumber)
        {
            device = _device;
            circleCenterVectors = _circleCenterVectors;
            radius = _radius;
            circleNormalVectors = _circleNormalVectors;
            mNumber = _mNumber;
            nNumber = _nNumber;
            VertexDeclaration();//定义顶点
            IndicesDeclaration();//定义索引
        }
        private void VertexDeclaration()//定义顶点
        {
            vertices = new CustomVertex.PositionColored[(mNumber + 1) * (nNumber + 1)];
            float cosAlpha = circleNormalVectors.Y / circleNormalVectors.Length();
            float sinAlpha = (float)Math.Sqrt(1 - cosAlpha * cosAlpha);
            float sinBeta = circleNormalVectors.Z / (float)Math.Sqrt(circleNormalVectors.X * circleNormalVectors.X + circleNormalVectors.Z * circleNormalVectors.Z);
            float cosBeta = (float)Math.Sqrt(1 - sinBeta * sinBeta);
            Vector3 R0Vector = new Vector3();
            R0Vector.X=radius*cosAlpha*cosBeta;
            R0Vector.Y=-radius*sinAlpha;
            R0Vector.Z=radius*cosAlpha*sinBeta;
            float theta = (float)Math.PI*2 / mNumber;
            for (int i = 0; i < mNumber + 1; i++)
            {
                Vector4 tempRVector =Vector3.Transform(R0Vector,Matrix.RotationAxis(circleNormalVectors,theta*i));
                for (int j = 0; j < nNumber + 1; j++)
                {
                    vertices[j + i * (nNumber + 1)].X = circleCenterVectors.X + tempRVector.X * j / nNumber;
                    vertices[j + i * (nNumber + 1)].Y = circleCenterVectors.Y + tempRVector.Y * j / nNumber;
                    vertices[j + i * (nNumber + 1)].Z = circleCenterVectors.Z + tempRVector.Z * j / nNumber;
                    vertices[j + i * (nNumber + 1)].Color = Color.Yellow.ToArgb();
                }
            }
        }
        private void IndicesDeclaration()//定义索引
        {
            indexData = new int[6 * mNumber * nNumber];
            for (int i = 0; i < mNumber; i++)
            {
                for (int j = 0; j < nNumber; j++)
                {
                    indexData[6 * (j + i * nNumber)] = j + i * (nNumber + 1);
                    indexData[6 * (j + i * nNumber) + 1] = j + i * (nNumber + 1) + 1;
                    indexData[6 * (j + i * nNumber) + 2] = j + (i + 1) * (nNumber + 1);
                    indexData[6 * (j + i * nNumber) + 3] = j + i * (nNumber + 1) + 1;
                    indexData[6 * (j + i * nNumber) + 4] = j + (i + 1) * (nNumber + 1) + 1;
                    indexData[6 * (j + i * nNumber) + 5] = j + (i + 1) * (nNumber + 1);
                }
            }
        }
        /// <summary>
        /// 绘制圆
        /// </summary>
        public void DrawCircle()
        {
            device.DrawIndexedUserPrimitives(PrimitiveType.TriangleList, 0, (mNumber + 1) * (nNumber + 1), 2 * mNumber * nNumber, indexData, false, vertices);
        }
    }
}

						