openGL+VS2010的例程--太阳地球月球运动模型增强版（三维）

效果图如上：

步骤:请看注释，这里略。

实现代码如下：

  1 #include "windows.h"
  2 #include <gl\glut.h>
  3
  4 // 三者的大小比例
  5 #define SunSize 0.4
  6 #define EarthSize 0.06
  7 #define MoonSize 0.016
  8
  9 GLfloat SpeedMultiplicator = 0.01;// 运行倍数
 10 // 时间比例
 11 GLfloat DaysPerYear = 365.24; //OK, ok... but it is soo slow with 360!
 12 GLfloat DaysPerMoon =  27.321; // 月球公转一圈的天数
 13  //degrees 累计角度
 14 GLfloat EarthAroundSun = 0.0;
 15 GLfloat EarthItsSelf = 0.0;
 16 GLfloat moonAroundEarth = 0.0;
 17 GLfloat moonItsSelf = 0.0;
 18 // 半径
 19 GLfloat EarthOrbitRadius = 1.0; // 地球轨道半径
 20 GLfloat MoonOrbitRadius = 0.15;// 月球轨道半径
 21 // 角速度
 22 GLfloat EarthItsSelfSpeed =  360.0 / 1.0 * SpeedMultiplicator;  // 以一天为单位时间
 23 GLfloat moonAroundEarthSpeed = 360.0 / DaysPerMoon  * SpeedMultiplicator;
 24 GLfloat moonItsSelfSpeed = moonAroundEarthSpeed; // 月球同步自转
 25 GLfloat EarthAroundSunSpeed = 360.0  / DaysPerYear * SpeedMultiplicator;
 26
 27 void RenderScene(void)
 28 {
 29     glPushMatrix(); // 压栈1
 30         gluLookAt(    0.0,3.0,3.0, // 眼睛的位置 z轴+y轴=45%
 31                     0.0,-1.0,-1.0, // 眼睛的朝向的位置 z轴+y轴=45%
 32                     0.0,1.0,0.0); // 相片朝上的方向（因为你可以歪着头看同一个物体） y轴
 33         glColor3f(1.0,1.0,0.5);
 34         glutWireSphere(SunSize,20,20); // 绘制太阳
 35
 36         glPushMatrix(); // 压栈2
 37             glRotatef(EarthAroundSun,0.0,1.0,0.0); // 地球公转的轨道角度 y轴
 38             glTranslatef(EarthOrbitRadius,0.0,0.0);// 地球轨道半径
 39             glRotatef(-EarthAroundSun,0.0,1.0,0.0);
 40
 41             glPushMatrix(); // 压栈3
 42                 glRotatef(EarthItsSelf,0.4348,1.0,0.0);  //  地球自转的轨道角度
 43                 glColor3f(0.0,0.5,0.8);
 44                 glutWireSphere(EarthSize,8,8);  //Draw earth 绘制地球
 45                 //Draw earth rotation axis 地球自转轴线
 46                 glLineStipple (0.1, 0x0F0F);  // 虚化线 部分1
 47                 glEnable(GL_LINE_STIPPLE); // 虚化线 部分2
 48                 glBegin(GL_LINES); // 直线
 49                     glVertex3f(0.1087,0.25,0.0);
 50                     glVertex3f(-0.1087,-0.25,0.0);
 51                 glEnd();
 52                 glDisable(GL_LINE_STIPPLE);  // 虚化线 部分3
 53
 54             glPopMatrix(); // 出栈3
 55
 56             // 恢复到 地球球心的坐标系
 57             glRotatef(moonAroundEarth,0.0,1.0,0.0); // 月球环绕地球的轨道角度
 58             glTranslatef(MoonOrbitRadius,0.0,0.0); //  月球轨道半径 > 地球大小半径
 59             //The following 2 lines should be combined, but it is better to understand this way
 60             glRotatef(-moonAroundEarth,0.0,1.0,0.0); // 月球沿着Y轴逆时针自转
 61             glRotatef(moonItsSelf,0.0,1.0,0.0); // 月球沿着Y轴顺时针自转
 62             glColor3f(0.8,0.8,0.75); // 设置颜色
 63             glutWireSphere(MoonSize,8,8);  // 绘制球体
 64         glPopMatrix();// 出栈2
 65
 66     // 恢复到 太阳球心的坐标系
 67     glPopMatrix();// 出栈1
 68
 69 }
 70
 71 void Init(void)
 72 {
 73     glClearColor(0.0,0.0,0.0,0.0);// 清除颜色
 74     glClearDepth(10.0); // 清除深度
 75     glMatrixMode(GL_MODELVIEW);// 模型矩阵
 76     glLoadIdentity();// 把视景体截取的图像按特殊处理显示到屏幕上
 77 }
 78
 79 void Display(void)
 80 {
 81     glClear(GL_COLOR_BUFFER_BIT);
 82     RenderScene(); // 渲染
 83     glFlush();
 84     glutSwapBuffers();
 85 }
 86
 87 void Reshape(int x, int y)
 88 {
 89     if (y == 0) return;
 90     glMatrixMode(GL_PROJECTION); // 投影矩阵
 91     glLoadIdentity();
 92     gluPerspective(30.0,(GLdouble)x/(GLdouble)y,0.8,10.0); // 设定投影变换
 93     glMatrixMode(GL_MODELVIEW); // 模型矩阵
 94     glViewport(0,0,x,y); // 把视景体截取的图像按特殊处理显示到屏幕上
 95     Display();
 96 }
 97 static long long times = 0;
 98 void Idle(void)
 99 {
100     times++; // 延迟
101     if(times>50000)
102         times =0;
103     if(times% 50000== 0)
104     {
105         EarthItsSelf += EarthItsSelfSpeed; // 一天的速度
106         EarthAroundSun += EarthAroundSunSpeed; // 一年的速度
107         moonItsSelf += moonItsSelfSpeed; // 月球自转的转速
108         moonAroundEarth += moonAroundEarthSpeed; // 月球围绕地球的转速
109         Display();
110     }
111 }
112
113
114 int main(int argc, char* argv[])
115 {
116     glutInit(&argc, argv);
117     glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
118     glutInitWindowSize(800,600);
119     glutCreateWindow(argv[0]);
120     Init();
121     glutReshapeFunc(Reshape);
122     glutDisplayFunc(Display);
123     glutIdleFunc(Idle);
124     glutMainLoop();
125     return 0;
126 }