Opengl太阳系程序space源码+详解

/* * Solar.cpp 用于演示变换和坐标系 画了一个简单的太阳系，包括一个太阳，一个地球和一个月球 使用说明： * 按"r"键来启动和停止动画 * 按"s"键单步执行动画 * 向上和向下箭头用于控制动画中每一帧的时间间隔,每次按键时间间隔乘2或除2 * 按ESC键退出) */ #include <stdlib.h> #include <GL/glut.h> GLenum spinMode = GL_TRUE; // 控制动画运行和暂停 GLenum singleStep = GL_FALSE; // 控制单步执行模式开启和关闭 // 这3个变量控制动画的状态和速度 float HourOfDay = 0.0; // 一天中的小时数，初始为0 float DayOfYear = 0.0; // 一年中的天数，初始为0 float AnimateIncrement = 12.0; // 动画步长变量，表示时间间隔, 以小时为单位 float HourOfDayX=0.0; float DayOfYearX=0.0; // 显示回调函数 void Animate(void) { // 用背景色清空颜色缓存，将深度缓存恢复为初始值 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); glEnable(GL_NORMALIZE); //归一化法向量 if (spinMode) { // 如果动画开启 // 更新动画状态 HourOfDay += AnimateIncrement; DayOfYear += AnimateIncrement/24.0; HourOfDayX+=AnimateIncrement; DayOfYearX+=AnimateIncrement/36.0; // 防止溢出 HourOfDay = HourOfDay - ((int)(HourOfDay/24))*24; DayOfYear = DayOfYear - ((int)(DayOfYear/365))*365; HourOfDayX=HourOfDayX-((int)(HourOfDayX/36))*36; DayOfYearX=DayOfYearX-((int)(DayOfYearX/300))*300; } // 将当前矩阵(模-视矩阵)置为恒等矩阵 glLoadIdentity(); // 在观察坐标系(照相机坐标系)下思考，定位整个场景(第一种观点)或世界坐标系(第二种观点) // 向负z轴方向平移8个单位 //glTranslatef ( 0.0, 0.0, -8.0 ); //// 将模型平面绕x轴逆时针旋转15度 //glRotatef( 90.0, 1.0, 0.0, 0.0 ); gluLookAt(0.0,3.0,12.0,0.0,0.0,0.0,0.0,1.0,0.0); // 下面开始构建整个3D世界，在世界坐标系下考虑问题 // 太阳直接画在原点，无须变换，用一个黄色的线框球体表示 glColor3f( 1.0, 1.0, 0.0 ); glPushMatrix(); glRotatef(2*360.0*DayOfYear/365.0,0.0,1.0,0.0); glTranslatef(-1.0,0.0,0.0); glRotatef(-90,1.0,0.0,0.0); glutWireSphere( 0.8, 15, 15 ); glPopMatrix(); glPushMatrix(); glRotatef(2*360.0*DayOfYear/365.0,0.0,1.0,0.0); glTranslatef(1.0,0.0,0.0); glRotatef(-90,1.0,0.0,0.0); glutWireSphere( 0.8, 15, 15 ); glPopMatrix(); //绘制地球运动轨迹 glPushMatrix(); glColor3f(0.6,0.5,0.5); glRotatef(90,1.0,0.0,0.0); glutWireTorus(0.0,4.0,1,50); glPopMatrix(); // 对地球系统定位 // 用DayOfYear来控制其绕太阳的旋转 glPushMatrix(); glRotatef( 360.0*DayOfYear/365.0, 0.0, 1.0, 0.0 ); glTranslatef( 4.0, 0.0, 0.0 ); glRotatef( 360.0*DayOfYear/365.0, 0.0, -1.0, 0.0 ); glRotatef(40,0.0,0.0,-1.0); glColor3f(0.6,0.5,0.5); glBegin(GL_LINES); glVertex3f(0.0,0.6,0.0); glVertex3f(0.0,-0.6,0.0); glEnd(); // 下面开始在地球系统的小世界坐标系下考虑问题 // 绘制地球，地球的自转不应该影响月球 glPushMatrix(); // 保存矩阵状态 // 地球自转，用HourOfDay进行控制 glRotatef( 360.0*HourOfDay/24.0, 0.0, 1.0, 0.0 ); // 画一个线框球体用以表示地球 glColor3f( 0.2, 0.2, 1.0 ); glRotatef(90,-1.0,0.0,0.0); glutWireSphere( 0.4, 10, 10); glPopMatrix(); // 恢复矩阵状态 // 画月球 // 用DayOfYear来控制其绕地球的旋转 glPushMatrix(); //绘制月球运动轨迹 glColor3f(0.6,0.5,0.5); glRotatef(90,1.0,0.0,0.0); glutWireTorus(0.0,0.7,1,50); glPopMatrix(); glRotatef( 360.0*12.0*DayOfYear/365.0, 0.0, 1.0, 0.0 ); glTranslatef( 0.7, 0.0, 0.0 ); glColor3f( 1.0,1.0,1.0 ); glutWireSphere( 0.2, 10, 10 ); //绘制月球的卫星 glRotatef( 4*360.0*12.0*DayOfYear/365.0, 0.0, 1.0, 0.0 ); glTranslatef(0.5,0.0,0.0); glColor3f(0.3,0.7,0.3); glutWireSphere(0.1,5,5); glPopMatrix(); //绘制X行星 glPushMatrix(); glRotatef(360.0*DayOfYearX/300.0,0.0,1.0,0.0); glTranslatef(-4.0,0.0,0.0); glPushMatrix(); glRotatef(360.0*HourOfDayX/36.0,0.0,1.0,0.0); glColor3f(0.5,0.5,0.5); glRotatef(90,-1.0,0.0,0.0); glutWireSphere(0.5,10,10); //同步卫星 glColor3f(1.0,0.0,0.0); glTranslatef(0.6,0.0,0.0); glutWireSphere(0.2,10,10); glPopMatrix(); //逆时针旋转卫星 glPushMatrix(); glRotatef(8*360.0*DayOfYearX/300.0,0.0,-1.0,0.0); glColor3f(1.0,0.0,1.0); glTranslatef(1.0,0.0,0.0); glRotatef(90,-1.0,0.0,0.0); glutWireSphere(0.2,10,10); glPopMatrix(); glPopMatrix(); glutSwapBuffers(); // 交换缓存 if ( singleStep ) { // 如果是单步执行，则关闭动画 spinMode = GL_FALSE; } } // 初始化OpenGL的状态 void OpenGLInit(void) { glClearColor( 0.0, 0.0, 0.0, 1.0 ); // 背景为黑色 glEnable( GL_DEPTH_TEST ); // 开启深度检测 } // 窗口调整回调函数，当窗口大小发生变化时被调用 void ResizeWindow(int w, int h) { h = (h == 0) ? 1 : h; w = (w == 0) ? 1 : w; //glViewport( 0, 0, w, h ); // 视口占满整个窗口 float aspectRatio = (float)600/(float)360; if((float)w/h<aspectRatio){ int height=w/aspectRatio; glViewport(0,(h-height)/2,w,height); } else{ int width=h*aspectRatio; glViewport((w-width)/2,0,width,h); } // 设置投影矩阵 glMatrixMode( GL_PROJECTION ); glLoadIdentity(); gluPerspective( 30.0, aspectRatio, 1.0, 30.0 ); // 选择模-视矩阵为当前矩阵，这样在显示回调函数中就不用再选择当前矩阵了 glMatrixMode( GL_MODELVIEW ); } // r键处理 void Key_r(void) { if ( singleStep ) { // 如果之前为单步执行模式 singleStep = GL_FALSE; // 结束单步执行 spinMode = GL_TRUE; // 重启动画 } else { spinMode = !spinMode; // 切换动画开关状态 } } // s键处理(单步显示) void Key_s(void) { singleStep = GL_TRUE; spinMode = GL_TRUE; } // 普通按键回调函数 void KeyPressFunc( unsigned char Key, int x, int y ) { switch ( Key ) { case 'R': case 'r': Key_r(); break; case 's': case 'S': Key_s(); break; case 27: // Esc键 exit(1); } } // 方向键上处理 void Key_up(void) { AnimateIncrement *= 2.0; // 动画时间间隔翻倍，即加快动画速度 } void Key_down(void) { AnimateIncrement /= 2.0; // 动画时间间隔减半，即减慢动画速度 } // 特殊按键回调函数 void SpecialKeyFunc( int Key, int x, int y ) { switch ( Key ) { case GLUT_KEY_UP: Key_up(); break; case GLUT_KEY_DOWN: Key_down(); break; } } // 定时器，实现每秒绘制60帧 void myTimer(int value) { glutPostRedisplay(); // 刷新显示 glutTimerFunc(1000/60, myTimer, value); // 循环计时 } //设置光照 void SetupLights() { GLfloat ambientLight[]={0.2f,0.2f,0.2f,1.0f}; //环境光 GLfloat diffuseLight[]={0.9f,0.9f,0.9f,1.0f}; //漫反射 GLfloat specularLight[]={1.0f,1.0f,1.0f,1.0f}; //镜面光 GLfloat lightsPos[]={50.0f,100.0f,80.0f,1.0f}; //光源位置 glEnable(GL_LIGHTING); //打开光照 glLightfv(GL_LIGHT0,GL_AMBIENT,ambientLight); //设置环境光源 glLightfv(GL_LIGHT0,GL_DIFFUSE,diffuseLight); //设置漫反射光源 glLightfv(GL_LIGHT0,GL_SPECULAR,specularLight); //设置镜面光源 glLightfv(GL_LIGHT0,GL_POSITION,lightsPos); //设置灯光位置 glEnable(GL_LIGHT0); //打开第一个灯光 glEnable(GL_COLOR_MATERIAL); //使能跟踪材料的颜色 glColorMaterial(GL_FRONT,GL_AMBIENT_AND_DIFFUSE); //指定材料作色的面 glMaterialfv(GL_FRONT,GL_SPECULAR,specularLight); //指定材料对镜面光的反应 glMateriali(GL_FRONT,GL_SHININESS,100); //指定反射系数 } // Main函数：初始化OpenGL,设置回调函数,启动消息循环 int main( int argc, char** argv ) { glutInit(&argc,argv); glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH ); // 需要双缓存以用于动画 // 创建和定位图形窗口 glutInitWindowPosition( 0, 0 ); glutInitWindowSize( 600, 360 ); glutCreateWindow( "Solar System Demo" ); // 初始化OpenGL状态 OpenGLInit(); // 设置键盘按键的回调函数 glutKeyboardFunc( KeyPressFunc ); glutSpecialFunc( SpecialKeyFunc ); // 设置窗口调整的回调函数 glutReshapeFunc( ResizeWindow ); // 设置显示回调函数 glutDisplayFunc( Animate ); // 设置定时器 glutTimerFunc(100, myTimer, 0); SetupLights(); // 启动事件循环.glutMain