远近旋转球体

static int day = 20;
                void mydisplay(void)
                {
                	int a = clock();
                	glEnable(GL_DEPTH_TEST);
                	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);//清空颜色缓存与深度缓存
                	glMatrixMode(GL_PROJECTION);//接下来要进行的操作（投影）
                	glLoadIdentity();//将当前矩阵设置为单位阵
                	gluPerspective(75, 1, 1, 400000000);//设置可视空间
                	glMatrixMode(GL_MODELVIEW);//设置为模型视图与变换
                	glLoadIdentity();
                	gluLookAt(0, -200000000, 200000000, 0, 0, 0, 0, 0, 1);//观察点
                
                	//绘制
                
                	glColor3f(0.0f, 0.0f, 1.0f);
                	glRotatef(day / 360.0*360.0, 0.0f, 0.0f, -1.0f);
                	glTranslatef(150000000, 0.0f, 0.0f);
                	glutSolidSphere(15945000, 20, 20);
                
                
                	glutSwapBuffers();
                
                
                }
                void myidle(int v)
                {
                	++day;
                	if (day >= 360)day = 0;
                	mydisplay();
                
                	glutTimerFunc(10, myidle, 0);
                }
                int main(int argc, char *argv[])
                {
                	glutInit(&argc, argv);
                	glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
                	glutInitWindowPosition(100, 100);
                	glutInitWindowSize(400, 400);
                	glutCreateWindow("旋转");
                	glutDisplayFunc(mydisplay);
                
                	glutTimerFunc(10,myidle,0);
                	glutMainLoop();
                	return 0;
                }