Opengl惑星システム

#include <gl/glut.h>

static int year=0,day=0;

void init()
{
	glClearColor(0.0f,0.0f,0.0f,0.0f);
	glShadeModel(GL_FLAT);
}

void display()
{

	glClear(GL_COLOR_BUFFER_BIT);
	glColor3f(1.0f,1.0f,1.0f);
	glPushMatrix();
	glutWireSphere(1.0,20,16);
	glRotatef((GLfloat)year,0.0,1.0,0.0);
	glTranslatef(2.0,0.0,0.0);

	glRotatef((GLfloat)day,0.0,1.0,0.0);
	glutWireSphere(0.2,10,8);
	glTranslatef(1.0,0.0,0.0);
	glRotatef((GLfloat)day,0.0,2.0,0.0);// 
	glutWireSphere(0.2,10,8);

	glPopMatrix();
	glutSwapBuffers();

}

void reshape(int w,int h)
{
	glViewport(0,0,(GLsizei)w,(GLsizei)h);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	gluPerspective(60.0,(GLfloat)w/(GLfloat)h,1.0,20.0);
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	gluLookAt(0.0,0.0,5.0,0.0,0.0,0.0,0.0,5.0,0.0);

}

void keyboard(unsigned char key,int x,int y)
{
	switch(key)
	{
	case 'd':
		day=(day+10)%360;
		glutPostRedisplay();
		break;
	case 'D':
		day=(day-10)%360;
		glutPostRedisplay();
		break;
	case 'y':
		year=(year+5)%360;
		glutPostRedisplay();
		break;
	case 'Y':
		year=(year-5)%360;
		glutPostRedisplay();
		break;
	}
}
void timer(int value)
{
	year=(year+5)%360;
	glutPostRedisplay();
	glutTimerFunc(33,timer,value);// ， 。
}
int main(int argc,char** argv)
{
	glutInit(&argc,argv);
	glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);
	glutInitWindowSize(500,500);
	glutInitWindowPosition(100,100);
	glutCreateWindow("planet");
	init();
	glutDisplayFunc(display);
	glutReshapeFunc(reshape);
	glutKeyboardFunc(keyboard);
	glutTimerFunc(33,timer,1);// timer 
	glutMainLoop();
	return 0;
}