membuat kotak berputar

# include<GL/glut.h>

static GLfloat spin= 0.0;

void display(void)
{
glClear(GL_COLOR_BUFFER_BIT);
glPushMatrix();
glRotatef(spin,0.0,0.0,1.0);
glColor3f(1.0,1.0,1.0);
glRectf(-25.0,-25.0,25.0,25.0);
glPopMatrix();
glutSwapBuffers();
}
void spinDisplay(void)
{
spin=spin + 2.0;
if(spin>360.0)
glutPostRedisplay();
}

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

void reshape(int w,int h)
{
glViewport(0,0,(GLsizei)w,(GLsizei)h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
}

void mouse(int button, int state,int x,int y)
{
switch(button)
{
case GLUT_LEFT_BUTTON:
if (state==GLUT_DOWN)
glutIdleFunc(spinDisplay);
break;
case GLUT_MIDDLE_BUTTON:
case GLUT_RIGHT_BUTTON:
if (state==GLUT_DOWN)
glutIdleFunc(0);
break;
default:
break;
    }
}
int main(int argc,char** argv)
{
glutInit(&argc,argv);
glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);
glutInitWindowSize(300,300);
glutInitWindowPosition(100,100);
glutCreateWindow(argv[0]);
init();
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutMouseFunc(mouse);
glutMainLoop();
return 0;
}