我想在我的OpenGL程序中调用下面的代码作为函数。我的问题是：
1.是否可以在main（）之外调用glutIdleFunc（）？
1.我可以在我的主程序中调用下面的代码作为一个函数作为一个开关情况函数吗？

# include<GL/glut.h>

# include<math.h>

# include<stdio.h>

int bzco[4][2]={{0,0},{49,201},{201,99},{320,300}},c[4],n=3;
int s1x,s1y,s2x,s2y;
void bezierCoefficients(int n,int *c)
{
    int k,i;
    for(k=0;k<=n;k++)
    {
        c[k]=1;

        for(i=n;i>=k+1;i--)
            c[k]*=i;

        for(i=n-k;i>=2;i--)
            c[k]/=i;
    }
}

void display(void)
{
int k;

float x,y,u,blend;

    glClear(GL_COLOR_BUFFER_BIT);
    // To draw points
    glColor3f(0.0,1.0,0.0);
    glPointSize(3);
        glBegin(GL_POINTS);
        glVertex2f(80, 34);
        glVertex2f(85, 24);
        glVertex2f(78, 24);
        glVertex2f(46, 35);
        glVertex2f(67, 47);
        glVertex2f(85, 26);
        glVertex2f(78, 68);
        glVertex2f(86, 56);
        glVertex2f(82, 54);
        glVertex2f(56, 69);
    glEnd();
    glColor3f(1.0,0.0,0.0);
    glPointSize(3);
    glBegin(GL_POINTS);
        glVertex2f(34, 38);
        glVertex2f(46, 35);
        glVertex2f(56, 69);
        glVertex2f(43, 47);

    glEnd();
    glColor3f(0.0,0.0,1.0);
    glLineWidth(3.0);
    glBegin(GL_LINE_STRIP);

    for(u=0;u<1.0;u+=0.001)
    {x=0;y=0;
        for(k=0;k<4;k++)
        {
            blend=c[k]*pow(u,k)*pow(1-u,n-k);
            x+=bzco[k][0]*blend;
            y+=bzco[k][1]*blend;
        }
        glVertex2f(x,y);

    }
    glEnd();
    glFlush();
    glutSwapBuffers();
}
void myinit()
{
    glClearColor(1.0,1.0,1.0,1.0);
    glColor3f(1.0,0.0,0.0);
    glPointSize(5.0);
    gluOrtho2D(0.0,320.0,0.0,300.0);
}
void motion(void)
{
    bzco[1][0]+=s1x;
    bzco[1][1]+=s1y;
    bzco[2][0]+=s2x;
    bzco[2][1]+=s2y;
    if(bzco[1][0]<0||bzco[1][0]>320)
    {
        s1x=-s1x;
    }
    if(bzco[1][1]<0||bzco[1][1]>300)
    {
        s1y=-s1y;
    }
    if(bzco[2][0]<0||bzco[2][0]>320)
    {
        s2x=-s2x;
    }
    if(bzco[2][1]<0||bzco[2][1]>300)
    {
        s2y=-s2y;
    }
    glutPostRedisplay();
}

主要功能：

int main(int argc, char**argv)
    {
        glutInit(&argc,argv);
        glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);
        glutInitWindowSize(320,300);
        glutCreateWindow("Logistic Function");
        glutDisplayFunc(display);
        glutDisplayFunc(display);
        glutIdleFunc(motion);
        myinit();
        bezierCoefficients(n,c);
        s1x=-1;s1y=-1;s2x=-1;s2y=1;
        glutMainLoop();
        return 0;
    }

在我的主程序中，我在display（）函数中使用了switch cases，因为我必须调用上面的代码。