OpenGL 五角星

OpenGL 五角星用 vs 做的五角星代码 void myDisplay(void)
{

    glBegin(GL_TRIANGLES);
    glColor3f(1.0f, 0.5f, 1.0f);
    glBegin(GL_POLYGON);
    for (i = 0; i < n; i)
        glVertex2f(R * cos(2 * Pi / n * i), R * sin(2 * Pi / n * i));
    glEnd();

    //五角星
    glColor3f(0.0f, 1.0f, 1.0f);
    GLfloat a = 1 / (2 - 2 * cos(72 * Pi / 180));
    GLfloat bx = a * cos(18 * Pi / 180);
    GLfloat by = a * sin(18 * Pi / 180);
    GLfloat cy = -a * cos(18 * Pi / 180);
    GLfloat
        PointA[2] = { 0, a }, PointB[2] = { bx, by },
        PointC[2] = { 0.5, cy }, PointD[2] = { -0.5, cy },
        PointE[2] = { -bx, by };
    glBegin(GL_LINE_LOOP);
    glVertex2fv(PointA);    glVertex2fv(PointC);
    glVertex2fv(PointE);    glVertex2fv(PointB);
    glVertex2fv(PointD);
    glEnd();
    glFlush();//函数启动OpenGL绘图命令的执行，并将图形光栅化后输出在设备上。</span>
}