为什么GL_TRIANGLE_STRIP的边界边设置无效？glEdgeFlag、GL_EDGE_FLAG

Cocos2d-x
#1 
请把代码粘贴在这里

glPushAttrib(GL_EDGE_FLAG);
    glBegin(GL_TRIANGLE_STRIP);
    
        glEdgeFlag(GL_TRUE);
        glVertex2f(150.0,300.0);
        glEdgeFlag(GL_FALSE);
        glVertex2f(150.0,200.0);
        glEdgeFlag(GL_TRUE);
        glVertex2f(250.0,250.0);
        glVertex2f(300.0,150.0);
        
        
    glEnd();
    glPopAttrib();//GL_EDGE_FLAG

    glPushAttrib(GL_EDGE_FLAG);
    glBegin(GL_TRIANGLE_STRIP);
        glEdgeFlag(GL_TRUE);
        glVertex2f(300.0,270.0);
        glEdgeFlag(GL_FALSE);
        glVertex2f(250.0,250.0);
        glEdgeFlag(GL_TRUE);
        glVertex2f(350.0,200.0);
        glVertex2f(300.0,150.0);
        
    glEnd();
    glPopAttrib();//GL_EDGE_FLAG


```
#2

https://msdn.microsoft.com/en-us/library/ms537067(VS.85).aspx

The vertices of
connected triangles and connected quadrilaterals are always marked as boundary, regardless of the value of the edge flag.