opengl画三角，两段同样的代码一个能画出一个不能

glBegin(GL_TRIANGLES);
////glBegin(GL_TRIANGLE_STRIP);
glVertex3f(0.1,0.1,0.0);
glVertex3f(0.3,0.0,0.0);
glVertex3f(0.3,0.1,0.0);
glEnd(); glBegin(GL_TRIANGLES);
////glBegin(GL_TRIANGLE_STRIP);！！！！
glVertex3f(1.0,1.0,0.0);
glVertex3f(3.0,0.0,0.0);
glVertex3f(3.0,1.0,0.0);
glEnd();
代码如上，用vs2008
上面能画出，下面不能
跟上下位置无关
删去！！！！这一行，便能绘制出
应该是这一行出现了某些格式错误，例如与上一行或者与下一行之间存有某些特殊符号？
不过全删掉不留空隙还是不行
神了，很无聊的问题，但是纠结啊