OpenGL编程轻松入门之坐标变换.本节中的例子仅仅是将第二节的例子作了一点点改动。将myDisplay函数中画三角型的那一部分提出来写成一个函数drawTriangle。然后在myDisplay函数中用drawTriangle.-OpenGL programming easy entry of coordinate transformation. The examples in this section is the only example of section II, made a little change. MyDisplay function will draw part of the triangle to write a function to drawTriangle. MyDisplay function and then used drawTriangle.