在opengl中，如何在不重画图形的基础上放大，缩小图形？

[qwx2000]

举个例子，画一个立方体：
void __fastcall TForm1::RenderGLScene()
{
` glBegin( GL_LINE_STRIP );
glColor3f( 0.0, 1.0, 0.0 );

glVertex3f(0,0,10.0);
glVertex3f(0,10.0,10.0);
glVertex3f(10.0,10.0,10.0);
glVertex3f(10.0,0.0,10.0);

glVertex3f(0.0,0.0,10.0);
glVertex3f(0,0.0,0.0);
glVertex3f(10.0,0.0,0.0);
glVertex3f(10.0,0.0,10.0);

glVertex3f(10.0,0.0,0.0);
glVertex3f(10.0,10.0,0.0);
glVertex3f(10.0,10.0,10.0);
glVertex3f(0,10.0,10.0);

glVertex3f(0,10.0,0.0);
glVertex3f(10.0,10.0,0.0);

glVertex3f(0,10.0,0.0);
glVertex3f(0,0.0,0.0);
glEnd();
}
接着我希望放大图形
方法1：
void __fastcall TForm1::Button5Click(TObject *Sender)
{
glScalef(5,5,5) ;
glClearColor(1.0f, 1.0f, 1.0f, 1.0f);
glClear(GL_COLOR_BUFFER_BIT);
RenderGLScene();
glFlush();

}
方法2：
使用 glOrtho（）函数
但是两种方法都要用RenderGLScene()来重画，如何能够不重画就实现放大的功能？因为实际的画图函数数据量太大，而且在实时更新；

[我来看看CB]

好像不行

[Y___Y]

不大可能吧
不重画怎么显示呢？
加快显示速度可以用显示列表

[wenyongjie]

要重画的，这东西最麻烦，俺做过