改變邊界

按下按鍵改變邊界使他不破圖
 if(key==' ') {
eyex-=0.03,eyey-=0.02;
}
else if(key=='`'){
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-2,2,-2,2,-10,10);
glMatrixMode(GL_MODELVIEW);
}

或是將

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-2,2,-2,2,-10,10);
glMatrixMode(GL_MODELVIEW);
放到
int main()
{
 glutInitDisplayMode(GLUT_DOUBLE | GLUT_DEPTH);
 glutCreateWindow("week11");

 glutDisplayFunc(display);
 glutKeyboardFunc(keyboard);

 myLight();
  glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(-2,2,-2,2,-10,10);
glMatrixMode(GL_MODELVIEW);

 glutMainLoop();
}
最後一段
就可以不需按按鍵才改變邊界
!!!但注意要打在
 glutMainLoop();
之前
改變邊界使他不破圖