Glut subwindow toggle - opengl

Question

I have a program and i have created a subwindow from my main window. The problem is that its always there, my goal is to press a key and then get that subwindow "on" and when i press it again , to make it disappear. I managed to destroy it with glutDistroyWindow but then i dont know how to make it appear again. Here is my code:
void init(void)
{
// pregatim o scena noua in opengl
if(glutGetWindow() == mainWindow)
glClearColor(0.0, 0.0, 0.0, 0.0);
else
glClearColor(1.0, 1.0, 1.0, 1.0); fereastra
glEnable(GL_DEPTH_TEST);
glShadeModel(GL_SMOOTH);
glEnable(GL_LIGHTING);
glEnable(GL_NORMALIZE);
}
void reshape2(int w,int h){
glViewport(0,0,(GLsizei) w,(GLsizei) h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45,(float)w/h,1.0,40.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
init();
}
void reshape(int w, int h)
{
// Main Window
glViewport(0,0, (GLsizei) w, (GLsizei) h);
// calculare aspect ratio ( Width/ Height )
GLfloat aspect = (GLfloat) w / (GLfloat) h;
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluPerspective(45, aspect, 1.0, 100);
// init context
init();
if(damageWindow != -1)
glutDestroyWindow(damageWindow);
damageWindow=glutCreateSubWindow(mainWindow,0,0,w/5,h/5);
glutDisplayFunc(display);
glutReshapeFunc(reshape2);
glutKeyboardFunc(keyboard);
glutSpecialFunc(keyboard);
glutKeyboardUpFunc(keyboardup);
glutMouseFunc(mouse);
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE|GLUT_RGB);
int w = 800, h= 600;
glutInitWindowSize(w,h);
glutInitWindowPosition(100,100);
// Main window
mainWindow=glutCreateWindow("Tema4 - Asteroid Attack!");
glutDisplayFunc(display);
glutKeyboardFunc(keyboard);
glutKeyboardUpFunc(keyboardup);
glutReshapeFunc(reshape);
glutSpecialFunc(keyboard);
glutMouseFunc(mouse);
// Initializeaza scena 3D
initScene();
glutMainLoop();
return 0;
}
Ok so these are the functions that matters. In my keyboard function i want to toggle damageWindow. How do i do that ? I know how to destroy it but i can't seem to make it again.
LE: I keep getting downvotes because people dont really understand the question. The keyboard function is redundant because there is nothing there , thats what im asking you.But for the sake of you guys here it is:
void keyboard(unsigned char ch,int x,int y){
switch(ch){
case 27: exit(0);break;
case 'n':
view_subwindow=!view_subwindow;
if(view_subwindow == false)
glutDestroyWindow(damageWindow);
else{
//here i want to recreate my window DONT KNOW HOW
damageWindow=glutCreateSubWindow(mainWindow,0,0,w/5,h/5);
glutDisplayFunc(display);
glutReshapeFunc(reshape2);
glutKeyboardFunc(keyboard);
glutSpecialFunc(keyboard);
glutKeyboardUpFunc(keyboardup);
glutMouseFunc(mouse);
}
}
}

Answer 1

I don't think you're supposed to create or destroy any windows after you called glutMainLoop. During initialization you should create the subwindow, then afterwards you should just hide it instead, using glutHideWindow, possibly after calling glutSetWindow to make it the current window. To show it again, call glutShowWindow.
Also, you don't need to call functions like glutReshapeFunc or glutKeyboardFunc multiple times, do that just once during initialization. If you need them to do different things depending on a condition, use if's in the functions you passed to them.