static void KeyFunc(unsigned char key, int x, int y) { switch (key) { case 'c': case 'C': solver.ClearData(); break; case 'q': case 'Q': solver.FreeData(); exit(0); break; case 'v': case 'V': dvel = !dvel; break; case 'p': case 'P': pixel = !pixel; break; } }