Shut down imgui when exit.

Author: bitxue

examples/freeglut_opengl2_example/main.cpp

@@ -75,6 +75,9 @@ bool keyboardEvent(unsigned char nChar, int nX, int nY)
     ImGuiIO& io = ImGui::GetIO();
     io.AddInputCharacter(nChar);
 
+    if (nChar == 27) //Esc-key
+        glutLeaveMainLoop();
+
     return true;
 }
 
@@ -211,5 +214,7 @@ int main(int argc, char **argv)
     init();
     glutMainLoop();
 
+    ImGui_ImplGLUT_Shutdown();
+
     return 0;
 }