Topmost modal

[SuperWangKai]

Version/Branch of Dear ImGui:

Version: XXX
Branch: XXX (master/viewport/docking/etc.)

Back-end/Renderer/Compiler/OS

Dear ImGui 1.90.1 WIP (19002)
--------------------------------
sizeof(size_t): 8, sizeof(ImDrawIdx): 2, sizeof(ImDrawVert): 20
define: __cplusplus=199711
define: _WIN32
define: _WIN64
define: _MSC_VER=1938
define: _MSVC_LANG=201402
define: IMGUI_HAS_VIEWPORT
define: IMGUI_HAS_DOCK
--------------------------------
io.BackendPlatformName: imgui_impl_win32
io.BackendRendererName: imgui_impl_dx12
io.ConfigFlags: 0x00000443
 NavEnableKeyboard
 NavEnableGamepad
 DockingEnable
 ViewportsEnable
io.ConfigViewportsNoDecoration
io.ConfigInputTextCursorBlink
io.ConfigWindowsResizeFromEdges
io.ConfigMemoryCompactTimer = 60.0
io.BackendFlags: 0x00001C0E
 HasMouseCursors
 HasSetMousePos
 PlatformHasViewports
 HasMouseHoveredViewport
 RendererHasVtxOffset
 RendererHasViewports
--------------------------------
io.Fonts: 1 fonts, Flags: 0x00000000, TexSize: 512,64
io.DisplaySize: 1264.00,761.00
io.DisplayFramebufferScale: 1.00,1.00
--------------------------------
style.WindowPadding: 8.00,8.00
style.WindowBorderSize: 1.00
style.FramePadding: 4.00,3.00
style.FrameRounding: 0.00
style.FrameBorderSize: 0.00
style.ItemSpacing: 8.00,4.00
style.ItemInnerSpacing: 4.00,4.00

My Issue/Question:

For the docking branch, platform windows are on top of the main window. When we use modal, the platform window can cover and block the modal. This could totally block any user interaction. In my case, the modal window is used to confirm exit and it is always centered in the main window, in this case, if it is covered by any platform window, user cannot click on the buttons, causing an unusable situation.

Screenshots/Video

[SuperWangKai]

Another question is how to make a modal on top of others.
In the ImGui demo code, modal on top of another modal (Add another modal..) is demonstrated, however, in a more practical situation, like my exit confirmation popup, I could not embed it within other modals. How to make sure that the exit modal is always top most?

Thanks!