Method TranslateWindowsInViewport

imgui_tiny_app/imgui/imgui.cpp:16743–16760

Translate Dear ImGui windows when a Host Viewport has been moved (This additionally keeps windows at the same place when ImGuiConfigFlags_ViewportsEnable is toggled!)

// Translate Dear ImGui windows when a Host Viewport has been moved
// (This additionally keeps windows at the same place when ImGuiConfigFlags_ViewportsEnable is toggled!)
void ImGui::TranslateWindowsInViewport(ImGuiViewportP* viewport, const ImVec2& old_pos, const ImVec2& new_pos, const ImVec2& old_size, const ImVec2& new_size)
{
    ImGuiContext& g = *GImGui;
    //IMGUI_DEBUG_LOG_VIEWPORT("[viewport] TranslateWindowsInViewport 0x%08X\n", viewport->ID);
    IM_ASSERT(viewport->Window == NULL && (viewport->Flags & ImGuiViewportFlags_CanHostOtherWindows));

    // 1) We test if ImGuiConfigFlags_ViewportsEnable was just toggled, which allows us to conveniently
    // translate imgui windows from OS-window-local to absolute coordinates or vice-versa.
    // 2) If it's not going to fit into the new size, keep it at same absolute position.
    // One problem with this is that most Win32 applications doesn't update their render while dragging,
    // and so the window will appear to teleport when releasing the mouse.
    const bool translate_all_windows = (g.ConfigFlagsCurrFrame & ImGuiConfigFlags_ViewportsEnable) != (g.ConfigFlagsLastFrame & ImGuiConfigFlags_ViewportsEnable);
    ImRect test_still_fit_rect(old_pos, old_pos + old_size);
    ImVec2 delta_pos = new_pos - old_pos;
    for (ImGuiWindow* window : g.Windows) // FIXME-OPT
        if (translate_all_windows || (window->Viewport == viewport && (old_size == new_size || test_still_fit_rect.Contains(window->Rect()))))
            TranslateWindow(window, delta_pos);
}

// Scale all windows (position, size). Use when e.g. changing DPI. (This is a lossy operation!)
void ImGui::ScaleWindowsInViewport(ImGuiViewportP* viewport, float scale)