Separator(): output vertical separator when used in horizontal layout mode, so it works in menu bars.

imgui.cpp

@@ -9893,10 +9893,23 @@ bool ImGui::ColorPicker4(const char* label, float col[4], ImGuiColorEditFlags fl
 // Horizontal separating line.
 void ImGui::Separator()
 {
+    ImGuiContext& g = *GImGui;
     ImGuiWindow* window = GetCurrentWindow();
     if (window->SkipItems)
         return;
 
+    ImGuiWindowFlags flags = 0;
+    if ((flags & (ImGuiSeparatorFlags_Horizontal | ImGuiSeparatorFlags_Vertical)) == 0)
+    {
+        if (window->DC.LayoutType == ImGuiLayoutType_Horizontal)
+            flags |= ImGuiSeparatorFlags_Vertical;
+        else
+            flags |= ImGuiSeparatorFlags_Horizontal;
+    }
+    IM_ASSERT(ImIsPowerOfTwo((int)(flags & (ImGuiSeparatorFlags_Horizontal | ImGuiSeparatorFlags_Vertical))));   // Check that only 1 option is selected
+
+    if (flags & ImGuiSeparatorFlags_Horizontal)
+    {
         if (window->DC.ColumnsCount > 1)
             PopClipRect();
 
@@ -9916,7 +9929,6 @@ void ImGui::Separator()
 
         window->DrawList->AddLine(bb.Min, ImVec2(bb.Max.x,bb.Min.y), GetColorU32(ImGuiCol_Separator));
 
-    ImGuiContext& g = *GImGui;
         if (g.LogEnabled)
             LogText(IM_NEWLINE "--------------------------------");
 
@@ -9925,6 +9937,19 @@ void ImGui::Separator()
             PushColumnClipRect();
             window->DC.ColumnsCellMinY = window->DC.CursorPos.y;
         }
+    }
+    else if (flags & ImGuiSeparatorFlags_Vertical)
+    {
+        const ImRect bb(window->DC.CursorPos, window->DC.CursorPos + ImVec2(1.0f, window->DC.CurrentLineHeight));
+        ItemSize(ImVec2(bb.GetWidth(), 0.0f));
+        if (!ItemAdd(bb, NULL))
+            return;
+
+        window->DrawList->AddLine(ImVec2(bb.Min.x, bb.Min.y), ImVec2(bb.Min.x, bb.Max.y), GetColorU32(ImGuiCol_Separator));
+
+        if (g.LogEnabled)
+            LogText("|");
+    }
 }
 
 void ImGui::Spacing()

imgui_internal.h

@@ -48,6 +48,7 @@ typedef int ImGuiLayoutType;      // enum ImGuiLayoutType_
 typedef int ImGuiButtonFlags;     // enum ImGuiButtonFlags_
 typedef int ImGuiTreeNodeFlags;   // enum ImGuiTreeNodeFlags_
 typedef int ImGuiSliderFlags;     // enum ImGuiSliderFlags_
+typedef int ImGuiSeparatorFlags;  // enum ImGuiSeparatorFlags_
 typedef int ImGuiItemFlags;       // enum ImGuiItemFlags_
 
 //-------------------------------------------------------------------------
@@ -203,6 +204,12 @@ enum ImGuiSelectableFlagsPrivate_
     ImGuiSelectableFlags_DrawFillAvailWidth = 1 << 6
 };
 
+enum ImGuiSeparatorFlags_
+{
+    ImGuiSeparatorFlags_Horizontal          = 1 << 0,   // Axis default to current layout type, so generally Horizontal unless e.g. in a menu bar
+    ImGuiSeparatorFlags_Vertical            = 1 << 1
+};
+
 // FIXME: this is in development, not exposed/functional as a generic feature yet.
 enum ImGuiLayoutType_
 {